Abstract:
Throughout the year, fish are subjected to considerable environmental changes and fluctuations in availability and compositions of feed that will affect their proximate, amino acids and fatty acid compositions.The purpose of this study was to clarifythe seasonal variations in proximate, amino acid and fatty acid profile of wild and cultured Anabas testudineus.The proximate compositions, total amino acid and fatty acid profile were determined by AOAC, HPTLC and GC respectively. Theresultsindicated that proximate (Moisture, Ash, Protein and Lipid), amino acid and fatty acid profile varied significantly (p<0.05) between wild and cultured fishes depends on season.For both cultured and wild Anabas testudineus,amount of protein was higher in post-monsoon than in pre-monsoon period.The fat and fatty acid as well as protein and amino acid contents of the investigated fish species showed a significant (p<0.05) seasonal dependency. Among the 14 recorded amino acids (Essential Amino Acid-6, Non-essential Amino Acid-8), the major amino acid in the total crude protein were histidine, methionine, isoleucine, lysine, glutamic acid and glycine. The findings of the present study also showed that unsaturated fatty acids represented 59.88-60.98%and 60.12-61.32% of the total fatty acids, whereas saturated fatty acids accounted for 39.02-40.11% and 37.56-39.86% for wild and cultured koi fish depending on seasons.The major fatty acids from wild and cultured Anbastestudineuswere oleic acid (18:1), palmitic acid (16:0), linoleic acid (18:0), stearic acid, palmitoleic acid (16:1) andmyristic acid (14:0).Fatty acid profile resulted that some fatty acid (Lauric acid (C12:0), Pentadecyclic acid (C15:0), Arachidic acid (C20:0), Caproic acid (C6:0), Enanthic acid (C7:0), Caprylic acid (C8:0)) were not detected in cultured fish but present in wild investigated fish.Most nutritionally important docosahexaenoic acid (DHA, C22:6 n-3) was dominant in wild fish fillets instead of linoleic acid (C18:2 n-6) in the farmed fish. The ratio of Essential Amino Acid (EA)/Non-Essential Amino Acid (NEA)was higher in cultured fish of post-monsoon seasons. It is found that fatty acid composition and n-3/n- 6 is quite high in wild koi fish in post-monsoon and it is preferable for human diet than cultured fish. Therefore, a comprehensive study on cultured and wild fishes is required for the further confirmation of the result of present study.
Description:
This thesis submitted to the Department of Fisheries, University of Dhaka, in partial fulfillment of the requirements for the degree of Master of Science in Fisheries.
