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目的:通过对生鲜葱白自身酶解条件进行初步研究,为进一步研究葱白中的酶活性提供依据。方法:利用丙酮酸与2,4-二硝基苯肼-氢氧化钠系统发生显色反应原理,采用分光光度法测定丙酮酸的生成量来推算酶活力,同时根据丙酮酸的生成量间接反映含硫化合物的生成量,考察不同温度、pH、金属离子、时间以及不同灭活方式对酶解的影响。结果:温度在25～55℃之间酶活性较高,超过65℃后急剧下降;pH在6～8之间时,酶活性受到的影响比较小;Fe~(3+)、Cu~(2+)这两种金属离子对鲜葱白中酶活性有一定抑制作用,而Ca~(2+)、Zn~(2+)对葱白中酶的活性影响不是很大;酶促反应进行迅速,30min内完成;对比三种灭活方式的影响是微波>有机溶剂>高温。结论:葱白中酶有着其最适宜的反应温度、pH以及离子活性中心。
OBJECTIVE: To study the self-enzymatic hydrolysis conditions of fresh green onions to provide the basis for further study on the activity of green onions. Methods: The chromogenic reaction of pyruvic acid with 2,4-dinitrophenylhydrazine-sodium hydroxide system was used. The pyruvate production was measured spectrophotometrically to estimate the enzyme activity. At the same time, the pyruvate production was indirectly reflected The amount of sulfur compounds generated was investigated. The effects of different temperature, pH, metal ions, time and different inactivation methods on the enzymolysis were investigated. Results: The enzyme activity was relatively high at 25 ~ 55 ℃ and dropped sharply after the temperature was above 65 ℃. The enzyme activity was less affected when the pH was between 6 and 8; the activity of Fe ~ (3 +), Cu ~ (2) +) These two metal ions have a certain inhibitory effect on the activity of fresh green onions, while Ca ~ (2 +) and Zn ~ (2+) have little effect on the activity of green onion; the enzymatic reaction proceeds rapidly at 30 min Completed; the impact of three inactivation methods compared to microwave> organic solvents> high temperature. CONCLUSION: Inulin has its optimum reaction temperature, pH and ionic active center.