Lima Bean ( Phaseolus lunatus) Protein Hydrolysates with ACE-I Inhibitory Activity

Abstract

Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE) inhibit-tory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed flours were hydrolyzed with Alcalase 2.4 L or pepsin-pancreatin sequential hydrolysis, and ACE inhibitory activity measured in the different hydrolysis treatments. Protein hydrolysate production was analyzed with a 2 3 factorial design with four repli-cates of the central treatment. Evaluated factors were protein concentrate source (ungerminated seeds, PC 1 ; germinated seeds, PC 2), enzyme/substrate ratio E/S (1/50 or 1/10) and hydrolysis time (0.5 or 2.0 h for Alcalase; 1 or 3 h for pep-sin-pancreatin). Degree of hydrolysis (DH) was high for the Alcalase hydrolysates (24.12% -58.94%), but the pep-sin-pancreatin hydrolysates exhibited the highest ACE inhibitory activity (IC 50 = 0.250 -0.692 mg/mL). Under the tested conditions, the hydrolysates with the highest ACE inhibitory activity were produced with sequential pep-sin-pancreatin using either PC 1 at 1 h hydrolysis time and a 1/10 E/S ratio or PC 2 at 1 h hydrolysis time and a 1/50 E/S ratio. Lima bean protein hydrolysates prepared with Alcalase or pepsin-pancreatin are a potential ingredient in the pro-duction of physiologically functional foods with antihypertensive activity.