Chicken collagen hydrolysate cryoprotection of natural actomyosin: Mechanism studies during freeze-thaw cycles and simulated digestion

The cryoprotective effect of chicken collagen hydrolysate (CCH) obtained from chicken skin was investigated at 0%, 4%, 8% and 12% (w/w) on natural actomyosin (NAM) model system to elucidate the possible mechanism. Ice dimensions in the NAM dispersions were measured after 7 thermal cycles (stabilized at −20 °C and cycled between −16 °C to −12 °C) using a polarized microscope, demonstrating a significant reduction of ice crystal size induced by CCH. To determine the ice-controlling effect of CCH on protein freeze-denaturation, NAM samples were subjected to 7 freeze-thaw cycles between −20 °C and 4 °C. The results suggest that the presence of CCH can inhibit the ice crystals growth in NAM to reduce protein freeze-denaturation and oxidation similarly to the commercial cryoprotectants, resulting in higher protein solubility and a better gel structure with higher digestibility after freeze-thaw cycles.