阅读说明：本技术 一种加硒金银花茶的制备方法 (Preparation method of selenium-added honeysuckle tea ) 是由 邓菲菲 邓仕运 于 2019-11-26 设计创作，主要内容包括：本发明提供一种加硒金银花茶的制备方法,包括以下步骤：采摘开花前、表面无水的金银花花蕾,用常压蒸汽加热5-10分钟进行杀青,均匀分布在干燥筛盘上,进干燥箱,先在35-45℃、相对湿度低于50%条件下干燥2-3小时,再在45-55℃、相对湿度低于40%条件下干燥2-4小时,取出筛盘,向金银花雾化喷入亚硒酸钠水溶液,喷液完成后重新装入干燥箱；最后在65-70℃、相对湿度低于30%条件下干燥1-2小时,出料精选包装得金银花茶。本发明方法实现了金银花的低温脱水干燥,脱水干燥时间缩短,能耗降低；所得加硒金银花茶的品相、冲泡饮用效果皆较好,加硒方法简单易控,效果确定,冲饮后可为人体补硒,改善身体健康状况。(The invention provides a preparation method of selenium-added honeysuckle tea, which comprises the following steps: picking up honeysuckle flower buds which are not water-containing before blooming and have surfaces, heating the honeysuckle flower buds for 5-10 minutes by using normal pressure steam for de-enzyming, uniformly distributing the honeysuckle flower buds on a drying sieve tray, putting the honeysuckle flower buds into a drying box, drying the honeysuckle flower buds for 2-3 hours at the temperature of 35-45 ℃ and the relative humidity of less than 50%, drying the honeysuckle flower buds for 2-4 hours at the temperature of 45-55 ℃ and the relative humidity of less than 40%, taking out the sieve tray, atomizing and spraying a sodium selenite aqueous solution into the honeysuckle flower, and re-filling the honeysuckle flower buds into the; and finally drying for 1-2 hours at the temperature of 65-70 ℃ and the relative humidity of less than 30%, discharging, selecting and packaging to obtain the honeysuckle tea. The method realizes the low-temperature dehydration and drying of the honeysuckle, shortens the dehydration and drying time and reduces the energy consumption; the selenium-added honeysuckle tea has good taste and brewing drinking effect, the selenium adding method is simple and easy to control, the effect is determined, and the selenium can be supplemented for human bodies after being brewed and drunk, so that the health condition of the human bodies is improved.)

1. A preparation method of selenium-added honeysuckle tea comprises the following steps:

(1) picking up honeysuckle buds with anhydrous surfaces before blooming;

(2) deactivating enzyme of flos Lonicerae bud by heating with atmospheric steam for 5-10 min;

(3) uniformly distributing the de-enzymed honeysuckle on a drying sieve tray, and putting a drying vehicle loaded on the drying sieve tray into a drying box;

(4) setting the drying box conditions to 35-45 ℃ and the relative humidity to be lower than 50%, and drying for 2-3 hours under the conditions;

(5) setting the temperature of the drying oven at 45-55 deg.C and relative humidity below 40%, drying for 2-4 hr, and drying flos Lonicerae until water content is 30-40%;

(6) pushing out the drying vehicle from the drying box, taking down the sieve tray, atomizing and spraying a food-grade sodium selenite aqueous solution into the honeysuckle, wherein the concentration of selenium in the sodium selenite aqueous solution is 0.2-0.5mg/ml, the liquid preparation amount is 5-10ml per kg of dried honeysuckle, and stirring the honeysuckle in the liquid spraying process to ensure that the honeysuckle is uniformly soaked; after spraying liquid, reloading the honeysuckle sieve tray into the drying vehicle and pushing the honeysuckle sieve tray into the drying box;

(7) the drying oven is set at 65-70 deg.C and relative humidity below 30%, and is dried for 1-2 hr;

(8) and discharging the dried honeysuckle, selecting and packaging to obtain the honeysuckle tea.

2. The method for preparing the selenium-added honeysuckle tea as claimed in claim 1, wherein the surface water-free in step (1) means that no dew or rainwater exists on the surface of the flower buds of the honeysuckle before picking, or the dew or rainwater is aired to be dry.

3. The preparation method of the selenium-added honeysuckle tea as claimed in claim 1, wherein the honeysuckle is distributed with a thickness of 3-10mm on a mesh belt or a sieve tray when the honeysuckle is de-enzymed in the step (2).

4. The preparation method of the selenium-added honeysuckle tea as claimed in claim 1, wherein the honeysuckle on the drying sieve tray in the step (3) is distributed with a thickness of 3-15 mm.

5. The preparation method of the selenium-added honeysuckle tea as claimed in claim 1, wherein in the steps (4), (5) and (7), the temperature of the drying oven is realized by heating hot air circulating in the drying oven through circulating hot water by a heat exchanger; the circulating hot water is supplied by a hot water boiler and/or a solar water heater, or is realized by heating hot air circulating in the drying box through an air energy heat pump heat exchanger.

6. The preparation method of the selenium-added honeysuckle tea as claimed in claim 1, wherein in the steps (4) - (5), the humidity of the circulating air in the drying box is controlled by a compression refrigeration dehumidifier arranged outside the drying box, the dehumidifier comprises a low-temperature heat exchanger and a precooling heat exchanger for evaporating and absorbing heat of a refrigerant, the circulating air firstly passes through the countercurrent heat exchange of the precooling heat exchanger before the low-temperature heat exchanger, and the condensed dehumidifying air is heated after heat exchange and then returns to the drying box.

7. The preparation method of the selenium-added honeysuckle tea as claimed in claim 1, wherein in the step (7), the humidity of the circulating air in the drying oven is controlled by an air-cooled heat exchange dehumidifier arranged outside the drying oven, the dehumidifier comprises a low-temperature heat exchanger for absorbing heat and cooling air and a precooling heat exchanger, the precooling heat exchanger exchanges heat with the low-temperature air for heat exchange and dehumidification by air cooling in a countercurrent mode before the air-cooled heat exchanger, and the air-cooled heat exchanger returns to the drying oven after heat exchange and temperature rise.

Technical Field

The invention belongs to the field of tea production, and particularly relates to a preparation method of selenium-added honeysuckle tea.

Background

Honeysuckle, also known as honeysuckle, blooms in spring, turning white at the beginning and yellow at the end, so it is named.

The honeysuckle is a common traditional Chinese medicinal material, is cold in nature and sweet in taste, enters lung, heart and stomach channels, has the effects of clearing away heat and toxic materials, resisting inflammation, tonifying deficiency and treating wind, and is mainly used for treating diseases such as distending pain, epidemic febrile disease, fever, toxic heat, carbuncle and ulcer, tumors and the like.

The flos Lonicerae can be used alone or mixed with other common materials including some Chinese medicinal materials to make into tea, and can be drunk after soaking with boiling water to remove summer-heat and improve eyesight or treat some exogenous diseases, for example, flos Lonicerae, flos Chrysanthemi, radix Platycodi and Glycyrrhrizae radix can be drunk after soaking with water to prevent and treat pharyngolaryngitis and tonsillitis.

Generally, the better the quality, the better the efficacy and the higher the value of the honeysuckle, and the honeysuckle is more easily accepted as tea capable of being brewed and drunk; the purchase and sale price of honeysuckle as tea is generally obviously higher than that of the honeysuckle as medicinal materials. The best dried honeysuckle product is prepared by drying unopened buds, is rod-shaped, thick at the upper part and thin at the lower part, slightly bent, green and white in surface, thick and slightly hard in corolla, has top hand feeling when being held, is fragrant in smell, sweet in taste and slightly bitter, and opens flowers, breaks buds and yellow strips, and is not more than 5%; no black strips, black heads, branches and leaves, impurities, worm damage and mildew.

Traditionally, high-quality honeysuckle tea is generally prepared by drying buds to be opened in the shade or airing the buds under a low-light condition. Because of centralized large-area planting, a large amount of drying of high-quality honeysuckle tea cannot be realized by drying in the shade or airing under a low-light condition, so that a low-temperature dehydration drying technology is developed and applied, but the existing low-temperature dehydration drying technology is usually more focused on temperature control, and the attention degree on humidity control is usually not enough, so that the rationality of a honeysuckle dehydration drying process and the appearance and quality of a dehydrated and dried honeysuckle tea product are influenced.

In the prior art, moisture released in the honeysuckle drying process is removed by continuously discharging moisture-containing airflow; since the low temperature dehydration stage is long and the moisture concentration of the moisture-containing gas stream discharged at low temperature is low, the discharge amount of the low temperature moisture stream is large, resulting in excessive fragrance loss.

On the other hand, most of the population in China still has the problem that the health is influenced due to selenium deficiency. Selenium is an indispensable trace element for maintaining the normal functions of human bodies, and the selenium deficiency of the human bodies can cause various diseases. Research shows that selenium has the effects of improving the oxidation resistance of organisms, enhancing the immune function of human bodies, effectively removing in-vivo garbage, promoting the health of human bodies, delaying senility and the like. Generally, the daily intake of selenium of each person is not less than 50 micrograms, and the daily food contains extremely low selenium content, which cannot meet the normal needs of the human body. It has been counted that 72% of the nationwide regions belong to selenium-deficient or low-selenium regions, and the population above 2/3 has insufficient selenium intake in different degrees.

The tea is taken as a daily drink for people in China, the recommended selenium content is 0.25-4.00 mg/kg, and the tea is preferably added into plants through fertilization in the planting process, and the regeneration matters are converted into organic selenium with high human body utilization efficiency; however, the planting process has long process flow, is not easy to control, has an uncertain effect, and is inconvenient to be used for the tea leaves of the young people, such as honeysuckle.

Disclosure of Invention

In order to solve the technical problems, the invention provides a preparation method of selenium-added honeysuckle tea, which comprises the following steps:

(1) picking up honeysuckle buds with anhydrous surfaces before blooming;

(2) deactivating enzyme of flos Lonicerae bud by heating with atmospheric steam for 5-10 min;

(3) uniformly distributing the de-enzymed honeysuckle on a drying sieve tray, and putting a drying vehicle loaded on the drying sieve tray into a drying box;

(4) setting the drying box conditions to 35-45 ℃ and the relative humidity to be lower than 50%, and drying for 2-3 hours under the conditions;

(5) setting the temperature of the drying oven at 45-55 deg.C and relative humidity below 40%, drying for 2-4 hr, and drying flos Lonicerae until water content is 30-40%;

(6) pushing out the drying vehicle from the drying box, taking down the sieve tray, atomizing and spraying a food-grade sodium selenite aqueous solution into the honeysuckle, wherein the concentration of selenium in the sodium selenite aqueous solution is 0.2-0.5mg/ml, the liquid preparation amount is 5-10ml per kg of dried honeysuckle, and stirring the honeysuckle in the liquid spraying process to ensure that the honeysuckle is uniformly soaked; after spraying liquid, reloading the honeysuckle sieve tray into the drying vehicle and pushing the honeysuckle sieve tray into the drying box;

(7) the drying oven is set at 65-70 deg.C and relative humidity below 30%, and is dried for 1-2 hr;

(8) and discharging the dried honeysuckle, selecting and packaging to obtain the honeysuckle tea.

Wherein, the surface waterless in the step (1) means that no visible moisture such as dew and rainwater exists on the surface of the flower buds before the honeysuckle is picked, or the visible moisture such as the dew and the rainwater is aired to be dry, so as to avoid uneven or incomplete steam de-enzyming.

And (3) when the honeysuckle is subjected to water removing in the step (2), the honeysuckle is distributed on the mesh belt or the sieve tray to a thickness of 3-10 mm. The purpose of the enzyme deactivation is to kill the activity of biological enzyme in the honeysuckle, and avoid the bud phase, the change of flavor and the loss of useful components in the low-temperature drying process. The water removing can also shorten the dehydration and drying time of the honeysuckle. The useful components in flos Lonicerae mainly include chlorogenic acid, flavone and linalool.

In the step (3), the distribution thickness of the honeysuckle on the drying sieve tray is 3-15 mm.

In the steps (4), (5) and (7), the temperature of the drying box can be realized by heating hot air circulating in the drying box through circulating hot water by a heat exchanger; the circulating hot water is supplied by a hot water boiler and/or a solar water heater, and can also be realized by heating hot air circulating in the drying box through an air energy heat pump heat exchanger, wherein the electric heating efficiency of the air energy heat pump can reach more than 3.0 generally, and the energy consumption cost of the two methods is lower.

In the steps (4) to (5), the humidity of the circulating air in the drying box can be controlled by a compression refrigeration dehumidifier arranged outside the drying box, the electrothermal efficiency of the dehumidifier can reach more than 8 under the temperature condition, and the circulating air returns to the drying box after heat exchange and temperature rise because the circulating air has already passed through the counter-flow heat exchange of the precooling heat exchanger before the low-temperature heat exchanger of the compression refrigeration dehumidifier.

And (6) atomizing and spraying a sodium selenite aqueous solution to the semi-dry honeysuckle to ensure that the selenium content of each kg of dried honeysuckle reaches 1-5mg, wherein the added sodium selenite can be basically and completely dissolved out when the honeysuckle is soaked by adding boiled water, and the sodium selenite is utilized by a human body after drinking tea water. Although sodium selenite is used as inorganic selenium, the utilization rate of the sodium selenite by human bodies is low, the cost is low, and the selenium adding amount is controllable, and under the condition of daily brewing amount of honeysuckle tea such as 10-30g, the daily selenium supplementing amount is 10-150 mug, which is lower than the upper limit of the commonly permitted daily selenium supplementing amount of 400 mug. The sodium selenite is used as an effective component of a human selenium supplement medicament, has been applied for decades, is safe and reliable, and has obvious effect.

In the step (7), the humidity of the circulating air in the drying box can be controlled by an air-cooling heat exchange dehumidifier arranged outside the drying box, low-temperature air subjected to heat exchange dehumidification through a precooling heat exchanger and the air-cooling heat exchange dehumidifier is subjected to counter-current heat exchange before an air-cooling heat exchanger of the air-cooling heat exchange dehumidifier, and the circulating air returns to the drying box after the heat exchange temperature is raised.

The water content of the selenium-added honeysuckle tea obtained in the step (8) can be lower than 12%, the insect egg infectious microbes and viruses are killed, and the selenium-added honeysuckle tea is free from insects and mildew after being hermetically packaged, stable in quality and long in quality guarantee period of more than one year.

Compared with the existing low-temperature dehydration drying technology which does not pay attention to the humidity control technology, the method combines temperature control and humidity control, realizes low-temperature dehydration drying of the honeysuckle by dehumidifying internal circulating hot air, shortens the dehydration drying time by about one third to one half, basically prevents hot air from being discharged outwards, reduces the energy consumption by more than 35 percent, and has less fragrance loss; the dried honeysuckle has good appearance, water content, fresh flavor and brewing drinking effect, has strong fragrance and meets the quality requirement of the honeysuckle tea; the honeysuckle tea prepared by adding the sodium selenite into the honeysuckle in the step (6) contains selenium, the method is simple, the selenium adding amount is easy to control, the effect is determined, and the honeysuckle tea can supplement the selenium for human bodies and improve the health condition after being brewed and drunk.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Examples

The honeysuckle tea is prepared by the following steps:

(1) picking up honeysuckle buds with no dew, rain and other visible water on the surface before blooming;

(2) deactivating enzyme of picked flos Lonicerae bud in a water-removing machine, wherein the distribution thickness on the mesh belt is about 8mm, and the water-removing condition is heating with steam at 100 deg.C under normal pressure for about 8 min;

(3) uniformly distributing the water-removed honeysuckle on a drying sieve tray, wherein the distribution thickness of the drying sieve tray is about 12mm, loading the drying sieve tray on a truck, and pushing the truck into a drying box;

(4) setting the conditions of the drying oven at 40 ℃ and 50% relative humidity, and drying for 2.5 hours under the conditions;

(5) setting the temperature of the drying oven to be 50 ℃ and the relative humidity to be 40%, and continuously drying for 2.5 hours under the conditions;

(6) pushing the drying vehicle out of the drying box, taking down the sieve tray, atomizing and spraying a food-grade sodium selenite aqueous solution into the honeysuckle, wherein the concentration of selenium in the sodium selenite aqueous solution is 0.3mg/ml, the liquid preparation amount is 10ml per kg of dried honeysuckle, and stirring the honeysuckle in the liquid spraying process to ensure that the honeysuckle is uniformly soaked; after spraying liquid, reloading the honeysuckle sieve tray into the drying vehicle and pushing the honeysuckle sieve tray into the drying box;

(7) setting the conditions of the drying oven at 67 ℃ and 30% relative humidity, and continuing drying for 3 hours under the conditions;

(8) and discharging the dried honeysuckle, selecting and packaging to obtain the honeysuckle tea.

The temperature of the drying box is realized by heating hot air circulating in the drying box through circulating hot water by a heat exchanger, and the hot air is basically not discharged outwards; the circulating hot water is supplied by a hot water boiler and a solar water heater.

In the steps (4) to (5), the humidity of the circulating air in the drying box is controlled by a compression refrigeration dehumidifier arranged outside the drying box, the electrothermal efficiency of the dehumidifier can reach more than 8 under the temperature condition, and the circulating air returns to the drying box after heat exchange and temperature rise because the circulating air has already passed through the counter-flow heat exchange of the precooling heat exchanger before the low-temperature heat exchanger of the compression refrigeration dehumidifier.

In the step (6), the sodium selenite aqueous solution is atomized and sprayed to the semi-dry honeysuckle, so that the selenium content of each kg of dried honeysuckle reaches 3mg, the cost is low, the selenium adding amount is controllable, the sodium selenite is basically completely dissolved out when the honeysuckle is soaked by adding boiled water, and the sodium selenite is utilized by a human body after drinking tea water; the selenium adding amount is 30 mu g when the honeysuckle tea is drunk for 10g once, and is 60 mu g when the honeysuckle tea is drunk for two times, so that the honeysuckle tea beverage is safe and reliable.

In the step (7), the humidity of the circulating air in the drying box is controlled by an air-cooling heat exchange dehumidifier arranged outside the drying box, low-temperature air subjected to heat exchange dehumidification through a precooling heat exchanger and the air-cooling heat exchange dehumidifier is subjected to counter-current heat exchange before an air-cooling heat exchanger of the air-cooling heat exchange dehumidifier, and the circulating air returns to the drying box after heat exchange and temperature rise. And (3) the amount of the sodium selenite aqueous solution atomized and sprayed to the semi-dry honeysuckle in the step (6) is less, most of the sodium selenite aqueous solution can be absorbed into honeysuckle buds, and the influence on the drying process and the effect in the step (7) is less.

The dried honeysuckle obtained in the step (8) has good appearance, water content, fresh flavor, brewing and drinking effects and strong fragrance, and meets the quality requirements of the honeysuckle tea.

Comparative example 1

And (4) basically repeating the dehydration drying process in the steps (4) to (6), wherein the total hot air circulation is basically the same as that in the embodiment, and the difference is that the internal hot air circulation rate is about 65 percent, the external discharge rate is about 35 percent, cold air is automatically supplemented before hot water heat exchange, and the relative humidity of the circulating hot air is not controlled by a compression refrigeration dehumidifier or an air cooling heat exchange dehumidifier. As a result, the drying time under the three temperature conditions of the steps (4) to (6) is required to be prolonged by 1 to 1.2 hours; the quality and the water content of the dried honeysuckle obtained in the step (6) are basically the same as those of the honeysuckle obtained in the embodiment, but the honeysuckle has slightly poor fresh flavor and brewing drinking effect.

Comparative example 2

And (3) basically repeating the dehydration drying process in the steps (4), (5) and (7), wherein the total amount of hot air circulation is basically the same as that in the embodiment, and the operations of spraying the food-grade sodium selenite aqueous solution and pushing the honeysuckle into and out of the drying oven in the step (6) are not performed. The obtained dried honeysuckle tea has the same appearance, water content and fragrance as the selenium-added honeysuckle tea obtained in the examples.