Study on properties of boneprotein hydrolyzate and konjac and their applications as antifreeze in frozen carp surimi

Konjac gel experiments and antioxidant properties of bone protein hydrolyzate experiment to determine the optimum use amount of high antioxidant activity of the bone protein hydrolyzate and the high gel konjac were 4% and 0.5%, respectively. As the same time, compounding boneprotein hydrolysates and konjac as cryoprotectant was compared with commercial cryoprotecta nts. The water holding capacity (WHC) (cooking loss, thawing loss) , thiobarbituric acid reactive substances ( TBARS) of carp surimi and the gel properties (hardness, spring, WHC, whiteness) of surimi protein were measured to study protective effect on frozen surimi (-18℃, 180d) with the compounding group. Results indicated that the cooking loss, thawing loss, TBARS and carbonyl content of compounding group decreased by 62.71%, 50.25%, 71.83%, 36.51% at the end of the storage compared to the control groups. While the hardness, spring, WHC and whiteness of protein gel increased by 52.80%, 42.19%, 10.67%, 12.88%, and the indicators increased 15.79%, 6.45%, 36.17%, 10.00%, 14.78%, 14.55%, 3.55%, 4.84% compared to the commercial cryoprotectants group (p<0.05) , respectively. The results demonstrated that compounding boneprotein hydrolysates and konjac could inhibit fat oxidation, prevent protein denaturation by frozen sorage, and improve WHC, gel strength of surimi significantly. The best formula of the frozen surimi cryoprotectants was 4% bone protein hydrolyzate, 0.5% konjac.