The objective was to identify peptides with dual antioxidant and angiotensin I converting enzyme (ACE) inhibitory activities released from lentil proteins by Savinase®. The influence of gastrointestinal digestion on peptide bioactivity was also assayed. Fragments from vicilin, convicilin and legumin were the most abundant peptides identified. Peptides LLSGTQNQPSFLSGF, NSLTLPILRYL, TLEPNSVFLPVLLH showed the highest antioxidant (0.013-1.432μmol Trolox eq./μmol peptide) and ACE inhibitory activities (IC=44-120μM). Gastrointestinal digestion of peptides improved their dual activity (10-14μmol Trolox eq./μmol peptide; IC=11-21μM). In general, C-terminal heptapeptide was crucial for their dual activity. ACE inhibition relies on the formation of hydrogen bonds between C-terminal residues of lentil peptides and residues of the ACE catalytic site. The present study helps clarifying the relationship between structure and dual antioxidant/antihypertensive activity of lentil peptides opening new opportunities to food industry such as the application of lentil protein hydrolysates as ingredients for development of functional foods.

Angiotensin I converting enzyme (ACE) inhibitory and antioxidant peptides are receiving attention due to their beneficial effects in the prevention/treatment of hypertension. The objective was to explore the effect of high hydrostatic pressure (HP) on proteolysis by different proteases and the release of bioactive peptides from lentil proteins. Pressurisation (100-300 MPa) enhanced the hydrolytic efficiency of Protamex, Savinase and Corolase 7089 compared to Alcalase. Proteolysis at 300 MPa led to a complete degradation of lentil proteins and increased peptide (<3 kDa) concentration by all enzymes. Proteolysis at 300 MPa by Savinase gave rise to lentil hydrolysates (S300) with the highest ACE-inhibitory and antioxidant activities that were retained upon in vitro gastrointestinal digestion. The peptides responsible for the multifunctional properties of S300 hydrolysate were identified as different fragments from storage proteins and the allergen Len c 1. These results support the potential of HP as a technology for the cost-effective production of bioactive peptides from lentil proteins during enzymatic proteolysis.

Available online A B S T R A C TProduction of novel functional ingredients from legume proteins is a valuable strategy to boost their food use and intake. Aimed at a better exploitation of the functional properties of pinto bean hydrolysates, the effectiveness of two subtilisins (Alcalase and Savinase) for the simultaneous release of bioactive peptides and phenolics with antioxidant, angiotensin I converting enzyme (ACE) inhibitory and anti-inflammatory activities was investigated.A higher proteolytic efficiency was observed for Alcalase that increased the concentration of small peptides in hydrolysates after 120 min. Savinase improved hydroxycinnamic acids and flavonoid contents in hydrolysates after 90 min due to its higher esterase activity. The most active hydrolysates combined potent free radical scavenging (326-348 mmol TE/g), ACE inhibitory (IC50 = 0.22-0.26 mg/mL) and anti-inflammatory (28-16% inhibition) activities. Peptide characterization of active hydrolysates confirmed the presence of bioactive fragments derived from phaseolin. These results evidence the promising potential of pinto bean hydrolysates as functional ingredients in the design of healthy foods.

The aim of this study was to produce multifunctional hydrolysates from lentil protein concentrates. Four different proteases (Alcalase, Savinase, Protamex, and Corolase 7089) and different hydrolysis times were evaluated for their degree and pattern of proteolysis and their angiotensin I-converting enzyme (ACE) inhibitory and antioxidant activities. Alcalase and Savinase showed the highest proteolytic effectiveness (P ≤ 0.05), which resulted in higher yield of peptides. The hydrolysate produced by Savinase after 2 h of hydrolysis (S2) displayed the highest ACE-inhibitory (IC50 = 0.18 mg/mL) and antioxidant activity (1.22 μmol of Trolox equiv/mg of protein). Subsequent reverse-phase HPLC-tandem mass spectrometric analysis of 3 kDa permeates of S2 showed 32 peptides, mainly derived from convicilin, vicilin, and legumin containing bioactive amino acid sequences, which makes them potential contributors to ACE-inhibitory and antioxidant activities detected. The ACE-inhibitory and antioxidant activities of S2 were significantly improved after in vitro gastrointestinal digestion (P ≤ 0.05). Multifunctional hydrolysates could encourage value-added utilization of lentil proteins for the formulation of functional foods and nutraceuticals.

Pinto bean protein concentrate was hydrolyzed by subtilisins at 0.1, 100, and 200 MPa and 50 °C for 15 min. Alcalase hydrolysis at 100 MPa led to higher ACE inhibition, reducing power, and free radical scavenging activity of hydrolysates. However, hydrolysate obtained by Savinase at 200 MPa showed the best ACE-inhibitory and radical scavenging activities. Proteolysis by Savinase at 200 MPa was considered the most effective treatment to increase small peptides (<3 kDa), flavonoids, total phenolic compounds, and oxygen radical absorbance capacity in hydrolysates. In this hydrolysate, small phaseolin fragments with reported ACE-inhibitory and antioxidant sequences were identified. Catechin, pelargonidin 3-glucoside, and ferulic acid were the main phenolic compounds. Hihg-pressure-assisted hydrolysis of common bean protein concentrates would provide benefits in the production of functional hydrolysates providing higher functionality and added value to the resulting hydrolysate due to synergistic effects of bioactive peptides and soluble phenolics.