The Study Of Isolation And Purification Angiotensin Converting Enzyme Inhibitor Peptide From Hydrolysis Chiken Egg Yolk Protein

Egg yolk antihypertensin peptide was prepared by hydrolyzing chiken eggyolk protein with alkali protease which has obviously antihypertensin functionin vitro. A series of isolated procedures are used to get active pepetides in thepurifying process. The research can give referrence to make the most of the eggprotein, raising the egg using value, accelarateing agriculture resource efficiencyused.Studing the discoloration of hydrolysis solution and finding out when 1.5%activated carbon was put to hydrolysis solution at 40℃with pH4.0 and decolou-rate 40minnutes. The discoloration ratio can get 83% and pepetide loss ratio is5.6%.The molecular weight 3.5kDa and 10kDa ultrafication membranes was us-ed to filter the discoloration hydrolysis solution, the result showed that the ope-rating pressure is kept at 0.3MPa,the temperature is kept at 40℃and 30℃and atthe 6% hydrolysate concentration of protein. The Jv of the two kinds of memb-rane can achieve 19 L·m^-2·h^-1and1.3 L·m^-2·h^-1.By measuring the different mole-cular weight peptide inhibitory to the ACE active,it was showed that the stron- gest inhibitory active peptide molecular weight are less than 3.5kDa and inhibit-tory ratio is 51.3%.The molecular less than 3.5kDa filter solution was isolatated with the ion-exchange and Sephadex Gel-15. The D61 resin can has better isolation effects atthe temperature 35℃, initial quality(protein's quality/wet resin volume) at 10mg·mL^-1, velocity at 0.5 mL·min^-1, liquid concentration at 1 mol·L^-1 NaCl andwith buffer liquid at pH4.1 acetic sodium solution.The peptides total yeild ratioget 82.4% and the inhibitory ratio get 62.7%. The pulling off peak was isolatedfive peaks with the Gel-15 at the 1.0 mL·min^-1 follow velocity, the acetic ammo-nia buffer liquid's concentration at 0.1 mol·L^-1 and initial concentration at 40mg·mL^-1. the fifth peak have the strongest inhibitory to ACE. the total yield over90% can be reached. The fifth peak's sample was injected the RP-HPLC experi-ment equipment,it can be separated into twelve components. 5^#-a-a2 has theactive inhibitory to ACE and it's HPLC purity can reach 96%.The maginifyingexperiment result show that the enzyme hydrolysate yield ratios can reach 81%;the ultrafication yield over 76.8% can be got; peptides yeild get 68.8% withGel-15 isolation.The antioxidate experiments showed that ACEI have the simulate effects asthe contrast at 2.5%(w/v) lipin concentration and at 0.02%(w/v) ACEIconcentration.