Preliminary findings on the effect of light-oxidation on Asiago d'allevo vecchio protected designation of origin cheese

Food is exposed to light during processing, packaging, distribution and retail storage, resulting in deterioration of the product quality. Milk and other dairy products are among the most sensitive due to the high content of riboflavin, vitamin B2, which is an efficient photosensitizer for oxidative processes. Photooxidation in cheese induces degradation of nutritional quality such as proteins, lipids, and vitamins. Moreover, it causes formation of off-flavours, off-odours and gradual bleaching. The objective of this study was to evaluate the effect of light exposition on sliced Asiago d'allevo cheese (lowland vs alpine) aerobically packaged stored for 336 h under both fluorescent light and in the dark. Alpine cheese showed higher b* (P<0.001) and a* indexes (P<0.001) and also a higher lipid oxidation (P<0.01) than lowland one. Riboflavin content was significantly higher (P<0.001) in lowland cheese. Cheese samples exposed to the light were significantly lighter (P<0.001) than those exposed in the dark and they also showed a decrease in yellowness (P<0.001) and redness (P<0.001) as well as in riboflavin content (P<0.001). Lipid oxidation did not produce statistically significant change. Storage time significantly affected riboflavin content (P<0.001), TBARs (P<0.001) and cheese colour (P<0.001). Results suggest that light exposition had a pronounced effect on cheese characteristics.