Angiotensin I-converting enzyme (ACE) inhibitory activities of enzymatically hydrolyzed jackfruit seed protein

Abstract

Importance of the work: Angiotensin-converting enzyme (ACE) has been well-recognized
for its role in blood pressure regulation. Jackfruit seed protein hydrolysates (JSPs) are
produced via enzymes.
Objectives: To assess the potential of jackfruit seed proteins as a functional food for high
blood pressure treatment based on bioactive peptides.
Materials and Methods: The ACE inhibitory activities were investigated of the JSPs
produced via pepsin, trypsin and chymotrypsin enzymes. After hydrolysis, smaller
JSP molecules (≤ 3 kDa) were collected following ultrafiltration and further purified
using solid phase extraction (SPE). The ACE inhibitory activity analysis of all peptides
revealed positive results. Hence, the peptides were further separated into fractions
using hydrophilic interaction liquid chromatography (HILIC) and reversed phase-high
performance liquid chromatography (RP-HPLC) and subsequently, analysis of the
inhibitory properties of JSP fractions against ACE was carried out.
Results: The mean (± SD) yield of protein from jackfruit seeds extracted using sonication
at 30% amplitude was 18.52 ± 0.6% dry basis. The JSPs had a mean (± SD) ACE-inhibitory
activity of 77.75 ± 0.17% and a half maximal inhibitory concentration (IC50) of 0.54 mg/mL.
The impediment to ACE activity by the HILIC 90%_JSP_ACN+0.1%FA fraction was the
highest. Based on further RP-HPLC fractionation of this HILIC fraction, the inhibition
efficiency of fraction 6 (HILIC90%_JSP_RP-HPLC_6) against ACE was exemplary.
Main finding: JSPs are promising alternative sources of antihypertensive functional
food, food ingredients and nutraceuticals.