Novel tea leaf production method for removing pollutants inside and outside tea leaves

Abstract

The invention discloses a novel tea leaf production method for removing pollutants inside and outside tea leaves, belonging to the technical field of tea leaf production and processing. The novel tealeaf production method sequentially comprises the steps of: washing of fresh tea leaves; water addition and crushing, and pulping; solid-liquid separation; electrodialysis for fluorine removal; membrane filtration, concentration and dehydration; solid-liquid mixing, stirring and slurrying; and granulation. The fresh tea leaf particles obtained by using the method provided by the invention can be prepared into green tea, black tea, yellow tea or dark green tea. The method provided by the invention can completely remove the pollutants like dust and pesticide residues on the surface of the tea leaves, and can greatly remove fluoride salt in the tea leaves, so the content of fluorine is reduced to 300 mg / kg or below after raw tea leaves with a fluorine content of 700-1000 mg / kg are prepared into a finished tea product; all beneficial ingredients and flavor substances in the tea leaves are completely reserved; meanwhile, the drinking mode of the tea leaves is reserved; and an obtained tea finished product is rapid for inclusions to be dissolved out, is clear and transparent, does not need long-time boiling, is clear and convenient, is applicable to industrial production at the same time, and has good economic benefits.

Description

technical field [0001] The invention relates to the technical field of tea production and processing, in particular to a new tea production method for removing internal and external pollutants of tea. Background technique [0002] Ya'an Tibetan tea has been drunk in Tibet for more than a thousand years since the Tang Dynasty. Through a large number of experiments, black tea (Ya'an Tibetan tea) has a good effect on regulating the stomach, helping digestion, degreasing, resisting plateau hypoxia, and resisting plateau ultraviolet radiation. People who eat a lot of high-protein and high-fat people play a better role. There are Tibetan proverbs, "It is better to be without food for three days than to be without tea for a day", "The food of fishy meat can't be eaten without tea, and the heat of barley can't be understood without tea." ", which shows the importance of black tea (Ya'an Tibetan tea) in the daily life of ethnic minorities in the frontier. The production, supply and ...

AI Technical Summary

Problems solved by technology

[0004] The current Tibetan tea has a prominent problem: high fluorine content

[0007] At present, many efforts have been made in this field to reduce the fluorine content in tea, for example, the control of fluorine content in the planting process, including the cultivation of low-fluorine varieties, the reduction of fluoride in the cultivation environment, etc., and the use of fluorine-reducing agents for chemical Fluoride reduction, on the one hand, these methods have problems such as long cycle and high difficulty, on the other hand, there are problems such as secondary pollution in chemical defluorination

The patent with the publication number CN 109105586 A and the patent name "A Method for Preparing Low-Fluorine Instant Tea Powder" discloses a method for removing fluoride ions in tea water extracts by using electrodialysis. Ripe tea, that is, the finished tea product is pulverized, extracted with boiling water under pressure, and filtered to remove slag to obtain tea water extract, then electrodialysis is used to remove fluoride ions in the water extract, and then the water extract from which fluoride ions have been removed is dried to obtain tea powder ; This method has the following disadvantages: one is that the method is to process and remove fluorine after the tea leaves are made into semi-finished products. Many beneficial substances that are not easily soluble in water exist in the slag in the tea leaves and will be lost because of the slag removal, resulting in many in the tea leaves. Beneficial components will be lost, especially for black tea, in which tea polyphenols, tea polysaccharides, tea pigments and other beneficial components lose more, and the aroma substances lose a lot during drying; second, the low-fluorine tea obtained by this method The finished product is tea powder or tea cream (deeply processed product), and the processing cost is high. The third is that it is not easy to promote in terms of the way of drinking tea or the flavor. It is difficult for traditional tea drinkers to accept this kind of deep-processed tea products.

[0009] The inventor of the present application once tried to wash the raw materials with water before finishing, but found that the edge of the blade would be damaged after washing, and the water content on the surface of the blade after washing was too high. Unfavorable factors such as the quality of the resulting tea products, high energy consumption, etc.

The Chinese patent with the publication number CN 110353058 A and the patent name "A Tea Preparation Method for Reducing the Fluorine Content of Tea Leaves" is to add water and knead in the traditional kneading process to remove dust and impurities on the surface of the tea leaves, and part of the fluorine However, this method will also remove the tea juice dissolved in water, which will cause a greater loss of beneficial substances in the tea

[0010] That is to say, the patent application number 201811029264.4 is called a method for preparing low-melt instant tea powder, which is a deep-processing type of tea, which completely changes the traditional tea product form and drinking method, and the acceptance is low. The patent application number is: 2019910800532- - A method for preparing tea leaves that reduces the fluorine content of tea leaves. The method is to add water to rinse the rolling tea leaves when rolling the tea leaves, and remove the internal and external pollutants of the tea leaves. Although it has the effect of removing some internal and external pollutants, the amount of removal is limited. If it is to be achieved The national standard has a fluorine content of 300mg / kg, and the washing water loses more useful extracts in tea while rolling to remove internal and external pollutants, so it is not a good way to remove internal and external pollutants from tea

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