AMINO ACID PROFILE AND POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) OF SMOKED FARMED CLARIAS GARIEPINUS (BURCHELL, 1822) RAISED UNDER DIFFERENT CULTURE SYSTEMS IN IBADAN, NIGERIA

Abstract

Fish food quality and safety is critical to consumers due to its public health implication. To exploit huge export opportunities for smoked farmed catfish, there is need for strict adherence to international quality and safety standards. This paper examined amino acid profile and polycyclic aromatic hydrocarbons (PAHs) of smoked farmed catfish Clarias gariepinus raised under different culture systems with a view to determining its quality and safety. Six farms with the two most common fish culture systems (3 concrete tanks (CTs) and 3 earthen ponds (EPs) were purposively selected based on frequency of harvest and yield. Fish samples (500±10g) obtained from these farms after 4 months of culture were processed, smoked, packaged and stored for 36 weeks. Amino acid profile in farmed fresh and smoked C. gariepinus was determined at 12, 24 and 36 weeks of storage and polycyclic aromatic hydrocarbons (PAH) was determined at 0 and 16 weeks of storage. These were compared with traditional smoked wild catfish obtained from local fish processor (LFP). The amino acids with highest concentrations (mg/g) found in this study were leucine (22.16 - 31.61 and 13.89 – 29.64), lysine (16.31 – 20.19 and 9.86 – 18.08), arginine (15.16 – 12.29 and 8.97 - 15.86), valine (15.96 – 21.35 and 9.68 - 19.36 ) and asparagine (19.66 – 21.61 and 12.36 mg/g – 20.71mg/g) for fresh and smoked catfish respectively. Levels of other amino acids ranged from 1.5mg/g to 9.98mg/g in smoked fish and 2.95mg/g to 12.21mg/g in fresh fish. The mean total poly aromatic hydrocarbons in smoked catfish at 16 weeks of storage were 0.039±0.004µg/kg, 0.034±0.005 µg/kg and 0.053±0.005 µg/kg for EP, CT and LFP, respectively. Therefore smoked farmed catfish raised under different culture systems still contain essential amino acids and Benzo(a)pyrene which is a carcinogen was not at detectable level in the samples.