Intensity of lipid oxidation and formation of cholesterol oxidation products during frozen storage of raw and cooked chicken

<jats:title>Abstract</jats:title><jats:p>Raw and cooked chicken breasts were stored at −18 °C for 3 months under aerobic and vacuum conditions, and the intensity of lipid oxidation and the formation of COP (cholesterol oxidation products) were studied. Raw samples showed low COP levels (4.60–7.40 µg g<jats:sup>−1</jats:sup> fat), TBARS (thiobarbituric acid reactive substances) levels (0.01–0.03 mg kg<jats:sup>−1</jats:sup>) and peroxide values (not detected) under both aerobic and vacuum conditions. Cooked samples (grilled and roasted) showed TBARS levels of 0.36–0.99 mg kg<jats:sup>−1</jats:sup> in aerobic conditions and 0.21–0.70 mg kg<jats:sup>−1</jats:sup> in vacuum conditions, whilst peroxide levels reached 38–40 and 19–23 meq O<jats:sub>2</jats:sub> kg<jats:sup>−1</jats:sup> in samples stored under aerobic and vacuum conditions respectively. Total COP levels in grilled and roasted samples were 28.91 and 39.34 µg g<jats:sup>−1</jats:sup> fat in aerobic packaging and 4.90 and 20.24 µ g g<jats:sup>−1</jats:sup> fat in vacuum packaging respectively. Significant correlations were found between the lipid oxidation parameters and cholesterol oxidation indices. In general, TBARS were better correlated with total COP than with only 7‐ketocholesterol. Vacuum packaging was particularly efficient in slowing down the oxidation process during frozen storage of cooked samples. Copyright © 2004 Society of Chemical Industry</jats:p>