KNUST Research Week and Scientific Conference: Empowering Researchers to Achieve Impactful Outcomes

Postharvest losses in fish processing remain a critical challenge in Ghana, with traditional smoking methods often compromising product quality and posing health risks associated with exposure to polycyclic aromatic hydrocarbons (PAHs). This study addressed the question of how different smoking fuels (charcoal, charcoal briquettes, and traditional firewood) affect the nutritional quality, PAH levels, and sensory characteristics of African catfish (Clarias gariepinus). Catfish were smoked using an improved kiln with charcoal and briquettes, while firewood-smoked samples were obtained traditionally. Proximate and mineral analyses followed AOAC standards, and PAHs were determined by GC-MS after QuEChERS extraction of 16 US-EPA priority compounds. Charcoal-smoked fish showed superior nutritional quality, with the highest protein (60.00%) and fat (20.17%) contents, notably retaining the most nitrogen, whereas briquette-smoked fish had the highest ash content (20.18%). Firewood-smoked fish, while higher in calcium and potassium, contained PAHs. Charcoal-smoked fish had the lowest PAH levels (97.03 μgkg-1) with no carcinogenic PAHs detected. Briquette-smoked fish showed the highest total PAHs (248.46 μgkg-1), though carcinogenic PAHs remained absent. In contrast, firewood-smoked fish had a ∑PAH of 193.68 μgkg-1, including several toxic and carcinogenic PAHs such as benzo(b)fluoranthene and chrysene. Benzo(a)pyrene was not detected in any sample. Sensory tests conducted by 50 untrained panelists ranked charcoal-smoked fish highest in terms of appearance, texture, and overall acceptability. The findings underscore the need for enhanced smoking technologies and cleaner fuels (briquettes, LPG, or pelletized waste) to improve quality, reduce postharvest losses, and safeguard public health. Future studies should examine the economic feasibility and consumer acceptance of scaling up improved kilns in Ghana.

Keywords: Postharvest losses; smoked catfish; polycyclic aromatic hydrocarbons (PAHs); improved smoking technologies; nutritional quality