Oxidative stability, lipid composition and nutritional value of ruminant meat as affected by animal feeding system, sex and common household treatments

Ruminant meats have been suffered from a negative health image related to the nature of their lipid fraction, mainly due to the higher content in SFA. Even so, ruminant edible fats are the major natural source of CLA, provide proteins of high biological value and important micronutrients, such as A, group B, D and E vitamins, minerals and essential fatty acids all these components are associated with potential health benefits. Oxidation of lipids in foods is the major biochemical process that cause food quality deterioration, leading to the characteristic, unpalatable odour and flavour called rancidity. In addition to unpalatability, rancidity may give rise to toxic levels of certain compounds like malondialdehyde. In this PhD study UV/VIS absorbance spectroscopy was applied to determine the level of MDA in ruminant meat and its relationship with parameters like feeding, sex, cooking and storage conditions. Beef and lamb meat in this study were analysed. On beef and lamb meat, a study of lipid fraction before and after cooking was carried out to evaluate their chemical composition, fatty acid profile and some nutritional ratio. This manuscript reports the main results obtained in the five activities briefly summarized as follows: 1. effect of sex and cooking on nutritional value and oxidative stability in lamb meat; 2. evaluation of effects of diet on the oxidative stability of lamb meat during storage; 3. effect of sex and cooking on nutritional value and oxidative stability in beef meat; 4. evaluation of effects of diet on lipid oxidative stability and composition of beef meat; 5. effect of type of suckling and cooking on nutritional value and oxidative stability in lamb meat.