Microwave Drying Equipment for Common tea - Agriculture
Tea’s mellow and fragrant aroma comes from drying some fixed water content to remove the fresh green. Do you know something about the formation of tea? In our life, we may as well have some tea lovers who have studied tea, so we should understand that tea green removing is a very important tea-making process, most of the tea needs fresh green removing.
Tea is rich in polyphenol oxidase. If we do not remove some water content first, polyphenols will be oxidized and fermented under the action of enzymes, so that the tea will quickly lose its color and then spoil. Only by removing some water content first can the fragrance be emitted. As far as the known ways of removing fresh green tea are concerned, the equipment of tea microwave machine is the most efficient. In the process of tea processing, the removing some fixed water content is the key process to improve the quality of tea processing, and plays a key role in the shape and quality of tea.
At the present stage, in the rapid development of industrialization, according to the commonly used ways of removing some water content, the main methods of killing green include drum-type, hot air, steam and new microwave tea machinery and equipment. The effect of drying tea and the quality of tea are different with different equipment.
Common tea drying equipment:
- The drum-type green dryer has the advantages of high production efficiency, continuous operation, convenient use and good quality of tea. The finished tea is emerald green, fragrant and tasty. It has also been widely used in tea production in China. The disadvantage of drum dryer is that if the operation method is inappropriate, it will often cause the phenomenon of coke leaves.
- Hot-air tea-drying machine is a new product developed successfully in Zhejiang tea area in recent years. At present, it is widely used in Zhejiang, Sichuan and other places. Its main structure is composed of hot air generator, cylinder, fresh leaf hoist, belt conveyor and cooling unit. However, hot air is selected to drying at 300-350 C. The temperature difference between hot air and fresh leaves is large. The process of drying green tea is usually completed in a very short time. It is difficult to control the process. If there is a slight misoperation, it is easy to form a burning edge and a bursting point, and the tea contains the odor of smoke and char.
- In China, discontinuous box-type or mesh-belt type non-pressure steam-type green tea drying machines are commonly used in the way of steam-type green tea drying and the application of mechanical equipment. The structure is composed of feeding device, transmission device, vane conveying device, steam cleaning device, cooling device and other components. The moisture content of steam-drying leaves is generally slightly higher than that of fresh leaves. Although the leaf texture has softened, it can not be rolled or shaped immediately. It needs to be first baked so that the moisture content of steam-dried leaves can be reduced to 55% before entering the normal next process.
- Microwave tea-drying machine is a new type of tea-drying machine developed successfully in recent years in our country. The process of microwave tea-drying is a process in which heat is generated from the inside of the green tea leaves. There is no temperature gradient inside and outside the green tea leaves. There is no heat transfer process of general heating. It has fast heating, preheating time and low heat loss, which is conducive to automatic control and continuous production. The tea products treated by microwave green-killing machine have less chlorophyll change, green color, uniform drying and less loss of aroma, so as to achieve good green tea drying effect.
The mechanism and working principle of tea microwave green tea drying machine:
- Use rapid warming to passivate the active oxidase of fresh leaves, inhibit the accelerated oxidation of tea polyphenols and other enzymes in fresh leaves, prevent serious changes in color during subsequent drying process, and volatilize the taste of fresh leaves of Houttuynia cordata, so as to better form tea fragrance.
- When microwave tea-drying machine is used to kill green tea, the temperature should be increased rapidly, and all microwave power should be turned on. If the time is less than 1.5 minutes, the leaves will be red-mouthed; if the time is too long, the leaves will lose too much water, the tea will be dry and hard, affecting the later rolling and shaping.
- Microwave generator generates microwave. Microwave has the characteristics of short wavelength and high frequency. When fresh tea is irradiated by microwave, the polar molecules inside the tea are affected by the periodic change of microwave, and move periodically with microwave. In view of the high frequency of microwave, when the frequency is 915 MHz, the internal molecules of tea green leaves have 9.15 *108 times/second vibration wave. When the frequency is 2450 MHz, there are 2.45 *109 times/second vibration wave. As a result, the collision between them forms a large number of friction heat, which rapidly increases the temperature of tea green leaves, realizes the inactivation of enzyme activity at the same time and completes the killing of green leaves.
- Fast heating speed: Microwave green tea dryer can directly heat both inside and outside of the tea, without preheating, it can be processed on start.
- Heating uniformity: The electromagnetic wave produced by the magnetron is uniformly irradiated on the tea leaves, heating both inside and outside, no coke leaves, coke edges, debris and so on.
- Tea nutrition loss is less: tea stays in the microwave oven for a short time, and does not need air and steam heat conduction, so the microwave tea green-killing machinery and equipment can maximize the retention of nutrients in tea.
- Sterilization and alcoholization have great effects: tea is often contaminated by secondary pollution in the process of picking and making. Microwave sterilization and alcoholization have the characteristics of sterilization and drying. Microwave is especially effective for summer and autumn tea in addition to bitterness and astringency. This alcoholization function can not be latently replaced by other machines.
- Tea quality has been improved: the surface temperature of tea leaves is not high when microwave is used to dry green leaves, and there is no need to cool them by blowing when they emerge, so the green leaves change little, the color and lustre are green, the aroma loss is less, and the drying is even. At the same time, because of the rapid evaporation of water, it is easy to form porous, the product has good rehydration, and the content is easy to dissolve when tea is brewed.
In order to further improve the aroma and taste of tea, the principle evaluation of different equipments should be taken into account. The new type of green tea drying equipment, tea microwave green tea drying machine, should be considered. Compared with traditional pot-type and drum-type green-killing equipment, tea green tea drying equipment has fast speed, high efficiency and good effect. At the same time, microwave can also remove excess moisture from fresh leaves, which will become soft and plasticity after evaporation by hot gas. And tea green-tea drying machine can be widely used in tea, chrysanthemum, honeysuckle, flowers and other agricultural products for green tea drying, the effect is remarkable.