Hydrolysates from wheat bran albumin as color-adding agents and inhibitors of apple polyphenol oxidase

Albumin from wheat bran was subjected to proteolysis. Molecular weight profile and particle size distribution were analyzed in the hydrolysates, which were later assayed in both crude extracts and surfaces of apple mesocarp in order to test their effect on polyphenol oxidase activity and enzymatic browning; the latter measured as L*, hue° and chroma*. Both the electrophoretic pattern and the size distribution showed, upon the hydrolysis, the appearance of aggregates with higher molecular weight than albumin. Polyphenol oxidase in crude extracts of apple was inhibited up to 40% by hydrolysates in a mixed way. The application of hydrolysates to mesocarp resulted in the impartment of a slight brownish color to the tissue and there were significant differences on L*, hue° and chroma* with respect to treatments but not with respect to time (P<0.05).