Casein phosphopeptide as a high-performance cryoprotectant in frozen dough: Ice inhibition behaviors, stabilized...

Phosphate-type cryoprotectants, such as sodium tripolyphosphate (STPP), are economical and widely used for maintaining frozen food qualities. Despite the superior cryoprotective efficiency, their applications also raise increasing health concerns. To circumvent this dilemma, a clean-label and high-performance phosphopeptide alternative, casein phosphopeptide (CPP), was developed and systematically characterized in this study. The prepared CPP exhibited strong ice recrystallization inhibition activity and thermal hysteresis activity, reducing final ice crystal size by 58.3 % and lowering the crystallization temperature by 0.77 °C. When incorporated into frozen dough (0.5-3 %), CPP exhibited a dose-dependent cryoprotective effect, which even outperformed the conventional phosphate additive, STPP at the same usage levels. Treated dough exhibited obviously stabilized gluten network, secondary structures, disulfide bonding, reduced water migrations, and enhanced baking performance. Consequently, breads prepared from CPP-treated dough showed significantly improved quality attributes, including increased specific volume (from 3.86 to 4.53 mL/g), reduced hardness (from 606.63 to 413.92 g), and lower baking loss (from 10.55 % to 8.14 %). Our work establishes food-derived phosphopeptides as a new class of potent cryoprotectants for clean-label food innovations.