INVESTIGATION OF OPTICAL AND GEOMETRICAL PACKAGE FEATURES IN PHOTO-OXIDATION DECAY OF A SEMI-HARD CHEESE

The aim of this work was to investigate the role of optical and geometrical features of a semi-rigid packaging system in the photo-oxidation decay of a semi-hard cheese [Edam Holland) during a short storage. The packaging solution chosen for this study was a polystyrene tray sealed in air with transparent plastic film, largely used in the market for MAP products. A new approach based on the interpretation of integrating sphere signal output using a double beam spectrophotometer was developed to characterize and discriminate the transmitted spectral components of the films. To fully investigate the role of optical and geometrical package features in photo-oxidation decay of the cheese, a screening design was selected. The factors considered in the design were: a) the diffused component of the total transmitted light; b) the distance between the surface of the cheese and the lid; c) the colour of the tray. Reflectance spectra in the UV-visible range were converted into colour parameters (CIE L*a*b*) and the variation of the yellow-blue index (Db*) was used as response of the experimental design. [PUBLICATION ABSTRACT]