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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 as a result of 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. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Future applications of high‐internal‐phase emulsions (HIPEs) are highly regarded, but poor freeze–thaw stability limits their utilization in frozen products. This study aimed to characterize the structure of chickpea protein microgel particles (HCPI) induced by NaCl and to assess its impact on the freeze–thaw stability of HIPEs.The results showed that NaCl induction (0–400 mmol L−1) increased the surface hydrophobicity (175.9–278.9) and interfacial adsorbed protein content (84.9%–91.3%) of HCPI. HIPEs prepared with HCPI induced by high concentration of NaCl exhibited superior flocculation index and centrifugal stability, and their freeze–thaw stability was better than that of natural chickpea protein. The increase in NaCl concentration reduced the droplet aggregation and coalescence index of the freeze–thaw emulsions, diminishing the precipitation of oil from the emulsion. Linear and nonlinear rheology showed that the strengthened gel structure (higher G′ values) restricted water flow and counteracted the damage to the interfacial film by ice crystals at 100–400 mmol L−1 NaCl, thus improving the viscoelasticity of the freeze–thaw emulsions. Finally, the thawing loss of surimi gel with HCPI‐200 HIPE was reduced by 2.04% compared to directly adding oil.This study provided a promising strategy to improve the freeze–thaw stability of HIPEs and reduce the thawing loss of frozen products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Defatted chickpea flour (DCF), which is a by-product of chickpea oil extraction industry, is rich in nutrients that are beneficial to human health. In this study, the effects of temperature and DCF variation on the rheological properties, water holding capacity, freeze-thaw stability and microstructure of DCF heat induced gels were investigated. The results showed that the viscoelasticity, frequency dependence, and resistance strength of heat induced gels increased significantly with the increase of temperature and DCF variation. The degree of denaturation and water retention of heat induced gels increased significantly with increased variables within the temperature and variation windows of 75°C to 95°C and 13% to 21%. The CLSM results revealed that variations of both temperature and DCF variation could cause the proteins in the heat induced gels to aggregate gradually and to form protein aggregations. When temperature or variation exceeded certain value (85°C or 17%), the protein aggregations broke up and the protein clusters became smaller and more homogeneous. Therefore, the heat induced gels presented better water holding capacity, viscoelasticity, structural stability and gel property at a temperature of 95°C or a DCF variation of 21% within the present experimental range. [ABSTRACT FROM AUTHOR]

【Objective】 With the increasing demand of Fenyuan in the market, the effects of different starches on the quality of fenyuan were explored, and the relationship between starch structural characteris tics and Fenyuan quality was specified. This study could provide a theoretical basis for the development of high-quality Fenyuan products. 【Method】 Three cassava starches and two modified cassava starches (hydroxypropyl distarch phosphate and acetate starch) were used as raw materials to make Fenyuan. The differences in granule size, amylose content, swelling power, solubility, thermodynamic characteristics and freeze-thaw stability of starches, as well as the texture preperty of Fenyuan were analyzed. The correlation between starch structural characteristics and Fenyuan texture was also analyzed. 【Result】 There were significant differences in granule size, swelling power and solubility between different cassava starches and modified starches (P<0.05), and the granule size dispersion (1.17-1.27) and swelling power (30.48%-30.91%) of modified starches were significantly higher than those of cassava starches (0.89-1.08 and 24.60%-26.38%, respectively). There were significant negative correlations between the dispersion and swelling power of starches and the hardness and chewiness of Fenyuan (P<0.05), whereas the solubility of starches was positively correlated (P<0.05) with the adhesiveness of Fenyuan. The thermodynamic characteristics and freezethaw stability of the five starches were also significantly different (P<0.05), and the initial gelatinization temperature (55.45- 59.90 ℃) and water separation rate of modified starches were significantly lower than those of cassava starches (63.80-65.00 ℃). The gelatinization temperature, enthalpy change and water separation rate of starches were positively correlated (P<0.05) with the hardness and chewiness of Fenyuan.【Conclusion】 The dispersion of granule size distribution, swelling power and freezethaw stability of cassava starch from different brands were significantly correlated with the hardness and chewiness of Fenyuan. Fenyuan made from TPK cassava starch presented superior quality compared to those made from other two cassava starch; the modified starches had higher swelling power and freeze-thaw stability, which could reduce the hardness, chewiness and starch aging of Fenyuan, which were suitable for the processing of frozen Fenyuan and instant Fenyuan products. [ABSTRACT FROM AUTHOR]

Frozen pasta products have been ever increasingly favored in recent years, because of their convenience. Wheat starch is one of the most important components of buns, noodles, and cookies in the staple and leisure foods. The performance and quality of starch-based foods can depend seriously on the processing of wheat starches. Furthermore, starch-based foods easily lose water to be hard in the storage of retrogradation, indicating reduced elasticity. Therefore, it is very necessary to enhance the structure and properties of wheat starch. Starch can also be often modified by physical, chemical, biological and composite methods. Among them, physical modification has been widely used to modulate the properties of starch using hydrophilic colloids, due to their environmental friendliness, excellent performance and lower energy. Fortunately, the curdlan can be expected to compound with the starch for better functional properties, due to the excellent resistance to freeze-thaw stability and dehydration, water-holding, extreme stability, and emulsifying properties. In addition to being a prebiotic, curdlan can also improve the gastrointestinal health. The extrusion can be used as a biochemical reactor to promote the combination of wheat starch and curdlan, particularly for the high yield, easy operation, high degree of integration, and high temperature. The reason is that the high pressure, high shear and hydration can be generated to significantly change the structure and physicochemical properties of starch during operation. The complexes of curdlan and wheat starch can then be prepared to change the physicochemical properties of starch. The retrogradation and syneresis of wheat starch during freezing have been two of the most important limiting steps in the development of pasta products. This study aims to explore an effective way to inhibit the retrogradation and syneresis of wheat starch gels during freeze-thaw cycles. The composites with different concentrations of curdlan-wheat starch were investigated in the extrusion system. The effects of curdlan addition on the structural properties and freeze-thaw stability of wheat starch were analyzed using differential scanning calorimetry, X-ray diffractometry, and Fourier infrared spectrometry. In addition, the binding mechanism of curdlan-wheat starch composites in the extrusion field was revealed by combining the chemical reagents, Texture Analyzer and Scanning Electron Microscope. The results showed that the retrogradation of curdlan-wheat starch composites decreased and then increased with the increasing concentration of curdlan, while the syneresis rate showed a trend of decreasing and then increasing. The freeze-thaw stability of wheat starch was significantly improved to markedly inhibit the retrogradation with the addition of 0.6% curdlan in the extrusion system. The pasting temperature of wheat starch increased with the addition of 0.6% curdlan, compared with extruded starch. There was a decrease in the relative crystallinity, short-range ordering, and iodine binding of wheat starch, where the recrystallization of amylose was suppressed. Texture Analyzer and Scanning Electron Microscope revealed that the curdlanwheat starch composites were dominated by the hydrogen bonding and weak electrostatic interaction forces in the extruded system. Furthermore, the curdlan-wheat starch composites presented a more intact and dense structure, indicating better freezethaw stability. The retrogradation was also effectively inhibited. The finding can provide a strong reference to produce wheat starch-based foods with resistance retrogradation and low syneresis using an extrusion process. [ABSTRACT FROM AUTHOR]

Sodium caseinates–kefiran systems were studied to explore whether any potential interactions between them might exist. The study was performed using low‐deformation rheological techniques, which were dynamic and creep tests. The systems were prepared under various experimental conditions such as heating and acidification. Besides, the structure development of the systems in relation to time was also monitored using oscillatory shear rheometry. The results indicated that the structural characteristics of the systems were mainly affected by the state of the caseinates such as the formation of aggregates and to a lesser degree by the interactions of kefiran molecules with the caseinates. Freeze–thaw treatment produced cryogels with good thermal stability and fairly satisfactory mechanical properties. The morphology of the caseinate‐kefiran systems was also investigated by means of confocal laser scanning microscopy. [ABSTRACT FROM AUTHOR]

BACKGROUND: Concentrated emulsions have been formulated in many foods. The insoluble soybean fiber (ISF) can be utilized as a particle to stabilize concentrated emulsions. However, the approach to control the rheological properties and stability of the ISF concentrated emulsions is still worth investigating. RESULTS: In this study, alkali‐extracted ISF was hydrated by adding sodium chloride or heating and the prepared concentrated emulsions were subjected to freeze–thawing. Compared with the original hydration method, salinization reduced the absolute ζ‐potential of the ISF dispersions to 6 mV, resulting in a lower absolute ζ‐potential of the concentrated emulsions, which led to a decreased electrostatic repulsion and the largest droplet size, but to the lowest apparent viscosity, viscoelastic modulus, and stability. By contrast, hydration by heating promoted the interparticle interactions, and then a decreased droplet size (54.5 μm) but with a more densely distributed droplets was observed, together with enhanced viscosity and viscoelasticity properties. The fortified network structure improved the stability of the concentrated emulsions both against high‐speed centrifugation and long‐term storage. Additionally, secondary emulsification after freeze–thaw further improved the performance of the concentrated emulsions. CONCLUSION: The results suggest that the formation and stability of the concentrated emulsion could be regulated by different hydration methods of particles, which could be adjusted according to the practical applications. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Starch from the turion of Spirodela polyrhiza ZH0196 is a new resource with great development values. The solubility, swelling power, thermogravimetric analysis (TGA), enzyme susceptibility, and in vitro digestibility of Spirodela starch, paste clarity, settling volume, and the rheology property of Spirodela starch paste, strength, elasticity, and freeze-thaw stability of Spirodela starch gel were studied. The properties of Spirodela starch were compared with those of normal corn starch and rice starch. The possible relationship between properties and structure of three kinds of starch was analyzed by principal component analysis (PCA). The results showed that the rapidly digested starch, slowly digested starch and resistant starch were 86.63 %, 4.43 %, and 8.94 % respectively. Spirodela starch has higher strength (17.77 g), elasticity (4.98 g/s) of starch paste, and freeze-thaw stability of starch gel than those of normal corn starch and rice starch. The rheological results showed that the stickiness maintainability of starch paste was normal corn > Spirodela > rice and Spirodela starch paste had compact paste structures with the tan δ between 0.33 and 0.38. This study has significant value in the application of Spirodela starch. • Properties of starch from Spirodela , corn and rice were studied systematically. • Structure in relation to physicochemical properties were discussed. • Spirodela starch gel had good gel properties and freeze-thaw stability. • Spirodela starch was easy to absorb water and hydrolyzed by α –amylase. [ABSTRACT FROM AUTHOR]

Pickering emulsions with good freeze-thaw stability are essential in frozen food applications. This study developed a high freeze-thaw stabilized soy protein isolate (SPI)-maltose (M) Pickering emulsion and applied it to frozen doughs to investigate and reveal its impacts on the processing properties of the frozen dough. The results showed that after the freeze-thaw cycle, with a volume ratio of 1:2 of SPI to M, the appropriate amount of M changed the structure of SPI. This resulted in the Pickering emulsion prepared by the SPI exhibiting the least droplet coalescence and the best freeze-thaw stability. The results of dough rheological properties, textural properties, and binding capacity with water demonstrated that Pickering emulsions effectively inhibited the loss of gluten protein network structure in the dough after freeze treatment and increased the binding capacity of gluten proteins with starch and water in the dough. The best results were obtained with the incorporation of 3 % SPI-M high freeze-thaw stability, where the amount of bound water following three freeze-thaw cycles was 4.27 times higher than in doughs without Pickering emulsion. Overall, this study is significant for enhancing the freeze-thaw stability of Pickering emulsions stabilized by proteins and providing a new application route for Pickering emulsions. [Display omitted] • Soybean isolate protein-maltose stabilized Pickering emulsion with a 1:2 volume ratio have excellent high freeze-thaw stability. • Highly freeze-thaw stable Pickering emulsions improve the processing characteristics of dough during freezing cycles. • Preparation of SPI-M particles by Glycosylation reaction. [ABSTRACT FROM AUTHOR]

Konjac glucomannan/κ-carrageenan (KGM/KC) composite hydrogels often fail to meet industrial requirements due to their weak mechanical properties, while nanofillers are potential materials to address this challenge by taking advantage of their nano-size and filling effects. Herein, carboxylated cellulose nanocrystals (C–CNCs) were chosen as nanofillers to regulate the properties of KGM/KC composite hydrogels, with focus on the effect of C–CNCs concentration on the morphological and physicochemical properties. Meanwhile, an in-depth exploration of the possible mechanisms was also underlying. C–CNCs were well dispersed within the KGM/KC composite matrix, which positively enhanced the mechanical strength, as well as increased the apparent viscosity and modulus of the composite hydrogel greatly when the C–CNCs concentration was 10 % (w/w). This is mainly ascribed to the enhancement of hydrogen bond interaction among the KGM, KC, and C–CNCs, which were verified by Fourier transform infrared spectroscopy. Additionally, the results of low-field nuclear magnetic resonance confirmed the presence of C–CNCs in the hydrogel matrix reduced the water mobility of the hydrogel, which improved the freeze-thaw stability of the composite hydrogel. The fitting of the Power law model (R2 > 0.98) showed that the swelling mechanism of KGM/KC composite hydrogels belonged to Fickian diffusion, and the swelling behavior could be regulated by adjusting the C–CNCs concentration. However, the excessive C–CNCs might weakened the interaction of composite hydrogels, which partially explains the reversal of the reinforcement effects seen at the lower additions of C–CNCs inclusion. These results provide a basis for the development and design of KGM/KC-based products with desirable attributes. [Display omitted] • C–CNCs were chosen to regulate the KGM/KC composite hydrogel properties. • C–CNCs enhanced the mechanical and freeze-thaw properties of composite hydrogels. • The swelling property of composite hydrogels could be regulated by C–CNCs content. • The possible reinforcement mechanism of the nanocomposite hydrogels was discussed. [ABSTRACT FROM AUTHOR]

Stimuli-responsive antioxidant Pickering emulsions play crucial role in many industrial areas. This study demonstrated for the first time oil-in-water Pickering emulsions with outstanding antioxidation and responsive demulsification stabilized by functionalized cellulose nanocrystals (CNCs). Dialdehyde cellulose nanocrystals (DACs) were first prepared through the oxidation of CNCs with periodate, followed by the grafting of p-aminophenols (PAPs) onto their surfaces through Schiff base reaction, affording PAP grafted DACs (DAC -g- PAP) via dynamic covalent linkage. The degree of the oxidation (DO) of DACs had a significant effect on the yield of the targeting DAC -g- PAP nanoparticles. High DO (≥40 %) potentially led to the degradation of DACs during the grafting of PAP. The introduced PAP endowed DACs with excellent radical scavenging capability, thereby providing antioxidant properties while improving the hydrophobicity. DAC -g- PAP nanoparticles were then applied as Pickering emulsifiers to prepare oil-in-water Pickering emulsions. The resultant Pickering emulsions indicated exceptional antioxidant and pH-responsiveness together with good freezing-thaw stability. The structures of DAC -g- PAP nanoparticles were thoroughly characterized in this study. [Display omitted] [ABSTRACT FROM AUTHOR]

Soybean protein isolate (SPI) is widely used in the food industry. However, SPI-based emulsion gels tend to aggregate and undergo oiling-off during freeze-thawing. In this study, emulsion gels were prepared by a combination of heat treatment and ionic cross-linking using SPI and sodium alginate (SA) as raw materials. The focus was on exploring the mechanistic effects of the SPI-SA double network structure on the freeze-thaw stability of emulsion gels. The results showed that the addition of SA could form different types of network structures with SPI, due to different degrees of phase separation. In addition, SA appearing on the SPI network indicated that the addition of Ca2+ shielded the electrostatic repulsion between SPI and SA to form SPI-SA complexes. The disappearance of the characteristic peaks of SA and SPI in Fourier transform infrared spectroscopy analysis also confirmed this view. Low-field nuclear magnetic resonance data revealed that SA played a role in restricting water migration within the emulsion gels, increasing bound water content, and thereby improving the water-holding capacity of the emulsion gels. Therefore, the incorporation of SA improved the freeze-thaw stability of SPI emulsion gels. These findings offer a theoretical basis and technical support for SPI application in frozen products. [Display omitted] • One-step fabrication of double network emulsion gels through heat treatment and ionic cross-linking. • The addition of sodium alginate led to increased hydrophobicity and changes in the secondary structure of soybean protein isolate. • Various concentrations of sodium alginate significantly affected the emulsion gel microstructure. • Soybean protein isolate-sodium alginate emulsion gels exhibited favorable texture and freeze-thaw stability. [ABSTRACT FROM AUTHOR]

This study investigated the effect of ultrasound and enzymatic cross-linking on the freeze-thaw (FT) stability and release properties of whey protein isolate hydrogels. We evaluated the FT stability by the changes in the microstructure, riboflavin retention, syneresis, water holding capacity (WHC), and texture of gels subjected to 3 FT cycles. High-intensity ultrasound (HUS) and transglutaminase (TGase)-mediated cross-linking improved the FT stability of whey protein isolate hydrogels loaded with riboflavin (WPISAR), as demonstrated by a more uniform and denser porous structure, significantly higher riboflavin retention, WHC, and textural properties, and lower syneresis after 3 FT cycles than those of untreated hydrogels. Furthermore, HUS- and TGase-mediated cross-linking decreased protein erosion and swelling ratio of WPISAR in simulated gastrointestinal fluids (SGIF) and reduced the riboflavin release rate in SGIF both with and without the addition of digestive enzymes. After 3 FT cycles, faster riboflavin release occurred due to a more porous structure induced by ice crystal formation compared with their unfrozen counterparts as detected by confocal laser scanning microscopy. High-intensity ultrasound- and TGase-mediated cross-linking alleviated the FT-induced faster riboflavin release rate in SGIF. High-intensity ultrasound- and TGase-treated gel samples showed that both diffusion and network erosion were responsible for riboflavin release regardless of FT. These results suggest that HUS- and TGase-mediated cross-linking improved the FT stability of WPISAR with a high riboflavin retention, and might be a good candidate as a controlled-release vehicle for riboflavin delivery to overcome undesired FT processing. [Display omitted] [ABSTRACT FROM AUTHOR]

This review comprehensively discussed the recent developments in enhancing the freeze-thaw (F-T) stability of Pickering emulsions, which is important for their application as nutrient delivery vehicles in the food and pharmaceutical industries. Pickering emulsions, stabilized by solid particles, have demonstrated promising stability and encapsulation capacity for bioactive ingredients. However, their stability is often compromised by F-T cycles, leading to the particle aggregation and phase separation. This is due to the formation of ice and oil crystals during freezing and the appearance of coalescence after thawing. This review outlined various strategies to improve the F-T stability of Pickering emulsions, including optimization of the continuous and dispersed phases, modifying interfacial emulsifiers, and adjusting the processing conditions such as heating pretreatment, ionic strength and pH values. Furthermore, this review elucidated the impact of F-T cycles on the delivery efficiency of Pickering emulsions and emphasized the need for novel stabilization techniques and tailored strategies to meet the specific requirements of various applications in the food and pharmaceutical industries. [Display omitted] • Strategies to improve the freeze-thaw (F-T) stability of Pickering emulsion are summarized. • The instability mechanism of Pickering emulsion during F-T cycles is illustrated. • Interfacial layer enhancement and gel formation contribute to F-T stability of emulsion. • Improved stability of Pickering emulsion contributes to better delivery efficiency. [ABSTRACT FROM AUTHOR]

To improve the stability of pollock bone broth, compound emulsifiers were employed and evaluated in nano-emulsions from pollock bones (PBNs). The microstructure, creaming index, particle size, zeta potential, and viscosity of PBNs were characterized and the stability of PBNs was investigated. It revealed that the concentration of compound emulsifiers is one of the principal factors for particle size, zeta potential, and viscosity of PBNs, and 0.9% of sodium caseinate and sucrose fatty acid ester (CS-SE) can make the PBN display good stability. Its particle size changed from 81.17 ± 1.33 nm to 19.62 ± 0.21 nm when the temperature ranged from 40 °C to 80 °C, and its creaming index could reach a maximum (90.83%) among all PBNs in 4 months of freeze-thaw assays. PBN stability could be improved by the compound emulsifier (CS-SE), which offers a theoretical basis for the application of pollock bone broth. • Oil-in-water nano-emulsions from pollock bones (PBNs) were fabricated. • Compound emulsifiers on the properties of PBNs were investigated. • The particle sizes of PBNs decreased as emulsifiers' concentration increased. • The thermal and freeze-thaw stability of the PBNs were evaluated. • PBN of 0.9% CS-SE was relatively uniform and stable. [ABSTRACT FROM AUTHOR]

[Display omitted] • The properties of interfacial crystallized oleogel emulsions could be tailored by cooling rate. • The oleogel structure in the emulsion greatly improved freeze–thaw stability by providing rigid physical shell. • The tribological properties were better maintained for emulsions prepared at slow cooling rate. In this study, the influence of cooling rate on the freeze–thaw stability, rheological and tribological properties of interfacial crystalized oleogel emulsion was investigated. Results showed that slower cooling rate could promote formation of larger crystals and stronger network in oleogels. Additionally, oleogel emulsions showed higher freeze–thaw stability than those stabilized solely by emulsifiers. The slower cooling rate resulted in larger crystals adsorbed at the droplet surface. This led to greater steric hindrance that prevented the migration of oil droplets with higher resistance to disruption by ice crystals. The rheological and tribological measurements suggested that with appropriate amount of crystals, the tribological properties were better maintained for emulsions prepared at slow cooling rate after freeze–thaw treatment. This strategy greatly enriched oleogel emulsion formulations and provided important clues for potential applications in food products involved with freeze–thaw treatment. [ABSTRACT FROM AUTHOR]

Scheme 1. Schematic illustration showcases a fish oil nanoemulsion delivery system with a dense interfacial layer coated by HA-PG10-C18, highlighting enhanced gastrointestinal stability and extended shelf-life of droplets. [Display omitted] • HA-PG10-C18 is a promising candidate emulsifier for nanoemulsion delivery system. • Surface density for HA-PG10-C18@NE is 60% greater than for PG10-C18@NE. • HA-PG10-C18@NE possesses outstanding freeze-thaw and freeze-drying stability. This study aimed to synthesize a novel emulsifier, hyaluronic acid-poly(glyceryl)10-stearate (HA-PG10-C18), and employ it for the fabrication of nanoemulsions incorporating deep-sea fish oil to improve their apparent solubility and physicochemical stability. 1H NMR and FT-IR analyses indicated successful synthesis of HA-PG10-C18. Nanoemulsions of deep-sea fish oil loaded with HA-PG10-C18 (HA-PG10-C18@NE) were successfully fabricated by ultrasonic emulsification. The fixed aqueous layer thickness (FALT) of PG10-C18@NE and HA-PG10-C18@NE was determined and the FALT of both nanoemulsions was similar, while the surface density of HA-PG10-C18@NE (4.92 × 10−12 ng/nm2) is 60 % higher than that of PG10-C18@NE (3.07 × 10−12 ng/nm2). Notably, HA-PG10-C18@NE demonstrated an exceptional physicochemical stability when exposed to various stressed environmental conditions, especially its freeze-thaw stability. Moreover, after simulated in vitro digestion, the HA-PG10-C18@NE exhibited a comparatively greater liberation of free fatty acids (94.0 ± 1.7 %) when compared to the release observed in PG10-C18@NE (85.5 ± 2.2 %). [ABSTRACT FROM AUTHOR]

Although emulsion gels show significant potential as fat substitutes, they are vulnerable to degreasing, delamination, and other undesirable processes during freezing, storage, and thawing, leading to commercial value loss in terms of juiciness, flavor, and texture. This study investigated the gel strength and freeze-thaw stability of soybean protein isolate (SPI)/curdlan (CL) composite emulsion gels after adding sodium chloride (NaCl). Analysis revealed that adding low salt ion concentrations promoted the hardness and water-holding capacity (WHC) of fat substitutes, while high levels displayed an inhibitory effect. With 40 mM NaCl as the optimum concentration, the hardness increased from 259.33 g (0 mM) to 418.67 g, the WHC increased from 90.59 % to 93.18 %, exhibiting good freeze-thaw stability. Confocal laser scanning microscopy (CLSM) and particle size distribution were used to examine the impact of salt ion concentrations on protein particle aggregation and the damaging effect of freezing and thawing on the proteoglycan complex network structure. Fourier-transform infrared spectroscopy (FTIR) and protein solubility evaluation indicated that the composite gel network structure consisted of covalent contacts between the proteoglycan molecules and hydrogen bonds, playing a predominant role in non-covalent interaction. This study showed that the salt ion concentration in the emulsion gel affected its molecular interactions. [Display omitted] • Freeze-thaw treatment caused fat substitute dehydration, oil loss, and instability. • Salt ions improved the fat substitute freeze-thaw stability. • Low NaCl concentrations promoted the fat substitute gel strength. • High NaCl concentrations inhibited the fat substitute gel strength. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

All-natural plant protein-based high internal phase emulsion gels (HIPE-Gels) have attracted increasing attention recently in food, cosmetic, pharmaceutical, and other fields. Herein, HIPE-Gels were simultaneously fabricated by natural Quillaja saponin (QS) and soy protein isolate (SPI), and investigated the effects of environmental factors i.e. , storage, acidic, ionic strength, heating and freeze-thawing on their physical stability. The combination of SPI and QS enabled the highly stable O/W emulsion gels with a shear-thinning behavior. At the appropriate concentration (i.e. , 1.5% SPI and 0.09% QS), the emulsion gels exhibited high tolerance toward long-term storage and destabilizing environments. Although poor stability at a pH close to the isoelectric point of SPI, incorporating QS provided excellent acidic stability of plant-based emulsion gels. The strong electrostatic repulsion provided by QS would reduce the aggregation between droplets under acid environment and the electrostatic shielding of salt ions, improving the acid tolerance and salt tolerance of SPI-based emulsion gels. In addition, QS had also improved their thermal stability and freeze-thaw stability. These findings demonstrated that the combination of SPI and QS could provide an effective strategy to fabricate all-natural plant protein-based mayonnaise to withstand several environmental factors, developing label-friendly novel food products. [Display omitted] • All-natural plant-based HIPE-Gels simultaneously stabilized by Quillaja saponin (QS) and soy protein isolate (SPI). • Influence of environmental stresses (i.e. , storage, acidic, NaCl, thermal and freeze-thawing) on stability was systematically investigated. • HIPE-Gels simultaneously stabilized by SPI and QS showed a better physical stability. • These plant-based emulsifiers had synergistic effects on improving emulsion stability. • Providing important information about the formation of stable plant protein-based foods. [ABSTRACT FROM AUTHOR]

This work aimed to investigate the effect of double network emulsion gel (DNEG) as a substitute for pork back fat (PBF) on the freeze-thaw stability of minced meat gel (MMG). We used slow acidification with glucono-δ-lactone (GDL) to induce egg white protein (EWP) gelation, while CaCO 3 was affected by acidification to release Ca2+ to cross-link sodium alginate (SA), resulting in the gradual formation of DNEG networks. The MMG prepared using DNEG substitute for PBF had fine hardness and color after 5 freeze-thaw cycles (FTCs). This was due to the excellent plasticity of DNEG, which made it more capable of filling the voids of minced meat products, thus reducing the space for ice crystal growth. As a result, MMG prepared with DNEG could pass through the maximum ice crystal formation zone faster and avoid damage due to the formation of larger ice crystals. Notably, DNEG provided a barrier for the migration of immobilized water to bulk water in the sample. After several freeze-thaw treatments, the water holding capacity of samples prepared with DNEG decreased significantly slower, which slowed down the oxidation and decomposition of meat proteins. In summary, this study revealed the role of fat substitute DNEG as a favorable filling material for improving the freeze-thaw stability of minced meat products, and provided a technical reference for the development of healthy and storable meat products. [Display omitted] • DNEG with favorable plasticity could be sufficiently filled for MMG. • DNEG as fat replacement reduced frozen damage to MMG structure by FTCs. • DNEG hindered redistribution of water after freeze-thawing. • DNEG retarded oxidation and catabolism of muscle proteins during FTCs. • The excellent freeze-thaw stability made DNEG a promising cryoprotectant. [ABSTRACT FROM AUTHOR]

Summary: Phosphatidylcholine (PC)‐coated emulsion was unstable during the freezing process. This study aimed to investigate the influences of octenyl succinic anhydride modified starch (OSAS) to PC weight ratios on the properties of the OSAS–PC complex and freeze–thaw stability of oil‐in‐water (O/W) emulsions. The results of molecular dynamics (MD) simulation indicated that electrostatic interaction was dominant in the complex. When OSAS/PC weight ratios were 5:5, 6:4, and 3:7, the complex showed a relatively low interfacial tension, high interfacial layer thickness, and high apparent viscosity at low shear rate. Z‐average diameter in emulsions increased from 175.8 to 270.0 nm and zeta‐potential increased from –49.2 to –29.7 mV, when OSAS/PC weight ratio varied from 0:10 to 7:3. OSAS–PC complex in weight ratios of 3:7 and 5:5 remarkably improved the freeze–thaw stability of emulsions (no creaming and aggregates), which may be related to a thick and dense interfacial layer. These findings indicated that the freeze–thaw stability of PC‐stabilised emulsions could be improved by OSAS with low levels. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

To improve the freeze‐thaw stability of rice starch (RS), the soybean protein hydrolysates (SPHs), xanthan gum (XG), and the blends of SPHs with XG (SPHs‐XG) are added. The syneresis, thermal, texture, rheological properties, and morphological features of samples during seven freeze‐thaw cycles (FTCs) are investigated by syneresis measurement, differential scanning calorimetry (DSC), textural properties analysis (TPA), dynamic rheological, NMR, and SEM. As a result, SPHs‐XG is more effective for improving the freeze‐thaw stability and showed improved structure manifestations with the lower retrogradation rate (22.78%), hardness (153.29 g), gumminess (54.57), and solid‐like structure (p < 0.05). Moreover, the water‐holding capacity is increased and the microstructure is effectively stabilized. All these results suggested that SPHs‐XG could be a potential ingredient to improve the quality of rice starch‐based frozen foods. [ABSTRACT FROM AUTHOR]

Cassava stems contain up to 40% starch (by dry mass) and are currently discarded as agricultural waste. The current study aims to understand the physicochemical traits of cassava stem and root starches for investigating trends in industrial cassava applications. In total, 11 traits of both cassava stem and root starches of 15 genotypes are investigated. All the examined traits of cassava root and stem starches vary by genotype. The amylose contents of root and stem starches are in the range of 19.0–33.0% and 18.44–34.51%, respectively. The resistant starch of root and stem starches are in the range of 1.72–17.72% and 4.42–13.37%, respectively. Only the starch content, solubility, and swelling power of root starches are significantly higher than those of stem starches. The root starch gel is more stable than the stem starch gel after the fourth and fifth freeze‐thaw cycles. Furthermore, principal component analysis calculated based on starch and amylose contents, degree of swelling, digestibility, and freeze‐thaw stability demonstrates that genotypes GW46, GW88, S1, E26, and GC49 gain higher scores than control varieties South China 12 and South China 205, which are the most favorable ones by farmers in China because of good root yields. [ABSTRACT FROM AUTHOR]

The effect of mung bean seed coat polysaccharide (PS) on the physicochemical properties and freeze-thaw stability of rice starch (RS) gel was studied. Results showed that the addition of PS at concentrations of 0.25, 0.50, and 1.0% affected the physicochemical properties of RS. The onset gelatinization temperature of RS increased and the gelatinization enthalpy decreased with increasing the concentration of PS. PS caused a decrease in peak viscosity, breakdown, and setback but increase in pasting temperature. For the textural properties, PS at the concentration of 0.25, 0.50, and 1.0% reduced changes in RS gels hardness after 5 freeze-thaw cycles by 20.76, 35.91, and 47.57%, respectively, compared to the sample without PS. The syneresis of RS gels during freeze-thaw process was also reduced by the addition of PS especially at 1.0%. It is related with the results of ice crystal size when the addition of PS. Ice crystal image showed a dramatically reduced ice crystal size and modified ice shape influenced by PS. Retrogradation measurement, microstructure, and crystallinity of RS gels after repeated freeze-thaw cycles indicated the minimizing of starch retrogradation caused by PS. These results suggested that PS was effective in preserving quality in frozen rice starch-based products. [ABSTRACT FROM AUTHOR]

In this study, freeze-thaw cycle experiments were conducted on food-grade Pickering emulsions co-stabilized with konjac glucomannan (KGM) and xanthan gum/lysozyme nanoparticles (XG/Ly NPs). The rheological properties, particle size, flocculation degree (FD), coalescence degree (CD), centrifugal stability, Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and microstructure of Pickering emulsion stabilized by KGM before and after freeze-thaw were characterized. It was found that as the concentration of KGM increased, the flocculation degree (FD) and coalescence degree (CD) of the emulsion decreased after the freeze-thaw cycle compared to the control sample, and the microscopic images showed that the droplets became smaller and less affected by the freeze-thaw cycles. The rheological and water-holding properties also confirmed that the KGM-added emulsions still had a strong gel network structure and prevented the separation of the continuous and dispersed phases of the droplets after freezing and thawing. Freeze-thaw treatments had a negative effect on the stable emulsion of XG/Ly NPs, while the addition of KGM improved the freeze-thaw stability of the emulsion, which provided a theoretical basis for the development of emulsion products with high freeze-thaw stability. [ABSTRACT FROM AUTHOR]

In this study, soy protein isolate (SPI) and maltose (M) were employed as materials for the synthesis of a covalent compound denoted as SPI-M. The emulsion gel was prepared by transglutaminase (TGase) as catalyst, and its freeze-thaw stability was investigated. The occurrence of Maillard reaction was substantiated through SDS-PAGE. The analysis of spectroscopy showed that the structure of the modified protein was more stretched, changed in the direction of freeze-thaw stability. After three freeze-thaw cycles (FTC), it was observed that the water holding capacity of SPI-M, SPI/M mixture (SPI+M) and SPI emulsion gels exhibited reductions of 8.49 %, 16.85 %, and 20.26 %, respectively. Moreover, the soluble protein content also diminished by 13.92 %, 23.43 %, and 35.31 %, respectively. In comparison to unmodified SPI, SPI-M exhibited increase in gel hardness by 160 %, while elasticity, viscosity, chewability, and cohesion demonstrated reductions of 17.7 %, 23.3 %, 33.3 %, and 6.76 %, respectively. Concurrently, the SPI-M emulsion gel exhibited the most rapid gel formation kinetics. After FTCs, the gel elastic modulus (G′) and viscosity modulus (G″) of SPI-M emulsion were the largest. DSC analysis underscored the more compact structure and heightened thermal stability of the SPI-M emulsion gel. SEM demonstrated that the SPI-M emulsion gel suffered the least damage following FTCs. • The covalent reaction between maltose and SPI made the protein changed in the direction of freeze-thaw stability. • Grafting with maltose can enhance the freeze-thaw resistance of emulsion gel. • Maillard reaction remarkably improved freeze-thaw stability and strength of emulsion gels. • Rheological tests demonstrated that the maltose access contributed to increased gel mechanical strength and formation. • SEM confirmed microstructure changes of SPI-M emulsion gels after freeze-thaw cycles. [ABSTRACT FROM AUTHOR]

Pickering emulsions are of great interest to the food industry and their freeze-thaw stability important when used in frozen foods. Particles of soybean isolate (SPI) were heat treated and then crosslinked with transglutaminase (TG) enzyme to produce Pickering emulsions. The protein particles produced using unheated and uncrosslinked SPI (NSPI) was used as the benchmark. The mean particle size, absolute zeta potential, and surface hydrophobicity of protein particles produced using heat treatment and TG crosslinking (at 40 U/g) SPI (HSPI-TG-40) were the highest and substantially higher than those produced using NSPI. The thermal treatment of protein particles followed by crosslinking with TG enzyme improved the freeze-thaw stability of Pickering emulsions stabilized by them. The Pickering emulsions produced using HSPI-TG-40 had the lowest temperature for ice crystal formation and they had better freeze-thaw stability. The plant-based ice cream prepared by HSPI-TG-40 particle-stabilized Pickering emulsions had suitable texture and freeze-thaw stability compared to the ice cream produced using NSPI. The Pickering particles produced using heat treatment of SPI followed by crosslinking with TG (at 40 U/g) produced the most freeze-thaw stable Pickering emulsions. These Pickering particles and Pickering emulsions could be used in frozen foods such as ice cream. [ABSTRACT FROM AUTHOR]

Trypsin is a serine protease with important applications such as protein sequencing and tissue dissociation. Preserving protein structure and its activity during freeze-thawing and prolonging its shelf life is one of the most interesting tasks in biochemistry. In the present study, trypsin cryoprotection was achieved by altering buffer composition. Sodium phosphate buffer at pH 8.0 led to pH shift-induced destabilization of trypsin and formation of a molten globule, followed by significant activity loss (about 70%). Potassium phosphate and ammonium bicarbonate buffers at pH 8.0 were used with up to 90% activity recovery rate after 7 freeze-thaw cycles. The addition of non-ionic surfactants Tween 20 and Tween 80 led to up to 99% activity recovery rate. Amide I region changes, corresponding to specific secondary structures in the Fourier transform infrared (FTIR) spectrum, were modest in the case of Tween 20 and Tween 80. On the other hand, the addition of Triton X-100 led to the destabilization of α-helicoidal segments of trypsin structure after 7 freeze-thaw cycles but also increased protein substrate availability. Image 1 • Phosphate and bicarbonate buffers are suitable for trypsin freeze-thawing. • Sodium-phosphate destabilized trypsin to the molten globule upon freeze-thawing. • Tween 20 and Tween 80 modestly affect trypsin activity upon freeze-thawing. • Triton X-100 destabilized trypsin α-helicoidal structures upon freeze-thawing. [ABSTRACT FROM AUTHOR]

A novel antimicrobial gel composed of κ–carrageenan (KC) and a cinnamon essential oil (CEO)/hydroxypropyl–β–cyclodextrin (HPCD) composite was developed. The CEO/HPCD composite was characterized by UV–visible spectrophotometry and Fourier-transform infrared spectroscopy (FT-IR), and the changes in the principal components of CEO upon encapsulation by HPCD were analyzed by gas chromatography–mass spectrometry (GC–MS). The physicochemical properties, release kinetics and antimicrobial activity of the fabricated gels were investigated. The hardness of the KC gels increased with composite concentration in the range of 1.0–3.0% (w/v) and thereafter decreased. A similar trend was observed for the gumminess and chewiness, whereas the gel springiness remained essentially constant. The CEO/HPCD composite also enhanced the fluidity of the system, and the syneresis was positively correlated with the composite concentration. The controlled release of CEO from the gels was affected by the relative humidity (RH) and CEO content. The Ritger-Peppas model indicated that the CEO release kinetics from the gels proceeded through a combination of diffusion and framework erosion. The KC gel containing 5% CEO/HPCD composite displayed effective antimicrobial activity, prolonging the shelf life of sliced bread by at least two days. The reported gels may have potential applications as a promising material for food preservation. • CEO/HPCD composite was confirmed by UV–Vis spectrophotometry and FT-IR techniques. • CEO/HPCD composite enhanced plasticity and freeze-thaw stabilization of KC gels. • Release of CEO from gels was a combination of diffusion and framework erosion. • KC gels containing the composite prolonged the shelf life of sliced bread. [ABSTRACT FROM AUTHOR]

This study aims to investigate chitosan (CS) with five different molecular weight (Mw) on freeze–thaw stability of Arenga pinnata starch (APS) gel subjected to five freeze–thaw cycles (FTC). The syneresis of APS gels was reduced by adding CS and the APS gel with high Mw CS had lower syneresis duo to a higher water holding capacity (P < 0.05). The addition of CS significantly decreased the hardness and molecular ordered structure of APS gel. In addition, CS could improve the microstructural stability. The results suggested that CS could effectively improve the freeze–thaw stability of APS gel, and CS with higher Mw might have more practical utility to improve stability of APS gel. [ABSTRACT FROM AUTHOR]

[Display omitted] • The temperature for using high-temperature wet glycosylation is 120 °C. • The influence of high temperature on the physicochemical and functional properties of EWP glycosylation was determined. • Modified EWP has higher adsorption at the oil–water interface. • Modified EWP showed better emulsion stability. • High temperature wet glycosylation modified GEWPs stabilised HIPEs with good freeze–thaw stability. This paper investigates the freeze–thaw stability of oil-in-water emulsions stabilized by high-temperature wet heating glycosylation products. Glucose (Glu), D-fructose (Fru), xylose (Xyl), maltodextrin (MD), oligofructose (FO), and oligomeric isomaltulose (IMO) were chosen as sugar sources for the glycosylation reaction with egg white proteins (EWPs) at 120 °C to prepare the GEWPs. The study reveals that the type of sugar significantly influences the Maillard reactions with EWPs. The degree of glycosylation was highest in the Xyl group with the greatest reducing capacity and lowest in the MD, FO, and IMO groups. High-temperature wet glycosylation treatment induced changes in the secondary and tertiary structures of EWP. Elevated temperature exposed hydrophobic groups within the protein, while covalent binding of hydrophilic carbohydrates via the Maillard reaction decreased the protein's H 0 value. Improved foaming and emulsifying properties were attributed to the increase in α-helix content, disulfide bond formation, and reduced surface tension. Emulsions prepared from GEWPs exhibited higher apparent viscosity and G' compared to those from natural EWPs, with the GEWP/Xyl group showing the highest values. After freeze–thaw treatment, the GEWP/Fru and GEWP/FO groups demonstrated superior stability and reduced freezing point, along with minimal microstructural alterations. These findings underscore the importance of sugar type in the stability of high internal phase emulsions (HIPEs) stabilized by GEWPs, indicating that a tailored Maillard reaction can yield stabilizers with exceptional freeze–thaw stability for emulsions. [ABSTRACT FROM AUTHOR]

The poor freeze-thaw stability and weak thermal gel properties of plant-based egg substitutes limit their opportunity for application. In the current study, the impact of modification by pH-shifting and transglutaminase (TG) cross-linking on the freeze-thaw stability and thermal gel properties of mung bean protein-based emulsions made by two different oil phases (canola oil and coconut oil) were studied. The pH-shifting induced improved emulsifying activity (up to 77.6% increased) and smaller droplets sizes (from 39.27 to 7.03 μm). After the freeze-thaw process, no matter with TG cross-linking or in different oil phase systems, all emulsion samples prepared with pH-shifting treated mung bean protein (BMBP) exhibited a superior freeze-thaw stability than that with native mung bean protein (NMBP). The apparent viscosity of BMBP emulsion was higher than that of NMBP, and the viscosity of BMBP-based CO-emulsion (222.50 mPa s) before freeze-thaw process was closest to that of real egg liquid (184.86 mPa s). In particular, BMBP was more sensitive to TG, resulting in a superior thermal gel hardness of BMBP-based emulsion. This study could serve as a feasible solution to enhance the freeze-thaw stability and thermal gel properties of plant-based emulsions by pH-shifting and TG cross-linking, providing some novel strategies for their applications as stabilized plant-based egg substitutes. [Display omitted] • pH-shifting induced improved emulsifying activity and smaller droplet size. • pH-shifting mung bean protein emulsion exhibited a superior freeze-thaw stability. • pH-shifting protein is more sensitive to TG, resulting in higher gel hardness. • The viscosity of BMBP emulsion was higher than NMBP and was closest to real egg. • NMBP emulsion partially replaces egg, but BMBP emulsion makes higher substitute. [ABSTRACT FROM AUTHOR]

Freeze-induced instability of food products causes substantial losses to food manufacturers annually, and the inhibition of freeze damage is conducive to the development of frozen food industries. However, we lack sufficient information on using saccharides as cryoprotectants in frozen egg yolk systems to inhibit gelation. Therefore, we investigated the cryoprotective effects of several saccharides (sucrose, L-arabinose, xylitol, trehalose, D-cellobiose, and xylooligosaccharides) on frozen egg yolks, focusing on the water/ice tailoring effect of saccharides and the freeze–thaw stability of egg yolks. To evaluate the water/ice tailoring effects, we investigated the total water content, water activity, water state, and water distribution of egg yolks before and after freeze–thawing. We investigated the physical and structural changes in egg yolks before and after freeze–thawing to evaluate their stability. We observed that saccharides exhibited the ability to mitigate texture hardening, whitening in color, disorder in crystallinity, aggregation, and damage in protein integrity of frozen-thawed egg yolks by decreasing the freezable water content, bulk water content, and large ice crystal formation. L-arabinose was found most effective in regulating the freeze‒thaw-induced egg yolk instability, followed by xylitol. Their exceptional gelation-regulating capability and low-calorie nature render them highly suitable additives for the cryopreservation of frozen egg yolks. [Display omitted] • Saccharides were used to improve the freeze‒thaw stability of egg yolks. • The water properties of egg yolks had direct impact on gelation behavior. • Egg yolks had lower melting points in the presence of saccharides. • L-arabinose effectively decreased the freezable water content of egg yolks. • Saccharides with smaller molecular weight were more promising excipients. [ABSTRACT FROM AUTHOR]

[Display omitted] • The printing performance of different W/O wax-based emulsion gels were compared. • Stable droplets could ensure the continuous extrusion while printing. • Dense crystal network/interface crystallization offered good printing performance. • Hot-extrusion 3D printing could improve printing performance by recrystallization. Six kinds of natural waxes were used for emulsion gels preparation. The differences in printing performance were explored based on the crystal distribution and droplet stability. Firstly, the effect of crystal distribution was investigated through microstructures and rheological properties. It was found that the dense crystal network/interfacial crystallization could stabilize the droplet and provide modulus to ensure the self-supporting behavior after printing, whereas excessive crystal could lead to droplet rupture and coalescence. Furthermore, all emulsion gels could recrystallize by heating, which could enhance the performance of 3D printing. Then, the droplet stability was investigated after storing/freeze-thawing. It was found that emulsion gels with dense crystal networks/interfacial crystallization had more stable droplets, which ensure the continuous extrusion during printing. Finally, printing performance was investigated comprehensively. Three emulsion gels with denser crystal networks/interfacial crystallization had higher recovery rates (16.17–21.15%) and more stable droplets, which perform better in 3D printing correspondingly. [ABSTRACT FROM AUTHOR]

Freeze-thaw (F-T) stability of frozen foods has been a hot topic and focus in recent years. The F-T cycles caused by the fluctuations of temperature during storage and transportation have detrimental effects on the properties of fish myofibrils and myofibrillar protein (MP) gels. This review provides an outline of recent research progress to improve the F-T stability of fish myofibrils and MP gels, as well as the insight into the in-depth mechanism. There are five main strategies to improve the F-T stability of fish MP gels, which are direct heating to prepare fish gels, fast freezing technology, addition of protein hydrolysate or antifreeze protein, incorporation of polysaccharides, and addition of quinoa protein Pickering emulsion (QPE) into fish protein gels. Direct heating could decrease the ice crystal size compared with two-step heating process. Fast freezing technology deceases the ice crystal size and the free water content after thawing. The antioxidant activity of protein hydrolysate and polysaccharides weakens the oxidation of sulfhydryl groups, prevents the protein solubility from decreasing and maintains the secondary structure of proteins. QPE addition accelerates the freezing rate, which reduces ice crystal size, prevents water migration and maintains protein structure of fish MP gels. However, innovative and cost-effective methods are still needed from the perspective of industry. It is proposed that emerging freezing and thawing technology and incorporation of ice structuring protein should be effective to resist the F-T damage. The information presented in this review will be useful for future studies. [Display omitted] • Freeze-thaw cycles change protein structure, molecular forces and water mobility. • Direct heating improves F-T stability of fish gel compared with two-step heating. • Protein hydrolysate and polysaccharide weakens the oxidation of sulfhydryl groups. • Emerging thawing technology could decrease thawing loss of fish protein gel. • Ice structuring proteins repress crystallization and reduce amino acid exposure. [ABSTRACT FROM AUTHOR]

A comprehensive study was conducted to elucidate structural and functional properties of waxy starches. The specific objectives were to examine the relationship between gelatinization/pasting properties and morphology of starch cooks, determine how the retrogradation properties are affected by chain-length distribution, and use a novel sensory approach to assess freeze-thaw stability of starch pastes. Waxy potato starch had a greater degree of granule swelling, higher paste viscosities, and better paste clarity than waxy starches from maize, wheat, rice, and tapioca. Waxy starches typically had greater paste viscosities than their normal counterparts, but the exception was potato starches. Waxy potato starch, which had no amylose, had lower paste viscosity than normal potato starch. Both waxy rice and waxy tapioca starches had less retrogradation tendency, which was closely related to the higher proportion of chains with DP 6–11 and the lower proportion of chains with DP 12–24. The sensory evaluation in this study allowed for an easier assessment of water separation as compared to the conventional centrifuge methods. Waxy maize and waxy potato starches had noticeable water separation from the paste after 1–2 freeze-thaw cycles, whereas both waxy rice and waxy tapioca starches could survive 6 freeze-thaw cycles without apparent syneresis. Waxy wheat, waxy rice and waxy tapioca starches are potential starting materials from which clean-label functional starches may be produced. Image 1 • A comprehensive study was done on structure and properties of waxy starches. • Waxy potato starch had the best paste clarity among waxy starches. • A sensory approach was developed to assess freeze-thaw stability of starch pastes. • Waxy rice and waxy tapioca starches had the least retrogradation among waxy starches. • Unit chains with DP 6–11 and 12–24 correlated with cold stability of waxy starch. [ABSTRACT FROM AUTHOR]

Abstract Soybean oil-based organogel was structured using monostearin, and the organogel had a gel-sol melting temperature of 44.0 °C. Loading amount of hesperidin in soybean oil-based organogels could be about twice as much as metastable solubility of hesperidin in soybean oil. Organogel-in-water Pickering emulsion was formed using the soybean oil-based organogel as the oil phase and ovotransferrin (OVT) fibrils as the emulsifier. Visual observation indicated that organogel-based Pickering emulsions stabilized by OVT fibrils (40 mg/mL) at oil fractions of 0.50–0.85 had excellent storage stability and could withstand three cycles of freeze-thaw treatments. Conventional oil-in-water Pickering emulsion was prepared as control to better understand impact of organogel incorporation on freeze-thaw stability, and conventional Pickering emulsion was formed using soybean oil as the oil phase and OVT fibrils as the emulsifier. Freeze-thaw stability of organogel-based Pickering emulsions was better than that of conventional Pickering emulsions (without organogel) stabilized by OVT fibrils. In vitro digestion study revealed that organogel-based Pickering emulsion could improve both the extent of lipolysis and hesperidin bioaccessibility when compared with organogel. This study demonstrates the feasibility of formulating novel food-grade organogel-based Pickering emulsions with high nutraceutical loading, excellent freeze-thaw stability and improved nutraceutical bioaccessibility. Graphical abstract Image 1 Highlights • Organogel-based Pickering emulsions with a higher loading of hesperidin were developed. • Organogel-based Pickering emulsions stabilized by ovotransferrin fibrils had good storage stability. • Organogel-based Pickering emulsions could withstand three freeze-thaw cycles. • Organogel-based Pickering emulsion could improve the extent of lipolysis. • Organogel-based Pickering emulsion could improve hesperidin bioaccessibility. [ABSTRACT FROM AUTHOR]

Abstract Oil-in-water (o/w) emulsions stabilized by soybean protein isolate (SPI) and enzyme-modified soybean protein isolate (SPI + TGase, SPIH, SPIH + TGase) were subjected to three freeze-thaw cycles, and changes in the molecular weight distribution, secondary structure contents, particle size, oiling off (OF), creaming index (CI) and microstructures were investigated. The emulsions exhibited different freeze-thaw tolerance stabilities, which were dependent on the type of enzyme used to prepare the SPI as well as the cycle number of freeze-thaw treatments. Differential scanning calorimetry suggested that emulsion destabilization was mainly due to water crystallization. After three freeze-thaw cycles, the emulsion stabilized by SPIH + TGase showed a decrease of 78.89% in CI and 72.35% in OF compared with SPI. Correspondingly, the particle size decreased by 70.76% (in water) and 88.99% (in 1% SDS). The improvement in the freeze-thaw stability could be largely attributed to the increased molecular flexibility due to the increased α-helix and random coil contents after enzymatic hydrolysis and the formation of gel-like network structures after the addition of TGase cross-linking. The observation of the microstructure also indicated that SPIH + TGase was an effective food emulsifier. These findings could be of great importance for the formulation of food grade emulsions with excellent freeze-thaw stability. Highlights • Freeze-thaw stabilization of SPI, SPIH, SPI + TGase, SPIH + TGase was studied. • Different modification methods and freeze-thaw cycles were investigated. • ζ-potential, particle size, microstructure, OF and CI reflect the stability. • SPIH + TGase can effectively improve the freeze-thaw stability of the emulsion. [ABSTRACT FROM AUTHOR]

Abstract To investigate the freeze–thaw stability of oil-in-water emulsions, we prepared soy protein isolate (SPI), SPI was enzymatically hydrolyzed by papain or by a mixture of papain and phytase, and one cycle or three cycles of freeze–thawing were performed. Their stabilities were assessed by zeta potential, particle size, microstructure, oiling off, and creaming index measurements and the structural changes were characterized by circular dichroism spectroscopy. For emulsions prepared with modified SPI samples, the freeze–thaw stability improved with increasing degree of hydrolysis, especially when the combined enzymatic treatment was performed. Furthermore, the effects of a variety of environmental factors, such as NaCl concentration, pH, and the number of freeze–thaw cycles, were considered with respect to freeze–thaw stability. Emulsions prepared with the most extensively hydrolyzed samples by papain and combined enzymatic treatment, showed a higher freeze–thaw stability than those stabilized by the SPI. In conclusion, SPI modified by papain and phytase treatment can significantly improve freeze–thaw stability and can withstand several environmental factors. The results show promise for supporting the use of SPI as an emulsifier in the food industry. Highlights • Limited hydrolysis of soy protein isolates (SPI) could improve its freeze-thaw stability. • The SPI hydrolysis with papain or with papain and phytase mixed was investigated. • SPI, DH, P-DH were used to stabilize oil-in-water emulsions. • P-DH can improve freeze-thaw stability and withstand several environmental factors. [ABSTRACT FROM AUTHOR]

Abstract There is increasing interest in improving the freeze-thaw stability of emulsions by interfacial engineering in the food colloid field. The present work reported that for Pickering emulsions stabilized by heat-induced soy protein isolate (SPI) nanoparticles, their freeze-thaw stability could be well modulated by modifying the characteristics of the nanoparticles. The SPI nanoparticles with different characteristics (e.g., particle size, surface hydrophobicity) were obtained by heating the SPI solutions at initial concentrations (c i) of 0.25–6.0 wt% at 95 °C for 15 min. All the initial Pickering emulsions were formed at an oil fraction of 0.4 and protein concentration of 0.25 wt% in the aqueous phase, in the presence of 300 mM NaCl. In general, increasing the c i resulted in a progressive enhancement in freeze-thaw stability of the emulsions against creaming and coalescence, but accelerated the flocculation. The higher creaming stability at higher c i values seemed to be closely associated with the enhanced coalescence stability, as well as the strengthened gel-like network of these initial emulsions. There were close interplays between the freeze-thaw stability and the properties of the initial emulsions, or characteristics (e.g. particle size or surface hydrophobicity) of heat-induced SPI nanoparticles. The results confirmed that the SPI nanoparticles with larger sizes, higher surface hydrophobicity and more efficient packing at interface exhibit a greater potential to produce Pickering emulsions with higher freeze-thaw stability. The findings would be of relevance for understanding the freeze-thaw stability of Pickering emulsions stabilized by protein-based particles, as well as for the development of protein-stabilized emulsion formulations with a high freeze-thaw stability. Graphical abstract Image Highlights • Different SPI nanoparticles were fabricated by heating SPI solutions at different concentrations (c i). • Increasing the c i resulted in a gradual increase in particle size and surface hydrophobicity. • The freeze-thaw stability of the emulsions against creaming and coalescence inreased with the c i. • Close relationships between the particle characteristics and freeze-thaw stability of the emulsions were observed. • The gel-like network formation also contributed to the freeze-thaw stability. [ABSTRACT FROM AUTHOR]

Abstract Background Waxy tapioca starches, successfully developed less than two decades ago, have unique functionalities. In Africa, cassava is principally used as a staple food, whereas in Asia, cassava is mostly processed into starch. Tapioca starches, which are isolated from cassava, are heavily traded comparable to maize, potato and wheat starches. Scope and approach This review aims to highlight the properties of waxy tapioca starches compared to normal taopica starch and to waxy starches from other botanical sources and draw attention to food industries that can benefit from the unique functionalities of waxy tapioca starches. Key findings and conclusions Pastes of native waxy tapioca starches perform well in refrigerated and frozen foods as opposed to waxy starches and non-waxy starches from maize, wheat, and potato. Unmodified waxy tapioca starch yields thick, clear pastes with good shelf life. The cold-temperature stability of waxy tapioca is correlated to its amylopectin structure with a relatively high proportion of short branch chains of DP 6–12. The high stability of waxy tapioca starch under freeze-thaw conditions and refrigerated storage indicates that the starch is resistant to retrogradation. With a rising demand for clean-label foods by consumers and markets, the cold-temperature stability of waxy tapioca starch offers an attractive alternative to the use of chemically or genetically modified starch in frozen/refrigerated foods. In this review, we undertake to gain insight on waxy tapioca starches and other starches in order to identify approaches to further develop solutions to make products with desired functionality. Highlights • Development of waxy tapioca starch (WTS) was reviewed. • Properties of WTS were compared to the normal genotype and other waxy starches. • WTS had a low proportion of chains with DP 13–24 that associated with retrogradation. • WTS paste was stable to freeze-thaw and cold storage conditions. • WTS could serve as a clean-label thickener in frozen foods. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The whole hempseed contains about 27.6% of fiber, of which 5.4% and 22.2% are soluble and insoluble fiber, respectively. The defatted hempseed meal contains about 42.6% of total fiber. Despite the abundant amount of fiber in the hempseed, the application of hempseed polysaccharides (HSP) is currently limited in the food industry. It is necessary to understand their physicochemical properties to extend their food applications. Hence, the objective of the current study is to investigate the physicochemical properties of soluble hempseed polysaccharides in comparison with flaxseed polysaccharides. The physicochemical properties, including molecular weight distribution, shape conformation, total sugar content, uronic acid content, rheological properties, and emulsification properties, were evaluated. The results indicated that the HSP contains about 33% uronic acids, 53% total sugars, and possesses an oblate ellipsoidal shape (R g = 23.07 nm, R h = 22.61 nm). Compared to flaxseed polysaccharides and pectin, the HSP showed a high surface active behavior at concentrations above 0.5% (w/v). The dynamic flow curves demonstrated the shear thinning behavior of HSP at the low shear rate range (0.01–10 s−1), followed by a Newtonian behavior at the high shear rate range. The HSP exhibited a weak gel property and an elastic nature. The emulsion stability of HSP and flax polysaccharide did not show a significant difference. The effects of pH and heat treatment on HSP stabilized emulsion were insignificant compared to flax polysaccharides. Finally, the freeze-thaw stability of HSP was inferior compared to flaxseed polysaccharides and pectin. The study has revealed that the HSP could be a potential emulsifying agent in the food system. [Display omitted] • Hemp polysaccharides (HSP) possess an oblate ellipsoidal shape. • HSP showed excellent surface activity. • HSP revealed a characteristic of weak gel and showed its elastic nature. • HSP maintained emulsion stability by preventing droplet aggregation. • HSP and flaxseed polysaccharides displayed superior emulsion stability. [ABSTRACT FROM AUTHOR]

Animal or plant-based meat products are typically stored and transported using freezing. Freezing-thawing cycles can lead to detrimental changes in the texture, appearance, and mouthfeel of fat substitutes, thus affecting their quality. In this work, a protein/polysaccharide composite emulsion gel was created by emulsifying soybean isolate protein (SPI) and palm oil (PO), and incorporating curdlan (CL). It can serve as a potential replacement for animal fat in meat products, such as sausage, and plant-based meat. The study aimed to investigate the stability of the complex fat substitutes during freeze-thaw at various melting points and palm oil content. The results showed that the 52°C-palm oil samples were the most freeze-thaw stable compared to samples with other melting points. 52°C-palm oil samples were tested for texture and water holding capacity (WHC), increasing the oil content from 5g/100g–20g/100g improved the gel strength and WHC after freeze-thaw. The samples containing high melting point palm oil were less affected by temperature changes and showed higher stability as detected by low-field NMR and differential calorimetric scanning. The confocal laser scanning and rheological detection further confirmed the enhanced structural strength and freeze-thaw stability of the emulsion gels containing solid fat particles with high melting points. • Freeze-thaw treatment causes fat substitutes to syneresis and lose oil, creating folds and pores. • Increased content of low melting point oil will destroy the structure of emulsion gel. • High melting point oil will improve the strength and water holding capacity of the emulsion gel. • High melting point palm oil improves freeze-thaw stability of fat substitutes. [ABSTRACT FROM AUTHOR]

The alkali-induced heat-set konjac glucomannan (KGM) hydrogels have drawn increasing attention due to their high absorbency and thermal irreversibility ability, but pure KGM hydrogels generally have defects of low strength and high syneresis rate. Cellulose nanocrystals and their derivatives, which have a very high specific surface area, good biocompatibility, biodegradability, and low toxicity, are promising candidates to solve this challenge. In this work, we propose the use of carboxylated cellulose nanocrystals (C–CNCs) as nanofillers for the strengthening of KGM hydrogels. The effects of the C–CNCs content on the microstructure and physical properties of the KGM hydrogels and their possible mechanism were investigated. The compressive test results indicate great improvement in the mechanical properties upon the addition of the C–CNCs for the KGM hydrogel and reached a maximum value at 20% loading. The microstructure analyses of the KGM hydrogel revealed that the well-distributed C–CNCs can act as a physical cross-linker to connect the neighboring KGM chains to strengthen the resultant hydrogel, based on their strong interactions, including hydrogen bonding and chain entanglements. Moreover, adding 20% C–CNCs can significantly decrease the syneresis after five repeated freeze-thaw cycles of the KGM hydrogels. Compared to pure KGM hydrogels, KGM/C–CNCs nanocomposite hydrogels demonstrated higher water-binding capability based on Low-field nuclear magnetic resonance. These findings indicate that C–CNCs are considered anchors for KGM chains as well as reinforcement fillers in the polymer matrix, which contributes significantly to the mechanical property of the nanocomposite. Therefore, C–CNCs were a promising material to be applied for modulating the mechanical and freeze-thaw stability properties of the polysaccharide-based hydrogel in food and biomedical applications. [Display omitted] • C–CNCs were proposed as nanofillers for the strengthening of alkali-induced heat-set KGM hydrogels. • Nanocomposite hydrogels exhibited good mechanical property, enhanced thermal stability, and excellent freeze-thaw stability. • Physicochemical of nanocomposite hydrogels were regulated by controlling the content of C–CNCs. • C–CNCs can act as a physical cross-linker to connect the neighboring KGM chains to strengthen the resultant hydrogel. [ABSTRACT FROM AUTHOR]

[Display omitted] • High ionic strength endowed an outstanding FT stability to MMP emulsions. • MMP emulsions at 300–1000 mM ionic strength exhibited well after five FT cycles. • MMP emulsions at 100–200 mM occurred flocculation under electrostatic shielding. • Emulsions in 300–1000 mM could form more stable 3D network to resist FT treatment. The regulation mechanism of ionic strength (0–1000 mM) on the freeze-thaw (FT) stability of emulsions stabilized by myofibrillar protein microgel particles (MMP) was systematically investigated. High ionic strength emulsions (300–1000 mM) exhibited stability after five FT cycles. With ionic strength increasing, the repulsive force between particles gradually reduced, the flocculation degree (20.72 ∼ 75.60%) and apparent viscosity of emulsions gradually rose (69 ∼ 170 mPa·s), promoting the formation of protein network structures in the continuous phase. Concurrently, the interfacial proteins rearranged (18.8 ∼ 104.2 s−1) and aggregated rapidly, facilitating the formation of a stable interface network structure, ultimately improving its stability. Besides, scanning electron microscopy (SEM) images revealed that the interfacial proteins gradually aggregated, further forming a network with the MMP in the continuous phase, allowing MMP emulsions with enhanced FT stability at high ionic strength (300–1000 mM). This study was beneficial to produce emulsion-based sauces with ultra-high FT stability. [ABSTRACT FROM AUTHOR]

Binary gels with various microstructures, including apricot kernel protein isolate-gellan gum gels with high freeze-thaw stability, were obtained by combining transglutaminase covalent cross-linking and gellan gum modification. Adding 0–0.1% gellan gum (w/w) can form continuous protein network structures dominated by covalent networks and disulfide bonds. In addition to covalent cross-linking, the increase in the strength of hydrophobic and electrostatic interactions at gellan gum concentrations below 0.2% (w/w) facilitated the formation of a bicontinuous network (AGG3). When excess gellan gum was added (0.03%, w/w), gellan gelation occurred in the system, leading to the formation of heterogeneous aggregated structures (AGG4). Confocal laser microscopy revealed a dense porous structure in the continuous protein network after freeze-thaw treatment, and AGG4 showed heterogeneous and loose aggregated microstructure, while the bicontinuous network structure was maintained. The water holding capacity of AGG3 was increased by 21.36% after freezing compared with the gels without gellan gum, and AGG3 maintained high hardness and springiness. Low-field nuclear magnetic resonance and magnetic resonance imaging showed that the bicontinuous network was more conducive to the tethering ability and uniform distribution of hydrogen protons than the continuous network structure of proteins. Therefore, AGG3 exhibited excellent freeze-thaw stability. • Cold-set apricot kernel protein isolate-gellan gum binary gels were obtained. • Gels with various microstructures were fabricated by different interactions. • The TGase covalent cross-linking added a certain strength to the gel network. • The noncovalent interactions and chain entanglement could enhance gel springiness. • Gels with bicontinuous microstructures had excellent freeze-thaw stability. [ABSTRACT FROM AUTHOR]

Konjac glucomannan (KGM) has been widely studied because of its excellent gelling properties. However, the freeze-thaw stability and weak gel strength significantly limit its industrial application. To solve these issues, we innovatively introduced oxidized chitin nanowhiskers (O-ChNWs) under heating and alkaline conditions, thus achieving the improvement of the properties of KGM gels. In this study, rheological measurement and textural analysis were performed to verify the physicochemical properties of the as-prepared KGM/O-ChNWs. Results showed that the KGM/O-ChNWs dispersion exhibited a typical non-Newtonian pseudoplastic fluid behavior and the mechanical property of the gels enhanced with the amount of O-ChNWs increasing. Also, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) was applied to elucidate the interaction between KGM and O-ChNWs. It showed that both strong hydrogen bonding and amide bonds could be formed to stabilize the KGM/O-ChNWs structure. Additionally, morphological images show that O-ChNWs can influence the original KGM structure and then form more uniform pores. Furthermore, thermogravimetric (TGA) analysis and freeze-thaw measurement demonstrated that O-ChNWs could obviously improve the thermal and freeze-thaw stability of the nanocomposite gels. Taken together, this current work can provide new insights into existing KGM gel systems and stimulate the development of additional KGM-based nanocomposite gels with the desired mechanical strength and freeze-thaw stability. [Display omitted] • O-ChNWs acted as nano-filler of KGM and had strong hydrogen bond with KGM. • Microstructure and gel properties of KGM nanocomposite gels depended markedly on O-ChNWs concentration. • The introducing O-ChNWs improved freeze-thaw stability of the KGM-based nanocomposite gels. [ABSTRACT FROM AUTHOR]