Proximate, unsaponifiable lipid and fatty acid composition of bogue (Boops boops) and horse mackerel (Trachurus trachurus) from the Italian trawl fishery

This study was aimed at evaluating the nutritional properties of bogue (Boops boops) and horse mackerel (Trachurus trachurus), fish species present throughout the Mediterranean and highly represented in the catch of the Italian trawl fishery. In Italy such fish species are scarcely known by consumers and are not sought-after on the market, especially when the fish are small. Proximates, unsaponifiables and fatty acid profile of bogue and horse mackerel caught by trawlers in different seasons of the year along the southern Adriatic coast of Italy were evaluated. Results showed that both species were characterised by good protein contents (18–20 g/100 g) and low lipid (1–2 g/100 g) and cholesterol (50–70 mg/100 g) levels at any season considered. Along with α-tocopherol (0.45–0.70 mg/100 g), δ-tocopherol was found at a lower level (0.04–0.09 mg/100 g) while no detectable amounts of the γ-isomer were observed in either species. The fatty acid profiles of horse mackerel and bogue exhibited a seasonal fluctuation. They were characterised by high proportions of polyunsaturated fatty acids (PUFA), ranging from about 30% of total fatty acids in summer to more than 40% of total fatty acids in spring and winter, and by high n-3/n-6 PUFA ratio values (4.4–6.8 for bogue, 7.4–8.2 for horse mackerel). On a quantitative basis, in bogue total n-3 PUFA amounted to 0.29–0.43 g out of 0.33–0.54 g of total PUFA per 100 g wet fillet. In horse mackerel total n-3 PUFA ranged between 0.37 g and 0.43 g/100 g and total PUFA between 0.41 and 0.49 g/100 g wet fillet. The atherogenic (0.46–0.63) and thrombogenic (0.22–0.38) indexes calculated on bogue and horse mackerel were comparable to those of fish species of higher commercial value. The nutritional properties of these underutilised species may be considered comparable to those of other low-fat fish species from the wild and also from aquaculture present on the Italian market and meeting consumers’ preferences.