Influence of light and temperature on the colour and oxidative stability of processed cheese

Abstract

Pasteurised processed cream cheese stored in sealed glass containers for one year was found to undergo different types of chemical changes depending on storage temperature and light exposure. High temperature storage (37°C) induced browning reactions evident as colour changes developing linearly with time. Browning was less significant at ambient temperature (20°C) and absent at low temperature (5°C) and light exposure (2000 lx) had little if any influence on browning. Light exposure induced formation of lipid peroxides, which were found stable at 5°C, but not at higher temperatures. Riboflavin, a potential photosensitiser, was degraded on light exposure independently of storage temperature. β-Carotene was not degraded whereas α-tocopherol was, especially in samples exposed to light, but less than 20% after one year of storage at any of the storage temperatures. Cholesterol oxidation was only detectable after long-term storage while exposed to light at high temperature.