Effect of drying methods on nutrient quality of Basil (Ocimum viride) leaves cultivated in Ghana

Basil (Ocimum viride) leaves were dried using five different drying methods: microwave-drying at power 3, oven-drying at 110°C, hot-air-drying at 100°C, sun-drying at 33°C, and ambient-air-drying at 28°C. The object was to analyse the effect of the drying methods on the nutritional characteristics of the spicy basil leave. Moisture content of the fresh and dried leaves was determined using laboratory oven kept at 105±3°C for 24 h. Extracts from fresh and dried leaves samples were analysed for protein, iron (using UV spectrophotometer), and carbohydrates (using handheld refractometer). Microwave-drying and oven drying were the methods that produced the best results for preserving most nutrients compared to the fresh herb, whereas ambient-air-drying, hot-air-drying, and sun-drying brought about substantial losses in basil leave nutritional values. Microwave-drying was the optimum method for basil leave drying as it required shorter treatment time of 4 min and gave the best retention of protein and carbohydrates when compared to oven-drying which required 17 min, preserving 42% (wt) of iron.