International Journal of Agricultural Policy and Research Vol.2 (7), pp. 273-280, July 2014 Available online at http://www.journalissues.org/ijapr/ © 2014 Journal Issues ISSN 2350-1561 Original Research Paper Seasonal variations in proximate and fatty acid composition of golden grey mullet Liza aurata (R, 1810) from the Tunisian coast Accepted 23 June, 2014 Ilhem Ketata Khitouni 1 , Nourhène Boudhrioua Mihoubi 2 , Abderrahmen Bouain 1 and Faouzi Ben Rebah 3* 1 UR Biodiversité et Ecosystèmes Aquatiques, FSS, Sfax, Tunisia. 2 UR Ecophysiologie et Procédés Agroalimentaires, ISB-Sidi Thabet, Tunisia. 3 Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS, Sfax-Tunisia. * Corresponding Author Email: benrebahf@yahoo.fr Tel.: +21674675055 The aim of this work was to determine the seasonal variations of chemical composition of Liza aurata of the coastal catch from the Gabes Gulf, Tunisia. Maximal water were reached in July for females (77.89  0.27 mg / 100 g of fresh fish) and in May for males (77.68 mg / 100 g of fresh fish). Minimal water values were reached during September for both females and males (63.77  0.45 and 64.86  0.16 mg /100 g of fresh fish, respectively). Negative correlations between fat and water contents were observed. The higher fat contents were recorded during September for males and females (10.13  0.07 % and 15.07  0.12 mg / 100 g of fresh fish, respectively). Higher protein contents were observed over the year (except May, July and August for males and after the spawning period for females, from July to September). Palmitic acid was the most abundant fatty acid ranging from 20.03% to 31%, apart from the female in summer where oleic acid and palmitic acid were estimated at 28.98 and 23.35%, respectively. Oleic acid was the main unsaturated fatty acid, ranging from 13.36% to 28.98%. Liza aurata muscle contained appreciable levels of Omega-3 polyunsaturated fatty acids (14.47 % - 23.23 %) suggesting the use of this fish as a source of healthy diet for humans. Key words: water, fat, protein, mineral element, fatty acids, fish muscle, Liza aurata. INTRODUCTION The chemical composition of fish muscle varies greatly depending on species, sexual cycle, age, feed, stage of maturity, environment, season, organs and muscle location (FAO, 2002; Noël et al., 2011 and Roy et Lall, 2006). Actually, seafood products are well known to provide significant amounts of different beneficial nutrients such as proteins, essential minerals and lipid with highly unsaturated fatty acids (Simopoulos, 1997). However, various fish species do not provide the same nutrient profile depending on the seasons. Generally, fish is the excellent source of protein, because of the amino acid composition and degree of digestibility (Louka et al ., 2004). Moreover, fish fat is subject of a great deal of attention due to its high content of ω-͵ polyunsaturated fatty acids ȋω-3 PUFA) having a positive effect in the prevention of certain human diseases like hypertension, inflammation, psoriasis, aggression, depression and cancer (González et al ., 2006; Haliloglu et al., 2004). Interestingly, great seasonal variations of fatty acid composition for several marine organisms were reported in response to various factors. For example, the saturated fatty acids increased during the months of high fat content; period of the enhanced feeding activity (Gockse et al., 2004; Zlatanos and Laskaridis, 2007). To ensure the nutritional value as well as eating quality of fish, the seasonal biochemical evaluation is necessary. In Tunisia, Gabes Gulf coast is considered a main seafood resource (Ben Rebah et al., 2009; DGPA, 2004), very little information is available on the biochemical constituents in