Phenotypic correlations among quality traits of fresh and dry-cured hams

In this study, fresh and processing quality traits were collected on a total of 312 Country Hams. Phenotypic correlations between traits were estimated and numerous values were significantly different (P<0.05) from zero. Yield was significantly correlated with several fresh pork quality traits measured on the fresh hams, including subjective color (0.34) and lipid percentage (0.32). Some meat color traits were significantly correlated, including associations between the color scores taken on the fresh and cured hams. Correlations between fresh pork quality traits were also determined, with results showing significant correlations between ultimate pH and other pork quality traits. The results indicate that yield can be maximized if hams with good fresh pork quality parameters are used for curing. The correlations estimates are helpful for understanding of the biological mechanisms behind the production of dry-cured hams and can potentially be used to improve the efficiency of the dry-cured ham production chain.     

Extensive feeding versus oleic acid and tocopherol enriched mixed diets for the production of Iberian dry-cured hams: Effect on chemical composition, oxidative status and sensory traits

The present study aimed to analyse the chemical composition and oxidative status of Iberian dry-cured hams from pigs fed different finishing diets: extensive feeding on acorns and pasture in a "Montanera" traditional system (MON), fed in confinement with a mixed diet containing high-oleic sunflower oil (115g/kg of diet) and supplemented with 250mg/kg α-tocopherol (HOVE), and fed in confinement control mixed diet (CON) without added tocopherol and oleic acid fat. Muscles from MON dry-cured hams contained significantly (p<0.05) higher amounts of intramuscular fat (IMF) than those from HOVE and CON hams. The feeding background affected the tocopherol levels in dry-cured hams as those from MON and HOVE pigs had significantly higher levels of α-tocopherol than those from CON pigs whereas the extensive feeding provided muscles from MON pigs with significantly higher levels of γ-tocopherol than the experimental diets did to CON and HOVE pigs. The HOVE diet significantly increased the levels of oleic acid in Iberian dry-cured hams with these levels being similar to the oleic acid levels found in MON hams and significantly higher than those in CON hams. Compared to dry-cured hams from CON pigs, those from MON and HOVE pigs exhibited a higher oxidative stability as a likely result of a most favourable fatty acid composition and the presence of higher tocopherol levels. The principal component analysis (PCA) successfully discriminated between dry-cured hams from pigs fed different finishing diets.     

Accumulation and evolution of tocopherols in dry-cured hams from Iberian pigs as affected by their feeding and rearing system

The influence of feeding and rearing systems on the accumulation and evolution of α- and γ-tocopherols in relation to storage time in dry-cured ham slices and pieces was investigated. The accumulation of γ-tocopherol in Musculus Biceps femoris or fat of cured hams was lower in groups fed acorns indoors than in those fed outdoors. However, these differences were not detected in M. Semimembranosus. Hams from pigs fed acorns had higher proportion of RRR-α-tocopherol stereoisomer and could also be used to discriminate the feeding background of the animals but not the rearing system. Loss in α- and γ-tocopherols of ham slices with storage was not affected by the rearing system but by the feeding. The discrimination between groups is better during the first 7 days of analysis. Loss in redness and yellowness was lower in ham slices from outdoor group which would indicate that exercise or other compounds provided by grass are also of interest in these quality parameters.     

PRKAG3 and CAST genetic polymorphisms and quality traits of dry-cured hams-II. Associations in French dry-cured ham Jambon de Bayonne and their dependence on salt reduction

This study aimed to evaluate the effects of PRKAG3 Ile199Val and CAST Arg249Lys and CAST Ser638Arg polymorphisms on the quality traits of the French dry-cured ham Jambon de Bayonne and their interaction with salt reduction. Significant (p<0.05) and suggestive associations (p<0.10) between the polymorphisms and several quality traits of dry-cured ham, mainly related to processing and textural properties, were found. PRKAG3 Ile/Val and CAST 249Lys/638Arg presented the highest scores for sensory and processing properties, whatever the salt content.     

Accuracy of near infrared spectroscopy for prediction of chemical composition, salt content and free amino acids in dry-cured ham

The capability of near infrared (NIR) spectroscopy was examined for the purposes of quality control of the traditional Slovenian dry-cured ham “Kraški pršut.” Predictive models were developed for moisture, salt, protein, non-protein nitrogen, intramuscular fat and free amino acids in biceps femoris muscle (n = 135). The models' quality was assessed using statistical parameters: coefficient of determination (R²) and standard error (se) of cross-validation (CV) and external validation (EV). Residual predictive deviation (RPD) was also assessed. Best results were obtained for salt content and salt percentage in moisture/dry matter (R_CV² > 0.90, RPD > 3.0), it was satisfactory for moisture, non-protein nitrogen, intramuscular fat and total free amino acids (R_CV² = 0.75–0.90, RPD = 2.0–3.0), while not so for protein content and proteolysis index (R_CV² = 0.65–0.75, RPD < 2.0). Calibrations for individual free amino acids yielded R_CV² from 0.40 to 0.90 and RPD from 1.3 to 2.9. Additional external validation of models on independent samples yielded comparable results. Based on the results, NIR spectroscopy can replace chemical methods in quality control of dry-cured ham.     

Effects of vitamin A supplementation and weaning age on serum and liver retinol concentrations, carcass traits, and lipid composition in market beef cattle

Angus crossbred steers (n = 48) were either early-weaned (EW) at 137 days or weaned at a traditional age (TW) of 199 days to determine effects of weaning age and dietary vitamin A on serum and liver retinol, carcass traits, and lipid composition. Steers from both weaning ages were allotted to receive either 42,180 IU vitamin A/day (HA) or no supplemental vitamin A (NA). Early-weaned and TW steers consumed vitamin A treatments for 235 and 175 days, respectively. Serum and liver retinol of HA steers were dramatically higher (P < 0.01) than those of NA steers at the end of finishing. Steers were harvested in two groups 35 days apart at an average ultrasound 12th rib fat thickness of 1.0 cm. Live and HCW were similar (P > 0.10) between NA and HA steers, but HA steers had numerically greater (P  0.10) fat thickness (1.05 vs. 0.87 cm). Marbling score and %IMF fat were numerically (P > 0.10) higher for EWNA than EWHA steers. Ratio of marbling score/12th rib fat thickness was greater (P = 0.08), and ratios of either marbling or %IMF per unit of 12th rib fat thickness, days on finishing diet, unit of HCW, and tenth of yield grade consistently favored steers fed NA, particularly EW steers. Proportions of serum fatty acids changed (P < 0.05) during finishing; proportions of individual fatty acids of the longissimus muscle did not change. Restricting vitamin A during finishing has potential to increase carcass marbling and to decrease waste fat, particularly for EW.