Determination and comparison of volatile aroma compounds in fresh and dried leaves samples of citronella grass, lemongrass, and citronella incense products by micro-hydrodistillation

Abstract

In this study, micro-hydrodistillation (MHD) was conducted for the determination of volatile aroma compounds (VACs) in fresh and dried leaves of citronella grass, lemongrass, and citronella incense products. Optimum extraction of VACs was achieved when extractions were performed at 100 C with 0.5 g of sample in 3 mL of water for 60 min. Maximum recovery of VACs was achieved using hexane (2 mL) as extraction solvent. Six major VACs extracted from citronella grass were identified as citronellal, citronellol, neral, geranial, geraniol, and eugenol. Geraniol was the predominant VAC in citronella grass and neral was the major VAC extracted from the lemongrass leaves. Eugenol was not detected in lemongrass leaves extract. The validated method provided good recoveries of VACs ranging from 83.6 to 105.3% with the relative standard deviations of 6.2 to 11.0%. The results presented in this paper show that the amount of essential oils extracted from the fresh citronella grass and lemongrass leaves was significantly higher as compared to those extracted from leaves dried at the ambient room temperature for 3 days. Quantities of geraniol, eugenol, and neral extracted from leaves using MHD can be used as marker compounds to differentiate citronella grass from lemongrass leaves extracts. Both storage time and conditions significantly influenced the amount of VACs extracted from citronella incense products.