Abstract: In order to extent the storage period of Chinese prickly ash (Zanthoxylum schinifolium Sieb.et Zucc), a high-temperature short-time (HTST) steam treatment method was presented for Chinese prickly ash. A series of one-factor-at-a-time experiments were carried out to investigate the effects of steam pressure, treatment time and material load on volatile oil content and POD activity of Chinese prickly ash from Hanyuan. The best processing conditions, as determined using response surface analysis based on central composite design, were steam pressure 0.33 MPa, treatment time 12.4 s and material load 2696 g/m2. After thermal treatment under these conditions, the predicted volatile oil content was 0.41 mL/20 g.

Key words: Chinese prickly ash, high-temperature short-time steam treatment, response surface methodology