The effects of different drying methods on drying time, essential oil content and composition of basil (Ocimum basilicum L.)

Drying is one of the oldest methods for preservation of agricultural products after harvest. Basil (Ocimum basilicum L.) belongs to Lamiaceae family which is used as a medicinal and spice species. This experiment was carried out to determine the effect of different drying methods on drying time, essential oil content and composition of Basil. The experiment was conducted in a randomized complete blocks design with three replications and treatments were included two temperature levels (50 and 70 °C), six microwave powers (100, 180, 300, 450, 600 and 900 w), and two drying methods (sun and shade drying). The drying process was continued until the mass of the sample was reduced to a moisture content of about 0.10 on a dry basis or 10 % on a wet basis. Results indicated minimum and maximum drying times (4.1 minutes and 48 hours) were obtained at 900 w microwave powers and shade drying, respectively. Maximum and minimum essential oil content (1.3 and 0.3 %) were obtained by shade drying and in 450, 600 and 900 w, respectively. Microwave powers had negative effect on the main compositions of essential oil (geranial and methyl chavicol) but shade drying preserved them. According to the results, shade drying was identified as a suitable method for Basil, because essential oil content and composition were considerably maintained.