Amino acid composition and angiotensin-i converting enzyme inhibitory activity of Cowpea (<i>Vigna unguiculata</i>) pepsin-pancreatin protein hydrolysate fractions

Abstract

Legumes are high in protein and have been linked to the management and prevention of chronic diseases due to their bioactive components. This study investigated the amino acid composition of cowpea protein hydrolysate and its inhibitory impact on angiotensin-I converting enzyme (ACE-I). Cowpea (Vigna unguiculata) protein hydrolysate (CPH) was produced through sequential digestion with pepsin and pancreatin. CPH was then separated using G-50 gel filtration chromatography and reverse phase high performance liquid chromatography (RP-HPLC). The fractions' ACE-I inhibitory activity was then assessed. The IC50 value for the RP-HPLC fraction with the highest ACE-I inhibitory activity (P<0.05) was 6.23 μg/mL. The amino acid profile revealed that a large proportion of hydrophobic amino acids were present in the RP-HPLC fraction containing the peptide with the highest ACE-I inhibitory activity. These findings suggest that CPH has the potential to be employed in the development of functional foods that can aid in the prevention and treatment of hypertension.