淀粉类食品冻融稳定性的研究

This study aimed to investigate the effects of laminarin (LA) and ferulic acid (FA) on the gelatinization, rheological properties, freeze-thaw stability, and digestibility of cassava starch (CS). The results indicated that LA increased the peak viscosity, trough viscosity, final viscosity, storage modulus, and loss modulus of CS, while decreasing the breakdown viscosity. Conversely, FA exerted opposite effects. The addition of LA and FA delayed the setback viscosity of CS, thereby retarding short-term aging. In the ternary system, LA mitigated the adverse effects caused by FA, and further enhanced the gel properties, including viscoelasticity, thermal stability, and resistance to short-term retrogradation. Additionally, the short-term freeze-thaw stability of CS gels was enhanced by the inclusion of LA and FA. Fourier transform infrared spectroscopy (FTIR) showed that LA reduced the structural stability of CS, while FA was beneficial for the structural orderliness. However, the degree of orderliness in the starch gel network structure within the ternary system was compromised. Moreover, LA and FA also affected the digestibility of CS, with the CS + LA + FA ternary system exhibiting significantly higher contents of resistant starch and slowly digestible starch compared to CS, which was conducive to stabilizing blood sugar fluctuations. These findings contributed to the practical application of LA, FA, and CS, and provided a data reference for understanding the application of modified bioactive substances in starch-based food processing.

This study aimed to investigate the effect of the interaction of black rice anthocyanins (BRA), soluble dietary fiber from extruded rice bran (ES) and waxy rice starch (WRS) on the physicochemical properties of starch gels, including gelatinization properties, rheological properties, freeze-thaw stability, water migration, molecular structure and gel microstructure. The results showed that the pasting temperature (PT) of the mixtures was increased, and the peak viscosity (PV), trough viscosity (TV), final viscosity (FV) and setback viscosity (SV) were significantly reduced when ES and BRA were added to WRS in different proportions (ES:BRA, 4:0, 4:0.4, 4:1, 4:2, 8:0, 8:0.8, 8:2, 8:4). Both ES and BRA could enhance the viscosity of WRS gels, and ES exhibited strong ability on improving the strength of gels. The presence of ES and BRA improved the water retaining capacity of WRS gels, but weakened the freeze-thaw stability. ES, BRA and WRS formed non-covalent bonds (hydrogen bonds) through hydrophilic groups during gelatinization, which improved the gel properties. In addition, the steric hindrance formed by ES and BRA inhibited starch retrogradation. These results might contribute to the development of starch-based food formulations with good quality.

Amylopectin cluster (APC), a modified starch prepared using cyclodextrin glucanotransferase (CGTase), was utilized as a freeze–thaw stabilizer to improve the quality of dumpling wrappers containing Baromi 2, a rice variety used as a substitute for wheat flour. Texture profile analysis (TPA) showed that in the sample groups where the base wheat flour of the dough was substituted with 10% Baromi 2 and 3% amylopectin cluster, the hardness of the dumpling wrapper decreased by 7.9% compared to the control group. Differential scanning calorimetry (DSC), a method for measuring freezable water as an essential quality indicator for frozen foods, showed that B2APC1 exhibited the lowest freezable water content (5.2%) after three freeze–thaw cycles. Scanning electron microscopy (SEM) analysis demonstrated that the gluten structure in the APC‐added group was comparable to the control group. In addition, X‐ray diffraction (XRD) analysis revealed the highest peak intensity to be in B2APC1, indicating its enhanced gelatinization during cooking. These findings imply that the incorporation of APC into dumpling wrappers containing Baromi 2 can effectively improve freeze–thaw stability and texture properties.

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This study combined rice starch (RS) with cactus polysaccharide (CP) at different composites (0.6%, 1.2%, 1.8%, 2.4%, and 3.0%, w/w), and analyzed the variations in the complex gelatinization properties, rheological properties, thermal properties, structural properties, digestibility, and freeze–thaw stability. As a result, the pasting parameters (p < 0.05) and storage modulus (G′) together with the loss modulus (G″) decreased as the CP concentration increased; meanwhile, the RS and the CP–RS gels were pseudoplastic fluids. As revealed by differential scanning calorimetry (DSC), incorporating CP into the starch elevated the starch gelatinization temperature while decreasing gelatinization enthalpy, revealing that CP effectively retarded long-term retrogradation in RS. The gel microstructure and crystallization type altered after adding CP. Typically, CP inclusion could enhance the proportion of resistant starch and slowly digestible starch (SDS), thereby slowing RS hydrolysis. Concurrently, adding CP promoted the RS freeze–thaw stability. These findings could potentially aid in the innovation of CP-based food products.

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Improving the gel texture and stability of rice starch (RS) by natural hydrocolloids is important for the development of gluten-free starch-based products. In this paper, the effects of guar gum and locust bean gum on the pasting, rheological properties, and freeze–thaw stability of rice starch were investigated by using a rapid visco analyzer, rheometer, and texture analyzer. Both gums can modify the pasting properties, revealed by an increment in the peak, trough, and final viscosities, and prevent the short-term retrogradation tendency of RS. Dynamic viscoelasticity measurements also indicated that the starch–gum system exhibits superior viscoelastic properties compared with starch alone, as revealed by its higher storage modulus (G′). Compared with the control, the hysteresis loop area of the guar gum-containing system and locust bean gum-containing system was reduced by 37.7% and 24.2%, respectively, indicating that the addition of gums could enhance shear resistance and structure recovery properties. The thermodynamic properties indicated that both gums retard short-term retrogradation as well as long-term retrogradation of the RS gels. Interestingly, the textural properties and freeze–thaw stability of the RS gel were significantly improved by the addition of galactomannans (p < 0.05), and guar gum was more effective than locust bean gum, which may be due to the different mannose to galactose ratio. The results provide alternatives for gluten-free recipes with improved texture properties and freeze–thaw stability.

In this study, structural characteristics of Fenugreek (FG), Guar (GG), Locust bean (LBG), and Tara gums (TG) and their influence on physicochemical properties of corn starch (CS) gels were investigated. Results showed that FG presented a rigid rod structure, and GG, LBG, and TG showed an extended structure. The Mannose/Galactose (Man/Gal) ratio of FG, GG, LBG, and TG was 1.37, 1.96, 2.99, and 3.46, respectively. The molecular weight (Mw) of FG, GG, LBG, and TG was 0.89 × 106, 2.71 × 106, 3.61 × 106, and 2.77 × 106 Da, respectively. The structure-function relationship indicated that galactomannans with a high Man/Gal ratio and extended structure presented a higher apparent viscosity, formed gel more easily, and could limit retrogradation and improve freeze-thaw stability and textural profile of CS gels. Consequently, the results could be beneficial for the application of galactomannans in starch-based foods to improve their sensory characteristics and storage quality.

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In this work, we investigated the effects of sucrose (0%-30%, w/w) on the pasting properties, retrogradation, freeze-thaw stability, texture, and the possible interaction with corn starch-tamarind seed polysaccharide (CS-TSP) mixtures. Sucrose increased the gelatinization temperature (from 76.4 ± 0.1 to 87.6 ± 0.0°C), peak viscosity (from 3358.0 ± 1.4 to 7732.5 ± 44.5 cP), and final viscosity (from 3514.0 ± 31.1 to 7724.5 ± 142.1 cP) of CS-TSP mixtures. Further, sucrose limited the increase in the storage modulus of the mixture pastes, transfer of bound water to free water, and water syneresis during the freeze-thaw process. Additionally, sucrose resulted in a more complete gel structure with stronger resistance. Scanning electron microscope and fluorescence labeling analysis showed that the presence of sucrose helped in tight entanglement or cross-link between amylose or between amylose and TSP. Thus, these results in this study could help to improve physicochemical properties of starch-based products, such as glue pudding and other starch desserts.

In this study, the effects of the addition of pectin (PEC) on the physicochemical properties and freeze-thaw stability of waxy rice starch (WRS) were investigated. As PEC content increased, the pasting viscosity and pasting temperature of WRS significantly increased (p < 0.05), whereas its breakdown value and setback value decreased. Differential scanning calorimetry showed that the addition of PEC increased the gelatinization temperature of WRS, but decreased its gelatinization enthalpy. Rheological measurements indicated that the addition of PEC did not change the shear-thinning behavior of WRS–PEC blends, and the storage modulus and loss modulus were positively correlated with PEC content. Moreover, the textural parameter of WRS decreased with the increase in PEC content. Furthermore, the addition of PEC decreased the transmittance of starch paste, but enhanced the freeze-thaw stability of WRS to some extent. These results may contribute to the development of WRS-based food products.

This study evaluated four hydrocolloids (xanthan, guar, carrageenan, and konjac gums) for inhibiting rice cake retrogradation to extend shelf life and improve quality. Konjac gum exhibited the highest water-holding capacity, followed by xanthan, guar, and carrageenan. The type and concentration of hydrocolloid significantly influenced the moisture content of rice cakes. All additives reduced cooking loss and enhanced freeze-thaw stability, with 1 % xanthan or carrageenan formulations showing optimal processing stability. Fourier-transform infrared spectroscopy revealed hydrogen bonding between starch and hydrocolloids. X-ray diffraction demonstrated that 1 % xanthan gum most effectively inhibited retrogradation, forming a denser, ordered structure. These findings highlight hydrocolloids' functional benefits in maintaining rice cake textural integrity during storage while improving marketability. The results provide practical guidance for optimizing rice cake production and enhancing commercial value through targeted hydrocolloid applications, with xanthan gum showing particular promise for anti-retrogradation effects.

Three types of inulin with different degree of polymerization (average DP < 10, DP ≥ 10, and DP > 23) were used to improve the freeze-thaw stability of rice starch gel. The gels with or without addition of inulin were subjected to seven freeze-thaw cycles (FTC). Inulin enhanced the water holding capacity and reduced the amount of freezable water of the gels, thereby decreasing the syneresis of the gels during seven FTC. In addition, the amylose and amylopectin retrogradation of the gels were retarded. By adding inulin, the microstructure of gel network was stabilized, and the deterioration in viscoelastic properties of the gels during seven FTC was reversed. Therefore, inulin was an effective additive for preserving the quality of freeze-thawed rice starch gels. Furthermore, low DP inulin had higher water holding capacity than high DP one, as a result the inulin with lower DP was more effective.

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BACKGROUND Physically modified starches can be classified as natural ingredients on food labels and clean label products. Thus, the market demand for physically modified starch is increasing. Potato, tapioca, and corn starches were physically modified by mild heat treatment in an alcoholic solution to enhance their gelling property and freeze-thaw stability. RESULTS During mild heating of starch suspension (40% w/w) in 10% ethanol solution at the onset gelatinization temperature, granular swelling of starch occurred, followed by amylose leaching with medication of the surface structure of the starch granules. All treated starches exhibited increased gelatinization and pasting temperatures and decreased breakdown for pasting due to improved stability against shear and heat. The treated starches had higher hardness, cohesiveness, and springiness of gel than the respective native starches, and these gel properties were more pronounced in potato starch than in tapioca and corn starches. The treated starches showed substantially reduced gel syneresis during freeze-thawing. CONCLUSION Physical modification of starch by mild heat treatment in an alcoholic solution substantially improved its gelation ability and freeze-thaw stability. This article is protected by copyright. All rights reserved.

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Starches from some legume grown in Cameroon were evaluated for their granule structure and size, turbidity, firmness and gel strength, thermal and freeze-thaw properties. Amylose contents were in the range of 26.21%-44.85%. Morphological analysis of the starch granules showed bimodal distribution, multiple sizes and shapes from small spherical to the bigger kidney shape. Significant differences were observed among starch in light transmittance, firmness and gel strength. The thermal parameters of starches were evaluated using differential scanning calorimeter and significant differences were observed. The peak gelatinisation temperature was positively correlated to starch granule size but the amylose content showed no evidence of their impact on legume starch properties studied. The data reported can be useful to facilitate the selection of variety of legume and conditions closer to the desired application.

This study aims to evaluate the effects of structural changes in cross-linked mung bean starch (CLMB) on freeze–thaw stability and in vitro digestibility and explore its potential to prevent starch retrogradation and its applicability as a resistant starch (RS)- enhanced food ingredient. Mung beans of different varieties (Eohul, Geumsung, and Sohyeon) were cross-linked using an STMP:STPP ratio of 9:1. The structure and thermal properties of CLMB and its digestibility, as well as the textural properties of 10% CLMB gels and their freeze–thaw stability, were evaluated. As a result of the study, CLMB maintained an A-type crystalline structure, but structural changes due to the introduction of phosphate groups were observed during FT-IR analysis. Compared to natural mung bean starch (MBS), the swelling power and solubility decreased, and the gelatinization temperature range increased. Additionally, the cross-linking treatment increased the resistant starch (RS) content. In the case of the gel with 10% CLMB added, the freezing–thawing experiment results show a significant reduction in syneresis and it was confirmed that high stability was maintained even through repeated processes. Our results suggest that CLMB is a functional ingredient with potential applications in the development of food products offering extended shelf lives and tailored nutritional benefits.

Fucoidan (FU) and caffeic acid (CA) can modify the physicochemical properties of starch and confer various health-beneficial functional characteristics to cassava starch (CS) products. This study utilized Rapid Visco Analyzer (RVA), Differential Scanning Calorimetry (DSC), rheometer, Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) to investigate the effects of FU andCA on the gelatinization, rheological properties, freeze-thaw stability, and structural characteristics of CS. Results from RVA showed that FU boosted the free expansion, shear resistance and gel thermal stability of CS while reducing their gel formation capacity and delaying short-term retrogradation. CA decreased the free expansion, shear resistance and gel formation ability of CS while delaying the short-term retrogradation of CS. The analysis of DSC showed that FU and CA could decrease the gelatinization enthalpy of CS. The rheological results revealed that each gel system was typical weak gel and pseudoplastic fluid. Both FU and CA weakened the relative motion of amylose molecules and reduced the energy required to disrupt the CS gel system. FU significantly enhanced the pseudoplasticity of CS gel (upward: 0.48 to 0.44; downward: 0.566 to 0.488, p < 0.05), whereas CA significantly decreased the thickening ability in the upward stage. FU and CA increased the hardness of CS gel (except 2.5 % CA). Furthermore, the addition of FU and CA was not conducive to the improvement of freeze-thaw stability of CS gel. FT-IR and XRD analyses exhibited that non-covalent bond mediated the effect of FU and CA on CS gel. SEM observations showed that FU and CA induced the formation of denser "honeycomb" pores in the CS gel. Both FU and CA were found to effectively retard the short-term retrogradation of CS, while enhancing the microstructural integrity of the gel network. These findings suggested that the incorporation of FU and CA could be utilized as a means to modulate the quality attributes of cassava starch-based products.

This study aimed to enhance the texture of frozen cooked rice by magnetic field (MF) technology. Cooked rice was subjected to seven freeze-thaw cycles and MF treatment at intensities ranging from 0 to 10 mT. The texture was assessed, and the underlying mechanisms were examined in terms of water phase transitions, starch retrogradation, and grain structural properties of cooked rice. The results showed that, compared to the control (0 mT), MF treatment significantly reduced the hardness of cooked rice, with a 32.5 % reduction observed at 10 mT. MF treatment improved water molecule stability and inhibited ice crystal growth, as evidenced by reduced water loss, decreased water mobility, and shortened freezing phase transition time. Furthermore, MF treatment suppressed starch retrogradation in cooked rice, leading to a slight decrease in relative crystallinity. These alterations in water phase transitions and starch retrogradation contributed to improved structural stability in rice, thereby enhancing its texture quality. Overall, these findings provide valuable insights into the potential of MF technology to advance the frozen staple food industry.

The current research in the food industry regarding enzymatic modification to enhance the freeze-thaw (FT) stability of starch is limited. The present study aimed to investigate the FT stability of normal corn starch (NCS) modified using 1,4-α-glucan branching enzyme (GBE) derived from Geobacillus thermoglucosidans STB02. Comprehensive analyses, including syneresis, scanning electron microscopy, and low-field nuclear magnetic resonance, collectively demonstrated the enhanced FT stability of GBE-modified corn starch (GT-NCS-30) in comparison to its native form. Its syneresis was 66.4 % lower than that of NCS after three FT cycles. Notably, GBE treatment induced changes in the pasting properties and thermal resistance of corn starch, while simultaneously enhancing the mechanical strength of the starch gel. Moreover, X-ray diffractograms and microstructural assessments of freeze-thawed gels indicated that GBE treatment effectively hindered the association of corn starch molecules, particularly amylose retrogradation. The enhanced FT stability of GBE-modified starch can be attributed to alterations in the starch structure induced by GBE. This investigation establishes a foundation for further exploration into the influence of GBE treatment on the FT stability of starch and provides a theoretical basis for further research in this area.

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The purpose of this study was to investigate the effect of Tremella fuciformis polysaccharides on the physicochemical properties of freeze–thawed cone chestnut starch. Various aspects, including water content, crystallinity, particle size, gelatinization, retrogradation, thermal properties, rheological properties, and texture, were examined. The results revealed that moderate freezing and thawing processes increased the retrogradation of starch; particle size, viscosity, shear type, hinning degree, and hardness decreased. After adding Tremella fuciformis polysaccharide, the particle size, relative crystallinity, and gelatinization temperature decreased, which showed solid characteristics. Consequently, the inclusion of Tremella fuciformis polysaccharide effectively countered dehydration caused by freezing and thawing, reduced viscosity, and prevented the retrogradation of frozen–thawed chestnut starch. Moreover, Tremella fuciformis polysaccharide played a significant role in enhancing the stability of the frozen–thawed chestnut starch. These findings highlight the potential benefits of incorporating Tremella fuciformis polysaccharides in starch-based products subjected to freeze–thaw cycles.

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The use of unmodified starch in frozen foods can cause extremely undesirable textural changes after the freeze-thaw process. In this study, using cyclodextrin glucanotransferase (CGTase) and branching enzymes, an amylopectin cluster with high freeze-thaw stability was produced, and was named CBAC. It was found to have a water solubility seven times higher, and a molecular weight 77 times lower, than corn starch. According to the results of a differential scanning calorimetry (DSC) analysis, dough containing 5% CBAC lost 19% less water than a control dough after three freeze-thaw cycles. During storage for 7 days at 4 °C, bread produced using CBAC-treated dough exhibited a 14% smaller retrogradation peak and 37% less hardness than a control dough, suggesting that CBAC could be a potential candidate for clean label starch, providing high-level food stability under repeated freeze-thaw conditions.

The effects of konjac glucomannan (KGM) on the water status, starch recrystallization, and protein conformation of Youmian Yuyu (ONF) during freeze-thaw cycles (FTCs) were examined. The results showed that KGM markedly inhibited the rise in freezable water content, limited water migration throughout the FTCs, and reduced structural damage induced by ice crystals. Microscopic observations indicated that ONF with added KGM exhibited a more uniform and intact starch-protein network. The X-ray diffraction analysis revealed that KGM reduced the relative crystallinity and inhibited starch recrystallization. The protein structural analysis indicated that KGM addition promoted transition of the protein secondary structures from disordered to ordered conformations, thus effectively inhibiting disulfide bond disruption induced by FTCs. In summary, KGM significantly enhanced the freeze-thaw stability of oat noodles by regulating water distribution, inhibiting starch recrystallization, and stabilizing protein structures. These findings provide a theoretical basis for optimizing the industrial quality of traditional naked oat products.

The study was undertaken to reveal the effects of freeze-thaw cycles at different freeze temperature (-20 °C, -40 °C and -80 °C) and the number of freeze-thaw cycles (3, 6, 12, 18, 24 times) on physicochemical and structural properties of waxy corn starch. The number of pores on the surface of starch granules increased, but there was no significant (P < 0.05) effect on molecular weight, transparency, freeze-thaw stability and the crystal structure of starch after repeated freeze-thaw cycle. But the crystallinity intensity decreased after freeze-thaw cycles treatment and a tiny decrease in onset, peak, conclusion temperature and gelatinization enthalpy were found. The RVA analysis exhibited an increase in gelatinization temperatures and a decrease in breakdown and setback value after freeze-thaw treatment, which manifested an increase in the aging and heat resistance of waxy corn starch paste. However, there was no statistical (P < 0.05) difference between different freeze temperatures at the same number of freeze-thaw cycle on physicochemical and structural properties of starch. The obtained data could be helpful in evaluation of the repeated freeze-thaw treatment of waxy corn starch-based foodstuffs and providing the theoretical basic for revealing the effect of repeated freeze-thaw processes in manufacture applications.

This study compounded natural corn starch (CS), mung bean starch (MBS) and potato starch (PS) with tannic acid (TA) to stabilize O/W Pickering emulsion. The effect of TA/starch mass ratio (0-0.25) and three starch categories on particle properties, emulsifying properties, lipid oxidation, freeze-thaw stability, emulsion powder and digestive properties were comprehensibly investigated. In detail, the TA/starch complexes size increased gradually (91.14 nm-200.87 nm) and the hydrophobicity first increased and then decreased (TA/CS > TA/MBS > TA/PS) with increasing TA/starch mass ratio. In addition, the emulsifying ability of TA/starch complexes also increased first and then decreased with increasing mass ratio, especially TA/CS system was the best, which was the same as the hydrophobicity conclusion (θow = 80.46°). Moreover, four starch-based emulsion application characteristics were further evaluated to reveal interface structure. Compared to CS and PS system, TA/MBS emulsion had stronger ability to resist the oil oxidation (TBA = 2.54 μg/mL), destruction of ice crystal (whiter emulsion powder) and digestive enzymes (FFAs = 75.33 %). It mainly attributed to the crosslinking network structure and the highest surface load of TA/MBS complexes. This study would provide new ideas for the design and application of emulsifying properties and emulsion stability.

Highlights • Mechanical damage to starch granules deepened as freeze–thaw cycles increased.• ScAFP retarded the damage of ice crystals on granular and crystal structure of starch.• ScAFP improved thermal stability and gel texture properties of freeze-thawed starch.

Effects of starch formulation, highly concentrated sucrose solution, and coconut milk on the stability of starch gels kept under chilled and frozen conditions were determined. Gels containing rice starch (RS), tapioca starch (TS) (RS:TS of 1 : 0.85), and hydroxypropyl distarch phosphate (HDP, 0-50% of total starch) were prepared from 15% starch suspension using water, 45°Brix sucrose syrup or coconut milk as liquid media. After aging at 4°C for 21 days, starch gels had higher hardness and chewiness, with lower cohesiveness and springiness (p ≤ 0.05). Water-based gels containing HDP had less extent of texture hardening, lower degree of crystallinity, and more homogeneous microstructure during 4°C aging. However, for the starch gels in sucrose syrup or coconut milk, HDP induced greater gel hardening, higher degree of crystallinity, and denser gel microstructure during chilled storage. This could be due to the crystallization of sucrose or lipid/amylose-lipid complexes. Nevertheless, HDP enhanced freeze-thaw stability of the gels, regardless of the liquid media used (p ≤ 0.05). According to the consumer test of the model desserts subjected to a single freeze-thaw cycle, the sample containing 50% HDP gel in sucrose syrup or 25% HDP gel in coconut milk gained the highest hedonic score of texture and overall acceptance (p ≤ 0.05).

Foxtail millet starch was modified by annealing (AS), ultra-sonication (US) and a combination of the two treatments (annealing and ultra-sonication (AUS) or ultra-sonication and annealing (UAS)) and they were characterized. Compared to the native starch (NS), modified starches particularly UAS contained the highest amylose (27.96%). Ultra-sonication prior to annealing had a predominant effect on resistant starch (RS) level (UAS-45.59%). Among the modified starches, UAS had exhibited superior resistance to acidic (0.94) and shear (0.68) stability. Sonication, when used as the second treatment (AUS) elevated the final viscosity compared to its counter ones possibly due to the effects of cavitation promoted by sonication treatment. UAS had showed an A-type diffraction pattern and dominant peaks in FT-IR spectra. It can be inferred that dual modification of starch by ultra-sonication followed by annealing had exhibited the most desirable properties such as high acid and shear resistance, high freeze-thaw stability and improved gel texture.

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Starch is a primary energy source of human diet. Its physicochemical properties and digestibility can be improved by incorporating exogenous protein. In this study, mung bean protein isolate was covalently crosslinked using transglutaminase and proanthocyanidin to create crosslinked mung bean protein isolate. This modified protein was combined with corn starch to form crosslinked mung bean protein isolate-corn starch composite samples. Results demonstrated that these composite samples exhibited superior physicochemical properties, including reduced swelling capacity, enhanced freeze-thaw stability, improved thermostability, and enhanced antioxidant properties. During in vitro digestion, the improved corn starch digestibility was attributed to two factors: first, hydrogen bonding and electrostatic interactions between crosslinked mung bean protein isolate and corn starch; and second, the synergistic crosslinking of transglutaminase and proanthocyanidin promoting the formation of a stable protein network of mung bean protein isolate, serving as a physical barrier to protect corn starch. After co-treatment with transglutaminase and proanthocyanidin, significant changes of mung bean protein isolate occurred in their secondary and tertiary structures, enhancing its protein network strength, thereby improving the physicochemical properties of corn starch. These findings propose a new strategy for reducing rapidly digestible starch and provide a theoretical foundation for developing low glycemic index starch foods.

To improve paste stability of cassava starch, including acid resistance, high-temperature shear resistance and freeze-thaw stability, cassava starch was modified by sequential maltogenic amylase and transglucosidase to form an optimally denser structure, or branched density (12.76 %), molecular density (15.17 g/mol/nm3), and the proportions of short-branched chains (41.41 % of A chains and 44.01 % of B1 chains). Viscosity stability (88.52 %) of modified starch was higher than that (64.92 %) of native starch. After acidic treatment for 1 h, the viscosity of modified starch and native starch decreased by 56.53 % and 65.70 %, respectively. Compared to native starch, modified starch had lower water loss in freeze-thaw cycles and less viscosity reduction during high-temperature and high-shear processing. So, the appropriate molecular density and denser molecule structure enhanced paste stabilities of modified starch. The outcome expands the food and non-food applications of cassava starch.

Germination has been extensively studied, but the changes in different starch components have not yet been entirely elucidated. The aim of this study was to assess the effects of germination on the starch composition, physicochemical properties, and structure of red sorghum seeds.Germination of red sorghum starch led to decreased amylose, water absorption, and syneresis, but increased oil absorption, solubility, and swelling power. The freeze–thaw stability of germinated sorghum starch improved. However, the starch paste exhibited thinning under shear, suggesting its gel structure was susceptible to damage. The starch's peak viscosity and breakdown value increased significantly with the increase in germination time, whereas the setback value decreased. Germination treatment did not alter the chemical structure of the starch, but it increased the porosity and the number of dents on the surface of starch granules. Notably, the in vitro digestibility of the starch increased significantly after germination.The germination treatment of red sorghum affected the structure and physicochemical properties of the isolated starch to some extent.

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In this study, the physicochemical, rheological, in vitro starch digestibility, and emulsifying properties of starch extracted from pineapple stem agricultural waste were investigated in comparison with commercial cassava, corn, and rice starches. Pineapple stem starch had the highest amylose content (30.82%), which contributed to the highest pasting temperature (90.22 °C) and the lowest paste viscosity. It had the highest gelatinization temperatures, gelatinization enthalpy, and retrogradation. Pineapple stem starch gel had the lowest freeze–thaw stability, as evidenced by the highest syneresis value of 53.39% after five freeze–thaw cycles. Steady flow tests showed that pineapple stem starch gel (6%, w/w) exhibited the lowest consistency coefficient (K) and the highest flow behavior index (n), while dynamic viscoelastic measurements gave the gel strength in the following order: rice > corn > pineapple stem > cassava starch gel. Interestingly, pineapple stem starch provided the highest slowly digestible starch (SDS) (48.84%) and resistant starch (RS) (15.77%) contents compared to other starches. The oil-in-water (O/W) emulsion stabilized with gelatinized pineapple stem starch exhibited higher emulsion stability than that stabilized with gelatinized cassava starch. Pineapple stem starch could therefore be used as a promising source of nutritional SDS and RS, and as an emulsion stabilizer for food applications.

The processing properties of resistant starch (RS) and its digestion remain unclear, despite the widespread use of autoclaving combined with debranching in its preparation. In this study, the physicochemical, rheological and digestibility properties of autoclaving modified starch (ACB), autoclaving–pullulanase modified starch (ACPB) and native black Tartary buckwheat starch (NB) were compared and investigated. The molecular weight and polydispersity index of modified starch was in the range of 0.15 × 104~1.90 × 104 KDa and 1.88~2.82, respectively. In addition, the SEM results showed that both modifications influenced the morphological characteristics of the NB particles, and their particles tended to be larger in size. Autoclaving and its combination with pullulanase significantly increased the short-range ordered degree, resistant starch yield and water- and oil-absorption capacities, and decreased the syneresis properties with repeated freezing/thawing cycles. Moreover, rheological analysis showed that both ACB and ACPB exhibited shear-thinning behavior and lower gel elasticity as revealed by the power law model and steady-state scan. The degradation of starch chains weakened the interaction of starch molecular chains and thus changed the gel network structure. The in vitro digestion experiments demonstrated that ACB and ACPB exhibited greater resistance to enzymatic digestion compared to the control, NB. Notably, the addition of pullulanase inhibited the hydrolysis of the ACB samples, and ACPB showed greater resistance against enzymatic hydrolysis. This study reveals the effects of autoclaving combined with debranching on the processing properties and functional characteristics of black Tartary buckwheat starch.

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Properties of modified starch and its interaction with functional raw materials are of great interest to the food industry. Thus, this study aimed to evaluate the rheological and technological characterization of starches modified by the action of the enzymes α-amylase and amyloglucosidase and their mixtures with jaboticaba peel powder. The parameters of firmness, gumminess, and final viscosity of starches paste increased, and the tendency to setback was reduced with the addition of jaboticaba peel powder. Starches and mixtures presented shear-thinning behavior. The addition of jaboticaba peel powder to starches increased water, oil, and milk absorption capacity, while syneresis remained stable over the storage period. The addition of jaboticaba peel powder had a positive effect on native and modified starches' rheological and technological properties, qualifying it as an alternative for developing new functional food products.

In this research, the influences of Lycium barbarum polysaccharide (LBP) on gelatinization properties of potato starch (POS) were evaluated. The swelling power of POS was inhibited, and the leaching of amylose declined. The LBP increased the peak temperature (Tp), while decreased the enthalpy (ΔH) of gel from 6.62 to 4.87 J g−1. Compared with pure POS gel, the hardness of POS gel added with 0.6% LBP decreased by 13% after storage for 20 days. The syneresis of gels that exposed to four freeze–thaw cycles was significantly reduced from 65.8% to 41.2%. Rheological measurements revealed that the viscoelasticity of composites was enhanced. The addition of LBP can enlarge the particle size of composite gels, and make the microstructure of composite gels become smooth, compact, and thicker pore wall. Fourier‐transform infrared spectroscopy (FTIR) and interaction force test showed that the hydrophobic bond was likely to be the main force.The incorporation of LBP could improve the gelling characteristics of POS‐based gel by delaying the change on gel hardness of POS composites during storage, and reducing the undesirable impact of freeze‐thawing treatment on POS gel system. The research outcome of the gelling characteristics of POS‐based gel can be used for frozen food, low‐temperature refrigerated food, and soft food. And the results of rheological behavior on POS‐based gel can be used in sauces, thickeners, and puddings.

The changes in the structure, gelatinization, and rheological properties of wheat starch during freeze-thaw cycles are crucial for enhancing the quality of products. This study investigated the effects of oligosaccharide (16 % w/w) addition on starch structure and properties under repeated freeze-thaw (FT) conditions. Specifically, xylooligosaccharides (XOS), galactooligosaccharides (GOS), and fructooligosaccharides (FOS) were found to preserve the supramolecular stacking of starch after the unwinding and amorphization of the native starch molecules. Notably, XOS more effectively inhibited the reorganization of starch structures after freezing and thawing, which could reduce the setback viscosity by 39.3 % after 11 freeze-thaw cycles. This inhibition likely prevents water molecules from entering granules and forming hydrogen bonds with starch chains, thereby limiting the development of helical and short-range ordered structures. Furthermore, the XOS curtailed the formation of long-range ordered structures in the crystalline region. These effects contribute to the increased shear resistance and structural recovery of the starch paste after shearing. Additionally, the presence of oligosaccharides led to reductions in both storage and loss moduli resulting in a relatively weak gel network structure. This study provides valuable insights into the selection of functional sugar substitutes for frozen products during freeze-thaw cycles.

In this study, we aimed to use electrical impedance spectroscopy (EIS) to assess the freeze-damage level of starches from potato tubers treated with multiple freezing-thawing (FT) cycles. The results showed that the relationship between the physicochemical properties of starches and the impedance characteristics of starch paste is temperature-dependent. As the temperature rises to 70-90 °C, the impedance modules show a significant correlation with the amylose and mineral contents, gelatinization and pasting properties, short-range ordered structure, relative crystallinity, and damage level within the range of 10-1 MHz (p < 0.01). This could be because FT leads to a reduction in amylose and ion content. Compared to a high level of freeze-damaged starch (FDS), a low level of FDS has less amylopectin and more amylose. Additionally, the ions could be typically evenly distributed throughout the unbranched linear amylose structure in starch paste. At the peak gelatinization temperature, the starch paste made from a low level of FDS exhibits a weakened network structure, allowing more unbound water for ion movement and enhancing electric conduction. In conclusion, EIS can predict the damage level and properties of FDS, which can benefit the frozen starchy food industry.

Starch retrogradation is a complex process, affected by several factors including storage temperature and the presence of non-starch components (such as polysaccharide). In this study, the effects of the endogenous yam non-starch polysaccharide (YNSP) with different concentrations on the yam starch (YS) retrogradation behavior were investigated by asymmetrical flow field-flow fractionation (AF4), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Furthermore, the effects of isothermal and temperature-cycled storage on the retrogradation of YNSP + YS blend were systematically studied. An effect mechanism of the endogenous YNSP on the YS retrogradation during temperature-cycled storage was proposed. The results revealed that 4/-20 °C temperature-cycled storage facilitated YS retrogradation, owing to the formation of starch-rich regions during frozen storage. The mechanical squeezing force caused by the size growth of ice crystal during long-term frozen storage encouraged starch molecules to constantly rearrange, promoting YS retrogradation. Moreover, the YNSP can not only interact with amylose and amylopectin molecules to form aggregates that could promote YS short-term retrogradation, but also compete with amylopectin for water molecules, which might enhance the syneresis process during repeated freeze-chill storage, thereby facilitating YS retrogradation. The results suggested that a combination of AF4, FTIR, and XRD is a powerful method not only for monitoring the interaction between YNSP and YS, but also for investigating the effects of YNSP content and temperature on YS retrogradation. The present study might offer a theoretical foundation and guidance for the application of YNSP to starchy products.

Thermal-ultrasound treatment is a green technology that can significantly alter the structural and functional properties of starches. This research extend the effect of at different temperatures (25 °C, 45 °C, and 65 °C) and times (30 and 60 min) on the physicochemical, structural, and rheological properties of corn starch was studied. Amylose content, solubility, swelling power, and the least gelling content increased with increasing temperature and time. Starch treated at 45 °C for 30 min had the lowest syneresis among all treatments. Thermal-ultrasound treatment at 25 °C and 65 °C for 60 min caused increasing paste clarity. Microscopic observations demonstrated that the starch granules were agglomerated at 65 °C. Although the crystallinity of samples decreased from 35.42% to 8.94%, the storage modulus was more than the loss modulus during the frequency sweep test. Pasting properties showed that pasting temperatures shifted to higher values after treatment. Nonetheless, the maximum viscosity decreased, and the final viscosity of the treated samples demonstrated that short-term retrogradation could deteriorate. Results showed that thermal-ultrasound is a viable technique for starch modification compared to conventional thermal and ultrasound treatments.

The aim of this study was to characterize the physicochemical properties of starch isolated from two varieties of tigernuts. The results showed wide variations between the two types of tigernuts. Mean granule sizes were 11.1 and 6.1 μm, respectively, for starch from the yellow and black while amylose content ranged from 19 to 21%. Starch gels from the yellow variety were more stable to freeze-thaw and recorded 37.1% syneresis, compared to 56.5% after the first storage cycle. Pasting properties were significantly different (p < 0.05) among starch from the two tigernut varieties, with black recording higher peak viscosity, lower breakdown, and higher setback viscosity. Gels made from the yellow variety were clearer, softer, more adhesive, and more cohesive. Both gels showed a pseudoplastic flow behavior without thixotropy.

No abstract available

Waxy cassava roots of nine varieties successfully developed in Thailand by a non-genetic modification (non-GM), conventional breeding method were used for extracting starches and their starch physico-chemical properties were evaluated and compared with normal cassava starches, commercial waxy starches (i.e., waxy maize starch and waxy rice starch) and commercial stabilized starches (i.e., acetylated starch and hydroxypropylated starch). All waxy cassava varieties provided starches without amylose while normal cassava starches contained 18%–20% amylose contents. As determined by a Rapid Visco Analyzer (RVA) at 5% (dry basis), waxy cassava starches had the highest peak viscosity and the lowest setback viscosity. Cooked paste of waxy cassava starches had the greatest clarity and stability among all starches during storage at 4 ℃ for 7 days as evidenced by its high light transmittance (%T) at 650 nm. No syneresis was detected in waxy cassava starch gels after subjecting to four freeze-thaw cycles (4 weeks) indicating high potential use of waxy cassava starches, free from chemicals, to replace stabilized starches as thickening and texturing agents in food products.

Starch from jackfruit seeds shows potential for use in food production processes with high starch content. Modification of jackfruit seed starch to increase the resistant starch content makes it a promising candidate for prebiotics in the food industry. Carboxymethylation can provide benefits for starch utilization in improving starch functional properties such as solubility, viscosity, and resistant starch content. This study chemically modified starch through carboxymethylation at different concentrations of sodium hydroxide to investigate the effect of carboxymethyl substitution on the digestible properties of the starch. Carboxymethylation exhibited a high degree of substitution from 0.28% to 0.57% as a function of the concentration of sodium hydroxide (5–10 wt%). The treatment enhanced the swelling, water solubility, and water/oil absorption. The resistant starch content increased from ~ 21 to ~ 39.67%. However, the high degree of substitution showed structural deformation of the starch granules with a decrease in crystallinity from about 35 to 1% by SEM and XRD. The degree of carboxymethyl substitution increased resistant starch content, reduced rapidly digestible starch, and had negligible impact on slowly digestible starch. Jackfruit seed starch treated with 10% by weight of NaOH was the optimal value that increased carboxymethyl substitution to 0.57% and resistant starch content to ~ 40%. This concentration was also optimal for the functional properties of starch with the highest values of swelling degree (~ 27 g/g), water solubility (~ 50%), freeze–thaw stability (~ 20% of syneresis after 4 freeze–thaw cycles), and oil and water absorption (150% of oil absorption and 180% of water absorption).

In order to explore the potential application of combined physical treatment in producing highly lipophilic modified starch, the effects of ultrasound combined with freeze-thaw treatment on the microstructure and physicochemical properties of potato starch were investigated. The samples treated by combined treatment had the roughest structure and the oil adsorptive capacity value increased from 59.62% (native starch, NS) to 80.2% (7 cycles of ultrasound-freeze-thaw treatment starch, 7UT-FTS). Compared to NS, the crystalline type and chemical groups of modified starches did not change, but the relative crystallinity, enthalpy change, and paste viscosity decreased to varying degrees, while the gelatinization temperature increased. The digestibility of raw modified starch was higher than that of NS, but this phenomenon disappeared after gelatinization. 7UT-FTS showed better resist-digestibility than NS after encapsulating oil. Hence, this would be an efficient and environmentally friendly way to produce modified starch with safety, highly lipophilic and heat resistance.

The objective of this study was to investigate the dual modification of red rice starch using pulsed electric field (PEF) and α-amylase, focusing on morpho-structural, thermal, and viscoamylographic properties. Native starch (Control) underwent various treatments: PEF at 30 kV cm-1 (PEF30), α-amylase at 9.0 U mg-1 (AA0), and a combination of both (PEF30 + α and α + PEF30). The PEF30 + α treatment exhibited the highest degree of digestion (10.66 %) and resulted in morphological changes in the starch granules, which became elongated and curved, with an increased average diameter of 50.49 μm compared to the control. The starch was classified as type A, with a maximum reduction in crystallinity of up to 21.17 % for PEF30. The deconvolution of FT-IR bands indicated an increase in the double helix degree (DDH) for PEF30 and AA0, while the degree of order (DO) was reduced for PEF30, AA0, and PEF30 + α. DSC analysis revealed significant modifications in gelatinization temperatures, particularly for PEF30, and these changes were supported by a reduction in gelatinization enthalpy (ΔH) of up to 28.05 % for AA0. These findings indicate that both individual and combined treatments promote a decrease in starch gelatinization and facilitate the process, requiring less energy. Differences were observed between the formulations subjected to single and alternating dual treatments, highlighting the influence of the order of PEF application on the structural characteristics of starch, especially when applied before the enzymatic treatment (PEF + α). Regarding the viscoamylographic parameters, it was observed that AA0 presented higher values than the control, indicating that α-amylase enhances the firmness of the paste. The double modification with PEF + α was more effective in reducing syneresis and starch retrogradation, leading to improvements in paste properties. This study provided significant insights into the modification of red rice starch using an efficient and environmentally friendly approach.

No abstract available

Brown rice (BR) is a promising source for convenience rice that are mostly stored frozen. However, freezing and thawing may cause deterioration in rice texture quality. To investigate how rice texture is influenced by freeze-thaw cycles, BR, the pretreated BR with partially ruptured bran layer (UER) and white rice (WR) were cooked and treated with repeated freeze-thaw cycles, with their textural properties, variations in moisture distribution and starch structure being measured. Results showed that the repeated freeze-thaw treatment induced a progressive reduction in hardness and stickiness of all cooked rice. The reduced hardness of rice could be explained by the enlarged pore size of starch inside rice under scanning electron microscopy. Moisture migration in WR was the fastest responding to multiply freeze-thaw cycles, followed by UER, while water mobility in BR was slowest. Moreover, WR, BR and UER resulted in a similar extent of amylopectin retrogradation and chains length distribution after repeated freeze-thaw cycles. It indicated similar and minor effect of starch variations on determining the texture of different rice samples against freeze-thawing. Water mobility tended to be a main factor leading to the textural difference of fully gelatinized rice samples. This study focused on the relationship between water distribution and starch retrogradation, providing a better understanding on influences of multiple freeze-thawing on textural quality of cooked rice maintaining different extents of surface layer.

No abstract available

The production of quick-frozen wet rice noodles involves wet-milling, steaming, shaping, retrogradation, and freezing. This study investigated the changes in the quality and starch structural characteristics of frozen rice noodles (RN) prepared at different retrogradation times, freezing temperatures, and rice-water ratios. It was revealed that extending the retrogradation time would help to enhance the toughness of the product, increasing the rice-water ratio would reduce the hardness of the RN, and too low a freezing temperature would cause higher cooking losses. The RNs frozen at -32°C (6 h retrogradation, 1:1.5 rice-water ratio) exhibited higher chewiness, lower cooking loss (1.31%), and more uniform water distribution. Decrease in freezing temperature (-20 to -80°C) reduced the freezable water in RN (from 708.8 to 543.9 J/g), while retrogradation time and rice-water ratio showed no single change trend. All frozen RNs contained B + V-type microcrystals, and the crystallinity increased (from 3.02 to 4.16%) with the increase of rice-water ratio (from 1:1 to 1:2). But their short-range order structure was almost unchanged. Prolonging the retrogradation time enriched the aperiodic nanostructures, whereas decreasing the freezing temperature presented opposite effects. Too long a retrogradation time or an inappropriate freezing temperature (too high or too low) would produce unfavorable network structures in RNs. The correlation between the individual properties is not uniform in different conditions. The findings of this research provide essential data support for the formulation and manufacturing of quick-frozen wet rice noodles with desirable quality.

No abstract available

This work investigated the effect of retrogradation time (0 h, 2 h, 4 h, 6 h, 8 h) and freezing temperature (-20 °C, -32 °C, -80 °C) on the muti-scale structures of the rice starch-protein system of quick-frozen wet rice noodles. The Relative crystallinity and porosity of the rice starch-protein system increased with increasing retrogradation time. However, while longer retrogradation does lead to an improvement in relative crystallinity, it also results in significant damage to the microstructure. When the retrogradation time was 6 h, the microstructure of the rice starch-protein system was less damaged and the quality was better. The mass fractal dimension and relative crystallinity of the rice starch-protein system exhibited an increase as the freezing temperature was decreased from -20 to -80 °C. Additionally, the retrogradation degree of starch decreased, the size of ice crystals decreased, and the disruption of microforms was reduced. The muti-scale structures of the rice starch-protein systems were similar when quick-frozen at temperatures of -32 and -80 °C. Therefore, the optimal treatment method for practical production is to quick-freeze at -32 °C and age for 6 h to obtain high-quality quick-frozen wet rice noodles.

The study examined the effects of different freezing and thawing methods on cassava starch properties, comparing direct freezing (DF) using liquid nitrogen at -196 °C with indirect freezing (IF) in an ultra-freezer at -80 °C, followed by either conventional thawing at 25 °C or PEF-assisted thawing at 12 kV/cm for 8 min. DF caused less structural damage to starch granules than IF due to the formation of smaller, more uniform ice crystals. PEF during thawing proved particularly effective at preserving starch quality, maintaining crystallinity and molecular integrity while preventing the deterioration of thermal and rheological properties typically caused by freezing. PEF treatment facilitated molecular reorganization within the starch matrix, reducing retrogradation while enhancing overall stability. The combination of freezing methods with PEF-assisted thawing (DF12 and IF12) minimized the degradation of both amylose and amylopectin components, with measured values for gelatinization enthalpy and viscosity parameters closely matching those of the untreated control sample (P12).

The study evaluated the effect of freezing rate on the quality of water-added quick-frozen rice noodles and water-free quick-frozen rice noodles. Results indicated that the retrogradation enthalpy, relative crystallinity, freezable water content, and cooking loss of water-added quick-frozen rice noodles were higher than those of water-free quick-frozen rice noodles with increasing storage time. Furthermore, ice recrystallization accelerated the deterioration of the quality of the rice noodles, resulting in the enlargement of the pores within the rice noodles and the formation of many pores on the surface. This phenomenon was particularly evident in the rice noodles of Y-40 °C (freezing with water at -40 °C) and Y-60 °C (freezing with water at -60 °C). After 28 days of frozen storage, the hardness increased by 83.83 % for rice noodles of Y-20 °C (freezing with water at -20 °C), while the hardness decreased by 51.68 % and 45.80 %, respectively, for rice noodles of Y-40 °C and Y-60 °C. Consequently, the impact of the freezing rate on the quality of water-added quick-frozen rice noodles is more pronounced than that of water-free quick-frozen rice noodles. Moreover, a higher freezing rate can delay the deterioration of the quality of frozen rice noodles by postponing starch retrogradation and inhibiting ice recrystallization.

Frozen dough is suitable for industrial cold chain transportation, but usually experiences temperature fluctuations through the cold chain to the store after being refrigerated in a factory, seriously damaging the product yield. In order to analyze the influence mechanism of temperature fluctuation during the terminal cold chain on frozen dough, the effects of terminal freezing and thawing (TFT) on the quality (texture and rheology) and component (water, starch, protein) behaviors of dough were investigated. Results showed that the TFT treatment significantly increased the hardness and decreased the springiness of dough and that the storage modules were also reduced. Furthermore, TFT increased the content of freezable water and reduced the bound water with increased migration. Additionally, the peak viscosity and breakdown value after TFT with the increased number of cycles were also increased. Moreover, the protein characteristics showed that the low-molecular-weight region and the β-sheet in the gluten secondary structure after the TFT treatment were increased, which was confirmed by the increased number of free sulfhydryl groups. Microstructure results showed that pores and loose connection were observed during the TFT treatment. In conclusion, the theoretical support was provided for understanding and eliminating the influence of the terminal nodes in a cold chain.

No abstract available

In order to elucidate the mechanism underlying the effect of different-sizes potato starch on dough during freeze-thaw treatment, the rheological properties, moisture distribution, secondary structure, and relative crystallinity of dough were investigated. The results showed that the storage modulus (G'), loss modulus (G″), and complex modulus (|G*|) of dough increased as a result of the freeze-thaw treatment, and the effect was more obvious as the starch granular sizes increased. The higher β -sheet and T22 contents reflected the higher viscoelasticity and freeze-thaw sensitivity, which may be related to the higher degree expansion of amylose. In contrast, dough with small-sized starch had higher intermolecular interactions, and denser structure, lower water migration, showing that this has better resistance and higher stability. The presented mechanisms may contribute to the better understanding of the effects of freeze-thaw process on model dough properties.

This study aimed to investigate the effect of pre-swelling at 55°C for 1 hr followed by freezing-thawing cycles (PFTCs), and freezing-thawing cycles (FTCs) in the starch granules to improve the freeze-thaw stability and evaluate its impact on the molecular, morphological, and functional properties of potato starch (PS). FTCs at 1 cycle and 7 cycles were applied for both treated PS. Microscopical structure, thermal, molecular, and functional properties (i.e., swelling power, solubility, shear viscosity, and gel strength) were comprehensively analyzed. In terms of granule structures, treated PS by FTC showed a slightly affected on the surface of starch granules, while treating PS by PFTC showed an affected in the form of small cracks and holes in the outer surface of starch granules. The gelatinization enthalpy (∆Hgel ) values decreased in the treated PS compared with the native. Thus, decreasing was systemically increased with the number of applied cycles from 1- to 7-cycle. The viscosity of treated PS decreased systematically with molecular degradation or the physical modification, with remarkable reduction, particularly at a higher shear rate (150°C). Treated PS by FTC showed a clear difference (p ≤ .05) in gel values compared with the native at disintegration temperature 115°C. Finally, the degradation of the molecular properties showed significant differences between the native and treated PS either by the FTC or PFTC in molecular weight of starch and amylose without debranching and after debranching by pullulanase enzyme. PRACTICAL APPLICATIONS: Freezing is one of the standard preservation methods used for ready-to-eat products. When this type of food's exposed to more freeze-thaw cycles, the phase separation will be increased due to the increase in retrogradation of amylopectin. To avoid such changes during frozen storage, native potato starch (PS) was modified using both pre-swelling followed by freezing-thawing cycles (PFTCs) and freezing-thawing cycles (FTCs) at 1- and 7-cycle to enhance starch properties, such as swelling power, solubility, shear viscosity, and gel strength. The findings of this study might add to the theoretical understanding of modified PS and act as a guideline for modified starch manufacturing.

The physicochemical properties and structural characteristics of starches from three wheat flours with different gluten strength (S-YM20, S-ZM27, and S-ZM366) during freezing/thawing (F/T) cycles were studied. After F/T treatment, the damaged starch content of these three starches all increased, and the lowest increment of damaged starch content after 8 F/T cycles was S-ZM366; the most serious distribution of particle surface concave hole and fracture was S-YM20, followed by S-ZM27 and S-ZM366; additionally, the results of solubility, swelling power, thermal stability and pasting properties indicated S-ZM366 exhibited the strongest resistance to F/T cycles. The differences of freezing resistance among the three starches were possibly ascribed to the differences in compositions, crystallinity and microstructure among these three starches. This study provides theoretical contribution to the development of frozen dough industry from the perspective of wheat variety.

Properties of starches isolated from soft and hard wheat dough after freezing/thawing (F/T) treatment were investigated. Significance of results was observed between isolated hard wheat starch (HWS) and soft wheat starch (SWS), but both cultivars showed an increase in the amounts of damaged starch and leaching proteins, lipids, and amylose with F/T cycles. The freezing-treated HWS exhibited a higher swelling power and peak, trough, breakdown and final viscosity than SWS after F/T treatment. The onset, peak and conclusion gelatinization temperatures and the enthalpy of the isolated HWS determined by differential scanning calorimetry, decreased throughout F/T cycles. Concomitantly, the bread containing freezing-treated HWS exhibited a lower bread specific volume and harder crumb firmness, which might be associated with its significant structural changes induced by F/T treatment.

Fiber-enriched white sauces with apple (AF401), potato (KF200), and microcrystalline cellulose (MCC) were selected among six white sauces, all of them elaborated by replacing corn starch and milk with 3% of different dietary fibers. It was investigated the freezing/thawing (F/T) stability of these three enriched white sauces studying their physico-chemical (color, syneresis percentage, total soluble solids content), rheological (viscoelastic and steady measurements), and sensorial properties before and after a freezing/thawing treatment. White sauce with MCC resulted in being the most like the control (without fiber) showing a higher elasticity and a heat stability. Moreover, the sauce elaborated with MCC has a sensorial profile as a traditional corn starch sauce with high "creaminess" and lower "heterogeneity" after the F/T treatment. Therefore, the properties provided by MCC make this product interesting in food design, and MCC sauce could be used as an industrial frozen fiber-enriched white sauce. PRACTICAL APPLICATION: These days, there is an increase in the demand of precooked frozen dishes due to current lifestyles and because the use of fiber exhibits many proven health benefits. A béchamel sauce made from corn starch and enriched with different fibers was elaborated, frozen and thawed in microwave. Both fresh and frozen/thawed microcrystalline cellulose (MCC) sauces exhibited very similar rheological and sensorial properties to an industrial and traditional frozen white sauce without fiber. Therefore, MCC-enriched white sauce resulted to be a feasible strategy to produce a white sauce suitable for frozen dishes with good functional properties and sensorial quality.

No abstract available

The structural and functional properties of non-gelatinized waxy rice starch were investigated after 1, 3, 7, and 10 freezing/thawing cycles. Freezing caused an increasing damaged starch from 1.36% in native waxy rice starch to 5.77% in 10 freezing/thawing-treated starch (FTS), as evidenced by the cracking surface on starch granules. More dry matter concentration was leached, which was characterized by high amylopectin concentration (4.34 mg/mL). The leaching was accompanied by a decrease in relative crystallinity from 35.19% in native starch to 31.34% in 10 FTS. Freezing treatment also led to significant deviations in the functional characteristics, for instance decreased gelatinization temperature range, enthalpy, and pasting viscosities. The resistant starch content of 10FTS significantly decreased from 58.9% to 19%, whereas the slowly digested starch content greatly increased from 23.8% in native starch to 50.3%. The increase in susceptibility to enzyme hydrolysis may be attributed to porous granular surface, amylopectin leaching, and the decrease in the relative crystallinity caused by freezing water.

No abstract available

Small molecular sugars have gained substantial attention as common food additives for anti‐retrogradation of starch. However, the effect of small molecular sugars on the pasting and retrogradation behaviours of starchy foods with complex components is different from that of native starch owing to the interaction between different components. In this study, the pasting and retrogradation behaviours of Mesona chinensis polysaccharide/starch complexes combined with different sugars (trehalose, glucose, sucrose and lactose) were investigated by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), texture profile analysis (TPA), rapid viscometer analysis (RVA) and differential scanning calorimetry (DSC). SEM showed that the complex gel systems with various sugars exhibited smoother lamellar surfaces and profiles than those of the control group after refrigeration. RVA and DSC demonstrated that the addition of sugars significantly affected the pasting of the composite gel system. TPA, FT‐IR, XRD and SEM revealed that glucose, sucrose and lactose effectively inhibited the retrogradation of the composite gel system and that glucose was a candidate for inhibition of the retrogradation of the complex gel system. Additionally, the water separation of the composite gel system with sugars was lower than that of the control group after five cycles of alternating freezing and thawing, indicating that the sugars improved the freeze‐thaw stability of the composite gel system. These results provide a theoretical direction for the use of additives in the retrogradation of starchy foods containing multiple components.

In order to achieve preparation of cross-linked (CL) potato starch with the maximum degree of substitution, freezing pre-treatment (FS) in different modes as three days freezing (3D), two freezing-thawing cycles (3D + 3D) and 6 days freezing (6D) were conducted. Thereafter, native, frozen and cross-linked starches were characterized for morphological, structural and pasting properties as well as alkaline and intrinsic viscosity. Regarding obtained result, freezing pre-treatment as 3D + 3D was found to be an efficient method to achieve high level of cross-linking than native and other modes of freezing pre-treatments when exposed to POCl3 reagent. The crystallinity (%) and ratio of 1047/1022 cm-1 increased from 38.6 % and 1.112 (native potato starch; NPS) to 41.6 % and 1.269 (cross-linked native potato starch; CL) and 41.3 and 1.292 (cross-linked freeze- thawed starch 3D + 3D + CL) after being treated with POCl3. Data obtained by intrinsic viscosity was in line with the power-law model. Cross-linked starch with POCl3 exhibited the lowest k value and the highest n value, implying lower shear-thinning behavior of cross-linked starch after freezing pre-treatment than CL native starch. To sum up, low peak viscosity (determined by RVA) and intrinsic viscosity (by U-tube viscometer) could also explain the high level of cross-linking and low swelling power of 3D + 3D + CL.

The effects of fructooligosaccharides (FOS), galactooligosaccharides (GOS), and xylooligosaccharides (XOS) on gelatinization, retrogradation, thermal properties and particle size of wheat starch at different freezing temperatures were studied. The results showed that the wheat starch porosity, particle size, peak viscosity increased with increasing freezing temperature. With the addition of 16% oligosaccharides to starch, the porosity, particle size, crystallinity, initial gelatinization temperature, peak value, breakdown and retrogradation viscosity of the starch granules significantly decreased in the order of XOS > GOS > FOS. However, the pasting temperature of the granules increased. The addition of oligosaccharides (especially XOS, which has the most significant effect in inhibiting starch retrogradation) can inhibit the formation of starch crystal structures to a certain extent, reduce the damage from ice crystals to starch granules and delay starch retrogradation. Therefore, functional oligosaccharides can be used as a potentially effective additive to increase freezing stability in frozen starch-based foods.

The co-fermentation effect of adding taro-based yogurt strengthened the gluten network of frozen part-baked bread (FPBB). The underlying mechanisms were systematically investigated in terms of strain screening, dough stability, gluten structure and starch retrogradation behavior. Among the five lactic acid bacteria evaluated, taro-based yogurt fermented by Lactobacillus bulgaricus (LBF) was identified as the optimal improver, because it could provide higher fermentation intensity, acidification effect and water-holding capacity for the dough. LBF addition promoted the transformation of α-helix and β-sheet structures into β-turns, which softened the dough, increasing its extensibility and gas retention capacity, particularly at 10% LBF supplementation. The strong gluten network provided FPBB with excellent freezing performance, as confirmed by changes in microstructure, protein secondary structure, and starch short-range order after freezing for 28 days. LBF significantly reduced the enthalpy (ΔH) by 20.94% ∼ 26.99%. The water migration rate decreased from 11.84 to 6.58 days, and the crystallization rate was only 0.06 days.

Potato starch noodles (PSN), a characteristic gluten-free Asian food, are essentially high-concentration starch gels (about 35% starch) formed through gelatinization and retrogradation. This study systematically investigates freezing temperature effects, particularly across the glass transition temperature, on PSN texture and microstructure. We found that fresh PSN have a freezing point of −1 °C, supercooling temperature of −4.5 °C, and a Tg’ value of −3.1 °C. Freezing significantly reduced the adhesiveness of PSN and increased the hardness. During the 48 h freezing process, noodles frozen at −3 °C, the closest to Tg’, exhibited the highest hardness (14,065.77 g), springiness (0.98), cohesiveness (0.93), chewiness (11,971.06), and resilience (0.84), and the least adhesiveness. PSN frozen within the range near Tg’ (−3 °C) showed superior texture, continuous solid cross-section, and dense surface, attributed to the reverse transformation of starch, high mobility of starch chains, and smaller ice crystals. PSN frozen at −3 °C for 24 h displayed the most compact and desirable texture compared to the other samples. These findings deepen the understanding of the role of glass transition temperature in the texture formation of starch gel during freezing and provide valuable insights for optimizing the frozen processing of starch gel-based food.

Crisp meat, a traditional Chinese food, is widely consumed due to its convenience and long frozen shelf life. However, conventional preparation methods lead to excessive oil absorption during frying and ice crystal formation during freezing, causing coating softening and reduced crispiness after reheating. This study aimed to enhance the quality of crisp meat before and after freezing by incorporating modified starches into the batter. Four types—oxidized starch, hydroxypropyl distarch phosphate, starch acetate, and acetylated distarch phosphate—were tested at replacement levels of 10–40% for natural potato starch (NS). Results showed that all modified starches improved batter rheology by 20%, increased viscosity and stability during frying, and delayed retrogradation during freezing compared to NS. Among them, 20% acetylated starch has a better effect on improving the quality of frozen small crisp meat for enhancing water-holding capacity, increasing immobilized water content, reducing oil uptake by 12–18%, and improving product texture. Specifically, they helped maintain a crispier coating after reheating, addressing a key drawback of traditional crisp meat. In conclusion, modified starches significantly improved frying performance and minimized quality loss during freezing compared to NS. This study provides practical insights for the food industry in optimizing batter formulations for better-quality crisp meat products.

The purpose of the study was to explore the effects of curdlan on the textural and sensory qualities of frozen steamed bread (FSB), as well as water state and starch properties during freezing. The results showed that incorporation of curdlan improved the springiness and resilience, while it reduced the hardness and chewiness of FSB. The quality deterioration of FSB was largely caused by the growth and recrystalisation of ice crystals. However, incorporation of curdlan mitigated this adverse impact by regulating water state. Specifically, it increased water content, inhibited water migration, and significantly decreased freezable water content. Additionally, curdlan also decreased starch relative crystallinity, which hindered its retrogradation and thus maintained the overall quality of FSB. Notably, inclusion of 0.5% curdlan exhibited optimal effectiveness in improving quality as evidenced by the highest sensory score obtained.

Investigating starch properties of different adzuki beans provides an important theoretical basis for its application. A comparative study was conducted to evaluate the starch content, processing, digestion, and structural quality of 12 adzuki bean varieties. The variation ranges of the 12 adzuki bean varieties with specific analyzed parameters, including the amylose/amylopectin (AM/AP) ratio, bean paste rate, water separation rate, solubility, swelling power and resistant starch (RS) content level, were 5.52–39.05%, 44.7–68.2%, 45.56–54.29%, 6.79–12.07%, 11.83–15.39%, and 2.02–14.634%, respectively. The crystallinity varied from 20.92 to 37.38%, belonging to type BC(The starch crystal type is mainly type C, supplemented by type B). In correlation analysis, red and blue represent positive and negative correlation, respectively. Correlation analysis indicated that the termination temperature of adzuki bean starch was positively correlated with AM/AP ratio. Therefore, the higher the melting temperature, the better the freeze–thaw stability. The 12 varieties were divided into Class I, Class II, and Class III by cluster analysis, based on application field. Class I was unsuitable for the diabetics’ diet; Class II was suitable for a stabilizer; and Class III was suitable for bean paste, mixtures, and thickeners. The present study could provide a theoretical basis for their application in the nutritional and nutraceutical field.

This study investigated effects of fermentation on compositions, color, and functional properties of gelatinized potato flours from Atlantic and Kexin No.1 cultivars. Atlantic flour (AF) and Kexin No.1 flour (KF) were fermented using 1% yeast concentration, respectively. Fermentation further improved the nutritional and physicochemical features of gelatinized potato flours by means of increased protein and ash contents, and decreased the levels of moisture, lipid, soluble amylose, amylopectin, and total starch. The lightness and whiteness of potato flours were enhanced with the increase in fermentation time. There are gradual increases in water absorption index, emulsifying capacity and emulsifying stability of potato flours during fermentation. However, bulk density of them slightly reduced with the increase in fermentation time. In addition, fermentation has no significant effect on freeze-thaw stability of gelatinized potato flours. These results indicate that yeast fermentation could enhance certain processing characteristics of potato flours and improve the applicability of them in food formulations. PRACTICAL APPLICATION: Lately, China has started national project regarding the use of potato flour in foods. However, due to dark color and low protein content of potato flours, their application in food formulations was limited. This study analyzed the possible mechanisms by which yeast fermentation improved the nutritional and functional characteristics of Atlantic flour (AF) and Kexin No. 1 flour (KF). From applications standpoint, findings of this study could provide knowledge on the selection of potato flours for various food formulations.

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This study investigated the influence of five mill streams on the freeze-thaw (FT) stability of dough and steamed bread quality. The 1M2 stream (1st reduction) exhibited the longest stability time (7.24 min), maximum dough height (36.1 mm), and the highest specific volume (1.93 mL/g) of steamed bread. The 1S stream (1st sizing) had the highest water-extractable arabinoxylan content (0.62 %), which contributed to frozen dough stability and maintained a high specific volume (1.85 mL/g) throughout FT treatment. In contrast, the 3M stream (3rd reduction) showed the shortest stability time (5.83 min) and lowest specific volume (1.39 mL/g). Protein subunit and rheological analyses revealed that higher gliadin content in the 1M2 and 1S streams promoted dough extensibility, facilitating expansion during fermentation and steaming. These results demonstrate the key role of mill stream characteristics in determining dough FT stability and provide valuable insights for the use of specific mill streams in frozen dough.

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Modification of corn starch using ultrasonic waves to improve its freeze-thaw resistance in frozen model doughs and buns. Analysis was performed by rheometry, low-field-intensity nuclear magnetic resonance imaging, Fourier infrared spectroscopy, and scanning electron microscopy. The results showed that the addition of ultrasonically modified corn starch reduced the migration of water molecules inside the model dough, weakened the decrease of elastic modulus, and enhanced the creep recovery effect; the decrease in α-helical and β-fold content in the model dough was reduced, the destruction of internal network structure was decreased, the exposed starch granules were reduced, and the internal interaction of the dough was enhanced; the texture of the buns became softer and the moisture content increased. In conclusion, ultrasound as a physical modification means can significantly improve the freeze-thaw properties of corn starch, providing new ideas for the development and quality improvement of corn-starch-based instant frozen pasta products.

With the rise of healthy eating, fiber‐rich foods are gaining more attention. Insoluble dietary fiber (IDF) is widely used for its physiological benefits and nutritional value. However, it can negatively affect food quality, which limit its application. This study aims to enhance wheat bran IDF′s processing properties through modification (alkaline hydrogen peroxide treatment, hydroxypropylation, and esterification) and explore how native and modified IDF influence the characteristics of wheat starch and protein. DSC and RVA results showed that IDF reduced Δ H , improved thermal stability, and inhibited starch retrogradation, with effects strengthening as IDF content increased. IDF lowered freeze–thaw stability, modification can reduce water precipitation. Upon IDF addition, disulfide bond (S─S) and β‐sheet content first increased then decreased, while β‐turn content first declined then rose. CIDF achieved the greatest starch order and double helix structure, along with the highest S─S content, at 5% addition, whereas modified IDF performed best at 10%. Modification can improve the processing performance of IDF and increase its addition amount in flour‐based products. This study provides a theoretical basis for the development of dietary fiber products and functional foods.

The development of Green banana (GB) starch in prebiotic foods to address health problems such as diabetes. It is modified by phosphate cross‐linking to increase the resistant starch content, improve functional properties, and reduce digestible starch consumption. The starch is modified using a mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) with 6 to 12 wt%ratios in the presence of sodium sulfate. The results showed an increase in phosphorus content from 0.18% to 0.45% corresponding to the increase in sodium trimetaphosphate/sodium tripolyphosphate ratios. Resistant starch reached 60 wt% after increasing the concentration of phosphate agent above 10 wt% and rapidly digestible starch decreased significantly. Accordingly, the physicochemical properties of starch changed significantly. Phosphate cross‐linking led to disruption of the crystalline structure of starch granules and fragmentation, reducing enthalpy and increasing gelatinization temperature. The oil and water absorption and freeze‐thaw stability of treated starch increased. While water absorption and solubility index of starch decreased significantly as the result of phosphate cross‐linking. Modified starch is used for the production of rice noodles. From 10 to 30 wt% of 10P modified starch mixed, cooking fracture rate is not more than 10% and resistant starch content is over 41 wt%.

Ultrasonic treatment combined with resveratrol modification was used to improve banana starch’s solubility, thermal stability, and digestion resistance. The solubility and freeze-thaw stability of the modified starch complex significantly increased. The oil-absorption capacity increased by 20.52%, and the gelatinization temperatures increased from 64.10–73.92 °C to 70.77–75.83 °C. The storage modulus (G′) and loss modulus (G″) increased after ultrasound and resveratrol treatment, and the proportion of viscosity was increased after composition with resveratrol. Additionally, the in vitro digestibility decreased from 44.12% to 40.25%. The modified complexes had release-control ability for resveratrol. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy demonstrated that complex structures became more compact and organized, whereas crystalline patterns were unchanged. Scanning electron microscopy (SEM) showed that the resveratrol modification caused physical change on the granular surface by creating pores and fissures. The findings can help develop antioxidant functional foods using banana starch.

Native corn starch was modified by enzymatic debranching (ED), microwave assisted citric acid esterification (MCAE), and by dual ED/MCAE. The structure and properties of native starch (NS), and the resulting debranched starch (DS), microwave assisted citric acid esterified starch (MCS), and microwave assisted citric acid debranched starch (MCDS) were determined and compared. Both the morphology and crystalline regions of the modified starches were changed by ED and MCAE. ED increased significantly the amylose content and transparency, but decreased the in vitro enzymatic digestibility, freeze thaw stability and relative crystallinity of DS compared to those of NS. MCAE produced a decrease in amylose content, transparency, in vitro enzymatic digestibility, and relative crystallinity, but increased the freeze-thaw stability of MCS compared to NS, and of MCDS compared to DS. The A-type crystalline structure of NS and DS was changed to B-type crystalline structure after MCAE treatment, and a new FTIR characteristic band at 1735 cm-1 was observed for MCS and MCDS. This work provides insights for producing esterified corn starches by a combined enzyme, microwave and organic acid novel technology.

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Abstract In the present study, the native banana starch of cv. Poovan (Musa sp. AAB) was modified by subjecting to high-intensity ultrasound treatment at amplitude levels (40, 60, and 80 %) with power 80 W for 60 min. Ultrasonic modification not only created cracks and micropores to the starch surface but also weakened the amorphous regions and orderly molecular structures. The observed impacts were linearly correlated with amplitude levels and was limited to surface modification which had no negative impact at molecular level. The modified starches showed a higher L* (lightness) as compared with the native starch which signifies better pigment oxidation. Sonicated banana starch at 80 % amplitude drastically reduced the syneresis (%), which is justified by enhanced freeze-thaw stability value. The modified starch had a reduced relative crystallinity % (RC) on account of erosion of few crystalline matrices upon exposure to cavitation. The cumulative effect led to an improvement in the hydration, emulsification and foaming properties. The ultrasound aided modification in the native banana starch of cv. Poovan was able to bring about positive impacts in the physicochemical, and techno-functional properties of native green banana starch which can be used in enhanced freeze thaw applications and processing operations requiring a slower retrogradation behavior.

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The pasting properties of rice starch can be improved by blending it with native or modified starch. This research investigated the pasting profiles and gel properties of rice flour (RF) blended at different concentrations with tapioca starch (TS), lowand highdegrees of crosslinked starch (LCL and HCL), and lowand highdegrees of substitution of acetylated starch (LAC and HAC). The results showed that substituting RF with both native and modified starches tended to decrease the pasting temperature of the flour blends. The increase in HCL in flour blends resulted in a higher pasting temperature, final viscosity, and setback. At the same time, adding LAC and HAC did not affect the pasting temperature, but a significantly decreased final viscosity was observed. RF-HCL10 and RF-HAC10 exhibited significantly higher swelling power than RF alone. Blending RF with HCL at 5, and 10% by weight could improve the freeze-thaw stability of the gels made from each blend. The information obtained herein is useful for the prediction of product properties that are rich in starch.

Native cassava starch was subjected to HMT and ANN under varying temperature and treatment duration conditions, as designed using a response surface methodology. The physicochemical properties of the modified starch were compared to those of native starch. The two treatments resulted in distinct alterations of the starch properties. HMT and ANN caused changes in solubility, swelling power, pasting properties, freeze-thaw stability, water and oil absorption capacities, water activity, colour and gelatinization characteristics. Solubility increased by 1.4 % and 3.81 % under HMT 25 % and HMT 30 % respectively, whereas ANN at 1: 3 starch-to-water ratio reduced solubility by 4.02 % compared to untreated starch. Swelling power decreased in the modified starch compared to the control sample. Viscosity studies revealed that peak viscosity decreased from 3812 cP in untreated sample to 3267 cP and 3150 cP after HMT - 25 % and HMT - 30 % respectively. In contrast, ANN increased the peak viscosity to 4014 cP. Freeze-thaw stability was narrowed for both HMT and ANN treated starches compared to the untreated starch. The treatments enhanced water absorption capacity but reduced oil absorption capacity (OAC). The clarity of the modified cassava starch pastes slightly decreased compared to the native starch. Moreover, the whiteness of the treated cassava starch powder was marginally lower than that of the untreated starch, though the differences were not statistically significant. These consequences disclosed that HMT and ANN techniques effectively modified the physicochemical properties of cassava starch.

This study aimed to design and optimize an edible antimicrobial film incorporating thermally modified starches using a systematic experimental approach. A comprehensive analysis of six starch types—both native and dry heat–modified—was conducted to evaluate their gelatinization clarity, freeze–thaw stability, microstructure (CLSM), and in vitro digestibility. Corn and cassava starches were selected as optimal components based on their physicochemical performance. A series of single-factor experiments and a Box–Behnken design were employed to assess the influence of starch concentration, gelatinization time, glycerol, and chitosan content on film properties including tensile strength, elongation at break, water vapor permeability (WVP), and transparency. The optimized formulation (5.0% starch, 28.2 min gelatinization, 2.6% glycerol, 1.4% chitosan) yielded a transparent (77.64%), mechanically stable (10.92 MPa tensile strength; 50.0% elongation), and moisture-resistant film. Structural and thermal analyses (SEM, AFM, DSC, TGA) confirmed the film’s homogeneity and stability. Furthermore, the film exhibited moderate antioxidant activity and antibacterial efficacy against Escherichia coli and Staphylococcus aureus. These findings demonstrate the feasibility of using dry heat–modified Kazakhstani starches to develop sustainable antimicrobial packaging materials. However, further studies are needed to explore sensory attributes, long-term storage performance, and compatibility with different food matrices.

In the present study, protein-glutaminase (PG) from Chryseobacterium proteolyticum was applied to improve the processing properties of glutinous rice flour (GRF). After PG modification, the degree of deamidation of glutinous rice protein (GRP) reached 13.6% at 2.0 h, with smaller particle size and decreased zeta potential. The interaction of GRP with starch in PG-modified GRF (PM-GRF) was changed, exhibiting in protein aggregates decreasing and exposure of starch on the surface of GRF. Compared with unmodified GRF (UM-GRF), the solubility and turbidity of PM-GRF were both increased. The rheological properties reflected that the viscosity of PM-GRF paste was increased, and the freeze-thaw stability was also enhanced. Moreover, the textural characteristics showed that the hardness of PM-GRF balls remarkably reduced and the springiness increased. These results indicate that deamidation by PG could be an efficient method for improving characteristics of GRP and GRF.

The aim of this research was to obtain information about resistant starch (RS) content on modified arrowroot starch (AS) and its functional properties as a consequence of modification to meet suitable application in the food industry. Two treatments were used to increase RS content in the AS i.e. through branched chain cutting of AS using pullulanase enzyme with certain concentration (1.3 U/g or 10.4 U/g of AS) followed by autoclaving (heating)-cooling (AC) process, and combination of these treatments with acid hydrolysis (AH). Results show that the modification process significantly (p<0.05) influenced solubility, swelling power, water holding capacity (WHC), freeze-thaw stability, and color of AS pasta, but not RS content. Nevertheless, the modification process can change the gel strength and viscosity of the arrowroot RS. It had lower viscosity than the control model, making it may be applied to food products that have low viscosity.

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This work examined the effect of ultrasound and microwave treatments, separate and in combination, on the physicochemical and functional properties of chestnut starch. The results revealed that the ultrasonic-microwave (UM) and microwave-ultrasonic (MU) dually modified samples exhibited more severe surface damage, weaker birefringence, and lower relative crystallinity and gelatinization enthalpy than the native and single-treated starches. The UM samples showed the highest oil absorption capacity, and the MU samples showed the highest water absorption capacity and the best freeze-thaw stability (five cycles) among all samples. The swelling power, peak, trough, final, and breakdown viscosities, and pasting temperature all decreased regardless of single or dual modification. This study provides a reference for potential industrial applications of ultrasound and microwave treatments for the modification of chestnut starch.

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Dual-modifications of jet milling and hydroxypropylation were used to improve the functional properties of maize starch (HM, containing 67 % amylose). The fractions obtained in three sizes (HM-S, HM-M, HM-L) were further treated with 10 % and 30 % propylene oxide (PO10 and PO30). The infrared peak of starch at 2794 cm-1 indicated the successful introduction of hydroxypropyl groups. The molar degree of substitution (MS) increased with the degree of jet milling. The MS of HM-L-PO10 is 0.4, that of HM-M-PO10 is 0.7, and that of HM-S-PO10 is 0.9. The crystallinity of dual-modified HM increased, but the crystal type remained unchanged, still being B-type. Dual-modification significantly improved the performance of starch, and the higher the degree of modification, the better the optimization effect. The lowest enthalpy changes of gelatinization (ΔH = 3.49 J/g), the best freeze-thaw stability, the highest elongation at break (110.42 %) and transmittance (81.22 %) were shown in HM-S-PO30. The present study confirms that HM-S-PO30 films have the best physicochemical and mechanical properties, which provide new insights into optimizing starch-based packaging materials.

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Glutinous rice flour (GRF) and glutinous rice starch (GRS) were modified by dry-heat treatment and their rheological, thermal properties and freeze-thaw stability were evaluated. Compared with the native GRF and GRS, the water-holding ability of modified GRF and GRS were enhanced. Both the onset and peak temperatures of the modified samples increased while the endothermic enthalpy change decreased significantly (p < 0.05). Meanwhile, dry heating remarkably increased the apparent viscosities of both GRF and GRS. Importantly, compared with GRS samples, the storage modulus (G') and loss modulus (G") values of modified GRF increased more greatly and the tanδ values decreased more remarkably, indicating that the dry-heat treatment showed more impact on the GRF and a higher viscoelasticity compared with GRS. Our results suggest the dry-heat treatment of GRF is a more effective method than that of GRS, which omits the complex and tedious process for purifying GRS, and thereby has more practical applications in the food industry.

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This study evaluated how added gums, starch amounts, and sucrose levels affect the texture, sensory acceptability, and syneresis of milk puddings. The puddings were prepared with four ingredients, namely 0.3% polysaccharide (κ,ι-carrageenan, gellan gum, gelatin, or agar), 2.5–7.5% sucrose, 1–5% modified waxy corn starch, and whole milk. The physical and sensory properties were assessed through measurements of gel strength, breaking point, breaking force, rigidity, and hedonic testing. Results show that syneresis increased in all milk puddings during two weeks of refrigerated storage. Among the five polysaccharides, agar and κ-carrageenan showed the most significant effect on gel rigidity and strength, while gellan gum and ι-carrageenan were more effective at preventing syneresis compared to three commercial milk pudding products after 14 days of storage. As modified corn starch concentration increased (1 to 5%), gel strength, breaking force, and rigidity decreased. Lower modified waxy corn starch concentrations (5% to 1%) led to reduced syneresis when stored at 4 °C for 7 and 14 days. Sucrose significantly increased gel strength and breaking force in puddings containing κ-carrageenan, gellan gum, and agar. Gellan gum improved overall pudding acceptability. Based on sensory and syneresis data, the most acceptable milk pudding formulation contained 5% sucrose, 0.3% gellan gum, and 1% modified waxy corn starch.

The study was planned to evaluate the effect of non-commercial gums as compared to commercial gums. The concentration dependent effect of two commercial (arabic, xanthan) and four non-commercial (cress seed, fenugreek, flaxseed, okra) polysaccharide gums on the pasting, rheological, textural and thermal properties of chickpea were investigated by rapid visco analyzer (RVA), hybrid rheometer, texture analyzer and differential scanning calorimetry (DSC). Blends were prepared by replacing chickpea starch at 0.5% and 2.0% with gums, whereas native chickpea starch was used as a control. RVA data showed that peak and final viscosities were dramatically increased with xanthan contrary to reduction with gum arabic, flaxseed and okra gums. Hybrid rheometer displayed that storage and loss moduli were increased as a function of angular frequency and dominance of elastic properties over viscous ones. Xanthan blend was less temperature dependent due to dramatic decrease in activation energy value as compared to control while other gums were more temperature dependent. The magnitude of this effect was reliant on the type and concentration of gum. After storage for 21 days at −20 °C, total syneresis was reduced with the incorporation of xanthan and cress seed and also with high levels of gum arabic, flaxseed and fenugreek gums. The gel hardness was increased after overnight storage at ambient temperature (23 °C) with fenugreek while reduction in hardness was observed with xanthan, flaxseed and okra gums. The presence of gums resulted in significantly higher onset and peak temperatures determined through differential scanning calorimetry.

Egg sausages, an essential component of traditional Chinese hot pot cuisine, have specific storage requirements and are predominantly distributed through refrigerated channels. A significant consideration in the freezing of egg sausages pertains to syneresis and textural modifications that manifest in the protein gel structure upon thawing. This research investigated the efficacy of incorporating whey protein isolate, soy protein isolate (at concentrations of 0.5%, 1.0%, and 2.0%), and modified cassava starch (at concentrations of 1.0%, 2.0%, and 3.0%) to enhance the textural integrity and mitigate syneresis in frozen egg sausage gels. The research demonstrated that syneresis in frozen egg sausages could be significantly minimized from 9.01% to 1.16% through the incorporation of 3% modified cassava starch and 2% whey protein isolate, to 2.01% with 1.0% soy protein isolate, and to 3.05% with 1.0% whey protein isolate. Furthermore, the combination of modified cassava starch (3%) and whey protein isolate (2%) demonstrated enhanced textural characteristics in frozen egg sausages with 20% additional water content following a 15-day storage period. Notably, egg sausages formulated with 0.5% whey protein isolate exhibited superior sensory attributes, including springiness, texture, and overall acceptability, compared to other formulations. The incorporation of whey protein isolate yielded markedly improved sensory characteristics relative to soy protein isolate additions. The findings indicate that the incorporation of whey protein isolate (0.5–1.0%) in conjunction with modified cassava starch (3%) effectively improves textural properties while reducing syneresis in thawed egg sausages.

Abstract The study investigates the impact of fatty acids, i.e., oleic acid (C-18:1) and linolenic acid (C-18:3) addition with varying concentrations (1 %, 2.5 %, 4 %, and 6 %) on physicochemical, rheological, and thermal properties of water chestnut starch (WS) using the approach of molecular dynamic (MD) simulation. The findings revealed that incorporating fatty acids led to a marked reduction in syneresis (%) of WS up to 62.7 %, significantly enhancing the freeze-thaw stability of WS. Adding fatty acids substantially reduced the peak viscosity (up to 36.4 %), setback (up to 50 %), and breakdown viscosity (up to 33.5 %) of WS. Rheological analysis demonstrated that these blends exhibited a dominant elastic behavior, with storage moduli (G′) consistently surpassing loss moduli (G″) across all angular frequencies. MD simulation confirmed that starch formed a more stable complex with oleic acid than linolenic acid. The study concluded that fatty acids’ unsaturation and concentration were critical in modulating WS properties.

This study successfully made starch from taro tuber flour using immersion methods (AQ, SM) and centrifugation methods (CE). Taro starch with the AQ method produced the most starch content, thus improving the viscosity parameter in the pasting properties test. A simple mathematical model was used to control the taro starch pasting process and product. The highest R-value in the AQ sample was 309.88 s, indicating the strongest starch granule resistance. Meanwhile, the S-value in this study showed that all samples were above 1, which indicated that water penetration affected the swelling rate of starch granules. Taro starch with different isolation methods was analyzed for hydrogel formation using optical microscopy, SEM, swelling degree test, weight loss, color analysis, and texture profile analysis (TPA). The morphological images show three phases of a taro starch hydrogel formation: granular, potential cross-linking, and cross-linking hydrogel with a firm structure. Optimization of freeze-thaw process parameters was carried out to determine the optimum parameters of starch hydrogel formation, which was obtained under freezing conditions for 17 hours at -23°C and thawing for 7 hours at 4°C. The sample CE resulted in the most stable hydrogel formation, showing the highest amylose content, protein content, and the lowest impurities or ash content. The CE starch concentration of 10% resulted in the highest swelling degree and the lowest weight loss, indicating that the ability of the hydrogel to maintain its structure was stronger and more elastic. The textural properties of CE hydrogel at a concentration of 10% showed the most stability. It had the highest hardness, fracturability, chewiness, and springiness. Physical characteristics showed that the starch hydrogels had a dense, porous surface and formed a cross-linking structure. It can potentially be used in functional food applications to control the release of bioactive compounds. 

This study was undertaken to understand the functionality of quinoa starch (QS) in frozen foods. The effects of different cycles of freeze-thaw treatment (0, 2, 4, 6, and 8 cycles) on the functional, molecular, rheological, and thermal characteristics of starch from quinoa seeds were investigated. The extraction yield of QS was 52 %, with a purity value of 97.98 %. The study observed amorphization of starch molecule after repeated FT, as it primarily affected the crystalline domains. Reduction in the oil absorption capacity (OAC) of starch from 115 % to 95 % was linked to increase in surface roughness, which was further corroborated by scanning electron microscopy and contact angle analysis. Further studies also revealed reduction in relative crystallinity from 36.21 % to 32.34 %, degree of ordered structure from 1.59 to 1.06, and gelatinization enthalpy from 19.99 J/g to 8.48 J/g, as indicated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC), respectively. All starch gels showed a pseudo-plastic behaviour (η < 1), which the power law model described well. Additionally, the gel-forming ability of starches improved as indicated by higher values of storage (G') and loss (G″) moduli. In conclusion, the number of freeze-thaw cycles significantly influences the various characteristics of QS.

Role of milieu pH at 5, 8 and 11 has been investigated to determine the effectiveness of cross-linking by STPP (Sodium tripolyphosphate) to banana flour. Change in physicochemical and pasting properties due to the treatments have been studied. The characterization by XRD and FTIR has also been carried out to reveal the diffraction pattern and the change in the chemical functional group. The result showed that cross-linking at the pH studied did not change the diffraction pattern of banana flour. An investigation using FTIR indicated that peak absorbance at wavenumber 2300 and 928 cm−1 increased following the treatment with the increase of pH, suggesting the formation of diester phosphate and C-O-P linking respectively. Swelling volume and solubility were remarkably affected by crosslinking at pH 11 while freeze-thaw stability at pH 5. The effectiveness of cross-linking on changing the pasting properties was not affected by the pH but cross-linking per se decreased the breakdown viscosity compared to the native flour.

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Resistant starch (RS) has drawn considerable attention over the past decade due to its positive physiological properties as well as accessibility in many starchy foods. RS is the starch portion resistant to enzymatic hydrolysis in the human gut. Increased levels of RS in rice grains lower the glycemic index (GI) value ensuring a negative correlation with amylose content (AC). UKMRC-9 is a cross-bred red rice with GI=46 and an intermediate AC has been clinically proven to decrease postprandial blood glucose after ingestion. The objective of this study was to investigate the RS contents for cooked UKMRC-9 and its downstream products in the form of RTE (ready-to-eat). With the intention to optimise the RS contents through retrogradation of starch, these cooked rice and rice-based products were subjected to cooked-freeze and thawed cycles to simulate the modus operandi of food manufacturing and food service industry. Applying a method of enzymatically degrading starch samples according to the Association of Official Analytical Collaboration (AOAC) International, a total of 8 samples of UKMRC-9 and its downstream products were analysed for their RS contents. Cooked and frozen UKMRC-9 with coconut oil, UKMRC-9 raw and red rice noodles were computed with the highest RS at 16.52 g/100 g, 14.24 g/100 g and 11.42 g/100 g, respectively. The red rice bread, wholegrain bread and Kueh Angku have a RS value of 4.99 g/100 g, 4.97 g/100 g and 3.12 g/100 g. Based on RS classification, the RS contents of the former and latter can be categorised as high and intermediate. This study showed that UKMRC-9 was a good source of RS on its own, additional cooking and freezing processes and using it as an ingredient will further enhance the RS content of the final food products.

Abstract The physicochemical properties of starch acetates with an equal degree of substitution prepared from pea, corn, and wheat starch and their effects on frozen cooked noodle (FCN) quality were investigated. The result showed that the three kinds of starch acetates had different effects on the quality of FCN due to their different blue values, freeze‐thaw stability, and crystalline morphology analyzed by XRD (p < .05). The FCN with the addition of 20% CAS exhibited slow deterioration of textural properties during holding for 30 min. The analysis of the changes in the content of free SH group and glutenin macropolymer (GMP) demonstrated that the addition of CAS promoted protein disulfide cross‐linking and decreased protein mobility during holding. Fourier transform infrared spectroscopy (FT‐IR) revealed that FCN with the addition of CAS had low decrement in α‐helix and β‐sheet during holding, indicating that starch acetates contributed to the maintenance of the gluten network structure.

Starch from soft wheat and hard wheat varieties was evaluated for physicochemical properties, including pasting and retrogradation properties, swelling power and solubility, and granule morphology. Grain hardness index of soft and hard wheat varieties ranged from to 25 to 35, and 71 to 82, respectively. Soft wheat varieties showed a larger proportion of total starch (TS) and A-type starch (AS), and a smaller proportion of B-type starch (BS). The amylose content of starch from hard wheat varieties was significantly higher than that from soft wheat varieties. Starch from soft wheat varieties exhibited higher pasting viscosity, transmittance, swelling power, and smaller crystallinity as compared to starch from hard wheat varieties. BS from hard wheat exhibited the lowest average breakdown and setback viscosity, hardness, adhesiveness, and fracturability. AS exhibited the highest pasting viscosity, better transparency, gel properties, freeze-thaw stability, swelling power, clearer "Maltese cross", and higher crystallinity, whereas BS exhibited the highest gelatinization temperature, better gel stability and solubility. The study might broaden the recognition of starch from different wheat varieties, and provide a theoretical basis for wheat breeding and the potential utilization of different types of wheat starch and flour.

No abstract available

Investigating how cereal-derived polysaccharides mitigate the cold denaturation of dough carries substantial significance for improving the quality of cereal-based products. This study aimed to assess the effects of laboratory-prepared oat β-glucan and commercial oat β-glucan on the structural properties and quality of wheat flour, frozen dough, and the resultant steamed bread. Our data indicated that β-glucan with higher molecular weight (1.1 × 105 Da) endowed dough with superior freeze-thaw stability. Freezable water content of frozen dough with 5 % β-glucan was decreased by 15.7 % compared to control group, demonstrating the β-glucan inhibited ice crystal formation and destruction of gluten network. Moreover, steamed bread made from frozen dough containing 5 % β-glucan was softer with stronger antioxidant activities and storage stability. Those results proved that the β-glucan promoted cross-linking between gluten proteins and starch granules and could be used as food cryoprotectants to mitigate deterioration of frozen dough quality.

Currently, dysphagia-friendly foods enriched with hydrophilic polysaccharide colloids are gaining attention, which are valued by dysphagia or senile subpopulation for their appropriate texture, resemblance to regular food, and high nutritional density. In this study, multi-polysaccharides emulsion gels were prepared and evaluated for developing dysphagia-friendly food. The findings revealed that emulsion gels with 2 % polysaccharide and 1-8 % sunflower oil had a visual appeal with hardness of 1000-3000 N/m2, adhesion of less than 50 g·s, cohesion of 60-90 % and water retention of more than 90 %, which met level 4 criteria in the International Dysphagia Diet Standardization Initiative (IDDSI) framework, whether in the fresh or freeze-thaw group. Less oil led to the instability of the gel, while excessive oil increased the cross-linking degree of the gel, causing it to adhere to the mouth. In addition, the emulsified oil droplets were dispersed throughout the polysaccharide network by hydrogen bonds and hydrophobic interactions, acting as a filler, which leads to the formation of a denser gel network and a reduction in water fluidity. These effects jointly led to the maintenance of freeze-thaw stability of the gel, with its thawing loss and cooking loss reduced by up to 65.91 % and 39.76 % respectively. Moreover, surimi-based diets prepared with emulsion gels (with 1-4 % sunflower oil) complied within the IDDSI levels 4-5, which would be supplied as dysphagia-friendly food. These findings would provide individuals with dysphagia a broader range of dietary options.

Glutinous rice starch products are often limited by a short shelf life and reduced elasticity due to retrogradation. This study aimed to improve texture properties and delay aging by modulating gel behavior through the incorporation of hydroxypropyl starch into glutinous rice starch. As the proportion of hydroxypropyl starch increased, the ratios of R1048/1022 and R995/1022 decreased from 0.52 to 0.44 and from 1.01 to 0.93, respectively. These changes reflect the disruption of double helix structure and short-range ordered structures, indicating a significant reduction in crystalline integrity. The hydroxypropyl starch-dominated system formed stronger hydrogen bonds (90.299) and a denser network structure. The system exhibited superior freeze-thaw stability, water retention capacity (T21: 11.90%) and springiness (1.00). After 30 days of storage, the relative crystallinity of the samples decreased markedly from 40.3% to 8.5%. This work provides insights into the design of blended starch systems with desired processing performance and shelf life.

The quality of starchy foods is highly correlated with their amylose content. After boiling or roasting, the amylose content in cooked chestnut starch decreased to 16.6-26.8%, which was significantly lower than that of raw chestnut starch (26.6-28.1%). After cooking, the pasting temperature and peak time increased, while the breakdown, peak viscosity, final viscosity and setback of starches decreased. The amylose content showed a negative correlation with the pasting characteristics of the starch gel of cooked chestnut. The amylose content negatively affected the springiness and chewiness of starch gel, and positively correlated with its cohesiveness and stringiness. The freeze-thaw stability of starch from cooked chestnut was lower than that of raw chestnut. The amylose content was negatively correlated with freeze-thaw stability and positively correlated with the solubility of starch. The results demonstrated that amylose plays an important role in the pasting and gel texture properties of starch during cooking.

Several faults have been observed during the preparation of starch-based foods, including low gel strength, thermal instability, and a high glycemic index. Supplement of exogenous polysaccharides is effective to overcome the defects in starch processing. In this study, the effects of konjac glucomannan (KGM) and deacetylated konjac glucomannan (DKGM) on the gelatinization and pasting properties of 10 kinds of natural starches were compared. The processing stability, texture characteristics, and antidigestion performance of Solanum starch-DKGM composite vermicelli were focused. Results showed that the supplement of DKGM led to more significant improvement in the viscoelastic properties compared to KGM in the most starch. Conversely, KGM had a greater contribution to the viscosity during the starch gelatinization process. Thus, DKGM significantly enhanced the water retention and freeze-thaw stability of starch gels. Additionally, DKGM significantly decreased the cooking loss and enhanced the antideformation ability of vermicelli. Antidigestive performance was also found in Solanum starch-DKGM composite vermicelli, with the reduction of 7.88% RDS and 7.15% SDS and the increase of 15.03% RS in 2% DKGM treatment. We hope this work could provide theoretical support for the starch-based gel foods development.

The effect of pullulanase enzymatic hydrolysis time on the textural properties of acorn vermicelli was investigated by texture analyzer. And the influencing mechanism was revealed by exploring the physicochemical properties of acorn starch under the optimum enzymatic hydrolysis time by texture analyzer, scanning electron microscopy, X-ray diffraction and brabender viscograph. After acorn starch was hydrolyzed by pullulanase for 14 h, acorn vermicelli had excellent textural properties. In addition, the enzymatic hydrolysis transformed the acorn starch from spherical particles with smooth surface to polygonal particles with rough surface, as well as transformed the crystal structure of acorn starch from C-type to B-type. Compared with native acorn starch, enzyme hydrolyzed acorn starch had higher amylose content, better freeze-thaw stability, lower swelling power and, breakdown viscosity, stronger gel strength and, higher light transmittance. These excellent properties contributed to the exceptional textural properties and quality of acorn vermicelli. The results of this study may provide valuable information on the preparation of acorn vermicelli.

Repeated freeze-thaw (FT) cycles damage the quality of frozen starch-based foods and accelerate the digestion rate of starch. This study investigated how potato soluble dietary fiber (PSDF) affects the physicochemical characteristics and digestibility of potato starch (PS) after repeated FT cycles. Results indicated that repeated FT cycles of potato starch resulted in the enlargement of gel pores, an increase in hardness (from 322.5 g to 579.5 g), and a decrease in gel porosity, leading to reduced water-holding capacity (from 94.2 % to 85.4 %). However, the addition of PSDF stabilized the 3D structure of the PS/PSDF gel, with minimal fluctuations in hardness (413.0-447.5 g) and water-holding capacity (94.4-93.6 %). Meanwhile, PSDF enhanced intramolecular hydrogen bonding within starch molecules and promoted molecular interactions, increasing the PS/PSDF gel's helix structure; therefore, PSDF effectively addressed the increase in rapidly digestible starch caused by repeated FT cycles. Furthermore, PSDF might attach to the surface of starch particles, so limiting starch granule expansion and decreasing the peak viscosity increase caused by repeated FT cycles. The findings suggest that PSDF could be an effective component for improving the quality of potato starch-based frozen food.

No abstract available

No abstract available

Freeze-thaw cycles (FTC) could cause damage to food during storage. The effects of different FTC on Hot-dry noodles (HDN) in terms of quality, moisture, starch, and protein characteristics were studied. This study showed that FTC decreased the texture properties and water absorption of HDN. Meanwhile, cooking loss was significantly increased after FTC. The water content of HDN was decreased and water migration was increased during FTC. In addition, results showed that FTC destroyed the order structure and increased the crystallinity of starch in HDN. Under FTC, the disulfide bond of HDN was broken, the free sulfhydryl group was increased, and the electrophoretic patterns confirmed the protein depolymerization. The microstructure also showed that the gluten network became incomplete and starch was exposed outside the substrate. This study expounded the mechanism of HDN quality deterioration during FTC, which laid a foundation for the development and improvement of frozen and freeze-thaw noodles.

This study aimed to investigate the textural changes of cooked germinated brown rice (GBR) during freeze-thaw treatment and propose a strategy for enhancing its texture using magnetic field (MF). Seven freeze-thaw cycles exhibited more pronounced effects compared to 7 days of freezing, resulting in increases in GBR hardness by 85.59 %-164.36 % and decreases in stickiness by 10.34 %-43.55 %. Water loss, structural damage of GBR flour, and starch retrogradation contributed to the deterioration of texture. MF mitigated these effects by inhibiting the transformation of bound water into free water, reducing water loss by 0.39 %-0.57 %, and shortening the phase transition period by 2.0-21.5 min, thereby diminishing structural damage to GBR flour and hindering starch retrogradation. Following MF treatment (5 mT), GBR hardness decreased by 21.00 %, while stickiness increased by 45.71 %. This study elucidates the mechanisms through which MF enhances the texture, offering theoretical insights for the industrial production of high-quality frozen rice products.

Despite the widespread application of frozen starchy foods, the molecular mechanism by which ice crystals compromise their quality remains poorly elucidated. Yam, known for its characteristic waxiness texture, exhibits quality degradation upon freezing; however, the structural basis of this deterioration remains unexplored. In this study, we investigated the freeze-thaw induced changes in the waxiness of both raw and cooked yams through multiscale structural analysis and molecular dynamics simulations. Freezing reduced the waxiness values of raw yam by 51.50 % (76.86 → 37.28) and cooked yam by 70.24 % (76.86 → 22.87). In raw yam, ice crystal formation induced granule swelling and disrupted molecular organization, leading to a shift toward shorter amylopectin chains (6 < X < 36) and depletion of long amylopectin (36 < X < 100) and long amylose chains (5000 < X < 20,000). These structural changes were accompanied by an increase in gelatinization enthalpy (5.83 J/g → 8.72 J/g), an increase in glass transition temperature (Tg: 62.63 °C → 64.29 °C), elevated stiffness (E0↑), reduced viscosity (η₁↓), and diminished viscous modulus (G″↓). In cooked yam, severe damage to the starch gel network-including cell wall collapse, loss of bound water (T₂₁), and gel loosening-led to rougher surface texture and reduced elasticity and adhesiveness (G″: 165.0 Pa → 24.7 Pa). Molecular simulations confirmed that ice-induced conformational disruptions weakened starch hydration and continuity, ultimately impairing the gel's viscoelasticity. This study reveals how structural disintegration propagates through functional properties, to deteriorating sensory texture, offering mechanistic insights into enhancing freeze-thaw stability of starchy food matrices.

Starch retrogradation and freeze-thaw instability are two key factors leading to quality deterioration in fresh rice products. This study investigated the effects of pulsed magnetic fields (PMF, 0-10 mT) on the rheological properties, microstructure, water distribution, and textural characteristics of rice starch gels subjected to three temperature treatments (4 °C, -3 °C, and -18 °C). The results demonstrated that the PMF weakened the water molecule network, which formed spatial barriers, reduced intermolecular hydrogen bonding between starch molecules, and thereby inhibited starch retrogradation. Additionally, the magnetic field mitigated structural damage caused by ice crystals, suppressed starch molecular aggregation, and enhanced hydrogen bonding interactions between starch and water molecules, ultimately improving the freeze-thaw stability of rice starch gels. Compared to control groups (0 mT-4 °C, 0 mT--3 °C, 0 mT--18 °C), the application of the PMF intensity of 10 mT resulted in significant 22.98 % reduction, 18.97 % increase, and 81.91 % increase in hardness under corresponding temperature (p < 0.05), which further indicated that PMF could inhibit retrogradation at 4 °C and enhance freeze-thaw stability at -3 °C and -18 °C effectively. This work highlights the potential of PMF in suppressing starch retrogradation and improving the freeze-thaw stability of starch-based gel foods.