Multidisciplinary analytical investigation of phospholipids and triglycerides in offshore farmed gilthead sea bream (Sparus aurata) fed commercial diets

► We optimised a new preparative and analytical multitechnique method for fish analysis. ► TAG, PL and fatty acids were simultaneously quantified as a function of fish growth. ► We discussed the evolution of TAG/PL ratio as a function of adult gilthead growth. In this work, a quantitative characterisation of lipid (both triglycerides and phospholipids) rearrangements in the muscle of offshore-raised gilthead sea bream was carried out as a function of fish growth between April and September. Relative percentages of lipid classes and fatty acids/acyls composition of the commercial feeds and fish dorsal muscles were assessed by means of an interdisciplinary analytical approach. A combination of preparative chemistry and experimental results from NMR spectroscopy, GC, 3D-TLC as well as proximate analysis permitted the observed growth parameters in key metabolic events to be linked with fish fattening and lipid turnover. While defined effects of feed composition on fatty acid profiles of fillets were ascertained, the relative increase of fatty acyls in triglycerides and phospholipids were also estimated enabling detailed evaluation of TAG:PL ratio in adult offshore-farmed gilthead sea bream. NMR was also used to quantify PUFA regiospecific distribution in TAG and PL.