Study of factors affecting the absorption of aroma compounds into low‐density polyethylene

Abstract

Abstract A supercritical fluid extraction/gas chromatography method has been used to study the influence of different factors on the absorption of aroma compounds into low‐density polyethylene. Factors studied included concentration of aroma substances, storage temperature, pH and interactive effects of different food components. There were no significant differences in the partition coefficients when the concentration of the flavours was varied between 0.1 and 10 mg kg −1 . The storage temperature, however, affected the absorption significantly ( P < 0.05), approximately twice as much was absorbed at 75°C compared with 5°C. Acidification to pH 3 with acetic acid did not significantly alter the amounts of the aromas being absorbed. Further, when occurring alone in the model solutions the aroma substances had much larger partition coefficients than when in mixtures with others, indicating an antagonistic effect of different aroma compounds on absorption. Olive oil and, thereby, the flavours dissolved in the oil, were absorbed in large amounts by the plastic. Extractions of plastic films stored in concentrated apple juice were successfully carried out. In addition to many unknown substances, nine of the 10 aromas used in the model solution were detected in the plastic stored in concentrated apple juice.