The influence of Allium sativum or Cinnamomum verum on cow- and camel- milk yogurts: proteolytic and angiotensin-l converting enzyme- inhibitory activities

摘要

Yogurt is a nutritious dairy product, has established probiotics effects and may even be therapeutic for certain health conditions. Proteolytic activity of starter cultures during milk fermentation can be generating peptides with angiotensin-I converting enzyme (ACE- I; EC. 3.4.15.1) inhibitory activity. Effects of presence of Allium sativum or Cinnamomum verum on these peptides in yogurt were investigated. Two types of milk (cow and camel) were incubated (41°C) with starter culture in the presence of A. sativum or C. verum water extract until pH of yogurt was reduced to 4.5. The resulting herbal- yogurts were evaluated with respect to changes of in vitro ACE- I inhibitory activity and proteolytic activity during 21 days of storage. In the present study, the extent of proteolysis was higher (p<0.05) in presence of A. sativum than presence of C. verum during storage with cow milk yogurt being more susceptible than camel-milk yogurt. The presence of A. sativum or C. verum increased ACE-I inhibitory activity more in cow- than camel- milk yogurt during storage. All herbal-yogurts showed the highest inhibitory activity of ACE-I (40%- 70%) on day 7 of storage. Prolonged storage of both types of yogurt to more two weeks decreased ACE-I inhibition activity (37% - 50%; p<0.05). In conclusion, A. sativum and C. verum can enhance yogurt functional properties with potential therapeutic values for hypertension.