Preparation Of Decreasing Blood Pressure Peptides From Whey And Study On The Function

Whey is the production of produce cheese and casein, whey is very nutrient and contain alots offunctionality component. Active peptides from whey protein have the actively of the angiotensinâ… converting enzyme(ACE) inhibitory activity, thrombus inhibitory activety and so on, become the hotresearch field these years. This thesis mainly study whey protein on composite enzymes hydrolysis,purification and effect test.This thesis preparation decreasing blood pressure peptides from whey protein by compositeenzymes hydrolysis. The optimal conditions of composite enzymic hydrolysis technology by thesingle factor experiment and the orthogonal design. Research the effect to ACE inhibitory ratio andhydroxyl ratio(DH) with different [E/S], temperature and [E₁/E₂](alcalase: trypsin). By the threelevel and three case experiment found the best condition of composite enzymes hydrolysis, and thebest condition of composite enzymes hydrolysis is: [E/S] is 5%, [E₁/E₂] is 5:4, temperature is 45℃,pH8.0, hydrolysis time is 150min. On this condition the most ACE inhibitory ratio equal to 60.19%and DH equal to 11.92%.The purification of peptides from whey protein by composite enzymes hydrolysis was usedultrafiltration and Ion exchange tehnology. Separate the produced of whey on enzyme hydrolysis byselect MW cut-off 6kDa of ultrafiltration membrane. Research the effect to ACE inhibitory ratiowith different temperature and operated pressure. By the experiment found the best condition ofpurification of the peptides from whey protein by composite enzymes hydrolysis, and the bestcondition of purification of the peptides from whey protein by composite enzymes hydrolysis is:temperature is 25℃, pressure is 0.1Pa,.On this condition the ACE inhibitory ratio of passed liquidincreased 33%. To remove salt from hydrolyzed and passed liquid select Ion exchange tehnology, onthe condition of velocity of flow is 50r/min,the ratio of desalination was equal to 81% and proteinyield equal to 81% too, at the same time the ACE inhibitory activity have no changed when the saltwas removed from hydrolyzed and passed liquid.The effect on decreasing blood pressure peptides of purificational peptides from whey proteinis confirmed through feeding peptides from whey protein to the spontaneously hypertensive rats(SHR). Mensuration the weight, blood pressure, ACE active and viscera anatomise guide line.Research singed the f purificational peptides from whey protein have clear decreasing bloodpressure active. For 12 hours look in to the blood pressure of SHR found that the third hour have theneap blood pressure and then up to the original blood pressure slowly, result clear that the peptidesfrom whey depressed blood pressure is steady. On the side, anatomise the SHR find that they haveheart obesity. Finally, it is found that the decreasing blood pressure peptides from whey protein bycomposite enzymes hydrolysis have no effece to SHRs' weight.