Application Of Microwave Technology In Modern Tea Industry
Tea processing has a very broad development prospects. In recent years, there are many reports at home and abroad. As one of the modern deep-processing techniques of tea, microwave application technology has started to develop to large-scale production. Since 1945 people found that the microwave heat effect, the application of microwave heating is increasingly widespread. Due to the water contained in tea, water molecules are polarized in the microwave electromagnetic field and have the characteristics of dipoles. With the frequency of the electromagnetic field constantly changing the polarity direction, the molecules vibrate at high speed and generate frictional heat, causing the tea leaves to heat up deeply from the inside , And the same temperature everywhere. The use of microwave heating of this feature can make tea rapid heating, reaching the critical point of passivation enzyme temperature, speed up the migration of tea structure water is very suitable for green tea greening process and tea late drying operation. Thus it can be seen that microwave technology is the ideal way to kill and dry tea leaves. The key to the application is how to match the microwave frequency, power, material running speed, the structure of microwave heating equipment and the microwave technology used in tea Fixing, drying technology and other technical specifications.
Microwave fixing, drying is the microwave generator to microwave radiation to kill, dry material and penetrate into the interior, to induce the material such as water and other polar molecules with simultaneous rotation, rotating billions of times per second. As a result of such high-speed rotation, the material instantaneously generates frictional heat, causing the material surface and the interior to heat up at the same time, and the internal temperature is higher than the surface temperature of the material, causing the enzyme to lose its vitality. At the same time, some water molecules evaporate to achieve the purpose of fixing and drying. This fixing, drying method is characterized by short heating time, the same temperature inside and outside, the heat transfer direction from the inside to the outside and the wet transfer direction, different from the conventional heating mode takes some time to heat from the outside to the material inside, there Internal and external temperature difference and wet, heat transfer in the opposite direction. Microwave penetration into the material inside the heating and without the need for high temperature heat medium, when used in tea processing, fundamentally changed the traditional high temperature heating medium and heat conduction heating method, and microwave electromagnetic field in the fixing, drying process With non-thermal effects, greatly reducing the processing time, showing the unique advantages of microwaves.