Drying Kinetics of Date Fruits and the Effect of Temperature on the Sensory and Nutritional Properties

Abstract

The quality of date fruits obtained after processing is essential to the date palm value chain. This study was carried out to evaluate the effect of temperature on the drying characteristics, sensory characteristics and the primary nutritional properties of date fruits. This experiment was conducted at varying drying temperatures of 50, 60, 70, 80, 90 and 100°C using hot air electrical oven at a relative humidity of 75±5%. The brix index, total carbohydrates, pH and glossiness of the processed dried dates at different temperatures were determined. The drying curves showed that the drying rate decreases as temperature decreases. This trend did not hold for 50°C as its drying rate was higher than that of 60 and 70°C. The brix index was within the range of 19 to 29 with the highest at 100oC. There was no significant change or difference in the percentage total carbohydrate as well as the pH in all the drying temperatures. The fruit was glossier at drying temperature of 100oC and lowest at 80oC. In all, the date fruits dried at 50oC gave the best product based on drying characteristics.