Isolation of ice structuring collagen peptide by ice affinity adsorption, its ice-binding mechanism and breadmaking performance in frozen dough

Ice structuring collagen peptides (ISCPs) from porcine skin collagen hydrolysates were isolated by an affinity adsorption system, and then its antifreeze and cryoprotection activity, ice-binding mechanism and making performance of steamed bread were investigated. The results showed ISCPs with maximal thermal hysteresis activity (2.76°C) were obtained with a collagen hydrolysate concentration of 1 mg/mL, adsorption time of 10 hr and adsorption temperature of −5°C during the second round of adsorption. After purification, MS spectrum analyzed one of the ISCPs and inferred to be GLLGPLGPRGLL with a molecular weight of 1163.8 Da. The binding of ISCP to ice could be attributed to the structural match and hydrogen bond formation between ice surface and the ISCP. Compared with the control group, the baking and textural characteristics of frozen dough were significantly improved by ISCP at an addition concentration of 0.3% (wt/vol) after 4 weeks frozen storage. Practical applications Porcine skin represents a problematic by-product in meat manufacturing industry due to its high pollutant load, and it is usually discarded as waste or used for low value purposes. In order to find potential applications for this by-product, ISCPs from porcine skin hydrolysates were isolated by an affinity adsorption system. The result demonstrated that ISCPs exhibited a strong antifreeze and cryoprotection activity, and had a potential application in food preservation and cryo-protection of cells and tissues.