Effect of enzyme types on the stability of oil-in-water emulsions formed with rice protein hydrolysates.

Common oil-in-water plant-based emulsions are allergenic and unstable to environmental stress, leading to increased consumer concerns about the food industry. To solve the problem of safety and instability, we investigated the influence of environmental stress on the stability of emulsions containing various rice protein hydrolysates, and compared the performance to whey protein, a common food emulsifier.Rice protein hydrolysates were obtained by enzymatic hydrolysis with different proteases (neutrase, trypsin and alcalase). We evaluated the stability of emulsions produced with different hydrolysates according to storage, pH, ionic strength and thermal processing. Trypsin hydrolysates formed emulsion as stable as emulsion containing whey protein against a range of environmental stress containing pH (pH 6 to 7), salt (< 150 mmol L NaCl) and temperature (30-90 °C). Moreover, a higher partition coefficient of protein in emulsion showed that the trypsin hydrolysates were easy to adsorb at the oil-water droplet interface, indicating its higher stability.The results obtained in the present study suggest that trypsin hydrolysates could be utilized as natural emulsifiers to stabilize emulsion instead of traditional animal-based emulsifiers, opening many opportunities with respect to hypoallergenic emulsion systems in the food industry. © 2019 Society of Chemical Industry.