葛根中多酚氧化酶性质及葛根护色的研究

Enzymological Characterization of Polyphenol Oxidase from Radix Puerariae and Color Preservation of Fresh-cut Radix Puerariae

研究葛根多酚氧化酶(PPO)的性质,以及不同护色方案的护色效果,确定最佳护色方案。结果表明,以邻苯二酚为底物,葛根PPO的最适pH7.0,最适温度40℃,100℃热处理40s可钝化PPO的活性;抗坏血酸、抗坏血酸钠和亚硫酸钠为多酚氧化酶强烈抑制剂;但仅有亚硫酸钠能有效抑制葛根褐变的发生;结合颜色、护色效果、损失以及残留,确定0.2%的亚硫酸钠溶液为护色剂采用喷涂的方式进行护色。

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 Puerariae. Based on the consideration of safety and browning control effect, spraying 0.2% sodium sulfite solution was chosen as the optimum color preservation method for Radix Puerariae.