JP2013051894A - Method for preventing creaming down of tea and tea - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tea manufacturing method preventing the creaming down of tea that could happen when the tea is cooled after being brewed, so as to retain the caffeine contained in the tea, while removing undesirable flavor components and converting astringent components into polymerized catechin; and to provide tea manufactured.SOLUTION: Tea is put in a pressure container. Steam is blown into the pressure container and heated to substitute air contained in the tea with steam, so as to vaporize undesirable components and remove these undesirable flavors. An exhaust valve is closed and a heat treatment is performed at predetermined pressure and temperature to decompose a component that makes up the astringency of tea, i.e., catechin gallate causing the creaming down, and to dissociate gallic acid, so as to create tea with a fresh taste. The heating temperature is further elevated to convert catechin, i.e., the astringent component, into a functional polymerized catechin to reduce astringency. If a pressurizing and heating treatment is performed on the tea in the presence of calcium carbonate, a polymerization reaction of the astringent component catechin is promoted and it is converted into polymerized catechin. Thus, the tea preventing the creaming down that could happen when the extracted tea is cooled can be manufactured.

Description

The present invention relates to a method for processing tea, and relates to a method for producing tea that prevents a cream from being reduced when tea is leached and has reduced astringency components, and tea produced by the method.

The phenomenon that solids precipitate when the tea-decoction liquid is cooled is referred to as “tea cream-down”, and an undesired phenomenon is desired to develop a tea processing method that prevents this cream-down.

It has been proposed to solubilize solids contained in tea infusion obtained by brewing tea with an enzyme preparation (Japanese Patent Publication No. 48-24754). This is a method of solubilizing and removing the solid substance creamed by tannase. It can be used for food processing to produce tea drinks, but cannot be easily used in everyday homes.

Before processing tea leaves, let tannase act on raw tea leaves or ground tea leaves to break down catechin gallate that causes cream down, manufacture and process tea by conventional methods, tea manufacturing method that does not cause cream down Has been proposed (Japanese Patent Publication No. 52-42877). This method is suitable for instant tea processing, but not for leaf tea manufacturing.

As a result of research on the phenomenon of cream-down, it was clarified that caffeine and catechin gallate contained in tea make an inclusion compound to make a solid. It has been found that it is effective to prevent caffeine and catechin gallate from binding and not to form a solid by decomposing and eliminating catechin gallate in tea making by polymerization.

Japanese Patent Publication No. 48-24754 Shoko 52-42877

This invention retains caffeine, which is a functional component contained in tea produced by processing tea leaves, decomposes or converts catechin gallate, which is a bitter component that causes the formation of creamdown, to catechin catechin, The present invention relates to a method for producing tea that does not cause a cream-down phenomenon when brewed and cooled, and tea produced by the method.

The present invention pressurizes and heat-processes tea produced by processing raw tea leaves to decompose catechin gallate causing cream-down and further convert it to polymerized catechin, thereby preventing the generation of a cream-down phenomenon. It has been found that this processing can be achieved by applying pressure in a high-pressure vessel. The temperature adjustment of the heating container used in the present invention is performed by finely adjusting and setting the pressure in the vessel. Heated water vapor under pressure has a high heat capacity, can quickly conduct heat to the heated object, and is uniformly heat-treated. Put the crude tea made by the ordinary method into the pressure vessel, blow steam into the pressure vessel, replace the air contained in the crude tea with steam and heat it, evaporate the undesired components contained in the crude tea, Eliminate no odorous substances out of the container.

After removing undesirable aroma components, close the exhaust valve, heat treatment at the specified pressure and temperature, decompose the ester bond of catechin gallate, the component that constitutes the strong astringency of tea, dissociate gallic acid, EGC It can be converted to GC to make a refreshing tea.

When the treatment pressure is further adjusted and the heating temperature is raised, catechin is thermally decomposed and polymerized, and catechin is converted to polymerized catechin to reduce astringency. Caffeine is maintained without being sublimated or thermally decomposed by pressurization and heating under saturated steam.

When calcium carbonate is added to crude tea and placed in a pressure vessel, steam is blown in the same manner as (0008) (0009), and when crude tea is heated under pressure in the presence of calcium carbonate, decomposition of catechin and polymerization reaction are accelerated. It is converted into a catechin polymer, and the color tone becomes darker and the flavor becomes milder.

According to this invention, catechin gallate that causes cream down contained in crude tea is decomposed and further converted into polymerized catechin, and catechin gallate is removed, thereby providing a tea that does not cause cream down.

According to the present invention, the tea is humidified and heat-treated in a pressure-resistant container, and general viable bacteria and heat-resistant bacteria are completely sterilized. Therefore, the tea can be processed into a sanitary tea beverage by a normal extraction process. it can.

For the production of high-quality tea, early spring buds of tea leaves with less astringency are used. Growing summer tea has a lot of astringency and has a characteristic scent of summer tea, and summer tea is not used. However, the low-rated summer tea contains almost the same amount of caffeine as spring tea, and the tea is humidified and heat-treated in a pressure-resistant container to remove unpleasant aroma and cause cream down. Can be processed into a refreshing tea without catechin gallate.

Since caffeine, a unique functional component contained in tea, is heated under heat and humidity in a closed container, the sublimation property of caffeine is suppressed and retained in the processed tea.

The catechins of astringent components contained in tea are subjected to wet heat and pressure heat treatment in a closed container. First, the catechin gallate ester bond of tea components is decomposed by treatment at a set temperature (100 ° C.), and gallic acid. Is dissociated and converted to EGC and GC to make a refreshing tea. Subsequently, when the set temperature is raised, the catechins are converted into polymerized catechins. Polymerized catechins are a large number of mixtures that have been found to have special functionality and have been studied in detail. Polymerized catechins are golden when processed at low temperature (100 ° C), theaflavin-like color at medium temperature (115 ° C), and reddish brown when processed at high temperature (130 ° C) Take on.

When calcium carbonate is added to and mixed with raw tea and processed in the presence of calcium carbonate, the color tone is deeper than that of the treated tea extract treated under the same conditions. This confirms that the polymerization reaction of catechin was promoted.

The tea processed according to the present invention produces gallic acid that was not present in the raw tea, reduces the astringency components, and produces polymerized catechins. As a result of research, it is understood that the type and functionality of polymerized catechins differ depending on the setting of processing conditions, and desired polymerized catechins can be created by finely adjusting processing conditions.

Test of preventing the effect of cream-down on treated tea:
1: Condition of cream-down prevention effect test:
a: Sample: untreated black tea (target): treated black tea
b: Hot water extracted tea leaf concentration: 2% tea leaf (concentration of normal beverage)
(8 test points) 4% (dark eyes):
6% (severe dark eyes),
c: Thermal extraction (98 ° C hot water): After holding for 10 minutes, after filtration, 2 fractions (16 test points)
High temperature hold,
Cooling hold (10 ° C refrigerator).
2: Inspection method:
Turbidity test: (striped paper perspective test):
Flavor test: (fragrance: taste: color): (five senses compared with standard products, visual inspection)
3: Judgment result:
a: Turbidity test: Untreated: High temperature extract: Clear (extracted color tone is deep red according to the concentration)
All the cooled liquids were creamed down.
Treatment: High temperature extractant: Clearer (extracted color is dark red according to the concentration)
Cold storage: Neither cream-down was observed.
b: Flavor test; untreated 2% (color tone: good flavor): untreated 4% (dark tone: astringent taste)
6% untreated (color is extremely dark: astringent and poor flavor)
Treatment 2% (color tone: good taste): treatment 4% (color tone dark: taste a bit astringent)
Treatment 6% (Deep color: Astringent taste)
c: Comparing products with the same concentration, the processed product is darker, but the flavor is milder.
The processed product has no cream-down phenomenon when cooled.

In the present invention, tea obtained by processing tea leaves by a conventional method is used as a raw material. As the tea type, green tea, black tea, oolong tea and other teas processed from tea leaves can be used, and the type of tea is not limited. The pressure-resistant heating device to be used can utilize a sterilizer and a retort device that can maintain the required temperature.

Raw tea leaves are spread in layers and inserted into a pressure-resistant heating device. If necessary, moisten the raw tea leaves in advance or add and adjust calcium carbonate.

After the raw tea leaves are inserted into the pressure-resistant heating device, the processing temperature of the pressure device (first stage temperature: second stage temperature) is set. Temperature adjustment can be finely adjusted by setting a pressure control valve.
Steam is blown into the pressure vessel, the air contained in the crude tea is replaced with steam, unwanted components contained in the crude tea are evaporated and separated, and this undesirable odorous substance is removed outside the container.

After removing undesirable aroma components, close the exhaust valve, heat treatment at the second set temperature, decompose the ester bond of catechin gallate, the component that constitutes the strong astringency of tea, dissociate gallic acid, EGC, Switch to GC to make a refreshing tea.

In the pressure heating device set at the first stage temperature of 85 ° C, the second stage temperature of 115 ° C, and the second stage heating time of 15 minutes, 2 kg of raw tea is developed in layers, each stage is equipped with a thermometer and the five stages. Insert repeatedly. The pressure vessel door is completely locked and pressurized steam is blown in. The pressurized humidified steam is evenly sprayed on the raw tea leaves of each stage, confirming uniform heating, unpleasant aroma substances contained in the raw tea leaves from the exhaust port Is eliminated with excess steam. When the product temperature reaches the first stage temperature, the exhaust valve is closed and the second stage temperature is heated to 115 ° C. Since the temperature is controlled by adjusting the steam pressure setting in the container, the tea leaves at each stage are uniformly heated at 115 ° C., unlike when the tea is ignited at normal pressure. When the second stage heating time is over, the heating steam valve is closed, the exhaust valve is opened, the pressure-resistant container is opened at normal pressure, the container door is opened, the inserted tea is taken out, transferred to a cooling and dehumidifying drying device, and the processed tea is dried. I do.
As a result of analysis of the treated tea, the number of viable bacteria was 0, and the number of heat-resistant bacteria was 0. Caffeine was maintained at 1.0: raw tea 1.0: treated tea 1.0, catechin was converted to polymerized polyphenol, and gallic acid that was not present in the raw tea was generated and detected by decomposition of gallate catechin.
The catechin gallate, which constitutes the astringent taste, was decomposed and further converted into polymerized polyphenols, and when the processed tea was decocted and cooled, it was possible to produce a refreshing golden tea with no cream-down.

Add 300 g of water and 20 g of calcium carbonate to 10 kg of raw black tea and stir uniformly.
2 kg of processed raw tea leaves are spread in layers in a pressure heating device set at a first stage temperature of 100 ° C, a second stage temperature of 125 ° C, and a second stage heating time of 15 minutes. insert. The pressure vessel door is completely locked and pressurized steam is blown in. The pressurized humidified steam is sprayed uniformly on the raw tea leaves of each stage, heated, and excessive unpleasant aroma substances contained in the raw tea leaves are exhausted from the exhaust port. Excluded with steam. When the product temperature reaches the first stage temperature, the exhaust valve is closed, isolated from the outside, and heated to the second stage temperature of 125 ° C. Since the temperature is controlled by adjusting the steam pressure inside the container, the tea leaves at each stage are heated evenly at 125 ° C., unlike when the tea is ignited at normal pressure. When the second stage heating time is over, the heated steam valve is closed, the exhaust valve is opened, the pressure-resistant container is opened, the container is opened at normal pressure, the tea in the stepped form is taken out, transferred to a cooling dehumidifying and drying device, and processed. Dry the tea. As a result of analysis of the treated tea, the number of viable bacteria was 0, and the number of heat-resistant bacteria was 0. By treating the raw tea in the presence of calcium carbonate, calcium accelerates the degradation polymerization of the astringent tannin. The catechin gallate that constitutes the astringency decomposes to separate gallic acid, reduce the astringency, further convert to a polymerized polyphenol, exhibit a red color, and maintain a refreshing flavored tea that retains the caffeine functionality unique to tea. I was able to make it.
Catechin was converted to polymerized polyphenol, and gallic acid that was not present in the raw tea was detected. As a result of the analysis, caffeine was retained as raw tea 1.0: treated tea 1.0, constituting astringency. Catechin gallate decomposes and separates gallic acid, reduces astringency, and further converts to polymerized polyphenol to give a red color, making it possible to make a tea with a refreshing flavor that retains the caffeine functionality unique to tea. .

Claims (3)

A method for producing tea in which tea is put into a pressure vessel, heated steam is blown into it, unwanted fragrance is eliminated, the exhaust valve is closed and heated in a closed system, catechin gallate causing cream down is decomposed, and cream down is prevented. A tea production method that adds calcium carbonate to tea, blows heated steam, eliminates undesired aromas, closes the exhaust valve and heats it in a closed system, decomposes catechin gallate that causes cream down, and prevents cream down. Tea produced by the method of claims 1 and 2.