Predicting the Nutritional and Rancidity Properties of Dehydrated Catfish ( Clarias gariepinus ) Using Response Surface Methodology.

Catfish ( Clarias gariepinus ), the most popular fish species cultivated in Nigeria is rich in nutrients but highly perishable thus, it requires processing for preservation. In order to determine the optimal dehydration parameters, the combined effects of brine concentration [3.0, 6.0, and 9.0% (w/v)], brining time (30, 60, and 90 min), and drying temperature (90, 110, and 130°C) were investigated to predict the nutritional and rancidity properties of the dehydrated catfish using response surface methodology (RSM). The study showed that brine concentration, drying temperature, and the interaction of brine concentration and brining time significantly ( P <0.05) influenced the nutritional and rancidity properties of dehydrated catfish. However, the optimal process parameters: 7.83% brine, 90 min, and 110.38°C produced dehydrated catfish of high protein content (60%), low moisture (6.0%), free fatty acid (1.2%), thiobarbituric acid (0.10 mg malondialdehyde/kg), and total volatile nitrogen (10.0 mg nitrogen/100 g) with no detectable levels of peroxide value, indicating good nutritional quality and lower lipid oxidation for shelf stability. RSM models with a high range of predictive R2 (77~88%) were obtained at the set conditions showing the RSM potential as a feasible tool in this regard. The dehydration technique employed in this study is effective for high nutrient retention, especially the protein content, which could ameliorate the problem of malnutrition especially where fresh fish is not accessible, simple in operation and economical to encourage commercial applications with a potential for food security.