Changes in the quality of fish oils due to storage temperature and time

The effects of storage temperature on oil quality of various fishes were examined. Fish oils extracted from horse mackerel, shad, garfish and golden mullet were used in oil analyses. Crude fish oils obtained by a solvent extraction method were stored at +4 °C and −18 °C. Chemical quality of the oils was evaluated with various parameters, including iodine, ester, acid, saponification, peroxide, and thio-barbituric acid values and unsaponifiable matter at various time intervals for 150 days of storage. All quality parameters, except iodine and ester values, increased during storage at both of temperatures. Sample oils stored at +4 °C preserved acceptable characteristics for 90 days. Acceptability tolerance was found to be 120 days for shad oil and 150 days for golden mullet, garfish and horse mackerel oils stored at −18 °C. The highest oxidative deterioration was observed in shad oils. Among all samples, garfish oil showed the greatest stability against oxidation.