Application of microwave drying equipment in the field of tea drying

China is a big country of tea production, and tea industry is a traditional industry in China. After years of exploration and Research on microwave equipment, the application of microwave in the field of tea drying has made a significant breakthrough. It provides feasible ideas for microwave equipment to improve the quality of tea processing and industrial modernization. It is expected that the microwave technology will have a good application prospect in tea.

In the application of microwave in tea greening, microwave heating was used to quickly kill the green tea, so as to inactivate the activity of polyphenol oxidase, evaporate part of water, volatilize grass smell and soften tissue. At present, the method of frying is commonly used in production, and steam is used in a few places. The results showed that the quality of tea processed by microwave and stir frying was good, and there was no significant difference in microwave equipment, but the time of microwave was short (1 / 8 of stir frying time) and could be carried out continuously. However, due to the high moisture content of steam, the outer layer of raw materials is affected by high temperature, so the weight of tea is almost no loss, part of chlorophyll is damaged, and the nutrients in raw materials are partially lost with the condensation water, so the quality is not ideal. The main application of microwave in tea is its thermal effect. When the magnetron generates microwave and irradiates the tea, the polar molecules in the tea of the microwave equipment are affected by the periodic changes of the microwave and move periodically with the microwave. Due to the high frequency of microwave, the internal molecules of tea collide with each other at high speed and produce a large amount of friction heat, which can rapidly increase the temperature of the material, so as to achieve the effect of rapid heating.

The application of microwave in tea drying: in general, in the process of hot air drying, the material is heated externally, the surface is dried, and the heat is transferred inward, which is opposite to the direction of water diffusion, affecting the outward evaporation of water. Microwave equipment and microwave is internal heating, high water content parts of the faster heating. Therefore, in the process of microwave drying, the moisture migration from the inner layer to the outer layer is faster, and the drying speed is obviously faster than that of hot air drying. The application of microwave drying in tea drying has the following advantages: fast drying speed; good product quality; because the surface temperature of tea is not too high, the chlorophyll changes little, the color is green and durable, the aroma loss is less, and the microwave drying equipment is even; at the same time, because of the fast evaporation speed of water, it is easy to form porosity, the rehydration of the product is good, and the content is easy to dissolve when making tea. The quality of tea can be improved by one or two grades on the basis of traditional technology. At present, the tea drying equipment successfully developed by our company includes honeysuckle drying equipment and chrysanthemum drying equipment.