Effects Of Instantaneous Controlled Pressure Drop Applied On Green Tea Process

Cell-breaking extent is an important factor in tea processing, it not only has a great influence on the development of tea quality, but also directly determines the leaching behaviors of functional components in tea during tea making. In traditional green tea process, cell-breaking is achieved through rolling. However, as more attention has been paid on the shape of made tea, a reduction of tea rolling would be inevitable, which would make the leaching of inclusions in tea be difficult. Based on the principles of instantaneous controlled pressure drop and the characteristics of tea process, the instantaneous controlled pressure drop devices were designed and developed. And a further studies were made on the effects of the device applied in green tea process, including observations on whole leaf, tissues and singal cell, and the effects on inclusions of famous green tea, broken green tea and sun-dried tea were investigated as well. The results were shown as follows:1. The new instantaneous controlled pressure drop device had been designed scietificly aestheticly. It not only overcomed complex operation, inaccurate parameters regulation and non-uniform heating of stuff of the early ones, but also cut the cost remarkly by electronic operation which made the operation of device be more convernient and safe. All the features of the new instantaneous controlled pressure drop device indicated it had suited for industrialization.2. Instantaneous controlled pressure drop treatment increasing cell damage of tea leaves, which was directly reflected with microscopic inveatigation. as distorted cells, cell membrane and vacuole membrane were broken, and rearranged. Palisade tissue cells were loosened to some extents, and the the space between cells was widened, leading to the appearance of bubbles on lead surface and the browning of leaves after placed for a long time.2. It has been further proved that instantaneous controlled pressure drop technology application has a good effects on the process of traditional green tea, broken green tea and sun-dried green tea. This application should be regulated according to the degree of the following rolling process. The infusing temperature and time also had a very significant impact on the characteristics and advantages of the instantaneous controlled pressure drop technology. Better component leaching behavior was found in green tea manufacture by new technique at high temperature (≥80℃) with a shorter time (≤5min) and low-temperature (≤60℃) with a shorter time (≤30min) as compared with the traditional process. When the temperature reached 60 degrees or above and the time was increased to 30min or more, the results had no difference between the new technology and traditional process. These results provided a direct support for "cold-brewing tea" development.According to the features of instantaneous controlled pressure drop and the results of investigated, this technique also had a potential application on development of summer and autumn tea and tea deep processing.