Optimization of Enzymatic Hydrolysis Technology, and Functional Properties of white lentils Peptides

This study focused on optimizing the enzymatic hydrolysis process of white lentils to prepare peptides with high antioxidant activity and excellent functional properties, aiming to provide theoretical and technical basis for the high-value utilization of white lentils resources. White lentils protein isolated via alkali extraction and acid precipitation was used as the raw material. Hydrolytic efficiencies of four commercial proteases (trypsin, alkaline protease, neutral protease, papain) were systematically compared using degree of hydrolysis (DH) as the evaluation index. After screening the optimal protease, single-factor experiments combined with Box-Behnken response surface methodology (RSM) were employed to optimize hydrolysis parameters for maximum DH. Subsequently, in vitro functional properties of the resulting peptides were characterized. Results showed that alkaline protease exhibited the highest efficiency, with a DH of 22.09%±0.75% in preliminary screening. Optimal hydrolysis conditions were confirmed as: temperature 55 ℃, pH9.0, enzyme dosage 4239 U/g, substrate concentration 11%, yielding a DH of 23.48%±0.04%. Antioxidant assays showed that the half-maximal inhibitory concentration (IC₅₀) of the peptides for DPPH, ABTS⁺, hydroxyl and superoxide anion radical scavenging were 1.28, 2.07, 0.30 and 3.24 mg/mL, respectively. At 50 mg/mL, their total reducing power reached 1.85 (at 700 nm). Moreover, the peptides showed superior functional properties including solubility, water-holding capacity, oil-holding capacity, foaming capacity and foam stability. These results confirm that enzymatically prepared white lentils peptides have promising functional characteristics, making them a potential functional ingredient in the food industry and providing theoretical and experimental basis for the high-value exploitation of white lentils.