#576_KARSLI_bozza Ital. J. Food Sci., vol 29, 2017 - 266 PAPER SEASONAL VARIATION OF FATTY ACID AND AMINO ACID COMPOSITIONS IN THE MUSCLE TISSUE OF ZANDER (SANDER LUCIOPERCA LINNAEUS, 1758) AND THE EVALUATION OF IMPORTANT INDEXES RELATED TO HUMAN HEALTH EMRE ÇAĞLAK* and BARIŞ KARSLI Recep Tayyip Erdoğan University, Faculty of Fisheries, Department of Processing Technology, 53100 Rize, Turkey *Corresponding author. Tel.: +90464 2233385; fax: +90464 2234118 E-mail address: emre.caglak@erdogan.edu.tr ABSTRACT In this study, the seasonal fatty acid and amino acid amounts in the muscles of the zander from Beyşehir Lake, Turkey, and their important indices for human health were evaluated. It was found that aspartic acid, glutamic acid and lysine levels in zander were dominant among the amino acids. The ratio of essential amino acids (EAA) to non-essential amino acids (NEAA) was between 0.69 and 0.78. In all seasons, the polyunsaturated fatty acid (PUFA, 89.85-109.11 mg/100g) amount in zanders was higher than saturated fatty acids (SFA, 55.08-81.89 mg/100g) and monounsaturated fatty acids (MUFA, 29.16-78.89 mg/100g). It was determined that EPA, DHA and omega-3 rates were high. The fatty acid quality indices (AI, TI, FLQ, w6/w3, h/H) were found at proper levels for human health. Summing up the results, it was found that seasons influenced both the compositions of amino acids and fatty acids of zander. Keywords: amino acids, Beyşehir Lake, fatty acids, seasons, zander Ital. J. Food Sci., vol 29, 2017 - 267 1. INTRODUCTION Seafood includes healthy nutrients being rich in protein, unsaturated essential fatty acids, minerals and vitamins they contain (SIDHU, 2003). Fish and shellfish play important roles for human health because of their fatty acid and amino acid varieties (GULER et al., 2008). Fish, as a source of food, have protein with high biological value. The building stones of the proteins consist of amino acids (WHO, 2007). Amino acids exist in seafood in important amounts and are classified as essential, non-essential and semi-essential amino acids according to their biological status (WU, 2010). These amino acids are the start-up material of many important substances for organisms, and have an important role, especially in energy metabolism. In addition, fish contains essential amino acids (threonine, valine, leucine, isoleucine, lysine, methionine, phenylalanine, tryptophan, histidine, and arginine) in proper amounts in their bodies (POLAT, 1999; VARLIK et al., 2011). The polyunsaturated fatty acids in fish oil are a vital importance for human health. Consuming fish and fish oil decreases the risk of coronary heart diseases. The nutritional importance of the fish consumption is closely related to the ω-3 fatty acid content of each species. These health benefits are also in a close relationship with ω-3 PUFAs. Long-chain ω-3 PUFAs cannot be synthesized by humans, and therefore they have to be taken with food. It was demonstrated with clinical and epidemiological studies that the major source of EPA and DHA, which constitute most ω-3 PUFAs, is the seafood (GULER et al., 2008; CENGIZ et al., 2012). DHA and EPA fatty acids are significant for the body because they could prevent coronary artery diseases (CONNOR, 2000; MOZAFFARIAN et al., 2005). Since DHA is the main component of the brain, eye retina and heart muscles, its importance for human health is undeniable. It was reported that EPA is beneficial in brain diseases and cancer treatment (CENGIZ et al., 2012). Fish are a good source of EPA and DHA. Some countries (Canada, Sweden, United Kingdom, Australia, Japan), World Health Organization (WHO) and North Atlantic Treaty Organization (NATO) declared the daily ω-3 need as 1.1.-1.6 g; and suggested that the intake should be as 0.3-0.5 g EPA+DHA and 0.8-1.1 g α-linoleic acid (ERKAN, 2013). When compared to sea fish, freshwater fish have higher C18 PUFA and lower EPA and DHA levels. Freshwater fish are generally characterized with high n6 PUFA (especially linoleic acid (18:2n6) and arachidonic acid (20:4n6)). For this reason, freshwater fish contain lower n3 PUFA and n3/n6 levels than sea fish (ÖZOĞUL et al., 2007; ÇELIK et al., 2005). In addition, the criteria such as atherogenic index (AI), thrombogenic index (TI), flesh lipid quality (FLQ) and hypocholesterolemic/hypercholesterolemic ratio (h/H) provide information on the lipid quality of fish (ULBRICHT and SOUTHGATE, 1991; ABRAMI et al., 1992; SANTOS-SILVA et al., 2002). The fish oil and fatty acid compounds show biochemical changes depending on ecological factors and the physiological status of the fish. Even among the same species, the fatty acid component may vary according to the nutrition, region, season, gender and environmental conditions (UYSAL, 2004; ÖZOĞUL et al., 2007; GULER et al., 2007). The rich amino acid and fatty acid contents in the bodies of freshwater fish make them nutritious, and therefore they are used as animal protein source all over the world (STEFFENS, 2006). The zander is a predatory freshwater species from the Percidae family, and is an important nutrient because of its high protein, low lipid rate, and essential ω-3 fatty acids. The zander is a lean carnivorous fish with high economic value spreading in inland waters in Turkey (UYSAL, 2004; ÇELIK et al., 2005). Ital. J. Food Sci., vol 29, 2017 - 268 The aim of this study was to determine the seasonal fatty acids and amino acid amounts in the muscles of the zander, and evaluate their important indices (AI, TI, FLQ, w6/w3, h/H) for human health. 2. MATERIALS AND METHODS 2.1. The study area and period This study was conducted in 2012-2013 seasonally, in Beyşehir Lake located within the borders of Konya and Isparta in 37°47′0″N, 31°33′0″E coordinates. 2.2. Fish material The zander (Sander lucioperca Linnaeus, 1758) whose height was between 34.85±1.33 cm and weight was between 395±44.76 g in 2-3 years of age were obtained from the fishermen in the Beyşehir side of the lake. The fishermen stated that they used stretching nets for fishing. A total of 32 fishes were examined throughout the study. The head, tail, fins, and viscera of zander were removed and muscle tissues of zander were kept at -70 oC until analysis of fatty acid and amino acid composition. 2.3. Amino acid analysis Zander samples were sent to The Scientific and Technological Research Council of Turkey (TUBITAK) Marmara Research Center (MAM) Food Institute for analysis of amino acid. In amino acid analysis, an in-house method was created by modifying those of DIMOVA (2003) and GHESHLAGHI et al. (2008), and the sample analysis was carried out. The analysis process was performed using a UFLC (Ultra-Fast Liquid Chromatography) device and a UV detector. The amino acid analyses were conducted in triplicate. 2.4. Analysis of fatty acid methyl esters Analysis of fatty acid methyl esters (FAME%) was carried out according to TUFAN et al. (2013). Lipid extraction of the samples was carried out in triplicate based on the method of BLIGH and DYER (1959), using chloroform:methanol (2:1, v/v). Methyl esters were prepared by transesterification using 2M potassium hydroxide (KOH; Merck, Darmstadt, Germany) in methanol and n-hexane (Sigma-Aldrich, Steinhein, Germany) according to the method described by ICHIHARA et al. (1996) with minor modification; 10 mg of extracted oil were dissolved in 2 mL n-hexane, followed by 4 mL of 2M methanolic KOH. The tube was then vortexed for 2 min at room temperature. After centrifugation at 4,000 rpm for 10 min, the hexane layer was taken for gas chromatography (GC) - Mass Spectrometry analyses. 2.5. Gas chromatography-mass spectrometry conditions The identification of fatty acids was conducted on gas chromatography-mass spectrometry (GC-MS) device (QP2010 Ultra with AOC-20i+s model auto sampler) using a mass selective detector (GC-MS QP 2010 PLUS) equipped with GC/MS solutions software (Shimadzu, Kyoto, Japan). FAME mix standards were separated on a Restek RT-2560 column (USA Cat no: 13199 Serial no: 47623-07; 100 m × 0.25 mm internal diameter, Thickness: 0,20μm) with helium (1.0 mL/min) as the carrier gas. The injection temperature Ital. J. Food Sci., vol 29, 2017 - 269 was 240 ºC, and split ratio 50 injection mode was used. The oven temperature was programmed as follows: Column oven temperature was started as 140 ºC, then at 4th min, the temperature increased to 240 ºC and held at this temperature for 20 min, and then held at this temperature for further 50 min starting at 25th min. The MS was scanned from m/z of 45 to 550. The ion source and interface temperatures were 200 ºC and 240 ºC, respectively. Fatty acids were identified by comparing the retention times of FAME with Supelco (tm) 37 component FAME mixture (Cat. No. 47885-U) and the results were confirmed by using WILEY/NIST 2011 library. Quantification of FAME was carried out using the area normalization method. According to the area value of each compound, area compositions were detected and results were shown as FAME%. The fatty acid content in the zander was calculated according to WEIHRAUCH et al. (1977). 2.6. Lipid quality indices Lipid quality indices as atherogenicity index (AI), thrombogenicity index (TI), fish lipid quality (FLQ) and hypocholesterolemic/hypercholesterolemic ratio (h/H) were calculated with the formulas below (ULBRICHT and SOUTHGATE, 1991; ABRAMI et al. 1992; FERNÁNDEZ et al., 2007). AI= [(12:0+(4x14:0)+16:0)]/[(n-6 PUFA+n-3 PUFA)+∑ MUFA] IT= [14:0+16:0+18:0]/[(0.5x∑ MUFA)+0.5(n-6 PUFA)+3(n-3 PUFA)+(n-3 PUFA/n-6 PUFA)] FLQ= (EPA+DHA)/total lipids h/H=(C18:1+C18:2+C18:3+C20:3+C20:4+C20:5+C22:4+C22:5+C22:6)/(C14:0+C16:0 2.7. Statistical analysis Statistical analysis was performed using the JMP 5.0.1 (SAS) package program. Analysis of variance (ANOVA) was used to compare the results the among seasons, and the Tukey's test was applied to the groups demonstrating difference (P<0.05) (SOKAL and ROHLF, 1987). 3. RESULTS AND DISCUSSIONS The amino acid contents of the zander in seasonal periods are shown in Table 1. The protein contents of the zander are the lowest in spring (17.75%) and the highest in autumn (19.35%). While the protein amount in summer and winter seasons showed statistical similarities to each other (p>0.05), they were found to be different from the other seasons (p<0.05). When the amount of the amino acids of the zander, which contain 16 types of amino acids, are examined, the methionine, which is one of the essential amino acids, had the lowest value with 465.5 mg/100g and aspartic acid, which is one of the non-essential amino acids had the highest value with 3202.5 mg/100g. It was determined that ten of the amino acids (phenylalanine, lysine, valine, leucine, isoleucine, tyrosine, glycine, proline, arginine and alanine) were at maximum level in autumn; five of them (histidine, threonine, aspartic acid, glutamic acid and serine) were at maximum level in summer; and one of them (methionine) was highest in winter. It was also seen that in spring, when the zander reproduce, all the amino acids except for lysine were at the lowest level. Lysine, leucine, threonine and valine were dominant in EAA. The aspartic acids, glutamic acid, alanine and serine were at the highest level in NEAA. Similarly, MOHANTY et al. (2012) Ital. J. Food Sci., vol 29, 2017 - 270 found that in giant river-catfish (Sperata seenghala) histidine, threonine and leucine from EAA; and glutamic acid, aspartic acid and serine amino acids from NEAA were dominant. It was observed that the highest values of the total essential amino acids (ΣEAA) were in autumn; the highest values of the total non-essential amino acids (ΣNEAA) were in summer. The ΣEAA/ΣNEAA ratio is an index that shows the protein quality (SWENDSEID et al., 1963). The ΣEAA/ΣNEAA ratio, which was obtained seasonally, changed between 0.69-0.78. IWASAKI and HARADA (1985) reported the EAA/NEAA ratio as being 0.70 in average in seawater fish species. MOHANTY et al. (2012) noted the ΣEAA/ΣNEAA ratio of giant river-catfish as being 0.89. In another study, the ΣEAA/ΣNEAA ratio (1.08) of Puntius sophore, which are among freshwater fish, was found to be higher than those reported in other studies (MAHANTY et al., 2014). It is considered that the differences between the ΣEAA/ΣNEAA ratios are resulted from the fish species, seasons, nutrition and location. Table 1. Seasonal amino acid contents of zander samples. EAA*: Essential amino acid, NEAA: Non-essential amino acid, AA: Amino acid. Different letters (a,b,c,d) in the same line indicates statistical differences among seasons (p<0.05). Amino acids (mg/100g) Spring Summer Autumn Winter Protein (%) 17.75±0.01a 18.75±0.11b 19.35±0.05c 18.73±0.26b Methionine* 465.5±7.78a 509±1.41b 499±0.00b 513±5.66b Phenylalanine* 661±9.90a 687.5±6.36b 812±1.41c 749±2.83d Lysine* 2052.5±17.68a 1975±2.83b 2544.5±12.02c 1969.5±6.36b Histidine* 492±12.73a 643±1.41b 628±28.28b 632.5±26.16b Valine* 790.5±13.44a 861±1.41b 928±7.07c 887±11.31d Leucine* 1119.5±19.09a 1181±5.66b 1317.5±7.78c 1198±9.90b Isoleucine* 701.5±12.02a 744±2.83b 839.5±3.54c 809±5.66d Threonine* 808±12.73a 933±1.41b 878.5±0.71c 836.5±2.12d Tyrosine 579±0.00a 603±1.41b 682.5±2.12c 630±1.41d Glycine 613±8.49a 706.5±4.95b 764±1.41c 682±2.83d Proline 496±8.49a 543±24.04ab 604.5±0.71c 579.5±2.12bc Arginine 724.5±10.61a 744±1.41a 851.5±0.71b 806±2.83c Alanine 1034.5±16.26a 1116±31.11b 1194±1.41c 1125±2.83bc Aspartic Acid 2779.5±47.38a 3202.5±31.82b 2783.5±3.54a 3079±16.97c Glutamic Acid 2781±42.43a 3174±2.83b 3097.5±4.95b 2985±4.24c Serine 809±14.14a 899±2.83b 851.5±4.95c 866±7.07bc ΣEAA 7090.5±70.00a 7533.5±23.33b 8447±9.90c 7594.5±4.95b ΣNEAA 9816.5±147.79a 10988±79.20b 10829±7.07b 10752.5±14.85b ΣAA 16907±217.79a 18521.5±55.86b 19276±2.83c 18347±9.90b ΣEAA/ΣNEAA 0.72 0.69 0.78 0.71 Ital. J. Food Sci., vol 29, 2017 - 271 The World Health Organization recommended methionine, phenylalanine, lysine, histidine, valine, leucine, isoleucine and threonine requirements for adults of 10, 25, 30, 10, 26, 39, 20, respectively and 15 mg amino acid/kg body weight per day (WHO, 2007). When the results of our study are evaluated according to the reports of WHO (2007), it is clear that if a person whose weight is 70 kg consumes 200 g meat of zander, he or she receives methionine, lysine, histidine, isoleucine and threonine amino acids; and if one consumes 300 g zander, all his or her amino acid needs could be met. The fatty acid contents of the zander in each season are shown in Table 2. Table 2. Seasonal fatty acid contents of zander samples. Fatty Acids mg/100g Spring Summer Autumn Winter C14:0 1.79±0.32a 2.38±0.13a 3.10±0.25a 5.80±0.79b C15:0 0.74±0.01a 0.72±0.12a 0.87±0.19a 1.65±0.14b C16:0 38.05±0.60a 51.87±0.93b 54.05±0.90b 52.99±3.70b C17:0 0.96±0.09a 1.14±0.09ab 1.14±0.02ab 1.76±0.34b C18:0 10.65±0.18a 18.99±0.25b 15.35±0.10bc 11.83±1.96ac C20:0 0.22±0.03a 0.31±0.01a 0.51±0.02b 0.56±0.06b C21:0 1.84±0.10a 2.03±0.15a 3.49±0.36b 5.67±0.45c C24:0 0.84±0.04a 0.80±0.00a 0.77±0.07a 1.65±0.10b ΣSFA 55.08±0.93a 78.24±1.42b 79.28±0.14b 81.89±3.95b C16:1 7.51±0.16a 5.50±0.27a 12.65±1.02a 25.31±3.95b C17:1 0.75±0.00a 0.47±0.00a 0.81±0.10a 2.02±0.22b C18:1n9t 0.13±0.00a 0.24±0.01ab 0.31±0.00b 0.57±0.08c C18:1n9c 20.51±0.53a 22.42±0.99a 36.17±2.00b 49.48±0.77c C20:1 0.59±0.10a 0.53±0.00a 0.63±0.12a 1.50±0.18b ΣMUFA 29.49±0.58a 29.16±1.27a 50.58±3.24b 78.89±5.20c C18:2n6c 4.68±0.05a 5.01±0.45ab 8.46±0.47b 12.05±0.57c C18:3n6 0.30±0.19a 0.55±0.00a 0.57±0.17a 1.26±0.00b C20:2n6 0.17±0.00a 0.42±0.00b 0.69±0.03c 0.63±0.00c C20:3n6 0.60±0.01a 0.42±0.03a 0.55±0.07a 0.90±0.06b C20:3n3 0.28±0.00ab 0.13±0.03a 0.34±0.07b 0.86±0.04c C20:4n6 18.33±0.30ab 19.01±0.16a 15.56±0.80b 18.06±1.06ab C20:5n3 9.19±0.22a 11.08±0.15a 23.04±1.32b 15.47±1.19c 22:5n3 8.14±0.38bc 5.35±0.03a 6.69±0.02ab 9.29±0.63c C22:6n3 48.17±1.23ab 53.28±1.72a 42.76±3.29b 50.60±1.58ab ΣPUFA 89.85±1.06a 95.26±1.47ab 98.66±4.81ab 109.11±4.71b Different letters (a,b,c,d) in the same line indicates statistical differences among seasons (p<0.05). Ital. J. Food Sci., vol 29, 2017 - 272 It was observed that in all seasons, the PUFAs are the highest (ave. 43.32%), MUFA’s are the lowest (ave. 19.64%). The palmitic acid (C16:0) has the highest amount among saturated fatty acids. The 16:0 amount was detected between 18.52%-24.52%. Similarly, in a study conducted by JANKOWSKA et al. (2003), C16:0 was determined as 19.91% in wild zander, 20.24% in cultured zander (fed artificial feed) and 20.33% in cultured zander (fed natural food), respectively. The total saturated fatty acid (∑SFA) were found in spring, summer, autumn and winter as 55.08 mg/100g, 78.24 mg/100g, 79.28 mg/100g and 81.89 mg/100g, respectively; which shows the values in spring were different from the other seasons (p<0.05). Among the monounsaturated fatty acids (MUFA), palmitoleic acid (C16:1), cis-10-heptadecanoic acid (C17:1) and cis-11-eicosenoic acid (C20:1) values were observed minimum in summer; while the lowest values of elaidic acid (C18:1n9t) and oleic acid (C18:1n9c) were found in spring. The values of C16:1, C17:1, C20:1, C18:1n9t and C18:1n9c in winter was found different from other seasons (p<0.05). The ∑MUFA amounts were determined between 29.49-78.89 mg/100g and there were significant differences among the seasons (p<0.05). Polyunsaturated fatty acids (∑PUFA) showed constant increase from spring till winter. The majority of ∑PUFA consisted of docosahexaenoic acid (C22:6n3) DHA, arachidonic acid (C20:4n6) and eicosapentaenoic acid (C20:5n3) EPA. In all seasons, the DHA amount was found higher than the other PUFA amounts at a significant level (p<0.05) and was determined as 48.70 mg/kg in average. The SFA (28.62%-30.01%), MUFA (13.79%-27.57%) and PUFA (38.19%-48.95%) amounts of zander in this study were found similar to the results reported in zander as 31.8%, 13.8% and 42.4%, respectively in the study conducted on seawater and freshwater fish species of Turkey by ÖZOĞUL et al. (2007). In another study, the SFA, MUFA and PUFA contents of the zander were determined in Seyhan Lake as 32.9%, 28.0%, 20.8%, in Eğirdir Lake as 30.5%, 20.3%, 30.5% (ÇELIK et al., 2005). The fatty acid contents of the zander examined in this study were more consistent with the results of the zander of Eğirdir Lake than those from Seyhan Lake. However, the PUFA rates were found to be lower than our results. It is considered that this difference occurs from the undetected % fatty acid rates being high in the study conducted by ÇELIK et al. (2005). In another study, the SFA%, MUFA% and PUFA% rates of the wild zander were found as 27.84%, 21.36% and 50.80, respectively (JANKOWSKA et al., 2003). The PUFA/SFA ratio must be minimum 0.45 (JUSTI et al., 2003; TUFAN et al., 2011). The data of this study were 1.22-1.63, which is consistent with the values recommended in terms of health (Table 3). The PUFA/SFA ratio determined in spring (1.63) was statistically different from those determined in other seasons (p<0.05). ÖZOĞUL et al. (2007) reported that the PUFA/SFA ratio changed between 0.78-1.56 is freshwater fish, and in zander this ratio was 1.33. This PUFA/SFA ratio was found to be similar with our results especially recorded in winter. It is reported that the atherogenic (AI) and thrombogenic (TI) indices that are higher than (>1.0) is harmful for human health (OURAJI et al., 2009). If this value gets lower, the risk of coronary heart diseases decreases (CUTRIGNELLI et al., 2008). The AI (0.38-0.49) and TI (0.22-0.31) values obtained in this study were found lower than this value in all seasons (Table 3), and it was also determined that there were no risks for human health. SOUSA BENTES et al. (2009) reported that the h/H ratio of fatty acids is the indicator of whether the fat in the product is nutritionally adequate. The h/H ratio was found between 2.17-2.77 in this study, and no differences between spring and winter, also between summer and autumn were determined (p<0.05). Ital. J. Food Sci., vol 29, 2017 - 273 Table 3. Fatty acid ratios and lipid quality indexes. Fatty acid Spring Summer Autumn Winter ∑PUFA/∑SFA 1.63±0.05a 1.22±0.04b 1.24±0.06b 1.33±0.01b ∑PUFA/∑MUFA 3.05±0.10a 3.27±0.19a 1.96±0.22b 1.39±0.15b EPA+DHA 57.36±1.01a 64.36±1.57a 65.8±4.61a 66.06±2.77a ∑n3 PUFA 65.78±0.64a 69.84±1.57a 72.83±4.56a 76.21±4.57a ∑n6 PUFA 24.07±0.43a 25.42±0.1b 25.83±0.25b 32.9±0.14c ∑n3/∑n6 2.73±0.02ab 2.75±0.07a 2.82±0.15a 2.32±0.13b ∑n6/∑n3 0.37±0.00a 0.36±0.01a 0.36±0.02a 0.43±0.02b AI 0.38±0.02a 0.49±0.01b 0.45±0.01bc 0.41±0.00ac TI 0.22±0.01a 0.31±0.01b 0.28±0.01bc 0.25±0.01ac FLQ 32.89±0.67a 31.76±0.97a 28.79±1.80ab 24.47±0.71b h/H 2.77±0.08a 2.17±0.05b 2.35±0.02b 2.70±0.07a AI: atherogenic index, TI, thrombogenic index, FLQ: flesh-lipid quality, h/H: hypocholesterolemic/hypercholesterolemic ratio. Different letters (a,b,c,d) in the same line indicates statistical differences among seasons (p<0.05). If the FLQ value is high, this indicates that there are nutrient lipids with good quality (ABRAMI et al., 1992). The highest FLQ values were seen in spring (32.89), and the lowest in winter (24.47). The difference between them was significant (p<0.05) (Table 3). The FLQ values in winter were found to be similar only to those in autumn (p>0.05). The EPA+DHA amounts in zander were determined between 57.36-66.06 mg/100g (Table 3). There were differences between the seasons (p>0.05). The EPA+DHA amounts in the zander caught in the same lake were determined as 29.23%, 21.32%, 28.27% and 24.24% for spring, summer, autumn and winter, respectively (GULER et al., 2007). These results show similarity with this study except for the summer season. The n6/n3 ratio is recommended max. 4 by the UK Department of Health (JUSTI et al., 2003). The ∑n6/∑n3 ratios in this study were found in the recommended limit value. The ∑n6/∑n3 ratio in winter (0.43) was found higher (p<0.05) than the other seasons (0.36-0.37) (Table 3). JANKOWSKA et al. (2003) found the ∑n6/∑n3 ratio of the wild zander as 0.31. ÖZOĞUL et al. (2007) determined that the n6/n3 ratio of zander is 0.46 similarly with our winter data. On the other hand, GULER et al. (2007) reported that n6/n3 ratio of zander is between 0.67-1.39 in all seasons. 4. CONCLUSIONS As a conclusion, the zander, which are also called freshwater seabass, have an important fatty acid composition. It was determined that the EPA, DHA and omega-3 rates of the zander, which played an important role in human nutrition are high. In addition, the fatty acids quality indexes were found at proper levels for human health. Moreover, it was observed that the zander have high protein and rich amino acid content although the rate of amino acids changes according to the seasons. The lowest amino acid rates were found in spring, the period of reproduction. At the end of the seasonal examination of amino Ital. J. 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Functional amino acids in growth, reproduction, and health. Adv. Nutr. 1:31. Paper Received August 8, 2016 Accepted December 15, 2016