【摘要】 研究了热处理苹果汁(加或不加防褐变剂)、苹果浆使其中的PPO完全及部分失活所需要的温度和时间。结果为:在90℃处理苹果汁15s可使其中的PPO完全失活,而对于苹果浆则需要90℃处理20s以上。加了防褐变剂的苹果汁经90℃处理10s可使其中的PPO完全失活;此外,经80℃处理30s以上虽不能使其中的PPO完全失活,但添加的防褐变剂及果汁自身的pH值可抑制残余的PPO从而防止酶促褐变的发生。70℃处理苹果汁40s不能防止其中的酶促褐变。更多还原

【Abstract】 The heating-treatment parameters of apple juice ,containing anti-browning reagent or not, apple puree for completely or partly inactivating the polyphenoloxidase(PPO) in them were studied .When apple juice was heated at 90℃ for 15s,the PPO in it was completely inactivated and for apple puree more than 20s was necessary. When apple juice including anti-browning reagent was heated at 90℃ for 10s,the PPO in it was completely inactivated. In addition, though apple juice including anti-browning reagent was heated at 80℃ for more than 30s the PPO in it was not completely inactivated ,the enzymatic browning in it would not occur due to the anti-browning reagent and low pH of apple juice. Heating apple juice at 70℃for 40s could not avoid enzymatic browning in it.更多还原