葛根加工过程中酶促褐变及其护色效果研究

Enzymatic Browning and Its Reaction under Control During Radix Pueraria Processing

为有效控制新鲜葛根加工过程中发生的酶促褐变,研究了新鲜葛根中多酚氧化酶(PPO)的部分酶学性质,包括PPO的最适pH值、最适温度、热稳定性等,以及不同化学抑制剂对PPO的抑制效果。结果表明,葛根PPO的最适pH值为4.4,最适温度为55℃;在90～100℃下热处理1～3min,可使该酶基本失活,质量分数1.5%的氯化钠,0.75%的柠檬酸和0.3%的氯化钙配成的复合护色液,对葛根PPO活性具有较强的抑制作用。加工过程中,采用复合护色液对切分成型后的葛根半成品进行护色处理,可使其维持原有组织的洁白色泽。

To effectively control the enzymatic browning occurred during the procession of fresh radix pueraria, some properties of polyphenol oxidase （PPO）, including optimum pH value, optimum temperature and thermal stability, and different effects of chemical inhibitors on PPO are studied in this experiment. The results show that the optimum pH value of PPO is 4.4, and the optimum temperature of PPO is 55 ℃. PPO is deactivated under the heating treaiment of 90-100 ℃ for 1-3 min, compound reagent made of 1.5% sodium chloride, 0.75% citric acid and 0.3% calcium chloride have a strong inhibition on PPO activity of pueraria. During the procession, the compound reagent is used to keep the original color of radix pueraria products.