香草兰O-β-葡萄糖苷酶底物特异性和温度稳定性研究

香草兰是最重要的食品香料之一,其主要香味成分为香兰素,主要存在于香草兰豆荚中。香兰素一般由成熟豆荚中的香兰素葡萄糖苷经过漫长的发酵过程转化而来。O-β-葡萄糖苷酶在发酵生香的过程中起着关键作用。研究结果表明:香草兰的根、茎、叶和豆荚中都具有O-β-糖苷酶活性,豆荚活性最高,叶片活性最低;来自不同器官的O-β-糖苷酶的底物特异性一致,都能降解香兰素糖苷、2-NPG、4-NPG,都不能降解n-OG及硫代葡萄糖苷;香草兰糖苷酶提取物在50～60℃处理1 min,对酶活性影响很小,70℃处理1 min,酶活性丧失约40%,说明香草兰糖苷酶对高温具有一定耐受性,杀青后剩余糖苷酶活性在漫长的发酵过程中能够满足酶促反应的需求。

Effects of Different Coconut Husk Chip Treatments on the Growth of Anthurium and Dendrobium sp

Coconut husk block as an coconut processing wastes, this paper were used the coconut husk block as material that collected from different sites from Wenchang Hainan. The experiment were designed eight treatments (YKD1, YKD2, YKD3, YKM1, YKM2, YKX1, YKX2, YKX3). The mineral elements of each treatment and the effect of different treatment on the physiological changes of Anthurium and Dendrobium sp were also studied. The result showed as followed the compound treatment showed higher chlorophyll content and root vigor, especially the YKX3 treatment showed significantly higher than normal treatment. It concluded that compound treatment were better for the development of Anthurium and Dendrobium sp. Anthurium can grow normally in YKX1, YKX2 and YKX3. The most suitable treatment for Dendrobium sp was YKX3 treatment. Chlorophyll content and root vigor as important indicators for evaluation. This result showed important significant on the utilization of coconut wastes.