Seasonal Change of Lipid and Fatty Acid Composition of Little Tuna Euthynnus Alletteratus-By-Prodvcts

Abstract

Little tuna (Euthynnus alletteratus) is an important Mediterranean commercial fish species. In this study, the lipids of tuna filet, head, viscera, liver, and gonads fished in Tunisian waters were examined in summer and winter. Total lipid content in most organs showed a significant variation due to seasonal change. The highest lipid content was found in head in little tuna fished in winter and summer (14.2%). The lowest levels were attributed to gonads (1.5%). The major fatty acids classes were polyunsaturated fatty acids (PUFA) followed by saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA). The lowest percentage of (MUFA) was recorded in winter season (9.77%). In summer, the proportion of PUFA decreased while that of SFA increased. The major contributing factor to the seasonal change of PUFA was n-3 fatty acids especially eicosapentaenoic acid (EPA) and docosahexaenoic (DHA). The lowest levels of PUFA/SFA were registered in summer. Little tuna by-products are an adequate raw material for fish oil production and excellent sources of n-3 fatty acids, the highest levels of PUFA were found during winter.

Bioenergetics of captive Pacific bluefin tuna (Thunnus orientalis)

“…The percentage of total muscle tissue (red and white muscle) reported in Table 5 was comparable to the reported value of 60% (Graham et al, 1983), and the percentage of fat found in the head is comparable to previously published data (Nguyen et al, 2012;Selmi et al, 2008) with values ranging from 12% to 14%. However, Nakamura et al (2007) performed proximate analysis of wild and cultured Pacific bluefin (average mass = 33 kg) and reported lipid contents in the musculature that were substantially higher than those found in this study.…”

Temporal and inter-specific variations in forage fish feeding conditions in the NW Mediterranean: lipid content and fatty acid compositional changes

“…This study demonstrates temporal variations in feeding conditions between and among adult forage fishes collected from the NW Mediterranean Sea in summer (July 2010) Selmi et al 2008) and are linked to regionally specific trophic dynamics, particularly food supply (quality and quantity), which dictate the nutritional condition of consumers.…”

By-products of farmed European sea bass (Dicentrarchus labrax L.) as a potential source of n-3 PUFA

“…The fish heads and trimming resulting from processing were employed for oil production from Alaskan processed seafood (Oliveira & Bechtel 2005) and tuna fish (Chantachum et al 2000;Selmi et al 2008). In particular, fish head and liver have long been a source of fish oil and consumed to improve vision and growth (Selmi et al 2008).…”

“…In particular, fish head and liver have long been a source of fish oil and consumed to improve vision and growth (Selmi et al 2008).…”

“…Variable percentage of EPA and DHA were observed in fish oil obtained from commercial Alaskan fish by-products (Oliveira & Bechtel 2005;Bechtel & Oliveira 2006) and tuna by-products (Chantachum et al 2000;Selmi et al 2008).…”