Thinking different strategies for indexing fatty acids in fish fillets Part II: gilthead seabream as case-study

The Western population considers seafood as nutritious and healthy thanks to their content in polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Nevertheless, marine finfishes, such as gilthead seabream (Sparus aurata) have a scarce ability to synthesize long chain FAs; hence, their intake is guaranteed by the diet. Since marine ingredients have been deeply reduced in aquafeeds, a reduction of n-3 PUFA has been observed in fillets,thuslowering the health and nutritional quality in sea bream fillets. Many quality indexes are available to highlight these latter requirements, and among these, the Indexes of Atherogenicity (IA) and Thrombogenicity (IT) are certainly the most used. Recently, two Healthy Fatty Indexes (HFI1 and HFI2) have been set considering the various classes of FAs by increasing or decreasing their relative content expressed in weight, according to their health impact. The aim of the present study was to compare the effectiveness of the HFI, compared to the IA and IT in evaluating the nutritional differences ofsea bream fed commercial (COM), marine ingredient-based (FISH), vegetable-based (VEG), or insect- based (INS) diets. The EPA+DHA content (mg/100 g fillet) was calculated since it is the only parameter with a suggested value, considering the positive effect on human health. No differences were obtained for TI; the best (p<0.05) AI was calculated for COM (0.10), followed by VEG (0.12), INS (0.17) and FISH (0.18) groups. The HFI1 index discriminated COM (1.91) and VEG (1.34) groupsfrom the FISH (1.25) and INS (1.23) ones. Noteworthy, EPA+DHA amounts significantly differed between FISH and COM groups, while VEG and INS had intermediate content. In conclusion, HFI indexes did notseem to effectively sum up the healthy potential of sea bream lipids; thus, an inclusion of EPA and DHA in the HFIs would be useful. Thanks to European Union – Next generation EU M4C2 – Investimento 1.4 – Centri Nazionali – CN2 AGRITECH SPOKE 9 CUP B13C22001020007 for financing the Post-Doc grant of Lina Fernanda Pulido Rodríguez.