Changes in fatty acid composition, cholesterol contents and quality attributes of bolti (Tilapia nilotica) fingerlings in relation to dietary lipid levels and sources in feeding regime

This study was carried out to determine the fatty acids composition, cholesterol levels and quality attributes in muscle tissue (filet) of bolti (Tilapia nilotica) fingerlings as affected by feeding different sources and levels of lipids during 90 days. Corn oil and cod liver oil were added to the feeding regime (2 \%, 4 \% and 6 \%) alone or as mixtures (1 : 1, w/w). The total lipids and cholesterol contents were found in the range of 2.55-8.14 g/100 g and 42-53 mg/100 g fish, respectively. All feeding treatments presented oleic acid C18:1 n-9, as predominant fatty acid followed by linoleic C18:2n-6, palmitic acid C16: 0 and stearic acid C18: 0, respectively. The highest amount of total polyunsaturated fatty acids was detected when a mixture of 1 \% corn oil and 1 \% fish oil was enclosed in the fish diet. Concerning quality parameters (pH, TVN, TMA and TBA), there were no effects for dietary tat levels and sources on the quality attributes of the fish flesh.