| dc.description.abstract | The demand on traditional herb medicine @mu in Indonesia) shows a tremendous increase. Until then recent years, the jamu drying is accomplished by corrventional merho&, which cause quality deterioration due to /he high temperature applicaiion. This experiment is aimed to study rhe freeze drying churacieristics of the herb medicine, and to asses the qualiq ofthe fieeze driedpruducts. The experimental results show that higher chamber pressure or faster freezing rate tends to shorten the primary drying time but lengthen the secondary drying time. The quality of the freeze-dried producf was slightly lower than !he qua& of the raw material, but there was a tendency of higher solure content in water, which is accounted for /he hydro-drjhsion ndure of h e solufe, INTRODUCTION lndonesia is bountiful with biodiversity, including those usable for medicinal herb. About 300 variety of the medicinal herb, out of more than 1000 known varieties, are commonly used as traditional medicine (Faroug, 1985). Among them, ginger (Zingiber oficionnle), and Javanese piper (Piper retrofrucium, Vahl) are the most commonly used for the traditional herb medicine Cjamu) in Indonesia, kside for flavourish. Ginger also shows a tremendous increasing demand for export commodity, either in form of volatile oil or powder. Drying is very important for preserving the product and it is commonly performed with a high temperature drying (40-60 "C). The temperature sensitive of the active material in the product could not be preserved with the drying method, and thereby should be performed with freeze drying method. However, freeze drying is commonly known as a high cost drying method, due to its high energy consumption. In order to decrease the energy consumption, it is necessary to study the optimal drying condition while maintaining the high quality of the product. Initial concentration of the product to be freeze-dried is an important factor in affecting the drying characteristic. Sagara (1984) showed that thermal conductivity of freeze dried coffee is higher if the initial concentration is high. However, material | id |
