Effects of different preservation methods on the nutritional quality of Clarias gariepinus from Calabar river, South East Nigeria

Abstract

The objective of this study was to determine the effect of different preservation methods on the nutritional quality and shelf life of the African Catfish Clarias gariepinus from the Calabar River, Nigeria. A total of forty five (45) samples of C. gariepinus were collected between April and June, 2015 from Nsidung beach, Calabar River, Nigeria. Fish samples were washed severally with dechlorinated tap water, then with distilled water before subjecting them to different preservation methods including frying, smoking, boiling and freezing. The fried, smoked, boiled, frozen and fresh samples were subjected to proximate analysis for moisture, ash, protein, fat, fibre and carbohydrate content following standard methods. Results showed that the highest moisture content was observed in the boiled sample (91.40%), while the lowest moisture content was observed in the fried fish sample (13.96%). The highest ash content was observed in the smoked fish (8.85%), while the lowest ash content was observed in the fried fish (5.64%). The highest protein content was observed in the fresh fish (39.32%), while the lowest was observed in the fried fish (11.30%). The highest fat content was observed in the fried fish (18.39%), while the lowest was observed in the smoked fish (5.18%). The highest fibre content was observed in fried fish (0.69%), while the lowest was observed in smoked fish (0.19). The highest carbohydrate content was observed in the smoked fish (48.80%), while the fresh fish had the least (39.47%). There were significant difference in nutrients contents for the fresh, frozen, boiled, smoked and fried fish samples at P<0.05. It was therefore concluded that frying was the best means of preservation, but nutritionally reduced the moisture, ash and protein below the FAO acceptable limit. Frying increased the fat and fibre content above the acceptable limit.