Efficiency analysis of two improved kilns for smoking five indigenous fish species in Northern Nigeria

Abstract

Fish smoking is an important post-harvest preservation method in Nigeria, particularly among artisanal fishers who rely on efficient smoking techniques to enhance product quality and shelf life. This study assessed the smoking efficiency of two improved kiln technologies—Modified Drum Kiln and FUTY Kiln—using five indigenous fish species: Clarias gariepinus, Oreochromis niloticus, Heterotis niloticus, Mormyrus rume, and Bagrus bayad. A total of 150 fish were processed across both kilns, and weight changes were monitored at intervals of 0, 2, 4, 6, and 8 hours. Results showed that the Modified Drum Kiln consistently achieved faster moisture reduction and greater smoking efficiency in most species, with lower standard error values, indicating higher measurement reliability. Oreochromis niloticus and Heterotis niloticus experienced more effective dehydration in the drum kiln, while Mormyrus rume displayed an irregular drying pattern, suggesting the need for process calibration. Overall, the Modified Drum Kiln was found to be more efficient in terms of drying time, fuel economy, and consistency of results. The findings support the promotion of the Modified Drum Kiln for artisanal fish processors and suggest improvements to FUTY Kiln design to enhance performance.