Abstract: To optimize the process of diced Rhei Radix et Rhizoma fresh processing on origin, the effects of slice thickness, drying temperature before slicing, drying degree and drying temperature after slicing on water content, free anthraquinone, total anthraquinone and drying time of diced Rhei Radix et Rhizoma were investigated by orthogonal test. The results showed that the influence of four factors on the total anthraquinone content of diced Rhei Radix et Rhizoma was not significant. The slice thickness and drying temperature before slicing had significant effects on the free anthraquinone content of diced Rhei Radix et Rhizoma. The drying degree had an extremely significant effect on the moisture content of diced Rhei Radix et Rhizoma. All factors had significant or extremely significant effects on the total drying time of diced Rhei Radix et Rhizoma. The best processing technology of diced Rhei Radix et Rhizoma fresh processing on origin was as follows： The first step was to cut fresh Rhei Radix et Rhizoma rhizomes into 12 mm thick slices; the second step was to dry the slices at 60 ℃ until the water content was 60%; then, the slices should be diced to 12 mm length and 12 mm width; finally, the diced Rhei Radix et Rhizoma should be dried at 70 ℃ to a moisture content below 13%. With the above processing technology, the content of free anthraquinone of diced Rhei Radix et Rhizoma was higher, the drying time was shorter and the content of total anthraquinone was not significantly decreased.

Key words: Diced Rhei Radix et Rhizoma, fresh processing on origin, free anthraquinone, total anthraquinone, total drying time, orthogonal test