Proximate, Fatty Acid, Amino Acid and Mineral Composition of Tuna (Thunnus sp.) By-Product from West Sumatra Province, Indonesia

Abstract

Tuna is an important commodity of marine fisheries with the total production in 2011 amounted to 230,580 tonnes. Examples of exported tuna products are canned and froze tuna (tuna loin). On tha t products mentioned, not all parts of tuna are used, it will produce by-products which can be environmental waste. By-products of tuna can be developed to be products having added value. This study aimed to determine proximate, fatty acid composition, amino acid composition and mineral composition of tuna by- products from West Sumatra Waters. By-product used in this study comprised skin, gonad, red meat and tail. The result of study showed that the highest protein content was found in the skin (29.98%) and the highest fat was found in the tail (3.35%). The dominant saturated fatty acid (SFA) was palmitic acid, which the highest value can be found in the skin (17.00%). The dominant monounsaturated fatty acid (MUFA) was oleic acid, which the highest value can be found in the skin (13.47%). The dominant polyunsaturated fatty acid (PUFA) was DHA and the highest value of DHA can be found in the tail (24.18%). The highest amino acid content was glycine 6.18%, it can be found in the skin. The results of the analysis showed that the heavy metal content of the four samples had mercury concentration below 0.001 mg/kg, Pb concentration exceeded the maximum limit permitted in fish oil products and chromium concentration above the limit of the maximum contaminant level.