Do you know something about the formation of tea?In our life, we must have also met people who love drinking tea and have studied tea. Then we should know that water-removing is a very important tea making process, and the vast majority of tea needs to remove green.
Tea is rich in polyphenol oxidase, if you do not remove water, polyphenols will carry out oxidative fermentation under the action of enzymes, so that the tea will lose color soon, and then bad.
Only kill “green gas”, can sweet smell sends out.From known ways of water-removing,tea microwave killing machine equipment have the highest efficiency, water-removing is the key step to improve the quality of tea in the tea process, playing a key role to the shape and quality of tea .
At the present stage, in the rapid development of industrialization, according to the current commonly used way of killing, water-removing mainly includes drum killing, hot wind killing, steam killing and new microwave tea killing machinery and equipment.The leader microwave equipment company killing effect and tea quality are different with different killing equipment.
Common equipment for water-removing:
1.The drum-type killing machine has the advantages of high production efficiency, continuous operation, convenient use and good tea quality. The finished tea is green in color, fragrant and tasty.It is widely used in tea production in China.The disadvantage of the drum killing machineis that, if the operation method is not correct, often cause coke leaf phenomenon.
2.Hot air tea machine is a new product developed in Zhejiang tea area in recent years,at this stage in Zhejiang, Sichuan and other places have more use.The main structure is composed of hot air generator, barrel, fresh leaf elevator, belt conveyor and cooling unit.
However ,hot air chooses 300 ~ 350 ℃ high temperature to remove water, the temperature difference between hot air and fresh leaves is big. Water-removing usually finished in a very short period of time, the process is difficult to control. If operation is slightly improper, steamed leaf is easy to form coke side, flash point.When becomes tea, it contains smoke caramel flavour.
3.In the way of steam killing in China and the application of mechanical equipment commonly used is the cabinet type discontinuous killing machine or network belt type steam killing machine without pressure.The structure is composed of feeding device, driving device, conveying device, steam killing device, cooling device and other components.
The water content of steam killed green leaves is generally slightly higher than that of fresh leaves, although the leaves have become soft, but it is not immediately put into rolling or shaping, need to go through the initial drying, so that the water content of steam killed green leaves dropped to 55% before and after, to enter the next normal process.
4.Microwave tea killing machine is a new type of tea killing machine successfully developed in China in recent years.Unique advantages of this equipment are as follows,the heat is generated from inside the tea leaves, and there is no temperature gradient inside or outsideand no general heat transfer process.
It also has advantages such as fast heating,short preheating time, small heat loss, and conducive to automatic control and continuous production.After treated by microwave sterilization equipment, the tea product has less chlorophyll change, bright green color, uniform drying and less aroma loss, so as to achieve good sterilization effect.
Mechanism and working principle of tea microwave sterilizer:
1.The active oxidase of fresh leaves was passivated by rapid heating to inhibit the accelerated oxidation of tea polyphenols and other enzymes in fresh leaves, prevent the serious color change in the subsequent drying process, and at the same time volatilize the smell of fresh leaves, so as to better form the tea flavor.
2.When microwave tea killing machine removing water, it need to quickly increase the temperature and open all the microwave power.If the time is less than 1.5min, the red mouth will appear.If the finishing time is too long and the water loss of green leaves is too much, tea leaves will appear dry and hard, affecting later rolling and shaping.
3.The microwave generator creates the microwave which has the characteristics of short wavelength and high frequency.When fresh tea leaves are irradiated by microwave, the polar molecules inside the tea leaves are affected by the periodic change of microwave and move with the microwave periodically.
In view of the microwave frequency is very high, when the frequency is 915 MHZ, tea leaves internal molecular umbels 9. 15 x 108 times per second vibration wave, when the frequency is 2450 MHZ, there are 2. 45 x 109 times per second vibration wave, the collision between each other to form a large amount of friction heat, quickly promoted tea green leaf temperature, enzyme activity and the passivation, filming for the finish.
Advantages of tea microwave fixation:
1、High heating speed: the microwave sterilizer can directly heat the inside and outside of the tea at the same time, without preheating, starting processing.
2、Uniform heating: the tea dechlorinating machine irradiates the electromagnetic wave generated by the magnetron to the tea evenly, and simultaneously heats the tea inside and outside without scorched leaves, scorched edges, crumbs and so on.
3、Tea nutrition loss is little: the time that tea stays in microwave heating box is shorter, do not need air and steam to conduct heat again, so microwave tea leaves sterilizes mechanical equipment to be able to retain the nutrition composition in tea maximally.
4、Strong sterilization and mellow effect: in the process of picking and making tea leaves, there is often the possibility of secondary pollution. Microwave sterilization and drying have the functional characteristics of sterilization and mellow.
5、The quality of tea has been improved: the surface temperature of tea is not high when the microwave is used to kill the leaves, and there is no need to cool the leaves with blowing air, so the green leaves change less, the color is bright green and resistant to storage, the aroma loss is less, and the drying is even.
Combining the principles of different equipment to further improve the tea aroma, taste of the shortage, can consider the way to kill is a new type of killing equipment – tea microwave killing machine.Compared with the traditional pot and drum killing equipment, the tea killing equipment has the advantages of fast killing speed, high efficiency and good effect.
At the same time, the microwave can also remove the excess water in the fresh leaves, which will become soft and plastic after being volatilized by the hot air.And tea killing machinery can be widely used in tea, chrysanthemum, honeysuckle, flowers and other agricultural products for killing, killing effect is significant.