茶叶中游离态和键合态香气组分对茶云纹叶枯病致病菌的抑制作用

Antifungal activities of free and bound form aroma components in leaves of tea against Colletotrichum camelliae Massea

从茶鲜叶中提取糖苷类物质，用茶叶粗酶水解后气相色谱分析挥发性酶解产物。结果表明：顺-3-己烯醇、芳樟醇氧化物、芳樟醇、水杨酸甲酯、香叶醇、苯甲醇和苯乙醇是水解后挥发性苷元的主要成分，且挥发性苷元含量远高于相应的游离态香气；茶叶游离态香气组分和键合态糖苷类香气前体对茶云纹叶枯病致病菌均具有显著的抑制作用。抗菌试验结果表明，当茶叶游离态香气组分为0．5-2．5μL·mL^-1时，其对茶云纹叶枯病致病菌具有不同程度的抑制作用，其中香叶醇抑制作用最强，最小抑制浓度（MIC）为0．5μL·mL^-1；当茶叶键合态糖苷类香气前体质量浓度为5～25mg·mL^-1时，其对茶云纹叶枯病致病菌也具有显著的抑制作用。

A crude glycosidic fraction was extracted from fresh tea leaves and hydrolyzed with the crude tea enzyme, and cis-3-hexenol, linalool oxides, linalool, methyl salicylate, geraniol, benzyl alcohol and phenylethanol were monitored to be the major agly- cone moieties by gas chromatography （GC） analysis. Quantitative analysis showed that the amount of the aglycone moieties was higher than that of free form. Both the free and bound form tea aroma components exhibited antifungal activities against Colletotrichum camelliae Massee obviously. Volatile tea aroma components exhibited different antifungal activities during a concentration between 0. 5 μL·mL^-1 to 2. 5 μL·mL^-1 in potato dextrose agar （PDA） culture medium. Geraniol showed the strongest antifungal activity with a minimum inhibitory concentration （MIC） of 0. 5 μL·mL^-1. Glycosidically bound form tea aroma precursors also exhibited antifungal activities in concentrations between 5 mg · mL^-1 to 25 mg · mL^-1 in PDA culture medium.