Influence of carbohydrates on self‐association of mung bean protein hydrolysate in the presence of amphiphilic asiatic acid

This study investigated the influence of surface‐inactive carbohydrates on association characteristics of amphiphilic mung bean protein hydrolysate (MPH) and asiatic acid (AA) in aqueous suspension (11.72–11.94% total solids). The carbohydrates investigated were trehalose, maltodextrin, mixed trehalose–maltodextrin and mixed maltodextrin–starch. The presence of low‐molecular‐weight carbohydrates enhanced micellisation of AA to form micrometre‐sized particles due to depletion flocculation. Nonetheless, the presence of starch retained the submicrometre size of AA. In contrast, the presence of starch enhanced self‐association of MPH via segregative phase separation. However, the mixed suspensions containing MPH, AA and carbohydrate in a ratio of 1:0–0.072:2.34, respectively, retained particle sizes of around 300 nm regardless of the carbohydrate used. It was found that the MPH–AA co‐aggregates were stable against the osmotic effect of carbohydrates. The results suggest that carbohydrates regulated the aggregate size and surface hydrophobic region of MPH and MPH–AA by controlling surface‐induced aggregation.