Seasonal variation of nutritional constituents in muscles of silver scabbard fish Lepidopus caudatus (Pisces: Trichiuridae) from Eastern coast of Tunisia

Abstract

Seasonal variation in amino and fatty acids and mineral contents was investigated in 72 Lepidopus caudatus muscle fillets, averaging 803 ± 317 g in total wet weight and 110 ± 9.85 cm in total length, and collected from the Eastern coast of Tunisia, to give information on its nutritional constituents’ quality and determine the appropriate period for its consumption. Results showed significant differences in ash, moisture, crude protein, and total lipid content. Fatty acid composition varied significantly between the four seasons, with total PUFAs, predominated by docosahexaenoic acid, exhibiting high levels in spring, followed by total SFAs dominated by palmitic acid in spring and total MUFAs represented by oleic acid in autumn. Glutamic and aspartic acids showed high concentrations in autumn, with total essential amino acids and their non-essential acids ratio exhibiting a significant seasonal variation. Analysis of seasonal variation of minerals indicated that P revealed a high concentration in autumn, followed by K, Na, and Mg in summer and Ca in spring. The high quality of these nutritional constituents indicates the importance of L. caudatus muscle fillet as a source of energy and nutritional value throughout the year and thus can be added to the Tunisian food composition table.