Nutritional Evaluation in Five Species of Tuna

Abstract

Proximate composition was determined in different body parts (skin, white muscle, red muscle, head muscle and belly flap) of five species of tuna; Katsuwonus pelamis (skipjack, balaya,) , Thunnus albacares (yellow fin tuna, kellawalla), Auxis rochei (Bullet, tuna, ragoduwa), Auxis thazard (frigate tuna, alagoduwa) and Euthynnus affinis (kawakawa, attawalla.) obtained from the Negombo fish landing site. Fatty acid profiles were also analyzed in the skin, red and white muscle of the five species. No significant differences between the tuna species were observed with respect to protein, total fat, and moisture contents. The ash content in Frigate tuna and Kawakawa were significantly higher than the other species. The muscle tissue in all the species was rich in protein (20-25%) and low in fat «2%). The skin of all the species recorded high protein (27-32%) and lipid (6-8%) levels. The moisture content was low in the skin compared to the other tissues. All five species of tuna studied here recorded less SFA (11-33%) and more PUFA (50-74%) in the muscle tissues. The MUF A content in muscle tissue ranged from 8-25% and all the species contained both EPA (eicosapentaenoic acid, C20:5n-3) (2- 19.7%) and DHA (docosahexaenoic acid, C22:6n-3) (4-42%) in varying amounts.