Supplementation of Rosemary extract in the diet of Nero Siciliano pigs: evaluation of the antioxidant properties on meat quality

In the present study, the effect of Rosmarinus officinalis L. dietary supplementation on meat quality and oxidative stability of Nero Siciliano pigs was examined. During the growing-fattening period, 32 Nero Siciliano pigs were allotted into two treatment groups consisting of 8 replicates with 2 pigs per pen. For 90 days, the animals received a basal diet: one group (CTR) was not dietary supplemented, whereas the other group received (1 g/kg) rosemary extract (ROX). Supplementation with rosemary extract significantly improved the polyunsaturated fatty acid content of the meat, which showed higher values in the meat of the ROX group compared with the CTR group (P<0.001); in detail, values for 18:2n-6 (P=0.001), 20:4n-6 (P=0.001), 22:6n-3 (P=0.012) and PUFA/SFA ratio (P=0.004) appeared to increase in the dietary supplemented group. On the other hand, atherogenic and thrombogenic indexes showed slight differences among the groups (IA: P=0.079; IT: P=0.084). Dietary supplementation with R. officinalis L. was not effective in protecting meat from oxidative deterioration, considering that the lipid oxidation, measured in meat across 5 days of refrigerated storage in darkness, progressed similarly in both the groups during storage (P>0.05). Color measurement performed in the present study on meat samples from the two dietary treatments showed that redness decreased (P=0.046) and hue values increased (P=0.036), indicating that a deterioration of the initial color occurred and that the rosemary extract was ineffective in preventing color deterioration. Nevertheless, the lightness, yellowness and chroma color descriptors showed similar values in relation to dietary treatment (P>0.05). Considering the nutritional value of meat as an important contributor to the overall quality, the results obtained in this study support the possibility of the dietary supplementation with R. officinalis L. extract in pigs as a functional additive in livestock feeding.