Mutual interaction of glycosides and enzymes in the development of plant food aroma

1.以苷元形式存在的香气化合物中的糖苷类化合物的分离鉴定：采用甲醇萃取，经ODS柱、离心逆流和高效液相色谱分离得到粗品糖苷组分。结果：1.鉴定了多种糖苷和黄花苷。以新鲜茶叶粗酶为底物，分别合成了苯甲醇、苯乙醇、香叶醇和芳樟醇的苷类化合物。以香叶基报春花苷为原料得到的游离苷元的得率最高，一般情况下，报春花糖苷和萜醇糖苷均为苷元。对茶叶和红茶中的糖苷组分进行了三氟乙酰化和GC分析，发现茶叶香气的主要成分是糖苷和/或黄花苷的苷元。红茶鲜叶中以主要香气化合物为苷元的糖苷类物质减少，说明糖苷是红茶香气的主要前体，对糖苷的酶促反应是植物香气形成的主要因素。

1. Separation and identification of glycosides containing of aroma compounds as aglycones.Crude glycoside fraction was obtained by methanol extraction and separated with ODS column, centrifugal counter-current and high performance liquid chromatographies. Various kinds of glucosides and primeverosides were identified.2. Hydrolysis of synthetic glycosides with crude enzyme prepared from fresh tea leaves.As the substrate of enzymatic reaction, glucosides, primeverosides and visianosides of benzyl alcohol, phenyl ethanol, geraniol and linalool were synthesized respectively. The maximum yield of the freed aglycon was obtained from geranyl primeveroside and generally the primevelosides were highly hydrolyzed as well as the glycosides of terpene alcohol as aglycon.3. The presence of glycosides in fresh tea leaves and black tea.The crude glycoside fraction was trifluoroacetylated and analyzed by GC.The main constituents of tea aroma were found as aglycon of glucoside and/or primeveroside. The glycosides with main aroma compounds as aglycon in fresh tea leaves decreased in black tea.All these results suggest that the glycosides are main precursors of black tea aroma and enzymatic reaction to glycoside is main factor of the plant aroma formation.