Influence of genetic type on the characteristics of intramuscular fat of pig thighs destined for the PDO production

Italian heavy pig production uses both “traditional” breeds, whose carcass fat content has been reduced because of consumers’ demand, and commercial hybrids, whose fat depots are often low, and richer in PUFA. The increasing degree of lipid unsaturation requires a continuous monitoring to avoid undesired effects on typical products. The aim of this work was to compare the characteristics of intramuscular fat (IMF) of fresh thighs, destined for the production of PDO Italian dry-cured hams, obtained from heavy pigs of two genetic types (GT), reared in the same farm and feed with a standard cereal-soybean based commercial diet. Samples of biceps femoris from left thighs of 46 Italian Landrace x Large White pigs (TP), and 32 Goland commercial hybrids (GH) (average carcass weight 130.4±11.8 kg) were analyzed for IMF, TBARS (24h p.m.) and fatty acid (FA) contents. Data were subjected to ANOVA by SPSS statistical package using GT and sex as fixed effects. GH showed, in comparison of TP, similar contents of IMF (2.2 vs 2.7%) and TBARS (0.07 vs 0.07 mg MDA/kg meat), but higher levels of PUFA (201.5 vs 157.5 mg/100g meat, 17.9 vs 11.3%; P<0.01), mainly due to higher C18:2 and C20:4 contents; lower SFA (468.8 vs 582.3 mg/100g meat, 37.4 vs 39.5%; P<0.01) mainly due to lower C18:0 and C20:0; lower MUFA (572.4 vs 730.7 mg/100g meat, 44.7 vs 49.2%; P<0.01), mainly due to lower C18:1 content. The fatty acid composition of IMF confirms the results obtained from the covering adipose tissue of the same thighs, and agrees with many results from literature. Notwithstanding the positive lack of difference between the two genetic types for the amount of IMF and TBARS, it seems necessary a systematic check of lipid composition, to avoid undesired negative response of meat to processing due to possible oxidative phenomena during seasoning period.