Oxidative stability and health assessment index of rainbow trout (Oncorhynchus mykiss L.) farm reared in the Valnerina

Forty rainbow trout (Oncorhynchus mykiss L.) reared in Valnerina (umbria, italy) were studied to determine the oxidative stability of fillets during a 5-day storage period at 2°c under continuous cool white fluorescent illumination. chemical, physical and microbiological analyses were carried out. high quality fresh trout fillets were characterized by a low lipid and cholesterol content (4.2% and 37 mg/100 g, respectively), a high hypo-cholesterolemic/hyper-cholesterolemic fatty acid ratio (2.9) and low atherogenic and thrombogenic index values (0.45 and 0.21, respectively). After three days of display, the oxidative stability of the fillets decreased (2.7 vs 0.8 mg mDA/ kg, P<0.05) compromising the quality of the product. the lipid profile of the fillets also changed: the sFA and muFA increased due to PuFA oxidation and/ or drip loss, while EPA and DhA tended to decrease. nevertheless the levels of both long-chain PuFA were higher with respect to the baseline values, indicating that drip loss, more than oxidation, affected the amount of these compounds in fillets at the end of the experimental storage. hence, to preserve the nutritional value of this product, better packaging and storage conditions must be used.