Can raw thighs classified as E be suitable for the production of PDO hams?

The aim of the present work was to collect information at the slaughterhouse on the relationship between carcass composition (lean meat content assessed according to the EUROP classification grid) and the quality of the raw thighs. Quality was assessed based on indicators included in the product specifications for Parma ham: trimmed weight, thickness of the fat layer (measured vertically at the head of the femur -best end-), presence of fat at the “coronet” (visually assessed), iodine number, linoleic acid content (C18:2). The research included 11 slaughter plants. In each plant, 10 slaughtering batches and about 20 raw thighs per batch were selected. All pigs assessed had a carcass weighing more than 110 kg, in agreement with the definition of heavy pig. Overall, 2126 raw thighs were evaluated. At least 25% of the selected raw thighs in each batch derived from a carcass classified as E in the EUROP grid (F-o-M classification). Out of them 32.6% were classified as E, 35.5% as U, 24.7% as R and 7.1% as O. In 6 slaughtering plants, from each slaughtering batch we collected 10 samples of subcutaneous fat (including both inner and outer fat layer), of which 5 from raw thighs belonging to the E class and 5 from raw thighs belonging to the other classes (U, R, O). In order to assess if the fat from the raw thighs classified as E is more frequently non-compliant (iodine number > 70; C18:2 > 15%) with Parma ham production rules than U-R-O thighs, iodine number analysis was carried out on the subcutaneous fat samples, while the gas chromatography analysis of fatty acid composition is presently in progress. Trimmed weight, fat thickness and iodine value were analyzed with one-way ANOVA using the EUROP grid (E vs URO) as the main effect As expected, despite the similar (P>0.48) weight of the trimmed thighs (14.525 kg for E vs. 14,486 kg for URO thighs) the thickness of the fat layer was lower (P<0.001) in thighs from E class than in thighs from URO classes (24.29 vs. 32.67 mm). Iodine value was significantly lower in thighs from URO than in thighs form E classes (65.62 vs 67.48; P< 0.001). Our preliminary results also show that the majority of the raw hams classified as E are compliant with Parma ham production rules for fat thickness (83.1%), fat at the “coronet” (97.6%) and iodine value (for this parameter only 73.9%). If the compliance observed will be confirmed also by the gas chromatographic analysis (C18:2 content), it would be interesting to follow class E thighs also during the dry-curing process, to assess the final quality of the hams. It is reasonable to expect that, if the animals’ diet is formulated to keep the iodine number and the linoleic acid content within the range prescribed by the production rules, the majority of thighs classified as E could be suitable for the long curing process.