Recrystallization Of Ice Crystals Research Articles

Effect of bovine hide gelatin antifreeze peptides on the quality of frozen dough treated with freeze-thaw cycles and its steamed bread

The structure of frozen dough was damaged due to the recrystallization of ice crystals during freeze-thawing. Therefore, the effect of bovine hide gelatin antifreeze peptides (BgAFPs) on the quality of frozen dough treated with freeze-thaw cycles and its steamed bread was investigated. The results showed that BgAFPs exhibited a high thermal hysteresis activity at 1.64 °C and possessed the significant ability to inhibit ice crystals growth due to its -Gly-X-Y- (where X was mostly proline or hydroxyproline, Y was any amino acid) repeating sequences. The decrease in gassing rate of frozen dough without BgAFPs (41.31%) was significantly greater than those of frozen dough with BgAFPs (36.32%, 27.74% and 24.30%), revealing that the BgAFPs had cryoprotective effect on yeast cells. Additionally, BgAFPs maintained a continuous apparent morphology of the frozen dough by inhibiting water migration. Specifically, the freezable water content in the frozen dough with 0% and 1.0% BgAFPs increased from 63.35% and 59.41% to 73.74% and 64.36%, respectively. Furthermore, BgAFPs increased the specific volume and springiness, decreased the hardness of the steamed bread. These results suggested that BgAFPs effectively attenuated the freeze-thaw induced damage to frozen dough and improved the quality of steamed bread.

Impact of frozen storage under static electric field on frozen gluten rheological properties

AbstractBackground and ObjectivesElectrostatic fields, as a new food physical processing technology, can effectively improve the quality of frozen food. The purpose of this study is to investigate the effect of electrostatic field‐assisted frozen storage (SEF) on dough rheological properties, gluten structure, and its mechanism.FindingsThe results showed that the G′ and G" of the gluten were efficiently maintained by SEF throughout frozen storage. Meanwhile, after 8 weeks of frozen storage, the relative contents of α‐helices were 25.28% and 24.76%, respectively, and the relative contents of random coils were 40.58% and 41.25%, respectively, in SEFs compared with the control group. This suggested that SEFs might affect the recrystallization of ice crystals by changing the orientation of water molecules, which, in turn, alleviated the disruption of protein secondary structural order. SEF had no effect on the gauche‐gauche‐gauche conformation. SEF reduced damage to protein senior structure by frozen storage. The glutenin macropolymer (GMP) depolymerization of the control and SEF groups was 28.55% and 28.17%, respectively, and the SEF decelerated the GMP depolymerization.ConclusionsSEF slowed the disruption of the molecular structure by reducing the depolymerization of GMP and slowing the depolymerization of the α‐helix, thus maintaining the viscoelasticity of the gluten.Significance and NoveltyExploring the mechanism of the effect of electrostatic field‐assisted frozen storage on gluten quality.

Physics of Ice Nucleation and Antinucleation: Action of Ice-Binding Proteins.

Ice-binding proteins are crucial for the adaptation of various organisms to low temperatures. Some of these, called antifreeze proteins, are usually thought to inhibit growth and/or recrystallization of ice crystals. However, prior to these events, ice must somehow appear in the organism, either coming from outside or forming inside it through the nucleation process. Unlike most other works, our paper is focused on ice nucleation and not on the behavior of the already-nucleated ice, its growth, etc. The nucleation kinetics is studied both theoretically and experimentally. In the theoretical section, special attention is paid to surfaces that bind ice stronger than water and thus can be "ice nucleators", potent or relatively weak; but without them, ice cannot be nucleated in any way in calm water at temperatures above -30 °C. For experimental studies, we used: (i) the ice-binding protein mIBP83, which is a previously constructed mutant of a spruce budworm Choristoneura fumiferana antifreeze protein, and (ii) a hyperactive ice-binding antifreeze protein, RmAFP1, from a longhorn beetle Rhagium mordax. We have shown that RmAFP1 (but not mIBP83) definitely decreased the ice nucleation temperature of water in test tubes (where ice originates at much higher temperatures than in bulk water and thus the process is affected by some ice-nucleating surfaces) and, most importantly, that both of the studied ice-binding proteins significantly decreased the ice nucleation temperature that had been significantly raised in the presence of potent ice nucleators (CuO powder and ice-nucleating bacteria Pseudomonas syringae). Additional experiments on human cells have shown that mIBP83 is concentrated in some cell regions of the cooled cells. Thus, the ice-binding protein interacts not only with ice, but also with other sites that act or potentially may act as ice nucleators. Such ice-preventing interaction may be the crucial biological task of ice-binding proteins.

The influence of γ-PGA on the quality of cooked frozen crayfish during temperature fluctuations

The purpose of this study was to compare the influences of gamma-poly glutamic acid (γ-PGA) (1, 2, 3, and 4 %) to see which could outperform conventional cryoprotectant mixture (4 % sorbitol + 4 % sucrose) on cooked crayfish properties, such as physicochemical, textural qualities, oxidation reaction, water distributions, and microstructure integrity, during different freeze–thaw cycles. Crayfish quality characteristics improved significantly as γ-PGA concentration increased compared to control samples.Adding γ-PGA 4 % reduced the carbonyl content from 4.20 to 3.00 nmol/ mg protein during fluctuation-1 (F1), and from 4.15 to 2.80 nmol/ mg protein during fluctuation-2 (F2) compared to control samples. Furthermore, it increased the total sulfhydryl content from 4.15 and 4.76 to 6.19 and 6.47 mol/105 g protein during F1 and F2 and after five freeze–thaw cycles (FTC). This suggests that this concentration was more effective at controlling protein changes than other concentrations. γ-PGA generally enhanced the water-holding capacity by preventing protein denaturation and limiting ice crystal recrystallization. As a result, microstructure stability was evident, texture degradation was avoided, and the crayfish's color was preserved.

Enhanced cryopreservation performance of PVA grafted monolayer graphite oxide with synergistic antifreezing effect and rapid rewarming

In cryopreservation of biological samples such as cells, the formation, growth and recrystallization of ice crystals can cause fatal mechanical damage to cells. Therefore, how to effectively regulate and inhibit ice crystals, reduce freezing damage, and improve cryopreservation efficiency is a critical scientific problem that needs to be addressed in the current cryopreservation field. In this paper, a series of PVA grafted single-layer graphite oxide (PVA-g-GO nanocomposites) with different degrees of polymerization and different proportions was ingeniously engineered by a one-step esterification reaction method to study their ice crystal control effect. The obtained PVA17-g-GO nanocomposite could effectively reduce the ice crystal size during the recrystallization process at low concentration by adsorption and lattice matching. The nanocomposite with a 10:1 mass ratio of PVA and GO exhibited the best ice control effect, which could reduce the ice crystal size to only 17 % of that of pure water. Surprisingly, the modification of PVA significantly enhanced the absorption value of GO in Visible and Near-Infrared light (380 nm–980 nm), giving it excellent photothermal conversion efficiency (39.7 %), accelerating ice thawing rate, and thus synergistically reducing the mechanical damage caused by ice recrystallization. Finally, using the prepared PVA17-g-GO as cryoprotectants (CPA), the cryopreservation experiments on Hela cells and A549 cells demonstrated that this material at low concentration of 20 μg/ml could achieve high cell survival efficiency (>85 %). The preparation and development of this efficient ice-recrystallization-inhibiting nanomaterial with bidirectional synergy can provide new ideas and methods for the safety and progress of current cryopreservation technology.

Ice crystal recrystallization inhibition of type I antifreeze protein, type III antifreeze protein, and antifreeze glycoprotein: effects of AF(G)Ps concentration and heat treatment.

This study compared ice recrystallization behaviors of frozen dessert model systems containing type I antifreeze protein (AFP I), type III antifreeze protein (AFP III), and antifreeze glycoprotein (AFGP) at -10 °C. Specifically, effects of AF(G)P concentration and heat treatment (95 °C for 10 min) were examined. The concentration dependence of the ice recrystallization rate constant reasonably well fit a sigmoidal function: the fitting procedure was proposed, along with cooperative coefficient α,and a new index of AF(G)P ice recrystallization inhibition (IRI) activity (C50). After 95 °C heat treatment for 10 min, AFP III lost its ice crystal recrystallization inhibitory activity the most: AFP I was less affected; AFGP was almost entirely unaffected. These different thermal treatment effects might reflect a lower degree of protein aggregation because of hydrophobic interaction after heat treatment or might reflect the simplicity and flexibility of the higher order structures of AFP I and AFGP.

The drip loss inhibitory mechanism of nanowarming in jumbo squid (Dosidicus gigas) mantles: protein structure and molecular dynamics simulation.

The magnetic nanoparticles plus microwave thawing (MNPMT), a new rewarming technology entitled 'nanowarming', can serve as an effective method to achieve rapid and uniform thawing, thus reducing drip loss. The purpose of this study was to decipher the drip loss inhibitory mechanism of MNPMT in jumbo squid (Dosidicus gigas) from the perspectives of protein structure and ice crystal recrystallization. A number of different techniques such as dynamic rheology, Raman spectra, intrinsic fluorescence measurement, and ultraviolet (UV) absorption spectra were conducted to analyze myofibrillar protein conformation and stability of jumbo squid. Scanning electron microscopy (SEM) and myofibrillar fragmentation index (MFI) were used to observe the growth of ice crystals. The interaction between magnetic nanoparticles (MNPs) and ice crystals was studied by using molecular dynamic (MD) simulation. MNPMT exhibited the highest storage modulus (G') value at 90 °C, suggesting the protein conformation was more stable. The increase in α-helices, fluorescence intensity and characteristic absorption peak of MNPMT illustrated that MNPMT can effectively maintain the secondary and tertiary structure of the protein. Compared with cold storage thawing (CST) and microwave thawing (MT), the MFI value of MNPMT was significantly decreased (P < 0.01). The result of MD simulation showed that MNPs displayed a tendency to gradually approach the surface of ice crystals, and induced a certain degree of damage to the ice crystal surface, thereby markedly inhibiting ice crystal recrystallization. MNPMT can reduce the drip loss by keeping the protein conformation stable and inhibiting the recrystallization of ice crystals during the thawing process. © 2022 Society of Chemical Industry.

Cryoprotective effect of wheat gluten enzymatic hydrolysate on fermentation properties of frozen dough

This study investigated the antifreeze activities and structures of wheat gluten enzymatic hydrolysates at different degrees of hydrolysis and studied the cryoprotective effects of the hydrolysate with the highest antifreeze activity on fermentation properties of frozen dough. We found that the hydrolysate with an enzymolysis time of 90 min had the highest thermal hysteresis value (0.46 °C) and significantly inhibited growth and recrystallization of ice crystals. This might be due to the differences in molecular weight, amino acid composition, secondary structures, and surface hydrophobicity of the hydrolysates. Peptides with a molecular weight of 500–2000 Da accounted for 41.5% of the hydrolysate at 90 min, and this hydrolysate had greater levels of alanine, leucine, glycine, and glutamic acid residues, β-sheet conformation, and surface hydrophobicity than other hydrolysates. Furthermore, fermentation results indicated that the optimum condition for the highest active hydrolysates to protect frozen dough was 0.5% relative to the flour amount, and 0.5% hydrolysate enhanced the fermentation capacity of the frozen dough. Accordingly, wheat gluten enzymatic hydrolysate hydrolyzed for 90 min can protect dough from damage caused by repeated freezing–thawing. This study offers new insights into the preparation of antifreeze peptides and the use of wheat gluten.

Effects of Ultrasound-Assisted Vacuum Impregnation Antifreeze Protein on the Water-Holding Capacity and Texture Properties of the Yesso Scallop Adductor Muscle during Freeze–Thaw Cycles

The effect of antifreeze protein (AFP) on the water-holding capacity (WHC) and texture properties of the Patinopecten yessoensis adductor muscles during freeze–thaw cycles (FTCs) were evaluated based on three impregnation methods: general impregnation (GI), vacuum impregnation (VI), and ultrasound-assisted VI (US-VI). The WHC, texture properties, and tissue microstructure were all evaluated. Results showed that the WHC and texture properties of adductor muscle were significantly improved in the VI and US-VI groups during FTCs (p < 0.05). The WHC of the adductor muscle in the US-VI group was maximally enhanced in terms of yield (6.63%), centrifugal loss, cooking loss, and T22. The US-VI group of the adductor muscle had the optimal chewiness and springiness compared to others, and the shear force and hardness were most effectively enhanced by VI. The growth and recrystallization of ice crystals in the frozen adductor muscle were significantly inhibited by VI and US-VI. The average cross-sectional area and roundness of ice crystals in the US-VI group were decreased by 61.89% and increased by 22.22% compared with those of the control, respectively. The partial least squares regression (PLSR) model further confirmed that the WHC and texture properties of the adductor muscle were correlated appreciably with the degree of modification of ice crystal morphology through the AFP.

Effects of different storage temperatures on the structure and physicochemical properties of starch in frozen non-fermented dough

This study investigated the effects of different storage temperatures on the structure and physicochemical properties of starch in frozen nonfermented dough. The results showed that the water activity and water loss rate of dough samples decreased with decreasing storage temperature. The density of hydrogen protons in the dough sample decreased as well. The freezable water content in dough increased with decreasing freezing temperature. The results showed that with decreasing freezing temperature, the formation and recrystallization of ice crystals in the process of freezing storage resulted in an increase in depressions and holes in wheat starch grains, internal and external damage to starch, and a gradual decrease in the relative crystallinity. The porous surface of starch particles and their loose molecular order structure promote the infiltration of water molecules into the interior of the starch particles. The combination of starch chain and water molecules makes the peak viscosity of starch in the dough gradually rise, but diminishes its stability when heated. Compared with the control group, the starch recovery value increased, and the starch enthalpy value increased gradually. The structure and physicochemical properties of starch in nonfermented dough stored at -12 °C and -18 °C were similar.

Investigation of the cryoprotective mechanism and effect on quality characteristics of surimi during freezing storage by antifreeze peptides

Freezing technology is important for storage of animal products such as surimi. However, mechanical damage caused by ice crystals would lead to quality deterioration. This study aims to investigate the protective effect of antifreeze peptides (AFPs) on the quality of surimi during freezing storage and its possible mechanism. We found that AFPs exhibited a strong inhibition of ice crystal recrystallization, and the molecular weight ranged from 180 to 3000 Da. AFPs can prevent the degeneration of myofibrillar protein by reducing the loss of Ca2+-ATPase activity, slowing oxidation of sulfhydryl groups to disulfide bonds, and maintaining surface hydrophobicity and solubility of myofibrillar protein. Moreover, AFPs can reduce the influence of freezing stress on water mobility, thereby protecting the surimi from losing immobilized water and bound water during frozen storage. These findings indicate that AFPs could potentially serve as a food ingredient with antifreeze functional for the storage of surimi products.

Strong Hydration Ability of Silk Fibroin Suppresses Formation and Recrystallization of Ice Crystals During Cryopreservation.

The cryopreservation (CP) of cell/tissue is indispensable in medical science. However, the formation of ice during cooling and ice recrystallization/growth in time of thawing present significant risk of cell/tissue damage upon analysis of CP process. Herein, the natural and biocompatible silk fibroin (SF) with regular hydrophobic and hydrophilic domains, were first employed as a cryoprotectant (CPA), to the CP of human bone-derived mesenchymal stem cells (hBMSCs), which has been routinely cyropreserved for cell-based therapies. Addtion of SF can regulate the formation of ice crystals during cooling process because of its strong hydration ability in the comparation to the cryopreservation medium (CM) without SF. Moreover, the devitrification-induced recrystallization/growth of ice during the thawing process is suppressed. Most importantly, the addition of 10 mg mL-1 SF can achieve 81.28% cell viability of cryopreserved hBMSCs as similar as those with the addition of 180 mg mL-1 Ficoll 70 (commercial CPA), and the functions of the cryopreserved hBMSCs are maintained as good as that of the fresh ones. This work is not only significant for meeting the ever-increasing demand of cell therapy, but also trailblazing for designing materials in controlling ice formation and growth during the CP of other cells and tissues.

Ice Inhibition for Cryopreservation: Materials, Strategies, and Challenges.

Cryopreservation technology has developed into a fundamental and important supporting method for biomedical applications such as cell‐based therapeutics, tissue engineering, assisted reproduction, and vaccine storage. The formation, growth, and recrystallization of ice crystals are the major limitations in cell/tissue/organ cryopreservation, and cause fatal cryoinjury to cryopreserved biological samples. Flourishing anti‐icing materials and strategies can effectively regulate and suppress ice crystals, thus reducing ice damage and promoting cryopreservation efficiency. This review first describes the basic ice cryodamage mechanisms in the cryopreservation process. The recent development of chemical ice‐inhibition molecules, including cryoprotectant, antifreeze protein, synthetic polymer, nanomaterial, and hydrogel, and their applications in cryopreservation are summarized. The advanced engineering strategies, including trehalose delivery, cell encapsulation, and bioinspired structure design for ice inhibition, are further discussed. Furthermore, external physical field technologies used for inhibiting ice crystals in both the cooling and thawing processes are systematically reviewed. Finally, the current challenges and future perspectives in the field of ice inhibition for high‐efficiency cryopreservation are proposed.

Recrystallization of Ice Crystals in Sucrose Solution Containing Sodium Alginate and Its Relationship to Dynamic State of Freeze-concentrated Matrix Evaluated by Dielectric Relaxation Measurement

Recrystallization of Ice Crystals in Sucrose Solution Containing Sodium Alginate and Its Relationship to Dynamic State of Freeze-concentrated Matrix Evaluated by Dielectric Relaxation Measurement

Effects of nanowarming on water holding capacity, oxidation and protein conformation changes in jumbo squid (Dosidicus gigas) mantles

To study the effects of nanowarming on the water holding capacity (WHC), oxidation, and protein conformation of jumbo squid mantles, jumbo squid mantles were subjected to cold storage thawing (CST), microwave thawing (MT), and magnetic nanoparticles plus microwave thawing (MNPMT). Thawing loss, centrifugal loss and low-field nuclear magnetic resonance (LF-NMR) were used to study WHC. Carbonyl content, total sulfhydrylcontent and dityrosine content were carrid out to observe protein oxidation. Protein solubility, particle size and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were conducted to analyze protein denaturation and aggregation. Raman spectra before and after isotope H/D exchange illustrated changes in protein structure. Optical microscopy showed that MNPMT can inhibit the recrystallization of ice crystals during thawing, making the jumbo squid fiber structure more compact. Compared with CST and MT, MNPMT can reduce protein oxidation and lipid oxidation during thawing, reducing the damage of ice crystals to muscle fibers and improving WHC. This study showed that the MNPMT is an effective method to achieve high thawing rate and the uniformity of temperature rewarming for frozen jumbo squid, and provided a theoretical basis for exploration of nanowarming techniques in the food industry.

Property changes of frozen soybean curd during frozen storage in “Kori-tofu” manufacturing process

It is generally accepted that the microstructure of frozen food changes even in freeze-storage due to the recrystallization of ice crystals. Kori-tofu is a traditional processed food in Japan, which is made from soybean curds availing refrigeration techniques to add an elastic texture. The elastic texture of soy bean curds which is Kori-tofu materials occurs during frozen-storage under subzero temperature, however, these mechanism have not clear. In this study, aiming to discuss the mechanism of the hard texture arising in soy bean curds during the freeze storage periods, characteristics changes in soy bean curds during frozen storage period such as texture, water holding capacity, ice crystal and frozen concentrated phase were investigated with time. In addition, how a character of soy protein changes was examined. The result indicated that the change in the balance of hydrophilic and hydrophobic region induced by dehydration with ice recrystallization at first stage of storage plays an important role in forming the new protein-protein interaction especially for amphipathic protein as α and α′subunit of β-conglycinin.

Analysis of protective mechanism of silk protein based cryoprotectants

Dimethyl sulfoxide (Me 2SO) supplemented with fetal bovine serum (FBS) is a widely used cryoprotectant combination. However, high concentration of Me 2SO is toxic to cells, and FBS presents problems related to diseases such as bovine spongiform encephalopathy and viral infections. Silk protein is a kind of natural macromolecule fiber protein with good biocompatibility and hydrophilicity. The aim of this paper is to analyze the cryoprotective mechanism of silk protein as cryoprotectant. Firstly, differential scanning calorimetry (DSC) was used to measure the thermal hysteresis activity (THA) of silk protein. The THA of 10 mg/mL sericin protein was 0.96°C, and the THA of 10% (V/V) fibroin protein was 1.15°C. Then the ice recrystallization inhibition (IRI) of silk protein-PBS solution was observed with cryomicroscope. The cold stage was set at - 7°C, after 40 minutes' incubation, the mean grain size rate (MGSR) of sericin protein and fibroin protein were 28.99% and 3.18%, respectively, which were calculated relative to phosphate buffer saline (PBS) control. It is indicated that sericin and silk fibroin have certain effects of inhibiting recrystallization of ice crystals. Finally, the structure and physicochemical properties of silk protein were analyzed by Fourier transform infrared spectroscopy (FTIR). The results showed that the content of the random coil was 75.62% and the β-sheet structure was 24.38% in the secondary of sericin protein. The content of the β-sheet structure was 56.68%, followed by random coil structure 22.38%, and α-helix 16.84% in the secondary of fibroin protein. The above analysis demonstrates the feasibility of silk fibroin as a cryoprotectant, and provides a new idea for the selection of cryoprotectants in the future.

Influence of temperature fluctuations on growth and recrystallization of ice crystals in frozen peeled shrimp (Litopenaeus vannamei) pre-soaked with carrageenan oligosaccharide and xylooligosaccharide

Temperature fluctuation is a common problem in the frozen storage of shrimp products. This study investigated the influence of carrageenan oligosaccharide (CO) and xylooligosaccharide (XO) on the growth and recrystallization of ice crystals in frozen peeled shrimp exposed to temperature fluctuations. Shrimp soaked with water and 3.0% (w/v) Na4P2O7 solution were designated as the negative and positive controls, respectively. Our data revealed that both CO- and XO-soaked shrimp had significant improvements in thawing and cooking loss, myofibrillar protein content, Ca2+-ATPase activity, and textural variables when exposed to temperature fluctuations compared to control samples. Microstructural imaging indicated that soaking the shrimp in CO and XO slowed the progression of damage caused to tissue myofibrils by large ice crystals, as well as inhibited the growth and recrystallization of ice crystals in muscle tissues. SDS-PAGE analysis confirmed that treatment with the oligosaccharides exhibited marked effects on the stability of muscle proteins and inhibited the degradation of muscle proteins affected by the temperature fluctuations. Based on these data, we hypothesize that the incorporated CO and XO may bind to muscle proteins and capture water molecules in the myofibrillar network through hydrogen bonding, thereby suppressing the myofibrillar denaturation and tissue structure destruction induced by the growth and recrystallization of ice crystals.

Bioinspired Ice Growth Inhibitors Based on Self-Assembling Peptides.

Antifreeze proteins (AFPs) are widely found in organisms living in subzero environments. Their strong ability to inhibit ice growth and recrystallization have inspired considerable bioinspired efforts to engineer artificial ice growth inhibitors for cryopreservation. However, it remains challenging to engineer biocompatible and cost-effective synthetic ice growth inhibitors to meet the increasing needs of cryoprotectants in biomedical research and industry. Here we report the design of artificial ice growth inhibitors based on self-assembling peptides. We demonstrate the importance of threonine residues as well as their spatial arrangement for effective ice binding. The engineered self-assembling ice growth inhibiting peptides show moderate ice inhibiting activity including suppression of ice growth rates and retardation of recrystallization of ice crystals. The applications of these peptides in cryopreservation of enzymes and cells were also demonstrated.

Evaluation of the antifreeze effects and its related mechanism of sericin peptides on the frozen dough of steamed potato bread

This study investigated the effects of sericin peptides (SPs) on frozen potato dough with trehalose as a reference. The results found that SPs decreased freezable water content in frozen dough and increased yeast survival ratio significantly after 4-week frozen storage. Additionally, compared with control group and frozen dough containing 5% of trehalose, frozen dough with 5% of SPs showed less starch granule separation and more complete gluten membrane during 8-week storage. Specific volume of the frozen dough with 5% of SPs decreased by 6.3%, significantly lower than the control and reference groups. Furthermore, compared with trehalose, SPs effectively decreased the hardness and gumminess of steamed potato breads, as well as enhanced their resilience. The quality improvement of frozen potato dough with SPs could be attributed to ideal structural matching, hydrogen bonds, and non-bond interactions between sericin peptides and ice surface, as well as the inhibition of the formation and recrystallization of ice crystals. Practical applications Frozen dough method is widely used in baked flour products, providing fresh, safe, consistent quality products and simplifies the manufacturing process. However, the overall quality of frozen dough decreased gradually during frozen storage. Traditional antifreezes (trehalose and sorbitol) have high calories, which are not conducive to diabetics and obese patients. Therefore, it is essentially important to find a new and efficient antifreeze to replace traditional antifreezes. SPs, the hydrolysate of sericin, exhibited a strong cryoprotection and antifreeze activity according to this study. We can expect a potential application of SPs in cell protection and food preservation.