Sorption of Volatile Compounds by Plastic Polymers for Food Packaging

Abstract

A fruit flavour solution was packaged into several kinds of pouches (Polyethyleneterephthalate (PET)/Aluminum foil (Al)/Polyethylene (High-density: HDPE, Middledensity: MDPE, Low-density: LDPE, Linear low-density: LLDPE, Ehylene vinylacetate copolymer: EVA)) and the sorption behavior of volatile compounds in the solution by plastic materials was investigated. (1) The distribution ratios (content in film/solution) of volatile compounds increased approximately linearly until 20th day, but after that, were almost constant. (2) The distribution ratios were influenced by functional groups of the volatile compounds. In homologous series, the distribution ratio increased with increasing carbon numbers. (3) Higher level of sorption was observed in CPP pouch than in HDPE one. (4) Among HDPE, MDPE and LDPE pouches, the distribution ratio was closely correlated to the density of film; r=-0.90--1.00. (5) The distribution ratios in LLDPE and EVA did not correlate to the density of film because quaternary carbons and vinylacetate units affected the sorption.