Effects of dietary high-oleic acid sunflower oil, copper and vitamin E levels on the fatty acid composition and the quality of dry cured Parma ham

Abstract

The effects of seven isoenergetic dietary treatments: (1) no sunflower oil, 35 mg/kg Cu, without α-tocopheryl-acetate added; (2) to (7) 6% high oleic acid sunflower oil (HOSO), 35 or 175 mg/kg Cu crossed with a 0, 100 or 200 mg/kg α-tocopherol addition, were tested on quality characteristics of dry cured Parma hams from a total 84 Large White gilts. No statistically significant effect was detected on parameters of early evaluation of seasoning loss of hams. The seasoning loss and intramuscular fat content of seasoned hams averaged 28.1 and 3.3%, respectively, with no effect of the diet composition. The CIE L* a* b* colour values taken on the surface of the lean from Parma ham were not affected by dietary oil inclusion, nor by copper levels and by α-tocopherol addition in the feed mixture, except for the ‘ a’ value that increased in HOSO groups ( P<0.01) and in groups with α-tocopherol addition ( P<0.01). The TBARS values in lean were reduced by the inclusion of HOSO ( P<0.05) and α-tocopherol supplementation ( P<0.10). Compared to the no oil group, the Parma hams in the HOSO groups showed a higher oleic acid content in the covering fat, but not different in neutral and polar fractions from semimenbranosus muscle. The oil inclusion reduced the saturated fatty acid content in subcutaneous fat and neutral lipids fraction from muscle to 30–34% No effect of α-tocopherol and copper levels were observed on fatty acids profiles. From the subjects fed the HOSO diet softer Parma hams were produced than those fed the control diet (χ 2<0.05), while α-tocopherol and Cu levels did not influence the sensorial evaluation of hams. The inclusion of an oleic acid rich source in heavy pig diet brought about an improved nutritional value, but also the possible need of a prolonged ageing time to achieve an ideal firmness of Parma ham. Dietary α-tocopherol supplementation improved the red colour slightly and the lipid stability in Parma ham, while the supplementation of Cu in the diet had no influence on the tested parameters.