The effect of oxygen exclusion during cooling of cooked turkey breast on the development of lipid oxidation in the stored product

In this study it was shown that cooling of freshly cooked turkey breast out of contact with air was highly effective in reducing the subsequent progress of lipid oxidation in the stored chilled (4 °C) product. Compared with cooling in contact with air, lipid oxidation in aerobically stored samples, as measured by muscle concentrations of hexanal and 2‐thiobarbituric acid‐reactive substances, was much lower for breast portions which were either cooled in a nitrogen atmosphere or subjected to hot vacuum packaging. Tissue hexanal concentrations of around 1.4 µg g−1 muscle, which have previously been shown to be associated with the initial stages of sensory detection of oxidised off‐flavours, were reached after 5 and 3 days of storage respectively in nitrogen‐cooled/air‐stored and vacuum‐packed/air‐stored samples compared to only 1 day in breast portions which were cooled and stored in air. Cooling and storing under nitrogen had the effect of almost completely inhibiting lipid oxidation in samples stored for 7 days. An acceptable flavour shelf‐life of approximately 7 days with respect to lipid oxidation was achieved when vacuum‐packed breast portions cooked to an internal temperature of 85 °C were packaged before the core temperature fell below about 60 °C.