Purification and identification of novel peptides with inhibitory effect against angiotensin I-converting enzyme and optimization of process conditions in milk fermented with the yeast Kluyveromyces marxianus

Effects of fermented skim milk drink by Kluyveromyces marxianus LAF4 co‐cultured with lactic acid bacteria to release angiotensin‐converting enzyme inhibitory activities

“…); the decrease in the concentration of lactose has been shown to correlate with cell growth and an increase in ethanol content (Li et al . ). Co‐culturing K. marxianus with L. helveticus and L. casei strains (881315, 881188 and 880474) for 0–12 h resulted in a significantly lower pH range (6.43 to 4.00, 3.71 and 3.11) compared to pH 6.00 when K. marxianus was grown alone (Belem and Lee ; Yadav et al .…”

“…Based on the average of the OPA index, the release of ACE‐I peptides in fermented milk is related to proteolysis by yeast cell's proteolytic system (Li et al . ). The proteolytic activity of K. marxianus is higher than that of S. cerevisiae , as evidenced by increased amino acid content in milk as previously reported (Roostita and Fleet ; Chaves‐López et al .…”

“…In contrast, Li et al . () reported that the OPA index of fermented milk by yeast K. marxianus Z17 increased slowly at the early stage of log growth due to the key role of fast‐growing cells in rapidly utilising peptides; the authors also stated that cell growth rate at the beginning of fermentation time slowed down but proteolytic enzymes still remained active and resulted in the production of peptides up to a higher level that could be reflected by increased OPA. Nevertheless, by contrast, only half hydrolysis of milk protein using K. marxianus was achieved, probably due to the tertiary structure of the protein, which makes it relatively resistant to proteolysis (Lönnerdal and Iyer ).…”

“…However, Li et al . () reported that the maximum ACE‐I activity of fermented milk by K. marxianus Z17 was 81.23% at 32 °C, pH 6.5, and rotation speed of bioreactor system was 189 rpm. Hence, co‐culturing of K. marxianus did not increase ACE‐I activity, as was shown by Chaves‐López et al .…”

Isolation and Purification of Antioxidant and ACE-Inhibitory Peptides from Yak (Bos grunniens ) Skin

“…In the past few years, several studies have reported that peptides isolated from animal skin had many biological activities, including the abilities of scavenging DPPH, hydroxyl, superoxide radicals (Senphan and Benjakul ; Ngo et al ; Nikoo et al ; Zhu et al ), antimicrobial properties (Goraya et al ), and ACE‐inhibitory activity (Lee et al ; Ngo et al ). Among them, the investigation of the ACE‐inhibitory peptides has aroused much attention due to its potential value to be antihypertensive agents without side effects (García‐Moreno et al ; Li et al ).…”