铁棍山药褐变特性研究

研究了铁棍山药的褐变特性,包括酚类物质的分布与褐变的关系,多酚氧化酶(PPO)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)的活性变化与褐变度的关系及pH和温度对其非酶褐变的影响。结果表明:酚类物质的分布情况与褐变发生部位相一致;PPO、POD和PAL的活性与褐变度呈正相关,其相关性依次为PPO>POD>PAL;酸性条件有利于抑制非酶褐变,低于或高于40℃,非酶褐变均有降低的趋势。

Browning Characteristics of Dioscorea batatas Decne

Browning characteristic of Dioscorea batatas Decne was studied, including the relationship between the distribution of phenols and browning, between the degree of browning and the activities of polyphenol oxidase(PPO),peroxidase(POD),and phenylalanine ammonialyase(PAL),and the effect of pH and tempreture on non-enzymatic browning.The phenols distribution mainly locates near periderm area and midribs in yam tuber, where the most serious browning is present.The relationship between the activities of PPO,POD,PAL and the browning degree shows positive correlation, and the correlation degree ranks:PPO>POD>PAL.Acidic condition is propitious to inhibiting non-enzymatic browning. Under the lower or higher temperature than 40℃,non-enzymatic browning all decreases.