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This study reveals information for the first time about the total lipid (TL) content and fatty acid composition (FA) of Mactra stultorum (M. corallina). Three edible organs (foot, mantle and adductor muscle) were the subjects of this research in order to determine the most favorable periods for their consumption in relation to seasonal variability. The results showed lower lipid content in the adductor muscles in summer (12.73 ± 2.55 mg/g dry matter); while a higher content was observed in winter (28.97 ± 3.50 mg/g dry matter). However, similar lipid contents were observed in the mantle and foot tissues among the seasons. The fatty acid composition of Mactra stultorum adductor muscles, mantle and foot was dominated by saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA). Palmitic acid (16:0) was the major saturated fatty acid (SFA) and reached higher levels during summer in the foot (26%), mantle (21%) and adductor muscles (25%). Among PUFA, eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) showed significant variation among seasons with high levels recorded during winter and spring. Monounsaturated fatty acids (MUFA) did not show any remarkable variation among seasons for the three studied tissues. Seasonal changes in fatty acids were observed for all samples, reaching a maximum level in winter or spring. [ABSTRACT FROM AUTHOR]

This study investigates the impact of season and sex variations on the total lipid contents and fatty acid composition of Scomber scombrus fillets from the Middle East Coast of Tunisia in order to dertermine the most favorable periods for consumption, and to see if the nutritional quality of the meat depends on the sex of the animal. The effect of fishing season induced significant changes in the lipid profile, and the highest values for total lipids were obtained in the spring for females with 13.2% and for males with 18.9%. The highest values for proteins were obtained in the summer for females with 22.0% and for males with 21.8%. Protein content variations were not significant (p > 0.05). The n-3/n-6 ratio showed a significant level, indicating a tendency toward n-3 fatty acid accumulation in mackerel fillets mainly represented by DHA, whose values were high during the study period for both sexes, except in autumun, which is the period of mackerel gonad maturation, when DHA decreased significantly (p < 0.05), reaching 23.2 and 34.0% for males and females, respectively. It was concluded that Scomber scombrus has high levels of proteins, lipids, and fatty acid contents mainly n-3 PUFA. DHA sex variations were not significant (p > 0.05). The Atherogenicity index (AI) and Thrombogenicity index (TI) were calculated. In our study the AI index was comprised between 0.3 and 0.6 for males and between 0.4 and 0.5 for females. The TI index values ranged from 0.6 to 0.8 for males, and was about 0.6 for females. [ABSTRACT FROM AUTHOR]

The copepod Lernaeosera lusci is a common ectoparasite of the hake Merluccius merluccius, which constitutes its definitive host. The present study is the first to investigate the impact of L. lusci and its infection intensity on the fatty acid (FA) composition and oil quality of its host. The results revealed a substantial decrease in the total FA content, which dropped by 50, 70 and 83% when fish was infected by one (L1), two (L2) and three (L3) parasites, respectively. The lipid profile showed a tendency for a significant decrease in the saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) levels in all parasitized groups and in a parasite load dependant manner (p < 0.05). The same tendency was observed for the most commonly analysed FA and in particular for essential FA, such as e arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, which showed smaller amounts associated with L. lusci co-infection. From a nutritional standpoint, our findings revealed that L. lusci is able to cause severe deterioration in the nutritional quality of its host oil. In addition to the increase in the thrombogenicity index (IT) and the high atherogenicity index (IA) values, the low hypocholesterolemic / hypercholesterolemic fatty acid ratio (H/H) and the modest amount of DHA+EPA (20 and 10 mg/100g) recorded at heavy infection levels make the parasitized fish inadequate sources of these PUFA and unsuitable for consumers with special dietary needs. [ABSTRACT FROM AUTHOR]

This study aimed to provide information about the changes in fatty acid composition and quality in Ruditapes decussatus tissue after four culinary treatments (steamed, baked, grilled and fried). All treated samples showed a significant decrease in moisture and protein. In contrast, a significant increase in fat content resulted from the grilled and fried treatments. Saturated fatty acid was significantly higher in fresh clams than all cooking processes, except in fried ones. Monounsaturated fatty acid and polyunsaturated fatty acid varied significantly between fresh and cooked clams with high values recorded for fried clams. The n-3/n-6 ratio, peroxide index, EPA+DHA and atherogenicity index decreased significantly after the cooking processes particularly in fried clams. The mineral levels (Mg, Ca and Mn) of cooked clams decreased considerably with grilled and fried treatments. The impacts of cooking on the fatty acid composition and protein content in clam tissue was evaluated by lipid peroxidation (TBARS, PV, FFA, TOR) and protein oxidation (AOPP and PCO), which varied statistically in fried, steamed, grilled and baked samples; indicating alterations in cooked clam tissues structure. Based on our results, steaming is recommended for the preparation of clams because it preserves the most nutritional tissue quality. [ABSTRACT FROM AUTHOR]