Boarfish protein recovery using the pH-shift process and generation of protein hydrolysates with ACE-I and antihypertensive bioactivities in spontaneously hypertensive rats

摘要

Boarfish (Capros aper Linnaeus) are frequently in European waters. In this work, the generation and identification of angiotensin-l-converting enzyme (ACE-I; EC 3.4.15.1) inhibitory and antihypertensive peptides from Boarfish proteins are reported for the first time. Boarfish proteins were recovered using the pH shift process and hydrolysates were generated using the commercially available proteolytic enzyme alcalase CLEA, papain and protease AP. Molecular weight cut off (MWCO) filtration methods were used to enrich for peptides less than 10- and 3-kDa in size. The angiotensin-I-converting enzyme (ACE-I; EC 3.4.15.1) inhibitory activity of the generated hydrolysates and MWCO fractions was assessed in vitro. The 3-kDa Boarfish protein hydrolysate (BPH) generated using protease AP inhibited ACE-I by 85.8% ( +/- 1.81) when assayed at a concentration of 1 mg/mL compared to the positive control captopril. Mass spectrometry was used to characterize the peptides within the BPH generated using protease AP. Moreover, the antihypertensive activity of this BPH was assessed in vivo using spontaneously hypertensive rats (SHRs) over a 24 hour period. Results obtained suggest that BPH generated using protease AP is a source of ACE-I-inhibitory peptides with antihypertensive effects in vivo. This hydrolysate has the potential for use as a functional food ingredient for the maintenance of normal blood pressure in hypertensive individuals.