The functional attributes of protein hydrolysates from horsegram (Macrotyloma uniflorum)

Abstract

The functional attributes of enzymatically derived horsegram protein hydrolysates from dehulled horsegram were investigated in this study. Hydrolysates were produced using commercial proteases, namely Alcalase® 2.4L and Protex 6L, at varying degrees of hydrolysis (DH) – specifically, 5%, 8%, and 10%. Maximum DH reached 11% with Alcalase® 2.4L and 11.5% with Protex 6L. Optimal hydrolysis conditions entailed a dehulled horsegram concentration of 2.5% (w/v), an enzyme–substrate ratio (E/S) of 0.001% for Alcalase® 2.4L and 0.002% for Protex 6L, at 55 °C and 60 °C, respectively, for 5 h, maintaining a pH of 7.5. Enhanced solubility was observed across a wide pH range (2–10), with HG-PH exhibiting an increase from 21% to 56%. Analysis of functional properties revealed a significant elevation (P < 0.05) in both water holding and oil holding capacities with increasing DH. Emulsion activity decreased from 0.5 to 0.1 in proportion to DH increase. Conversely, foaming capacity (FC) showed a positive correlation with the hydrolysis extent, rising from 24% to 98%. However, foam stability decreased across all samples, declining from 84% to 12%. These findings underscore the potential of incorporating these hydrolysates into diverse food applications, capitalising on their heightened solubility, water and oil holding capacities, and foam-forming characteristics. The comprehensive array of functional properties exhibited by HG-PH renders it a promising ingredient for integration into food product formulations.