摘要
对分离纯化后的微型薯的多酚氧化酶性质进行研究,以邻苯二酚为作用底物,用分光光度计在波长420nm处测定不同pH值、反应温度、底物条件下微型薯的多酚氧化酶(PPO)活性,以讨论微型薯的褐变机理。结果表明,微型薯的PPO最适pH值约为5.5,最适反应温度为35℃左右,该酶热稳定性差;最适作用底物为绿原酸、原儿茶酸和咖啡酸;FeSO4和抗坏血酸等化合物可以抑制PPO活性,CaCl2和CuSO4等则起促进作用。适度高温、强酸性或碱性条件、FeSO4或抗坏血酸等处理都可以抑制该酶活性。
Properties of polyphenol oxidase extracted and purified from min-tubers potato were studied to investigate the theory of browning. Polyphenol oxidase activities were spectrophotometrieally determined at 420 nm with catechol as sub- strate at different pH, temperatures and substrate concentrations and so on. The optimum pH for PPO activity was 5.5 with cateehol as substrate. The enzyme was relatively stable at low temperature, with the maximum activity was observed at 35℃. Chlorogenic acid, Protoeatechuic acid, and Caffeic acid were good substrates for the enzyme. FeSO4 and ascorbic acid markedly inhibited PPO activity, whereas CaCl2 and CuSO4 enhanced the activity. PPO of min-tuber potato was stable at low temperature, high temperature, high pH and ascorbic acid can inhibited the activities of the enzyme.
出处
《长江蔬菜》
2009年第01X期33-35,共3页
Journal of Changjiang Vegetables
基金
甘肃省科技厅重大专项"贮藏保鲜技术与设施产业化示范"的子课题"马铃薯贮藏条件设施技术改造"项目(0702NKDA035)
甘肃农业科学院自列项目资助
关键词
微型薯
多酚氧化酶
酶学性质
Min-tubers potato
Polyphenol oxidase
Enzymatic properties
