Photoxidation of lipids and proteins of different types of raw meats during storage under commercial retail conditions

One of the most important chemical reactions responsible for deterioration of meat quality is oxidation. While lipid oxidation has been extensively studied due to its effects on the overall quality of meat and its potential impact on human health, the influence and the mechanisms of protein oxidation in fresh meat and meat products are largely unknown and it is becoming a raising issue for the meat industry. The aim of this study was to determine the effects of photosensitized oxidation in both lipid and protein fractions of raw meat stored under commercial retail conditions. Meat slices of pork, beef, chicken and turkey were trimmed, overwrapped with an oxygen permeable polyethylene film and placed in an illuminated chill cabinet for 0, 1, 3, 5, 7 days. Lipid oxidation was assessed by measuring peroxide value (PV) and thiobarbituric acid-reactive substances (TBARs), while the quantification of sulfhydryl and carbonyl groups were used to evaluate the extent of protein oxidation. Possible interactions and correlations between both degradation processes were studied, to evidence how they could influence each other. An overall picture of meat oxidation will allow to better understand how meat quality could be improved when stored under commercial retail conditions.