Performance Evaluation of a Solar Dryer for Silver Cyprinid (Omena): Enhancing Food Security through Sustainable Preservation

Aim: The aim of this study was to design, construct, and assess a small-scale solar drying unit for drying Silver Cyprinid (Omena) fish. The rationale was to develop an effective, cheap and sustainable way to help local fishermen in Kenya, especially those around Lake Victoria, to advance the methods of drying fish and, hence, increasing the focus on preservation of nutrients.

Methodology: A solar drying unit was designed and constructed to harness solar energy as its primary heat source for drying fish. Performance evaluations were conducted at Egerton University, Kenya, where 5 kg of Omena fish were distributed across three tray decks (2 kg on the lowest, 2 kg on the middle, and 1 kg on the top tray). Temperature fluctuations within the dryer, including the inlet chamber, chamber entrance, and chimney, were monitored during sunlight exposure. The operational efficiency and drying time of the unit were also evaluated.

Results: Temperature variation in the dryer was between 25 0C and 37 0C, average temperature of 37 0C, 35 0C, 40 0C and 42 0C was observed for the product, ambient, collector and drying chamber respectively. From the study it was found that the dryer was able to dry approximately 12 kg of freshly harvested Omena during a day under 8 hours of sunlight with an efficiency of 51.94%. This confirmed that the drying process enhanced the quality attributes of the fish in terms of texture, flavor, smell and color, with an overall acceptance score of 4.125 of the dried fish on hedonic scale.

Conclusion: The study concluded that; utilizing technology of solar dryers in the drying of Omena fish improves on the hygiene level, the performance on the nutrient quality of the fish is not affected negatively by this technology and therefore, the way forward in producing food in a sustainable manner is adopted by applying this technology. This developed small scale solar dryer provided efficient and effective solution to the conventional open sun drying and smoking system. The study thus calls for more cost-outcome studies that will compare the above solar dryers with the conventional methods of drying in Kenya.