Lipid and protein oxidation, release of iron from heme molecule and colour deterioration during refrigerated storage of liver pâté

In the present work, lipid and protein oxidation, increase of non-heme iron (NHI) content and colour changes occurring during refrigerated storage (90 days/4 °C) of liver pâtés from Iberian and white pigs were studied. Iberian pigs were reared outdoors and fed on natural resources (grass, acorns) while white pigs were intensively reared and fed on a mixed diet. Lipid and protein oxidation were, respectively, measured by determining TBA reactive substances (TBARS) and protein carbonyl groups. Pâtés from Iberian pigs had better oxidative stability at all stages of storage, having lower amounts of TBARS and carbonyls compared to those from white pigs (p<0.05). NHI increased during refrigerated storage of liver pâtés, with those from white pigs having a higher amount of NHI at all stages of storage (p<0.05). During refrigerated storage, L*-values tended to increase while the evolution of a* and b* depended on the group and did not seem to be related to the oxidative processes.