Angiotensin-I-Converting Enzyme Inhibitory Peptides in Goat Milk Fermented by Lactic Acid Bacteria Isolated from Fermented Food and Breast Milk

Yuliana Tandi Rubak; Lilis Nuraida; Dyah Iswantini; Endang Prangdimurti

doi:10.5851/kosfa.2021.e55

Angiotensin-I-Converting Enzyme Inhibitory Peptides in Goat Milk Fermented by Lactic Acid Bacteria Isolated from Fermented Food and Breast Milk

Food Sci Anim Resour. 2022 Jan;42(1):46-60. doi: 10.5851/kosfa.2021.e55. Epub 2022 Jan 1.

Authors

Yuliana Tandi Rubak^{1

2}, Lilis Nuraida^{1

3}, Dyah Iswantini^{4

5}, Endang Prangdimurti^{1

3}

Affiliations

¹ Department of Food Science and Technology, IPB University (Bogor Agricultural University), IPB Dramaga Campus, Bogor 16680, Indonesia.
² Agrotechnology Study Program, Faculty of Agriculture, Universitas Nusa Cendana Kupang, UNDANA Lasiana Campus, Kelapa Lima, Nusa Tenggara Timur (NTT) 85228, Indonesia.
³ Southeast Asian Food and Agricultural Science and Technology (SEAFAST) Center, IPB University (Bogor Agricultural University), IPB Dramaga Campus, Bogor 16680, Indonesia.
⁴ Department of Chemistry, IPB University (Bogor Agricultural University), IPB Dramaga Campus, Bogor 16680, Indonesia.
⁵ Tropical Biopharmaca Research Center, IPB University (Bogor Agricultural University), IPB Taman Kencana Campus, Bogor 16128, Indonesia.

Abstract

In this study, angiotensin-I-converting enzyme inhibitory (ACEI) activity was evaluated in fermented goat milk fermented by lactic acid bacteria (LAB) from fermented foods and breast milk. Furthermore, the potential for ACEI peptides was identified in fermented goat milk with the highest ACEI activity. The proteolytic specificity of LAB was also evaluated. The 2% isolate was inoculated into reconstituted goat milk (11%, w/v), then incubated at 37°C until pH 4.6 was reached. The supernatant produced by centrifugation was analyzed for ACEI activity and total peptide. Viable cell counts of LAB and titratable acidity were also evaluated after fermentation. Peptide identification was carried out using nano liquid chromatography mass spectrometry (LC-MS/MS), and potential as an ACEI peptide was carried out based on a literature review. The result revealed that ACEI activity was produced in all samples (20.44%-60.33%). Fermented goat milk of Lc. lactis ssp. lactis BD17 produced the highest ACEI activity (60.33%; IC₅₀ 0.297±0.10 mg/mL) after 48 h incubation, viable cell counts >8 Log CFU/mL, and peptide content of 4.037±0.27/mL. A total of 261 peptides were released, predominantly derived from casein (93%). The proteolytic specificity of Lc. lactis ssp. lactis BD17 through cleavage on the amino acid tyrosine, leucine, glutamic acid, and proline. A total of 21 peptides were identified as ACEI peptides. This study showed that one of the isolates from fermented food, namely Lc. lactis ssp. lactis BD17, has the potential as a starter culture for the production of fermented goat milk which has functional properties as a source of antihypertensive peptides.

Keywords: Lc. lactis ssp; angiotensin-I-converting enzyme (ACE) inhibitory activity; antihypertensive peptides; goat milk fermented; lactis BD17; proteolytic specificity.