Performance and Nutrient Quality Evaluation of a Natural Convection Solar Dryer for Drying Pineapple

Abstract

Pineapple is a highly nutritious and widely consumed fruit in Bangladesh, yet postharvest losses continue to increase due to inadequate preservation technology. This study is aimed at developing and evaluating a natural convective solar dryer as a sustainable solution to reduce these losses while preserving fruit quality. The dryer’s performance was assessed by measuring drying temperature, solar radiation, and moisture reduction across treated and untreated pineapple samples. During the drying process, the average temperature within the dryer reached 40.73 ± 6.79°C, with solar radiation averaging 254.67 ± 141.50 W/m² and an observed 12.6°C temperature difference between the dryer chimney and ambient air. Results showed a final moisture content of 19% and 21% (wet basis) for treated and untreated samples, respectively, in the solar dryer, compared to 46.57% and 35.06% in open sun drying. The nutritional analysis indicated a significant retention and enhancement of vitamin, protein, and mineral content in dried samples. Consumer sensory evaluations confirmed the high acceptability of the solar-dried pineapple, demonstrating that this solar dryer is technically effective, eco-friendly, and well suited for small-scale farmers in rural Bangladesh.