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.