Stability of Food-derived ACE Inhibitory Dipeptides Containing Tyrosine Residue

Thermal stabilities and gastrointestinal digestion resistance of ACE(angiotensin converting enzyme)inhibitory dipeptides containing tyrosine residue were analyzed according to the retention rate and inhibitory activities of dipeptides by RP-HPLC.The results showed that,at the temperatures of 37,50,70℃,the food-derived ACE inhibitory dipeptides Ile-Tyr(IY),Leu-Tyr(LY),Ala-Tyr(AY)and Ser-Tyr(SY)had good thermal stability. Under 100℃,IY showed the best thermal stability,while SY showed slightly low thermal stability compared with IY,LY and AY. AY,IY,LY and SY all had good abilities for resistance to digestion and absorption. After 2 h of artificial gastric juice reaction,the dipeptide retention rate were over 90%. After 6 h of artificial intestinal fluid reaction,the dipeptide retention rate ranged from 83.99% to 87.27%. This study provided an important theoretical basis for further studies on stability and processing properties of food derived dipeptides.