Study On Antioxdation Peptides Of Hydrolysates From Hen Egg Ovalbumin

The hen egg is an important source of dietary nutrients for human beings, containing all of the proteins, lipids, vitamins, minerals and growth factors required by the developing embryo. The majority of proteins exist in egg yolk and egg white, and the species and contents of egg white proteins are the most abundant. Ovalbumin is the major protein, makes up 54% of the total egg proteins, and is a source of bioactivity peptides. In this study, our objective was to investigate hydrolysis parameter of ovalbumin, antioxidative activity of hydrolysates, and the separation and analysis of antioxidative peptides using enzyme hydrolysis, antioxdative activity assay, ion- exchang chromatography, RP-HPLC and ESI-MS/MS. Our results laid a theoretical foundation for the development and utilization of egg antioxidative peptides.1. A simple rapid procedure of preparation for highly purified ovalbumin from heg egg white was obtained. Q-Sepharose FF ion-exchange chromatography was used to separate and purify ovalbumin. The results showed that ovomucin could be precipitated to remove from egg white with the condition of egg white/water 1/2 (v/v), pH 6.0.The separation technologies of ovalbumin by 40mL Q-Sepharose FF column were loading volume 140mL of egg white, elution with NaCl(0.15 mol/L, pH 8.0) and 1058mg of ovalbumin was extracted, with 55% of recovery rate and 92% of. purity rate.2. The antioxidation effects of ovalbumin hydrolysates obtained by pepsin, trypsin and chymotrypsin were studied with hydroxy1 radical (HO·) scavenging activity as the criterion and the results showed that the pepsin hydrolysate presented rather more scavenging activity against hydroxyl radical (HO·) than the other two enzymatic hydrolysates.3. When hydroxyl radical scavenging activity of hydrolysates was more then 40%, the optimum technologies of hydrolysis were set up with response surface methodology (RSM) and they were substrate concentration 2.22%-3.76%, enzyme concentration 8738.24U-11176.63U/g·pro, hydrolyxing time 4.05-7.77 h.4. Multi-methods of antioxidation trials were firstly used to assay the antioxidation activity of hen egg ovalbumin hydrolysates. The test results in vitro indicated that hydrolysates had a distinctly inhibitory action to superoxide anion (O^-_2|·) made by...