The aim of this study was to investigate the effect of different storage conditions in market (ice box, glassy refrigerator, normal refrigerator without light (natural and electric power) and freezer) on alpha linolenic acid (ALA), a nutritional value of rainbow trout (Oncorhynchus mykiss). To investigate the effect of storage duration on fatty acid quality, samples stored after 1, 3 and 5 days in refrigerator and those stored for 60 days in freezer were collected to measure alpha-linolenic fatty acid in omega 3. The ALA contents of the samples were assessed by using gas chromatography. This study revealed that, the content of alpha linolenic fatty acid increased on the 3rd day of being stored in the refrigerator and it decreased on the 5th day due to oxidative reactions. Storage conditions had significant effects on ALA content (P<0.05 in one-way ANOVA). The mean percentage value of the ALA reduction in iced rainbow trout was 31.4%, while it was 16.9 and 11.9% for fish samples preserved in glassy and dark refrigerator, respectively. The amount of ALA in the freezer reduced every day and 29.9% of ALA was lost after 60 days. The data in this study revealed that the reduction amount of ALA content in the refrigerator without light usually not in the market was approximately 8.6% more than that in the freezer on the same storage day (5th). Therefore, it is very important to pay special attention to the methods of preserving fish and fish products sold in the markets, to obtain sustainable fish resource for poverty alleviation in the country.

Keywords: Gas chromatography, nutritional value, omega-3, rainbow trout (Oncorhynchus mykiss).