| 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...
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