The hot air (HA) method is the most widely implemented drying method for plants (herbs,
vegetables, and fruits). This method has a few drawbacks that include long drying time,
limited heat transfer, and limited thermal conductivity. This study investigated the effects of
HA and infra-red (IR) heating method on biologically active compounds from different herbs
(Khaffir lime, Lemongrass, Prai, Tamarind, and Turmeric). The efficiency of the drying
methods was evaluated by considering (a) moisture ratio (MR),(b) specific energy …