OBJECTIVETo optimize the conditions of the vacuum belt drying process (VBD) for drying Panax notoginseng extract and compare with methods of vacuum freezing drying and spray drying.

METHODThe optimum conditions of VBD were obtained by orthogonal design and validated by determinations of moisture content of the dried product and recovery of active ingredients. Experiments on different drying methods were also conducted.

RESULT AND CONCLUSIONThe optimum conditions are as follows, the feeding speed was 15 mL x min(-1), the belt speed was 4 mm x min(-1), and the heating temperature was (105, 100 degrees C). Comparing with the drying methods of vacuum freezing drying and spray drying, vacuum belt drying possesses some advantages, such as higher recovery of active ingredients, less moisture content of dried product and better overall yield.