The effects of dietary fat composition and vitamin E supplementation on the quality characteristics of dry-cured Iberian hams ripened for two years were studied. Thirty Iberian Duroc pigs were fed diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200mg α-tocopheryl acetate/kg diet). Dietary fat composition significantly affected total saturated fatty acids content of neutral and polar lipids from dry-cured Iberian ham ( p 0.012 and p 0.003, respectively). However, diet fatty acids composition did not influence either total monounsaturated or total polyunsaturated fatty acids of neutral and polar lipids. Vitamin E supplementation significantly enhanced dry-cured Iberian ham α-tocopherol content ( p 0.001). This, in turn, led to significantly lower levels of TBARS on days 6 and 9 of storage in slices from dry-cured Iberian hams made of vitamin E supplemented pigs and also lower oxidation levels in an induced lipid oxidation test in samples from those pigs. Dietary fatty acid composition did not significantly affect either TBARS during slices storage or malonaldehyde content in the induced oxidation test. No effect of vitamin E supplementation was observed in ham volatile aldehyde profile, but dietary fat significantly affected hexanal ( p 0.02), heptanal ( p 0.05) and total aldehyde content ( p 0.02), with those pigs fed a diet rich in PUFA showing higher values. Using diets supplemented in α-tocopherol and rich in monounsaturated fatty acids seemed adequate dietary strategies for feeding Iberian hams reared indoors.
Quantitative studies of hydroperoxide reduction by prostaglandin H synthase. Reducing substrate specificity and the relationship of peroxidase to cyclooxygenase activities.
