Crude polyphenol oxidase (PPO) extracted from Radix Puerariae was characterized for enzymological properties Based on this, the optimum color preservation technology for fresh-cut Radix Puerariae was investigated. Radix Puerariae PPO exhibited the highest activity using catechol as the substrate at pH 7.0 and 40 ℃. Heating treatment at 100 ℃ for 40 s could inactivate the enzyme. Ascorbic acid, ascorbic sodium and sodium sulfite were strong inhibitors for it, but only sodium sulfite could effectively inhibit the browning of fresh-cut Radix P...