Relationship between protein and lipid oxidation in rabbit hind leg meat

The present study aimed at evaluating the effect of the exposure to oxidative conditions as well as of the incubation with different malondialdehyde concentration (MDA) on protein oxidation assessed by measuring carbonyls and free thiol groups on rabbit hind leg meat. For this purpose, five rabbits (10 weeks-old, average live weight of 2.7 kg) were collected from a commercial processing plant and, after deboning the hind legs, the resulting meat was minced and divided into twelve aliquots/each: six exposed to strong oxidant conditions and six considered as fresh. Both fresh and oxidized samples were treated with the addition of different final concentrations of MDA (i.e. 0, 0.25, 0.5, 1.0, 2.5 and 5 mM) and subsequently used to assess carbonyls and free thiol groups content. The same experiment was repeated on turkey (100 days-old, average live weight of 9.7 kg) thigh meat. Data concerning rabbit and turkey meat were separately analyzed according to a 2 × 6 factorial design (ANOVA) to investigate the main effects of the exposure to oxidative conditions and MDA addition. The exposure to oxidative conditions resulted in a 3-fold increase (2.27 vs. 6.68 nmol/mg of proteins; P < 0.001) in carbonyl content together with a significant reduction (-52%) in free thiol groups (197.5 vs. 94.9 nmol/mg of proteins; P < 0.001) in rabbit hind leg meat. On the other hand, the incubation with different MDA concentration did not exert any relevant effect on protein oxidation. These results are in overall agreement with those obtained on turkeys’ thigh meat subjected to the same experimental design, even if rabbit meat proteins appear to be less prone to a lipid-induced oxidation. Overall, the findings of the present study show that rabbit meat is pretty resistant to main oxidative occurring to proteins. However, the occurrence of oxidative reaction affecting the polypeptide chains might change according cut-up characteristics, thus development of processing strategies aiming at reducing the extent of protein oxidation in rabbit meat and processed products needs to carefully consider its quality traits and attitude for further processing but also the processing steps as well as the storage conditions to which these meats will be subjected.