New method for drying oolong

Abstract

The invention provides a new method for drying oolong during the oolong processing. The method is characterized in that the oolong to be dried is not pre-frozen and directly put into a vacuum freeze drier to be dehydrated and dried in the conditions of low temperature (40 to 60 DEG C), vacuum (vacuity 100 plus or minus 30 Pa) and refrigeration (condenser frosted), without subliming process. The product has emerald green color, dense scent, pure flavor and good quality. Compared with traditional heated air drying, although the drying time is slightly longer and the energy consumption is slightly higher, the quality of the product is greatly improved. Compared with traditional vacuum freeze drying, the method not only also reduces the loss of the scent of the oolong and the oxidation of heat sensitive substances, but also improves the pure feeling of the flavor of the oolong, and the total quality is equivalent to the oolong prepared by traditional vacuum freeze drying. Moreover, the method does not require pre-freezing and subliming process, not only equipment and a larger amount of power required by pre-freezing are saved, but also 70 to 80 percent of drying time in the mass is reduced, the production efficiency is improved, and the technical practicability is higher.

Description

Technical field: [0001] The present invention relates to the invention of a new method for drying oolong tea in the processing research or production of oolong tea. Background technique: [0002] Oolong tea is a kind of tea unique to our country. Its processing process is generally: fresh leaves → sun-dried green → cool green → made green → greening → kneading (or wrapping) → drying. Oolong tea is favored by consumers for its natural, strong floral and fruity aroma and mellow aftertaste, and has become the most competitive product in the domestic tea market. However, the use value and sales price of oolong tea depend to a large extent on the aroma of oolong tea. In the sales market, the price of products with good floral aroma and high aroma is several times or even ten times higher than that of low aroma tea. The aroma of oolong tea is basically formed at the end of greening. Therefore, in the subsequent processing of oolong tea, how to keep the fresh and strong aroma and ...

AI Technical Summary

Problems solved by technology

Since this method is dehydrated under extremely low temperature vacuum conditions, the quality of the dried food is better than that of hot air drying, microwave drying, vacuum drying, etc. The required equipment investment and energy consumption are large, and the drying time is too long. Generally, the whole process takes 20 hours or even longer

In recent years, some people in China have used the vacuum freeze-drying method (hereinafter referred to as freeze-drying) to dry oolong tea. The resulting product has a high aroma and freshness, but the taste of the tea soup is slightly weaker, and the drying time is also too long (about 20 hours). ), large equipment investment, and large energy consumption, it is difficult to implement in production