FATTY ACID COMPOSITION IN MUSCLE TISSUES OF RAINBOW TROUT, Oncorhynchus mykiss, IRAN

Nassrin Mashaii*, Mohammad Hossein Mosaddegh, Habib Sarsangi, Farhad Rajabipour
10KM Bafq-Yazd Road, National Research Center of Saline Water Aquatics, Bafq, Yazd, Iran, P.O.Box 159
Email: Nassrinmashaii@yahoo.com

Iran has a great rate of coldwater fish culture in Asia since 2005. Rainbow trout, Oncorhynchus mykiss is the most common and important fish produced by Iranian fisheries. There is not enough information about carcass composition of cultured fish in Iran. Rainbow trout muscle samples were collected from six fish farms of Yazd province during February 2008. Muscle samples were frozen in -30οC after being homogenized. Proximate composition of samples was measured. Saturated fatty acids including palmitic acid, stearic acid, myristic acid and lauric acid, also unsaturated fatty acids oleic and linoleic were extracted from muscle tissue of fish of different farms, using gas chromatograghy (GC). Other unsaturated fatty acids including α-linolenic acid, Eicosa Pentaenoic Acid (EPA) and Docosa Hexaenoic Acid (DHA) had low concentrations in samples. Vitamin E level was 4.33-94.34 μg/100gr.

Oncorhynchus mykiss is one of the most important cultured fish in the world and the first cultured fish in Iran from 1960 (Miar et al., 1988). Iran has one of the highest rates of coldwater fish culture in the world since 2005 (Food and Agriculture Organization, FAO, 2005-2008). Rainbow trout, Oncorhynchus mykiss, is the most important fish for aquatic fish cultures in Iran.

Fish is one of the most important sources of animal protein, good fats and other elements for health. Food scientists recommended people to consume fish for prevention of cardiovascular disorders, some cancers and autoimmune diseases mainly because of their fatty acids.

Consumption of fish foods at least two times per week is recommended by the American Heart Association (AHA) to achieve cardio protective effects (Tabaka, 2009). There is a little information about carcass composition and fatty acids of cultured fish in Iran. Also some people have believed that cultured fish have lower quality than naturally growing fish.

In the present study, proximate analysis and fatty acid composition of muscle tissue of cultured O. mykiss in Yazd province of Iran are examined.

Results revealed low or high amounts of some saturated and unsaturated fatty acids especially the high level of ω6 linoleic acid and very low levels of EPA and DHA in fish food of the present study must be more considered.