This study targeted to design, fabricate and use a modified smoking kiln to reduce the drudgery in use of traditional smoking kiln with the aim of obtaining quality products that keep for longer periods. The dryer consisted of four major functional units; combustion chamber, heat exchanger, the blower, and drying chamber. Briquettes were made from Gmelina arborea and Swietenia macrophylla saw dust residues. The effects of using briquettes as source of fuel on the quality of Oreochromis niloticus samples was investigated. The drying rate for sample smoked was 0.276kghr-1. The average marginal effect of a 1°C increase in temperature on the moisture was a 0.1176% decrease in the moisture content. The proximate composition of smoke-dried sample showed moisture content of 10.81±1.23 and Crude Protein of 62.50±3.21. It also revealed optimum crude protein, fat and ash contents at decreased moisture level. Sensory evaluation of the smoked product using the 8 point Hedonic scale showed a score of 8.6±1.55 for smoked samples. Phenolic content of the smoky taste of fish species tested 75mgkg-1 for smoked samples. The smoked fish conformed to acceptable European standards for Phenol content. There is less risk of lung infection as common with the use of wood. In conclusion, the kiln proved effective in the smoking of fish to safe moisture level at a record time. The proximate composition of smoked fish showed a positive impact on the nutritive component of the fish. The test on the total phenolic content showed the products to be within the acceptable limits for safe consumption and sensory components presented fish to be of top quality.
Keywords: Briquettes, smoke-drying, organoleptic parameters, moisture content, phenols, drying rate.