Drying Profiles and Quality Evaluation of Smoke-Dried Catfish (Burchell, 1822) Using Traditional and Ecologically Friendly Kilns in Lagos, Nigeria

Catfish processing by smoke-drying using Traditional Drum Kiln (TDK) is a major source of livelihood in Nigeria. Challenges of standardization of smoke-drying process and quality of smoke-dried fish product prompted the construction of Ecologically Friendly Kiln (EFK). TDK was built according to existing standards while EFK was built to have flame, drying and electronic chambers and smoke filters were also installed. Smoke-drying was carried out for an average of twenty-four hours at a stretch at a temperature range of 60 - 80 ⁰C. Drying profiles were determined by calculating weight loss against time using both kilns while sensory and shelf-life parameters were ascertained with the use of a ten-man panel. EFK fitted with two layers of 0.3 cm smoke filters showed the least clogging and also had best drying profile while smoke-drying using TDK had to be stopped at eighteen hours because the smoke-dried catfish product was becoming very brittle. The sensory parameters of appearance, odour, taste, and flavour although were all scored high by the sensory panel, were significantly higher with the catfish samples smoke-dried using EFK. Mould growth was found to be significantly lower in samples smoke-dried using EFK. This study showed that maintaining smoke-drying temperature between 60 - 80 ⁰C generally produced high-quality smoke-dried fish but smoke-drying using Ecologically Friendly Kiln produced fish with significantly higher sensory and shelf life quality.