Technology of air-impingement drying for fresh cistanche

In this paper, effects of the drying conditions such as the air temperature in drying oven, wind speed and slice thickness on the qualities of fresh cistanche which contains color and medicinal compositions during the drying process were studied. To optimize the best drying process, the fresh cistanche was taken as materials, the cistanche slices was dried by gas impact jet flow method, the color of dry cistanche slice was identified by image analysis method, and the contents of galactitol, echinacoside and verbascocide in cistanche were determined by the high performance liquid chromatography method (HPLC). As a result, the best drying process in which the drying temperature was 70℃, the wind speed was 12 m/s, the thickness of the cistanche slice was 2 mm were obtained. Using the technology, cistanche slices were pale yellow and contained more galactitol were finally gotten. In all, the technology can efficiently promote the value of commodities and offer a guide during the drying process of cistanche slices.