Effect of infrared, hot air, and hybrid drying strategies on appearance acceptability, essential oil yield and quality of volatile compounds of lemongrass leaves (Cymbopogon citratus)

Abstract

Abstract This study aimed to investigate the effect of different strategies of drying with hot air (40, 50, 60°C), infrared (0.5, 0.6, 0.8w/cm2), sequential hot air/infrared, and Simultaneous hot air-infrared on the drying behavior, color, appearance and the yield and the components of essential oil of lemongrass leaves to increase the marketability of the product. Essential oils of lemongrass samples were extracted by hydro-distillation, and Volatile compounds were analyzed by GC-MS. Results showed: a) the suitable method for maintaining a higher color quality of lemongrass leaves was drying only by hot air drying at 60ºC; b) for preserving and obtaining a higher yield of the essential oil content of lemongrass, the best strategy was the simultaneous hybrid drying by hot air drying at 50ºC and infrared drying with radiation intensity of 0.6 w/cm2; and c) the data analysis represented that for obtaining the higher value of Volatile compounds of neral and geranial were drying only with infrared having the radiation intensity of 0.6 w/cm2 and drying with infrared radiation intensity of 0.8 w/cm2 respectively.