【作者】 曹叶中；

【导师】 陆兆新；

【作者基本信息】 南京农业大学 ， 食品科学， 2006， 硕士

【摘要】 绿茶在贮运过程中品质容易发生陈化劣变，从而降低其商品价值和经济价值。本研究在绿茶加工过程中采用蒸汽杀青技术与通过在绿茶中添加微生物菌制剂，提高绿茶贮藏过程中的品质稳定性。主要研究结果如下： 1．将枯草芽孢杆菌BS-16在无菌条件下接种到500mL牛肉膏蛋白胨液体培养基的摇瓶中，在37℃、120r／min的摇床内培养24h，再将摇瓶内种子液经高速离心所得菌体沉淀悬浮于脱脂乳中于-20℃干燥成菌粉。对绿茶(金坛雀舌)和加枯草芽孢杆菌BS-16菌粉绿茶(金坛雀舌)进行急性毒性评价。结果表明，对照绿茶和加枯草芽孢杆菌BS-16菌粉的绿茶均属实际无毒级。 2．将枯草芽孢杆菌BS-16、枯草芽孢杆菌EB1、枯草芽孢杆菌EB2菌粉分别以0.01％-0.02％的重量比掺入到新鲜绿茶中与空白对照绿茶一起放入37℃恒温箱中，每隔1周测定茶多酚、氨基酸、叶绿素、维生素C的含量。贮藏一个月后，添加枯草芽孢杆菌BS-16菌粉茶叶的茶多酚保留率88.77％、氨基酸保留率94.07％、叶绿素保留率88.84％、维生素C保留率88.82％；对照茶的茶多酚保留率为80.34％、氨基酸的保留率为76.70％、叶绿素的保留率为70.06％、维生素C的保留率为74.56％，分别比加枯草芽孢BS-16菌粉的茶叶低8.43％、17.37％、18.78％、14.26％。表明添加枯草芽孢杆菌BS-16菌粉的茶叶的茶多酚、氨基酸、维生素C、叶绿素的氧化劣变速度小于对照茶叶，说明枯草芽孢杆菌BS-16菌粉对绿茶贮藏过程中能起保鲜作用，该微生物保鲜技术可应用于绿茶的贮藏保鲜。 3．研究绿茶蒸汽杀青和优化工艺技术参数，获得最佳蒸汽杀青参数为：蒸汽速度600r／min，脱水速度1000r／min，杀青温度130℃。采用蒸汽杀青处理的绿茶维生素C更多还原

【Abstract】 Quality of tea especially high-grade green tea deteriorated easily during storage , Therefore,the commodity and economy value of green tea would be greatly decreased.The technology of steaming and application of biotechnology were used to improve the stable quality during storge.1. The Bacillus Subtilis BS-16 was inoculated in fermentation medium peptone under aseptic condition and carried out under 37℃ at 12rpm for 24 h .The seed liquid was dried into strain power at -20℃ after centrifugation and dissolved by skim milk. Acute toxicity experiment were performed on the tea. Result showed that the two kinds of tea is innocuity.2. The strain powder of Bacillus subtilis BS-16、EB1、EB2 by drying method was added to fresh green tea with 0.01%-0.02% weight and put in 37℃ together with blank contrast tea and the content of tea polyphenol, amino acid, chlorophyll and Vc were determined every week. After one month storage period, the retention rate of tea polyphenol, amino acid, chlorophyll and Vc of the sample tea added with Bacillus subtilis BS-16 powder were 88.77%, 94.07% , 88.84% and 88.82%,while their retention rate of blank contrast tea were 80.34%,76.70%,70.06% and 74.56%, lower than the experimental group 8.43%,17.37%,18.78% and 14.26% respectively. Furthermore, the oxidation and deterioration rate of these materials of the sample tea added with Bacillus subtilis BS-16 powder were less than the blank contrast tea. The results showed that the strain powder of Bacillus subtilis BS-16 could play a role of fresh-keeping during storage process of green tea and the microbial fresh-keeping technology could be applied in fresh-keeping and更多还原