Clearly, the location (surface or inner part), and the type of packaging (control or antioxidant active packaging) are the two factors determining the extent of oxidation in HP treated chicken
breast and thigh. The effect of the type of packaging on the observed progression of lipid oxidation is linked to the type of compound in contact with the meat surface. Recently, it was shown that the oxidation level in HP treated chicken breast was higher in air compared to vacuum packaged (Wiggers, Kröger-Ohlsen and Skibsted (2004). In the present study, the meat patties were simply wrapped in the film, which could possibly trap small amounts of oxygen between the meat surface and the film, resulting in the elevated lipid oxidation at the surface, as observed for the CS sample. Apparently, the antioxidant compounds from the antioxidant active package suppress the oxidation in both the surface part and the inner part and prevent formation of secondary lipid oxidation products. Interestingly, the elevated oxidation is constrained to the surface of the meat patties in the control package and no reactive compounds seem to be transferred to the inner part to accelerate oxidation, whereas the antioxidant active pack-
age, in addition to preventing oxidation at the surface (APS sample), perform some preventive effect on the inner part of the meat patties (API having the lowest oxidation level). In conclusion,the antioxidant active packaging is rather efficient to provide longer shelf-life of HP treated chicken meat.