Effect of Drying Methods on Yield and Quality Attributes of Clove Basil (Ocimum gratissimum L.) Leaves Essential Oil

Abstract

The present investigation entitled “Effect of drying methods on yield and quality attributes of clove basil (Ocimum gratissimum L.) leaves essential oil” was conducted during 2024–25 at the Research Laboratory, K.D. College of Horticulture and Research Station, Jagdalpur (Chhattisgarh). The experiment was laid out in a Completely Randomized Design with five treatments and four replications, comprising fresh leaves (T₁), shade drying leaves (T₂), sun drying leaves (T₃), oven drying leaves (T₄) and microwave drying leaves (T₅). Essential oil was extracted by steam distillation and analyzed for oil yield and quality attributes of essential oil. Results revealed that drying methods significantly influenced essential oil yield (p ≤ 0.05). Shade drying leaves (T₂) recorded the highest oil yield (0.90%), followed by fresh leaves (T₁) (0.79%) and oven drying leaves (T₄) (0.75%), which were statistically at par. Sun drying leaves (T₃) (0.49%) and microwave drying leaves (T₅)  (0.29%) resulted in significantly lower yields. Quality attributes such as density, specific gravity and refractive index showed non-significant variation among treatments, whereas acid value differed significantly (p ≤ 0.05), with the lowest value recorded under microwave drying leaves (T₅) (1.60 mg KOH g⁻¹). Overall, shade drying leaves (T2) was found to be the most suitable method for obtaining higher essential oil yield while maintaining acceptable quality attributes of clove basil essential oil. However, limited information is available on the comparative effect of different drying methods on essential oil yield and quality attributes of clove basil, which the present study aims to address.