甘薯加工过程酶促褐变及控制研究

Enzymatic Browning and Its Control During Sweet Potato Processing

摘要: 甘薯加工过程中极易产生酶促褐变。应用分光光度法，研究了甘薯中多酚氧化酶（PPO）的特性及褐变的控制方法。结果表明，甘薯皮部的PPO活性和褐变强度是心部的2倍左右，在pH值为4.5时其活性较低。在甘薯淀粉生产过程中，结合去皮工艺，分别选择添加0.01%～0.05%柠檬酸或0.005%～0.01%抗坏血酸或0.05%～0.1%亚硫酸钠，均可有效控制PPO产生的褐变，提高甘薯淀粉的质量。

Abstract: Enzymatic browning is formed easily in sweet potato processing. In this paper, the characteristics of Polyphenol Oxidase (PPO) from sweet potato and its control methods were studied by spectrophotometry. The results indicated that the activity and browning intensity of PPO from sweet potato peel was two times than those of internal tissue, and sweet potato had a lower PPO activity at pH 4.5. During sweet potato starch processing, the addition of 0.01%～0.05% citric acid or 0.005%～0.01% ascorbic acid or 0.05%～0.1% sodium sulfite, all combining with peeling sweet potato, would markedly inhibit the enzymatic browning caused by PPO, and improve the quality of starch.