Structure Characterization And Antioxidant Activity Of Polypeptide Mineral Chelate From Yanbian Yellow Cattle Bone

Yanbian yellow cattle,produced in Yanbian Korean Autonomous Prefecture,was a Korean characteristic of high-quality beef breeds.Research has shown that cattle bone is rich in fats,proteins,minerals and other essential nutrients for human body.In this study,Yanbian yellow cattle bone was used as raw material to extract protein.After screening by protease,albumin polypeptide and globulin polypeptide were prepared.Then the peptides were chelated with minerals(calcium,ferrous)to characterize them.Finally,the antioxidant activity of polypeptide mineral chelate was studied.The main research contents are as follows:(1)The Osborne method was used to classify the bone protein of Yanbian yellow cattle.Albumin content was 20.0±1.2 mg/g;globulin content was 10.0±3.0mg/g;glycolin content was 7.0±1.0 mg/g;alkali-soluble protein content was 8.0±3.0mg/g.Albumin polypeptide(AP)was obtained by enzymatic hydrolysis with a hydrolysis degree of 33.12%.Globulin polypeptides(GP)were prepared with a hydrolysis degree of 18.78%.(2)Yanbian yellow cattle bone AP and GP were chelated with calcium and iron ions respectively.The chelating rate of Albumin polypeptide chelating calcium(AP-Ca)was 27.65%and the yield was 23.99%.The chelating rate of Albumin polypeptide chelating ferrous(AP-Fe)was 34.78%and the yield was41.65%.The chelating rate of Globulin polypeptides chelating calcium(GP-Ca)was 24.78%and the yield was 21.03%.The chelating rate of Globulin polypeptides chelating ferrous(GP-Fe)was 29.89%and the yield was 33.50%.(3)By Fourier infrared spectroscopy analysis,the results showed that the absorption peaks of chelated ferrous and calcium appeared the phenomena of blue shift,red shift and disappear,and the polypeptide chelated with calcium and ferrous.Scanning electron microscope analysis showed that the structure of peptide-chelated iron was more denser than peptide-chelated calcium,there are spherical calcium crystals and iron crystals on the surface.Through automatic amino acid analysis,the amino acid nutritional value after chelation was similar to that before chelation.The particle size before chelation was smaller than that after chelating by laser particle size analyzer.(4)The ABTS~+·,DPPH·,hydroxyl radical scavenging ability,iron ion reducing ability and total oxygen radical trapping antioxidant parameter(TRAP)of AP-Ca,AP-Fe,GP-Ca and GP-Fe were determined.The results showed that the antioxidant activity of peptides after chelating with minerals was higher than before.The antioxidant activity of AP-Fe and GP-Fe was higher than that of AP-Ca and GP-Ca,and the antioxidant activity of AP-Fe was lower than that of GP-Fe.In conclusion,the AP and GP of Yanbian yellow cattle bone have good chelating degree with calcium and ferrous ion,and have certain antioxidant activity.It shows the bone of Yanbian yellow cattle has a good development prospect as a by-product.