SORPTION DEPRESSION OF FLAVORS INTO MODIFIED EVA FILM BY LOWERING FILM FLAVOR AFFINITY

Surface hydrolysis of ethylene-vinyl acetate copolymer (EVA) film resu lted in a specific sorption depression behavior of volatile compounds. The sorptions of hydrocarbons, ethyl octanoate, and decanal into hydr olyzed EVA film were depressed, whereas the sorptions for alcohols wer e all promoted. To elucidate the phenomena, the solubility parameter ( SP) concept was introduced. From the plots of sorptions against the SP values of volatile compounds, for all hydrocarbons, ethyl esters, and aldehydes with the cohesive energy of <19.3 SP value, the sorptions w ere depressed, while for hexanal and all alcohols with the SP value of >19.3 quite the opposite results were obtained. It was considered tha t the depression effect may be attributed to the lowering of compatibi lity at the surface between hydrolyzed film and volatile compounds. Se nsory evaluation also supported flavor preservation for hydrolyzed EVA film in lemon juice.