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[Display omitted] • Chickpea protein hydrolysate (CPH) can reduce deteriorations of frozen surimi. • CPH exhibited both thermal hysteresis and antioxidant activities. • Denaturation of myofibril protein was inhibited during freeze–thaw cycling. • Gelling properties of CPH-protected frozen surimi were also enhanced. Chickpea protein (CP) and its enzymatic hydrolysates are one of the most widely consumed pulse ingredients manifesting versatile applications in food industry, such as binders, emulsifiers, and meat protein substitutes. Other than those well-known functionalities, however, the use of CP as a cryoprotectant remained unexplored. In this study, we prepared the chickpea protein hydrolysate (CPH) and investigated its cryoprotective effects to frozen surimi in terms of the protein structure integrity and gelling behaviors. Results indicated that CPH could inhibit myofibrillar protein (MP) denaturation and oxidation during the freeze–thaw cycling, as evidenced by their increased solubility, Ca2+-ATPase activity, sulfhydryl concentration, and declined content of disulfide bonds, carbonyl concentration and surface hydrophobicity. Freezing-induced changes on MP secondary structures were also retarded. Moreover, gels prepared from CPH-protected frozen surimi demonstrated more stabilized microstructure, uniform water distribution, enhanced elasticity, gel strength and water holding capacity. The CPH alone, at a reducing addition content of 4% (w/w), exhibited comparable cryoprotective performance to that of the commercial formulation (4% sucrose and 4% sorbitol). Therefore, this study provides scientific insights for development of pulse proteins as novel and high-performance food cryoprotectants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chickpea protein hydrolysate optimized the quality of frozen dough. • Chickpea protein hydrolysate enhanced viability of yeasts under freeze–thaw stress. • Metabolomics reveals a role for alterations of yeast intracellular metabolites. • Chickpea protein hydrolysate is a novel cryoprotectant for industrial yeasts. The use of frozen dough is an intensive food-processing practice that contributes to the development of chain operations in the bakery industry. However, the fermentation activity of yeasts in frozen dough can be severely damaged by freeze–thaw stress, thereby degrading the final bread quality. In this study, chickpea protein hydrolysate significantly improved the quality of steamed bread made from frozen dough while enhancing the yeast survival rate and maintaining yeast cell structural integrity under freeze–thaw stress. The mechanism underlying this protective role of chickpea protein hydrolysate was further investigated by untargeted metabolomics analysis, which suggested that chickpea protein hydrolysate altered the intracellular metabolites associated with central carbon metabolism, amino acid synthesis, and lipid metabolism to improve yeast cell freeze–thaw tolerance. Therefore, chickpea protein hydrolysate is a promising natural antifreeze component for yeast cryopreservation in the frozen dough industry. [ABSTRACT FROM AUTHOR]