Comparative Evaluation of Solar Tent Drying Efficiency and Product Quality for Blue Whiting (Micromesistius poutassou) and Hake (Merluccius spp.)

Abstract

This study investigates the drying efficiency and product quality of two economically significant non-fatty fish species, Blue Whiting (Micromesistius poutassou) and Hake (Merluccius spp.), using a solar tent dryer. The objective was to optimize dryer configurations, focusing on vent number and polyethylene covering materials to balance drying performance with product quality. The dryer, comprising a metal frame covered with either low-density polyethylene (LDPE, 50 µm) or medium-density polyethylene (MDPE, 250 µm), was tested under three ventilation regimes (2, 4, and 6 vents). A Face-Centered Central Composite Design (FCCCD) within Response Surface Methodology (RSM) assessed the effects of these variables on internal drying conditions. Across 30 experimental trials, temperature and relative humidity were monitored, and data were analysed using ANOVA and Duncan’s New Multiple Range Test (DNMRT) at a 5% significance level. The result shows that covering material and its interaction with fish species significantly affected internal temperature, with LDPE and MDPE achieving thermal retention up to 42 °C. Increased venting reduced temperature but raised humidity, indicating a trade-off between ventilation and thermal efficiency. A consistent U-shaped diurnal humidity profile was observed. Species-specific drying responses emerged: Hake dried faster and reached lower final moisture content, while Blue Whiting retained superior sensory properties, particularly colour and texture. Microbial analysis demonstrated significant reductions in viable bacterial counts post-drying. The findings highlight the critical influence of dryer design on solar drying efficiency, product safety, and sensory quality, offering practical insights for improving fish drying processes in resource-limited settings. . It is strongly suggested that similar research should be replicated in other states or regions for effective and conclusive submission vis-à-vis establishing one in optimal conditions for the sampled fish storage and processing.