Ademola Adebukola Adenigba & Samuel Dare Oluwagbayide

This study presents the design, fabrication, and evaluation of a solar dryer as an advanced alternative to conventional sun drying methods. Focusing on enhancing product quality and minimizing nutrient loss, the research specifically investigates the drying characteristics of white ginger. Experimental evaluations involve drying 2.5 kg of white ginger slices at 3mm thickness, under varying blower operation cycles: 10 minutes on and 50 minutes off, 15 minutes on and 55 minutes off, and 20 minutes on and 1 hour off. Temperature, humidity, and weight measurements are collected at 2 hours intervals over the drying period. Results reveal that, 15- minute on and 55-minute off blower cycle emerges as optimal, yielding ginger with superior qualities. In-depth nutritional analyses demonstrate that dried ginger retains essential vitamins, minerals, and phytochemical compounds, rendering it suitable for food processing applications. During the three-day drying process, the ginger slices experienced the greatest weight reduction under the 15-minute on and 55-minute off blower cycle. The lowest moisture content achieved was 11.31%, while the final ginger weight was 0.51 kg. Proximate and phytochemical composition analyses revealed that this drying cycle resulted in ginger flour with reduced moisture, highest crude fiber (8.52%), crude protein (7.83%), and carbohydrate (66.20%) content. Moreover, the 15-minute on and 55-minute off blower cycle produced ginger flour with significantly higher levels of vitamins and phytochemical compounds. Based on the findings, it is recommended that subsequent solar dryer designs incorporate a blower operation cycle of 15 minutes on and 55 minutes off to achieve optimal drying outcomes for white ginger. Keywords: Solar dryer, White ginger, Drying characteristics, Nutritional preservation, Blower operation cycle 0150