Milk protein coatings prevent oxidative browning of apples and potatoes

Color analysis on apple and potato slices coated with calcium caseinate or whey protein solutions showed that the 2 coatings efficiently delayed brown ing by acting as oxygen barriers. The antioxidant properties of the films w ere realized using a model allowing the release of oxidative species by ele ctrolysis of saline buffer. Whey proteins were a better antioxidant capacit y than calcium caseinate. Furthermore, addition of carboxymethyl cellulose (CMC) to the formulations significantly improved their antioxidative power. Best scavenging of oxygen free radicals and reactive oxygen species was fo und for films based on whey proteins and CMC which inhibited by 75% the for mation of colored compounds produced by the reaction of the oxidative speci es with N,N-diethyl-p-phenylenediamine.