Assessment of the impact of locally fabricated oven and sun drying method on the proximate, mineral and microbiological composition of Clarias gariepinus (catfish)

Abstract

Drying is an age long practice which prevent fish from deterioration and spoilage, however, traditional drying is usually practiced in rural settings with poor hygienic conditions, thus, the nutritional and microbial quality of such products is uncertain. Therefore, the present study was aimed at evaluating the impact of a locally fabricated oven and sun drying method on the proximate, mineral and microbial composition of Clarias gariepinus (Catfish) using standard laboratory procedures. The results of the proximate analysis showed that the oven dried fish had the highest crude protein content (66.43 ± 3.37 %), crude lipid content (8.27 ± 0.28 %) and carbohydrate content (4.50 ± 0.22 %) which were statistically significant (p<0.05) when compared to the sun dried fish, while the sun dried fish had the highest ash content (16.30 ± 2.48 %) and moisture content (14.30 ± 0.82 %) which were statistically significant (p<0.05) when compared to the oven dried fish. Also, the mineral analysis showed that the oven dried fish had the highest calcium (821.49 ± 1.10 mg/kg), phosphorus (86.04 ± 0.83 mg/kg), potassium (254.72 ± 0.40 mg/kg), iron (40.73 ± 0.23 mg/kg), manganese (0.95 ± 0.01 mg/kg) and selenium (14.15 ± 0.39 mg/kg) content which were statistically significant (p<0.05) when compared to the sun dried fish, while the sun dried fish had the highest sodium (173.52 ± 0.12 mg/kg), cupper (0.87 ± 0.12 mg/kg), magnesium (39.01 ± 0.43 mg/kg) and zinc (2.83 ± 0.23 mg/kg) content which were also statistically significant (p<0.05) when compared to the oven dried fish. The study also showed that the total viable bacterial count was higher in the sun dried fish (6.23 x 10⁵ cfu/g) which was not statistically significant (p<0.05) when compared to the oven dried fish (5.65 x 10⁵cfu/g), while the fungal count was higher in the oven dried fish (6.55 x 10⁵ cfu/g) which was also not statistically significant (p<0.05) when compared to the sun dried fish (5.01 x 10⁵ cfu/g). The findings in this study showed that the locally fabricated oven was remarkably effective, yielding fish with significantly enhanced nutritional profiles and minimal microbial contamination. This approach offers a superior method for fish preservation, providing a promising alternative for improving food safety and nutritional quality.