Antihypertensive Angiotensin I-Converting Enzyme Inhibitory Activity and Antioxidant Activity ofVitishybrid-Vitis coignetiaeRed Wine Made withSaccharomyces cerevisiae

Yak milk casein derived from Qula, a traditional Tibetan acid curd cheese, was hydrolyzed by six commercially available proteases (Trypsin, Pepsin, Alcalase, Flavourzyme, Papain and Neutrase). These hydrolysates were assayed for their inhibitory activity of Angiotensin-I-converting enzyme (ACE). The hydrolysates obtained by Neutrase from Bacillus amyloliquefaciens showed the highest ACE inhibitory activity. The IC50 value of Neutrase-hydrolysate was 0·38 mg/ml. The hydrolysate obtained by Neutrase was further separated by consecutive ultra-filtration with 10 kDa and then with 6 kDa molecular weight cut-offs into different permeated parts and fractionated by gel filtration chromatography with a Sephadex G-25 column. The active fraction was subjected to RP-HPLC, in which five peaks were purified and identified. Amino acid sequence analysis confirmed that the peptides and origins were as follows: YQKFPQY (αs2-CN; f89–95), LPQNIPPL (β-CN; f70–77), SKVLPVPQK (β-CN; f168–176), LPYPYY (κ-CN; f56–61) and FLPYPYY (κ-CN; f55–61). Their amino acid sequences matched well with those of known bioactive peptides from bovine casein. The results indicated that yak milk casein could be a resource to generate antihypertensive peptides and be used as multifunctional active ingredients for many value-added functional foods as well as a traditional food protein.

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Effect of Different Proteases on the Degree of Hydrolysis and Angiotensin I-Converting Enzyme-Inhibitory Activity in Goat and Cow Milk

Biomolecules ◽

10.3390/biom8040101 ◽

2018 ◽

Vol 8 (4) ◽

pp. 101 ◽

Cited By ~ 7

Author(s):

Guowei Shu ◽

Jie Huang ◽

Chunju Bao ◽

Jiangpeng Meng ◽

He Chen ◽

...

Keyword(s):

Inhibitory Activity ◽

Goat Milk ◽

Cow Milk ◽

Degree Of Hydrolysis ◽

Converting Enzyme ◽

Angiotensin I ◽

Ace Inhibitory Activity ◽

Inhibitory Peptides ◽

Angiotensin I Converting Enzyme ◽

Ace Inhibitory

Angiotensin I-converting enzyme (ACE) peptides are bioactive peptides that have important value in terms of research and application in the prevention and treatment of hypertension. While widespread literature is concentrated on casein or whey protein for production of ACE-inhibitory peptides, relatively little information is available on selecting the proper proteases to hydrolyze the protein. In this study, skimmed cow and goat milk were hydrolyzed by four commercial proteases, including alkaline protease, trypsin, bromelain, and papain. Angiotensin I-converting enzyme-inhibitory peptides and degree of hydrolysis (DH) of hydrolysates were measured. Moreover, we compared the difference in ACE-inhibitory activity between cow and goat milk. The results indicated that the DH increased with the increase in hydrolysis time. The alkaline protease-treated hydrolysates exhibited the highest DH value and ACE-inhibitory activity. Additionally, the ACE-inhibitory activity of hydrolysates from goat milk was higher than that of cow milk-derived hydrolysates. Therefore, goat milk is a good source to obtain bioactive peptides with ACE-inhibitory activity, as compared with cow milk. A proper enzyme to produce ACE-inhibitory peptides is important for the development of functional milk products and will provide the theoretical basis for industrial production.

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