Study On Enzymatic Preparation Of Bone Collagen Peptides And Effects On Antioxidant Capacity And Calcium Utilization Of Mice

In this research, Alcalase protease was chosen to hydrolyze pig bone collagen to prepare antioxidative peptides. The effects of bone collagen peptides (BCP) and fish skin collagen peptides (FCP) on the antioxidant capacity, serum lipid metabolism and calcium utilization of mice fed with high-fat diet were investigated.Bone collagen was hydrolyzed by Alcalase protease and neutral protease separately. According to the free radicals scavenging capacity of the hydrolysate, Alcalase protease was chosen as the optimal protease to prepare BCP through single factor test and orthogonal test. The hydrolysate had the strongest antioxidant activities under the hydrolytic conditions of pH 8.0, temperature 55℃, substrate concentration 4%, enzyme/substrate 3135 U/g and duration 3 h. Free radicals scavenging rates of the hydrolysate on DPPH·,·OH and ABTS·were 78.39%, 84.87% and 55.55%, respectively.144 male KM mice were randomly divided into 9 groups, which were fed with basal diet, high-fat diet, high-fat-calcium diet, high-fat diet with 0.1% lipoic acid (LA), 1% BCP and 1% FCP and high-fat-calcium diet with 0.1% LA, 1% BCP and 1% FCP, respectively. After 6 weeks, 8 mice of each group were killed to determine antioxidant capacity and serum lipid level. The remained mice were fed to 10 weeks to study calcium utilization situation through calcium metabolic experiment. All mice were killed to determine the redox state, parathyroid hormone (PTH) and calcitonin (CT) contents in serum, bone density, bone strength and bone calcium contents were assayed after 12 weeks. The results showed that 1% BCP and 0.1% LA both could effectively enhance antioxidant capacity, which not only significantly reinforced bone quality, but also remarkably regulated serum lipid metabolism. These effects were much better than high-fat diet groups with 0.1% FCP.BCP could effectively inhibit oxidative stress caused by high-fat diet and enhance antioxidant capacity, which could improve calcium utilization capacity and bone quality.