Modelling the predictable effects of dietary lipid sources on the fillet fatty acid composition of one-year-old gilthead sea bream (Sparus aurata L.)

The present study aimed to ascertain the different fatty acid (FA) descriptors linking dietary and muscle FA composition in one-year-old gilthead sea bream. For that purpose, our own published data along with additional data from the present study were compiled and analysed. High linear correlations (r2 = 0.90, P < 0.001) between dietary and muscle fatty acid composition were reported for monoenes, C18 polyunsaturated FA (PUFA) and long-chain PUFA (LC-PUFA). Prediction deviations due to changes in muscle fatness were analysed in an independent trial with two different feeding levels (full ration size, 30% restriction ration). Regardless of feeding regimen, predicted values for muscle FA at low concentrations deviated (P < 0.001) from observed values, but good predictions with less than 6% deviations were found for abundant fatty acids (16:1n−7, 18:1n−9, 18:2n−6, 18:3n−3, 20:4n−6, 20:5n−3, 22:6n−3). All this highlights the predictable effects of dietary oils in the muscle FA composition of gilthead sea bream, although further research is needed to cover all the range of commercial fish size and for the up-scaling of laboratory results to different fish farming conditions.