IntroductionDrying has been well-known method for food preservation. Themain reason of drying in the food industry is to inhibit microor-ganisms and bacteria growth. Without the existence of water, thegrowth of those bacteria can be control and hence the food canbe stored longer. Despite the importance of drying process in pre-serving food products, high temperatures and long drying timesrequired to remove the water from the food material in convectionair drying may cause serious damage in flavor, color and nutrientsof the dried product (Lin et al., 1998). The development of dry-ing strategy at low air temperature and short drying times withlow economic cost becomes the popular research topic in the foodindustry.