鲜菊芋块茎加工过程中酶促褐变及其控制研究

Enzymatic Browning and Its Control During Sweet Stem Tuber Processing of The Artichoke

[目的]探讨新鲜菊芋块茎中多酚氧化酶（PPO）的活性,以及PPO最适pH值、最适温度、热稳定性等特性和不同化学抑制剂对PPO的抑制效果。[方法]采用分光光度法。[结果]菊芋皮部的PPO活性和褐变强度分别是心部的2.04和1.88倍;PPO最适pH值为7.4,最适温度为35℃,85～90℃热处理1～5min可使该酶失活。[结论]0.4‰的亚硫酸氢钠（NaHSO3）或柠檬酸（CA）对PPO活性有较强的抑制作用。

[Objective] Enzymatic Browning is formed easily in sweet artichoke processing.The activities of polyphenol oxdase （PPO） were studied in this paper including conditions of optimum pH,optimum temperature,stability to heat,and the effect of different inhibitors.[Method] With the artichoke sweet stem tuber as tested materials,the characteristics of PPO were studied by spectrophotometry.[Result] The activity and browning intensity of PPO from the artichoke peel were 2.04 times and 1.88 times respectively than those of internal tissue.The optimum pH and temperature of artichoke PPO were 7.4 and 35 ℃ respectively.The enzymeativation was suppressed under 85～90 ℃ heating treatment 1～5 min.CA and NaHSO3 were strong inhibitors,the effective concentrations of inhibitor was 0.4‰.