Effects of drying time on essential oil production of kaffir lime (Citrus hystrix DC) leaves at ambient temperature

Drying was one of the primary processes in essential oil production. Time factor in drying affects both the content and chemical compositions of essential oils. This study aims to evaluate the influence of the drying time of kaffir lime leaves on the yield at room temperature and the major volatile compounds in the essential oils by observing day-to-day treatments. As a key odorants in essential oils, the quantity of citronellal was determined by Gas Chromatography (GC) using the standard compound. Based on the daily observation results, a long-time drying gave a significant effect on the yield and the major volatile compounds. The highest yield 1.26 +/- 0.07 % (w/w) was obtained on the fourth day, while the highest content of citronellal compounds, 87.58 +/- 0.33% was achieved on the fifth day of drying,. A prolonged drying time resulted in a negative effect on not only the quantity, but also the quality of essential oils. Accordingly, this study suggests that the drying technique at room temperature best lasts for four until five days to obtain the most favorable quality and quantity of essential oils.