| This paper selected Tieguanyin ( fresh smell type, produced in spring 2007) and Benshan (produced in spring 2007 ) as the test materials, which were stored respectively in the temperature level 5℃and -18℃and applied to with three fresh-keeping agents combination. Tea sampling was carried out before the storage, and at the end of the storage for 1 month, 2 months, 4 months and 8 months for the analysis of moisture content, water extracts, tea polyphenol, amino acids, caffeine, water-soluble sugar, chlorophyll, flavone compounds etc. and the sensory tasting of the tea quality. During the storage for 8 months the colony total, mold and E.coli of the tea samples were investigated by sampling every 2 months. The teas from Fujian Tea Import & Export Limited Liability Company were also sampled for the examination of the colony total, mold and E.coli, including Anxi Tieguanyin ( grades 1-4 ), Sezhong( grades 1-4 ), Yongchun Shuixian ( grades 1-3 )and Jianou Shuixian( grades 1- 4 ). The results were as follows:1. At the end of storage for 8 months, the appearance of dry tea, aroma, taste, liquor color,and infused leaf of Tieguanyin and Benshan decreased in sensory scoring, and the above-mentioned components appeared to be irregular variation. Every combination of fresh-keeping agents revealed an effective effect on the sustaining of the tea quality and ranked in their effects as: the fresh-keeping agent②( Sodium pyrosulphate + Vitamin C )>the fresh-keeping agent③(Discoloration silical gel + Sodium pyrosulphate + Sodium ascorbate + Vitamin C )>the fresh-keeping agent①(Discoloration silical gel + Vitamin C ).2. Samples stored at the temperature level 5℃and -18℃without the fresh-keeping agents decreased in the above-mentioned qualities during the storage for 8 months, and their chemical components revealed an erratic variation. In this paper, samples stored at the temperature level 5℃and -18℃whether with or without fresh-keeping agents revealed an increase in moisture content, the ratio of tea polyphenols/amino acids and TFs,TRs,TB, otherwise a decrease in the contents of water extracts, tea polyphenol, amino acids, caffeine, water-soluble total sugar, chlorophyll, flavone compounds etc. during the storage for 8 months. In addition, the activties of PPO and POD were found in the Tieguanyin and Benshan before storage and Tieguanyin stored at the temperature level 5℃with the fresh-keeping agent①and③by adopting homogenized extraction method.3. In this experiment, the sensor qualities of Tieguanyin and Benshan stored at the temperature level 5℃was better than that at -18℃. The application of the three fresh-keeping agents combination when stored at the temperature level 5℃and -18℃had different effects. The remains of chemical components were higher in contents when stored at 5℃than at -18℃, but the sensor qualities at 5℃were better than those at -18℃. The fresh-keeping effect of low temperature with applicatoin of the fresh-keeping agents was better than that of single low temperature treatment. At the end of storage, the moisture content of tea samples treated by the fresh-keeping agents combination was higher than that of tea samples without the fresh-keeping agents combination, but in general the remains of chemical components of tea samples with the fresh-keeping agents were higher than those without the fresh-keeping agents, and the fresh-keeping effect with application of the fresh-keeping agent②( Sodium pyrosulphate +Vitamin C ) was the best, and its sensor qualities were also better than those of the tea samples without the fresh-keeping agents.4. In Tieguanyin and Benshan stored at the temperature level 5℃and -18℃during 8 months of storage, the contents of the colony total and mold had a slight increase in some tea samples in initial stage, and then gradually reduced. And the contents of the colony total and mold of tea samples without the fersh-keeping agents were higher than those of tea samples with the fesh-keeping agents, but E.coli was never found during 8 months of storage. In addition, the results revealed that Sezhong ( grade 1 ) had the highest contents of the colony total and mold among those Fujian Oolong teas investigated.
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