Oxidative stability of sardines as related to storage conditions

The aim of this research work was to evaluate the oxidative stability of fresh sardines as related to the storage conditions. Whole sardines were stored at 4 ° C for 4 hours under light exposure and at dark. The lowest levels of peroxide value (PV) (3.7 meq O2/kg fat), thiobarbituric reactive substances (TBARs) (0.6 mg MDA/kg meat), cholesterol oxidation products (COPs) (0.6 μg/g muscle) and the highest level of polyunsaturated fatty acids (PUFA) content (47.4%), especially PUFA n-3 (43.4%), were found in the fresh sardines (time zero). After light exposure, PUFA dramatically dropped (up to a 19% decrease), leading to a marked increase of PV (11.8 meq O2/kg fat), TBARs (3.7 mg MDA/kg meat) and COPs (3.7 μg/g muscle). Although cholesterol oxidation rate did not exceed 0.9%, further research is required about toxicity levels of the single COPs, to better understand if the COPs levels found in fresh and photoxidized muscle (0.62-3.72 μg/g of muscle) do not represent a risk for human health.