Release of Proteolysis Products with ACE-Inhibitory and Antioxidant Activities in Probiotic Yogurt Containing Different Levels of Fat and Prebiotics

Effect of the milk fat content and starter culture selection on proteolysis and antioxidant activity of probiotic yogurt

“…In general, it is obvious that the decline in pH is due to bacterial activity and acid production which is in agreement with previous findings. The obtained results in this study are in agreement with our previous finding and those reported by Adriana Dabija-2018 et al., who concluded that pH values of yogurt samples decreased during storage time [1, 3].…”

“…As the results shown, proteolysis levels increased for all samples during the storage period, representing proteolytic activity of lactic acid bacteria during the storage period [30, 31]. Also these results were in agreement with our previous study, where proteolysis increased over storage time until day 14, and decreased afterward until the 21st day (P > 0.05) [3]. The results were consistent with our previous findings that revealed probiotic organisms along with L. delbrueckii ssp.…”

“…By Barkallah et al. and other researchers have been reported that the ability of proteins to retain water and milk fat cells in the structure of yogurt is the main factor influencing syneresis and WHC in yogurt [3, 4, 29].…”

“…Sometimes they released through the fragmentation of milk protein by proteolytic starter cultures and extracellular enzyme action. After releasing within the gastrointestinal digestion or treating food by proteolytic enzymes, they might leave different effects on metabolism [3]. Antioxidant activity is one of the key functions of the peptides taken from milk proteins.…”

“…Antioxidant activity is one of the key functions of the peptides taken from milk proteins. Such activities are mostly due to tiny peptides from casein as well as whey proteins [3, 4, 5] Chelating of transition metals as well as scavenging free radicals are among antioxidant functions of such peptides [6]. The probiotic effects of lactic acid bacteria and fermented dairy products do not only result from both microorganisms and their cell wall constituents, but they can also originate from metabolites such as peptides and extracellular polysaccharides produced in fermentation [7].…”