JPS6215175B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing powdered black tea. Traditional black tea is made from tea buds (hereinafter referred to as original leaves) that are picked from tea plants in the production area and undergoes a series of fermentation processes: withering, rolling, mellowing, steaming, and drying, resulting in a distinctive orange-red light blue color. There is one that is made to emit the aroma of tea leaves and is infused with hot water for drinking.The other is that the tea buds (original leaves) are ground and fermented as they are without withering, and the oxidation effect of catechin is activated into small particles. A cell phone with items sealed in paper strainer bags for one bowl,
Teabag black tea, which is easy to drink, has become widely used.

However, the former requires time and effort to drink, as black tea is required to be quick and convenient, as each tea is poured into a tea strainer and hot water is added, while the latter requires a lot of effort to separate, and the bag after drinking is a nuisance and an eyesore. However, it also has the disadvantage that the unique aroma, which is important for black tea along with its orange-red color, is suppressed by the action of active catechins.

In addition, "black tea fermentation" in the black tea manufacturing process does not fall under the definition of "fermentation" due to microbial action in fermentation engineering, but the oxidation reaction of tea tannins by oxidizing enzymes in tea buds is the main reaction during fermentation, and the process Ripening is the chemical change that occurs in the tea buds. Yellowing of tobacco and ripening of fruit in the field of agricultural processing are seen as the same reaction, and are considered to fall under the definition of "ripening."
Hereinafter, it will simply be referred to as "fermentation." In addition, there is currently a powdered black tea disclosed in Japanese Patent Application Laid-Open No. 117754/1983.
This is a method of manufacturing by mixing mineral volcanic rock powder during the process, which loses its aroma and leaves minerals that are not beneficial to the human body, making it unsuitable for drinking.
The downside is that it doesn't feel good after drinking.

Therefore, the present invention aims to improve the drawbacks of the tea bags and provide a method for producing black tea powder that is rich in aroma and easy to drink.

The manufacturing method of the present invention is characterized by scraping off the surface of the original leaves (tea buds) as the first pretreatment step in the process of freezing, drying, and pulverizing the exuded black tea liquid. It is ground and then re-fermented. The whole process is as follows:
After rapid freezing and thawing the re-fermented raw leaf powder that has gone through the above pre-treatment process (first step), a clarifying agent (excipient) is added, water is added and stirred to emulsify, and after cooling, dehydration is performed and the extract is heated. The second step is to squeeze the extract and let it settle.
step, and the third step of freezing and concentrating and separating the supernatant.
After freezing and pulverizing the concentrated and separated raw black tea leaves, a vacuum freeze-drying operation called FD is performed to obtain powdered black tea.

The method for producing powdered black tea of the present invention will be explained in detail below.

1 1st step 1-1 Pre-treatment step: Black tea leaves (tea buds) are natural products and are not homogeneous depending on their type, production area, climate, etc. Also, depending on the fermentation situation, some are sufficient and some are insufficient. Among them, the best ones are commercialized as high-quality conventional black tea. Therefore, the present invention uses a large amount of the above-mentioned heterogeneous raw leaves, and the surface of the raw leaves (where many of the active ingredients of black tea are present through photosynthesis) is scraped thinly with a cutter, and this is scraped with a stone mill. The ingredients are ground by crushing and crushing with a wooden pestle, and are made into a coarse powder (2 to 3 mm screen) to unify the shape. In addition, when crushing, 0.3% of enzymes as active ingredients (pectinase, amylase, polyphenol oxidase, etc.) per raw leaf, 0.03% of calcium lactate (weight ratio) and warm water at 37 ° C were added. Mix until thick and crumbly (about 10 minutes). In the method of the present invention, it is important to form a homogeneous powder by this grinding.

1-2 Re-fermentation: In order to adjust the heterogeneity of the initial raw leaf fermentation in the local production area, the crumbly raw leaf powder is re-fermented. i.e. ambient temperature 36-42℃, humidity
Ferment (ripen) by sealing at 100% for 2 to 3 hours. This promotes an increase in the light blue component of black tea.

1-3 Freezing: The re-fermented raw leaf powder is rapidly frozen to stably maintain its quality in order to release the light blue component while preventing the oxidative deterioration of the active ingredients of the black tea. This freezing destroys and cuts the plant cell wall or fibrous tissue of the black tea leaf powder. This is because the water contained during re-fermentation and the water in the cells expands due to freezing and is destroyed without the need for heating or other means.

The above is the first step, which is a preparatory process.

Second step 2-1 Thawing: As a pre-step to the subsequent black tea liquid extraction operation, the frozen raw leaf powder is slowly thawed naturally.

2-2 Stirring: Add purified hot water and maltodextrin to the thawed raw leaf powder at a weight ratio of 3:2 to the raw leaf powder.
A clarifying agent (filling agent) is added thereto, the liquid temperature is brought to about 60°C, and the mixture is stirred and cooled to 35°C to form an emulsified state.
This "overemulsification" caused by stirring makes the "solid-liquid separation" operation in the subsequent step difficult, so care must be taken. The stirred solution at about 35° C. is used as it is, or a separately extracted solution is added and dehydrated by centrifugation or other means to obtain approximately the original amount of the extracted solution.

2-3 Heating: This is an operation for coloring the light blue component of black tea in the extract and eluating the taste component, and is heated to about 60°C. If the temperature exceeds the limit, the taste will become astringent and the water color will become dark and cloudy, so be careful. Moreover, after heating, it is rapidly cooled to about 5°C.

2-4 Solid-liquid separation: The extract is separated into a water-soluble (drinkable) portion and an insoluble (residue) portion by centrifugal force and squeezing force, and the extract is taken out.

2-5 Stationary precipitation: In order to improve the transparency of the reconstituted black tea (drinking liquid), the cloudy components in the extract are precipitated and separated. (Due to the effect of the clarifying agent added in the pre-operation, insoluble colloids aggregate and precipitate. Standing time is approximately 17 hours, and the container is sealed at an environmental temperature of 5 to 7° C.).

Third step 3-1 Clarification separation: Collect the supernatant portion of the statically precipitated extract (approximately 90% collection). Discard the cloudy substance that settles to the bottom.

3-2 Freeze concentration separation: For the purpose of concentrating the supernatant extract, it is frozen into lumps, and the ice blocks are separated by centrifugal force into a liquid part, that is, a concentrated extract, and an ice block part, that is, a dilute extract. (The diluted solution was added as a feed back to the above-mentioned separate pre-process.) The concentrated extract was about 30% of its original weight.

Fourth step: Vacuum freeze-drying (FD): The concentrated stock solution, which had been freeze-pulverized in advance, could be made into powdered black tea by vacuum freeze-drying. The product powder had a size of 5 to 20 meshes, which was a little less than 1/3 of the weight of the original leaves.

The method of the present invention described above scrapes the surface of the original leaves and crushes them in order to improve the fermentation, which is important for the flavor, i.e., the light blue color, and the aromatic components of black tea. As the pre-treatment is performed through additional fermentation, the raw black tea leaves can be used to the maximum extent possible, without the use of impure rock powder or solvents, and without adding excessive heating or stirring of water. We were able to obtain an excellent product without any damage.

Claims (1)

[Claims] 1. In the manufacturing process of powdered black tea, in which black tea exudate is freeze-dried and then crushed to make powdered black tea, the raw black tea leaves that have been picked and withered (roughly fermented) are crushed and crushed with the addition of anti-turbidity enzymes and water. After pre-treatment of re-fermenting and freezing at a specified temperature and time, thaw, add maltodextrin and warm water, stir, dehydrate the extract, separate solid and liquid, and dry the collected clear liquid to make a powder. A method for producing powdered black tea characterized by: