Studies On The Change Of Main Flavor Materials Of Instant Green Tea During The Process And Analysis Methods

As one of the beverages people like best, tea has broken through the traditional manufacture. Instant tea has been won the love by the broad masses of tea customers with its many kinds, easy and fast drinking way. However instant tea has not been as popular as instant coffee so far because some problems, such as lacking aroma, weak taste and so on, have not been solved efficiently. In the past the key point of researches on instant tea was the relationship between the technical indices and the quality during the process, most of them were the foreign invent patents. The objects of study were almost instant black tea or the manufacture way of involving green tea into instant black tea. There is little reports on instant green tea, especially the change of flavor of instant green tea during the process. So to start the study on this field, to seek the means of research and the way of analysis could be not only to enrich the basic theory of tea further manufacture, to fill in the gaps in the field of instant tea, but also to provide the basis for increasing the quality of instant green tea by improving the technical indices during the process of manufacture. It researched the objects of instant green tea during the process in KingLong instant tea factory. With the means of GC, GC-GM, HPLC of modern instruments and the way of tea taste it studied on the aroma change of instant green tea during the process, the difference of essential oil made by SDE method, Headspace absorb (HSA) method, Vacuum Distillation Extract (VDE) method, the rate of aroma recovery of different aroma methods, compared the aroma diversity of instant tea of Headspace absorb (HSA) method with that of Tea Liquid absorb (TLA) method, analyzed the change of main biochemical components of instant green tea during the process and the main biochemical components of tea liquids after making essential oil by different aroma methods. The results showed that the aroma components of essential oil got by three aroma methods could be repeated greatly by GC or GC-MS analysis, but the content and the numbers of components were remarkable difference. SDE method gained the highest content and the numbers of components of aroma, the next was HSA method, and VDE method got the lowest. Meanwhile the relative content of different groups was different. In the simulated test of the rate of aroma recovery, SDE method could recovered aroma in harmony and had higher rate of aroma recovery. HAS method almost recovered all the standard decanoic acid ethyl ester. VDE method had very low rate of esters recovery. It showed that there was certain different tendency of aroma decreasing in different aroma methods during the process of instant green tea. The aroma went down slowly in the concentration analyzed by SDE method, and the other tow methods decreased slowly in the spray dry. In addition, the tea liquid after making essential oil by different aroma methods was different in biochemical components and in tea taste, especially the liquid of instant green tea after making essential oil. It further explained that there was diversity between aroma methods. So to select an aroma method could not be depended on the content and the numbers of aroma got by it, and should be depended on the aroma which could reflect the characteristic of tea flavor. Although there were some problems exited in the VDE method, it was better to reflect the flavor of tea aroma, especially for the aroma analysis of instant green tea. Different dry process...