ACE inhibitory and antihypertensive properties of apricot almond meal hydrolysate

Abstract

Apricot almond meal was hydrolyzed simultaneously with Neutrase and N120P proteases. The hydrolysate almond peptide (AP) was fractionated into three ranges of molecular weight (AP-I, >5 kDa; AP-II, 1–5 kDa; AP-III, <1 kDa) using an ultrafiltration membrane bioreactor system. The AP-III brought about a high angiotensin-I-converting enzyme (ACE) inhibitory activity with IC50 value of 0.138 mg mL−1 and the content of hydrophobic amino acid of AP-III was 50.08%. Lineweaver–Burk plots suggested that AP-III acts as a non-competitive inhibitor to inhibit ACE. And we evaluated the stability and in vivo antihypertensive activity of AP-III. Multiple dose oral administration (100 mg kg−1 body weight (BW), 400, 800 mg kg−1 BW) to spontaneously hypertensive rats led to a significant decrease in blood pressure for AP-III. Additionally, the gel filtration and RP-HPLC were used to separate ACE inhibitory peptides from the hydrolysate. The results suggested that the peptide derived from apricot almond protein may have potential applications as functional food.