Preparation And Characterization Of Zinc-high-chelating Activity Of Caseinphosphate

Zinc is very important for human health,zinc deficiency lead to various diseases,and casein is a kind of polypeptide zinc ion absorption promoting activity,can be called chelating CPP chelated zinc,zinc as an agent.At present the market common zinc preparations such as zinc sulfate and other inorganic zinc salt,compared with casein phosphopeptide chelated zinc and other new generation of peptide zinc chelate zinc,although the source of low cost,easy to obtain,but stimulation degree is high,high toxicity and low bioavailability.Therefore,in this study,Casein Phosphopeptides(CPPs),which have zinc chelating activity,can be developed as a new generation of organic zinc supplements.The alkaline protease hydrolyzing casein phosphopeptides obtained as raw materials,by Q Sepharose FF anion exchange chromatography and RP-HPLC two step separation from CPPs,In pH 7,CPPs was chelated with the zinc source material at 4:1,60℃,and 80 min reaction conditions molecular weight 10 kd,chelating activity was 88.68μg/mg.The purified compared with crude peptide,zinc binding capacity increased by 10 times.With the above two casein phosphopeptide purification to obtain a high zinc chelating activity as raw materials,by comparison before and after chelating amino acid analysis,using UV spectra,IR spectra and NMR 13 C spectrum,1H spectrum,31 P spectrum analysis,the results show that the chelating structure and amino acid composition before and after CPPs was changed significantly.One of the phosphate groups involved in chelation,the main binding site is-COOH,-NH2 and P-OH in-OH.Simulated gastrointestinal environment in vitro,effects of casein phosphopeptide chelated zinc bioavailability(solubility and dialysis degrees),with zinc gluconate and Zn SO4,the CPP chelated zinc with high biological activity;acidification of casein phosphopeptide chelate zinc dependent on gastric acid can slow the release of Zn2+.Relative to the rapid release of ZnSO4 and zinc gluconate can reduce the stimulation of the stomach;in phytic acid and dietary fiber on the digestive process of zinc absorption under the influence of casein phosphopeptide chelated zinc has high bioavailability,higher than that of ZnSO4 and zinc gluconate,zinc supplements are ideal.Casein peptide zinc chelate is a good carrier for absorption and transportation of zinc in the process of simulating gastrointestinal digestion.