| In this dissertation,techniques included cold soaking fresh leaves extract spray process,secondary rolling and secondary fermentation process,provide oxygen complex,variable fermentation temperature technology were used to discuss the process of improving the content of black tea theaflavin.Techniques included freezed leaf of ZuoQing process,no pressure to turn rubbing process and variable temperature process to discuss the process of improving the content of oolong tea theaflavin.mass-production of raw tea were used as experiment material to analyze the difference of theaflavin content between black tea and oolong tea from varieties and seasons.The experiment results were shown as follows:1.Study on processing technology to improve the theaflavin content of black teaCold soaking fresh leaves extract spray process:Tieguanyin,Benshan,Huangdan,Jinguanyin those four varieties were used as experiment materials.Fresh tea leaf with a bud and two leaves were picked,freezed 6h in the-15?,removed the fresh leaf and cut up,then extracted with the pure water of 6?,prepared cold soaking fresh leaf extracting solution(the ratio between fresh tea leaf and the weight of water was 1:1),then were sprayed uniformly in the rolling leaf of black tea(the ratio between extraction and rolling leaf is 1:5),the results showed:setting different fermentation temperature(24?,18?),different fermentation times(2h,3h,4h),six different treatments were added into black tea,the theaflavin content of each treatment compared with CK were improved significantly,the treatment of fermentation temperature in 24? and 3h for fermentation of all varieties processing of black tea theaflavin content increased rates were between 66.63%?119.05%,the average increased rate was 92.96%.At the same time,the beverage concentration of tea liquid were improved and the durability of aroma were increased due to this process.Secondary rolling secondary fermentation technology:Tieguanyin and Benshan those two species were used as experiment material,rolling were divided into two times,the first rolling time was 60min,and then began to fermentation,when the fermentation to a certain extent,began to the second rolling with 30min,setting different fermentation temperatures(30?,24?,18?),and set three times ratio of secondary fermentation,there were nine treatments processed into black tea,the results showed:when fermentation temperature was in 18?,2h for first fermentation and 6h for second fermentation,the increased rates of theaflavin content of Tieguanyin black tea and Benshan black tea were 15%and 22.03%respectively,significant difference showed compared with CK showede.Provide oxygen complex technology:Tieguanyin,Benshan,Huangdan,Jinguanyin those four varieties were used as experiment materials,aerobic fermentation(2h?6h),then the fermented leaf tea were packed into ziplock bag in the late period of fermentation,began to anaerobic fermentation,discharged bad smell through opening the bag every 30min.Set different fermentation temperatures(30?,24?,18?),set three treatments of provide oxygen complex,there were nine treatments processed into black tea.The results showed:when fermentation temperature was in 18?,4h for aerobic fermentation then 4h for anaerobic fermentation,the increased rates of all varieties were during 20.00%and 41.20%,the average increased rate was 31.05%,significant difference were showed compared with CK.High temperature(30?)provided oxygen complex treatment had a negative effect on the sensory quality of black tea.Variable temperature fermentation technology:Tieguanyin,Huangdan and JinGuanyin those three varieties were used as the experiment material to discuss the effects of variable temperature fermentation environment on the theaflavin content of black tea.Three kinds of treatment from high temperature to low temperature were set and four kinds of treatment from low temperature to high temperature to low temperature were set in the process of making black tea,the results showed:Used fermentation temperature 18??24?? 18?,fermentation time 2h?2h?2h treatment had a positive effect on the theaflavin content improved,through the processing,the increased rates of theaflavin content of Tieguanyin black tea?Huangdan black tea and Jinguanyin black tea were 33.61%,29.52%and 26.20%,significant difference were shown compared with CK.2.The study of improving the theaflavins content of oolong tea from processing technologyZuoQing freezing technology:Tieguanyin,Benshan and Jinguanyin those three varieties were used as experiment materials.In the different stages of ZuoQing,-5? cryogenic treatment was used,then the frozen leaf were removed and began to tumbling when the leaves came back to room temperature,five treatments processed were added into oolong tea,the results showed:A positive effect on improving the theaflavin content of oolong tea if the leaf of ZuoQing freezed 30min before tumbling process,the theaflavin content increased rates of all varieties of Oolong tea were between 42.47%and 54.46%,significant difference were shown compared with CK.No-pressure rolling technique:Tieguanyin,Benshan and Jinguanyin those three varieties were used as experiment materials.No-pressure stiring and rolling in the leaf of ZuoQing and began fixation process after spreading process,different stiring and rolling time(5min,10min,15min)and different spreading time(30min,60min,90min)were set,multiple treatments were used to process oolong tea,the results showed:the treatment of stiring and rolling 10min,spreading 90min,and stiring and rolling 15min,spreading 30min had a positive effect on improving theaflavin content,the increased rates of theaflavin content of oolong tea through the two types treatments were 71.65%and 74.14%respectively,significant difference were shown compared with CK.Variable temperature ZuoQing technology:Tieguanyin and Benshan those two varieties were used as experimental material.The spreading temperature of oolong tea were inconsistent in experiment,6 kinds of oolong tea variable temperature treatment were set,the results showed:the fist spreading in 16?,second spreading in 30? and third spreading in 16? treatment was better,through this treatment,the increased rates of theaflavin content of Tieguanyin oolong tea and Benshan oolong tea were 25.04%and 30.69%respectively,significant difference were shown compared with CK.3.Analyzed the difference of theaflavin content of black tea and oolong tea among cultivars and seasons36 black tea samples and 52 oolong tea samples were selected from different seasons tea production and the theaflavins content of samples were determined.The results showed:the theaflavins content of Ruixiang 305 was higher level in black tea samples,the theaflavins content of Huandan and Benshan were higher in Minnan oolong tea;the theaflavins content of Qilan and Rougui were higher in Minbei oolong tea;the theaflavin content of Black tea showed a significant difference in level among the seasons,theaflavin content in Autumn was higher than in Spring.Anxi production of clean flavor of oolong tea average content of theaflavins were:Summer=Autumn>Spring.Summer and Autumn had no significant difference between each other but they were both shown significant difference compared with the Spring;Anxi production of heavy flavor oolong teas' average content of theaflavins were:Summer>Autumn>Spring,significant difference were shown between the Spring and Autumn;Wuyi region and Taiwan Nantou region of oolong tea theaflavins content were:Autumn>Spring,significant difference were shown among the seasons. |
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