Effects of Ginger and Black Pepper Seed Extracts on the Nutritional Quality of Oven-Dried Clarias Gariepinus

The nutritional quality of oven dried Clarias gariepinus pretreated with ginger and black pepper extract and stored in ambient temperature for a period of 21 days was assessed using proximate, microbial composition and organoleptic evaluation. Two hundred and ten (210) freshly caught Clarias gariepinus weighing 500g were killed, gutted, washed thoroughly with portable water and brimmed by dipping in 15% sodium chloride solution for 3minutes. They were drained and divided into 7 segments of 10 fish each in triplicates. The spices (ginger and black pepper extract) were grounded and diluted with water respectively and applied as 0ml for control, 10ml, 20ml and 30ml respectively for both the ginger and the black pepper. The fish were oven dried for five hours, cooled, packaged in bulk and stored in ambient temperature of 25°C for 21 days. The samples were subjected to organoleptic, proximate, microbial and biochemical analysis. Result of the proximate composition showed a significant difference among the samples. In the crude protein, 30% black pepper had the highest value of 69.92 followed by 20% black pepper with a value of 69.77 and then the 20% ginger with the value of 68.58 respectively while the control had the least value of 67.68. The moisture ranges from control 6.75 to the lowest value of 30% black pepper with a value of 6.47. The highest crude fat was recorded in 30% black pepper (8.41) followed by 20% black pepper with the value of 8.33. However, there were no significant difference among the 20% and 30% black pepper value (p<0.05). The control showed the least values for both the crude protein and the fat content. The organoleptic assessment studies showed differences within samples in respect to the appearance, flavour, texture and colours of the fish. General taste preference was given to black pepper at 30%. The microbial evaluation showed the control differed significantly within the spices of black pepper and the ginger (p<0.05). The values got from the control were high in total plate count, total coliforms, E. coli, pathogenic microorganisms such as (salmonella) and staphylococcus when compared to the ginger and black pepper. The treatments with spices had a positive effect on the nutritional quality of the products.