title: Characterization of angiotensin-converting enzyme inhibitory activity of fermented milk produced by Lactobacillus helveticus.
abstract: Hypertension affects up to 30% of the adult population in most countries. It is a known risk factor for cardiovascular diseases, including coronary heart disease, peripheral artery disease, and stroke. Owing to the increased health awareness of consumers, the application of angiotensin-converting enzyme (ACE)-inhibitory peptides produced by Lactobacillushelveticus to prevent or control high blood pressure has drawn wide attention. A total of 59 L. helveticus strains were isolated from traditional fermented dairy products and the ACE-inhibitory activity of the fermented milks produced with the isolated microorganisms was assayed. The ACE-inhibitory activity of 38 L. helveticus strains was more than 50%, and 3 strains (IMAU80872, IMAU80852, and IMAU80851) expressing the highest ACE-inhibitory activity were selected for further studies. Particularly, the gastrointestinal protease tolerance and thermostability of the ACE-inhibitory activity in the fermented milks were assessed. Based on these 2 criteria, IMAU80872 was found to be superior over the other 2 strains. Furthermore, IMAU80872 exhibited a high in vitro ACE-inhibitory activity at the following fermentation conditions: fermentation temperature at 40°C, inoculation concentration of 1×10(6) cfu/mL, and fermentation for 18h. Finally, by using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry analysis, we observed changes of the metabolome along the milk fermentation process of IMAU80872. Furthermore, 6 peptides were identified, which might have ACE-inhibitory activity. In conclusion, we identified a novel ACE-inhibitory L. helveticus strain suitable for the production of fermented milk or other functional dairy products.
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China; Synergetic Innovation Center of Food Safety and Nutrition, Jiang Nan University, Wuxi, Jiang Su 214122, P. R. China.
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China.
authors.forename: Changkun
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Xue
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China.
authors.forename: Lai-yu
authors.initials: LY
authors.lastname: Kwok
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China; Synergetic Innovation Center of Food Safety and Nutrition, Jiang Nan University, Wuxi, Jiang Su 214122, P. R. China.
authors.forename: Heping
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China. Electronic address: menghe@sjtu.edu.cn.
authors.forename: Bilige
authors.initials: B
authors.lastname: Menghe
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D043302:Cultured Milk Products / Q000737:chemistry* / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000502:physiology; D006358:Hot Temperature; D052198:Lactobacillus helveticus / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors
keywords: Lactobacillus helveticus; angiotensin-converting enzyme; fermented milk; peptide