تندي اكسيداتيو و هيدروليتيك چربي در ماهي اسبله (Silurus glanis) طي نگهداري به صورت منجمد

Oxidative and hydrolytic rancidity of lipid on catfish (Silurus glanis) during frozen storage

During storage and processing, result of some factors, fish quality will decrease .To determine of oxidative and hydrolytic rancidity of lipid in catfish (Silurus glanis) during frozen storage, catfish were caught in Anzali lagoon in January of 2006. The prepared fillets, were freezed at freezing tunnel -40°c for 12 hours, and then were stored at -18°° for 6 months. Process of lipid quality changes of these fillets were measured by some factors related to lipid rancidity, included, Peroxide value (PV), Free Fatty Acid (FFA), Thiobarbituric acid (TBA) and value of Heme iron, lipid, moisture, ash were measured, too. The experiments were performed at 0, 1,3 and 6 months. The Peroxide value were increased and showed significant changes during different months (P<0.05). Peroxide value at the end of experiments was 8.22 times more than initial value. During the storage period, increasing of TBA was perceived that at last months was significant (P<0.05) and reached to 3.32 mg of malonaldehyde at kg of fish flesh. Amount of FFA increased due hydrolytic rancidity and at the last 2 months of measuring was significant. Heme iron decreased at 6 months and changed between 8.92 and 6.77 ppm (p<0.05). Correlation relations at most of indicators showed significant relations between them. Oxidative and hydrolysis lipid indicators had positive and significant relation, together.