JPS61146150A - Production of tea extract - Google Patents

Abstract

PURPOSE:To obtain a concentrated tea extract having improved flavor and hue and high palatability with high efficiency, by extracting tea leaves with an aqueous solution of dextrin in a specific concentration at a given temperature. CONSTITUTION:Tea leaves, e.g. green tea, black tea or oolong tea leaves, are extracted with water. In the process, an aqueous solution of dextrin in about 5-30wt.% concentration is used to extract the tea leaves at >= about 80 deg.C. Components in the interior of the tea leaves are effectively extracted, and the aimed tea extract having improved clarity, flavor, taste, hue and stability and further flavor balance similar to that of the ordinary drinking tea and high palatability can be obtained with improved extraction ratio while suppressing the swelling of the tea leaves by water absorption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a tea extract useful in the food field such as food and beverages and luxury goods, and is aimed at producing a rich tea extract that is highly palatable and exhibits excellent flavor and color. This invention relates to an improved method for producing tea extracts that can be produced efficiently and industrially advantageously.

More specifically, the present invention provides a concentration useful for suppressing temperature swelling of the tea by hot water when tea is extracted with water to produce a tea extract.
The present invention relates to a method for producing a tea extract, which is characterized in that the extraction process is carried out using an aqueous dextrin solution in which about 30 to about 30 weight of dextrin is added and dissolved in advance and at an extraction temperature of about 80°C or higher.

For example, teas such as green tea, black tea, and oolong tea have been widely used by infusing or brewing tea leaves in hot water each time they are consumed. It has come to be used as a tea beverage by filling the infusion into bottles, cans, or paper containers, or as instant tea products made by removing water from the tea infusion and making it into powder or granules. Demand is rapidly increasing due to its simplicity.

In response to this demand, tea extracts have been produced on an industrial scale, and tea extracts can be produced by subjecting tea to water extraction treatment under appropriate heating conditions. It is being done.

However, the base extracts conventionally used in the production of processed tea beverages are generally those obtained by simply extracting leaves with boiling water or the like.

In the tea extract obtained by such hot water extraction treatment, excessive tannins etc. are eluted, the flavor balance such as bitterness and astringency is poor, and the quality is inconsistent.
When the obtained extract is cooled, cream down (cloudy phenomenon) occurs, and as a material for producing tea beverages with a relatively long shelf life, there are various drawbacks that need to be solved.

Conventionally, methods for preventing cream down when the hot tea extract is cooled include methods such as cooling the extract and removing the turbid substances generated by filtration, or decomposing and solubilizing using enzymes. has been proposed (Japanese Patent Publication No. 48-24754).

Another method is to extract tea at a low temperature and suppress the excessive elution of soluble components, so that the resulting extract does not cause cream-down even when cooled. For example, the extraction temperature is 15L.
-25℃ (JP-A No. 53-24099), 58℃ from 5℃
°C (Japanese Unexamined Patent Publication No. 53-52696), 2 oL-a 2 °C
(Japanese Unexamined Patent Publication No. 59-21346) has proposed water extraction treatment under temperature conditions.

However, in these proposals for water extraction treatment under relatively low-temperature conditions, tea is extracted at a low temperature of 60°C or less, and the resulting tea extract has a low degree of cream down during cooling. Although the amount is small, on the other hand, compared to the tea infusion or decoction made by the general tea ceremony method,
Its flavor is poor, watery, and lacks richness and strength.
Furthermore, it is difficult to extract the flavor components that are originally good in tea in a well-balanced manner, resulting in off-flavors such as greenishness, and the extraction efficiency is poor. However, many drawbacks remain, such as the need for heating and concentration in advance.

Furthermore, in JP-A No. 57-33544, a required amount of sugar is added to a predetermined amount of room-temperature water to make sugar water, and then a required amount of black tea leaves are added to the sugar water and allowed to soak in the bay. A proposed method of making iced tea (chilled black tea) that does not cause cream down (cloudiness) by storing sugar water in which black tea leaves have been soaked in the refrigerator for the required time and dissolving the black tea ingredients in the sugar water while cooling. has been done. However, since this method involves extraction at a very low temperature that suppresses solubility, although there is no cream-down, it takes a long time to extract, and the flavor components of the tea are not extracted sufficiently, resulting in a lack of flavor. However, this could hardly be an industrial manufacturing method.

Furthermore, Japanese Patent Application Laid-open No. 57-33545 describes black tea, green tea,
A method for producing instant teas is disclosed in which tea leaves of teas such as oolong tea are immersed in hot or cold water containing cyclic dextrin at 60° C. or lower to extract soluble components, and the extract is dried. However, even in this proposal, it is clearly stated that because the extraction temperature is as low as 60°C or less, the original desirable flavor of tea cannot be extracted. 60 behind
'A complicated process of reheating to -90°C is used. Furthermore, the cyclic dextrin used in this proposal is not only expensive, but also has a unique odor such as a chemical odor.In addition, its solubility in water is low, so it cannot be used in a concentrated aqueous solution.

Therefore, in the same invention, when drying the extracted product with cyclic dextrin-containing water, the actual situation is to perform spray drying after adding and dissolving other excipients after the extraction.

In addition to the many problems of the conventional technology as described above, teas such as green tea, black tea, and oolong tea absorb water and swell significantly during extraction, so continuous extraction using an extraction kettle or column on an industrial scale is difficult. However, there were many problems such as column clogging and reduced extraction efficiency.

The present inventors have improved the drawbacks of the above-mentioned conventional low-temperature extraction method at 60°C or lower and high-temperature extraction method at 80°C or higher, and have created a tea extract that maintains the preferable palatability of tea and is industrially advantageous. Research was conducted on the manufacturing method of kuto.

According to the research conducted by the present inventors, in order to produce tea extracts most economically on an industrial scale without impairing the inherent favorable flavor balance of teas, the temperature required for the aqueous extraction treatment of teas is at least about 80°C or higher, preferably about 90°C
It was confirmed that the temperature needs to be at least ℃.

Furthermore, tea extract extracted at a low temperature of 60°C or less, which is carried out with the utmost purpose of preventing creaming down of the tea extract, is blue and crisp compared to tea infusions that are normally used for drinking. It lacked richness and the flavor was unsatisfactory. The reason for this is that, according to the inventors' study using black tea, low-temperature extraction below 60°C.
Compared to the high-temperature extraction at about 80° C. or higher according to the present invention, the yield based on soluble solid content is about 30% lower, which is presumed to be due to insufficient extraction of the flavor components.

The present inventors investigated a method that can effectively utilize the advantages of high-temperature extraction of tea as described above and also suppress cream down when cooled.

As a result, when extracting teas such as green tea, black tea, and oolong tea with hot water, a solution of about 5 to about 30% by weight of dextrin dissolved in the hot water is used, and the extraction temperature is set to 80°C or higher. The present invention was completed based on the discovery that the above-mentioned drawbacks of conventional tea extract production can be solved all at once.

Therefore, an object of the present invention is to provide an extremely efficient and industrially advantageous method for producing a rich tea extract with excellent flavor and color tone and high palatability.

The above objects and many other objects and advantages of the present invention will become more apparent from the following description.

Examples of teas that can be used in the present invention include Japanese-style steamed teas such as sencha, bancha, haujicha, gyokuro, and matcha, and kettle-roasted green teas found in Chinese teas. Examples include various types of tea, such as unfermented tea, semi-fermented tea such as Baogra tea and oolong tea, and black tea, which is fermented tea.

In addition, examples of dextrins that can be used in the present invention include dextrins with various degrees of decomposition obtained by hydrolyzing starches using hydrochloric acid or enzymes, but preferably dextrins with dextrose equivalent (
Deztrose Equiva-1ant (hereinafter referred to as DE) can be exemplified by about 2 to about 20 dextrins.

Next, to illustrate a preferred embodiment of the present invention, for example, for 1 part by weight of the above-mentioned teas, dextrose (IJ) with a concentration of about 5 to about 30% by weight, which has been heated in advance to about 80°C or higher, is used. About 1 to about 100 parts by weight of a hot aqueous solution is added, and extraction is performed for about 1 minute to about 24 hours under standing or stirring conditions, and if desired, after rapid cooling, conventional methods such as filtering, squeezing, and centrifugation are performed. A solid-liquid separation process is performed to obtain an extract.

A more preferred embodiment of the present invention is a column extraction method that can effectively exert the effect of suppressing the swelling of tea leaves by the dextrin aqueous solution of the present invention. A column made of other suitable material is packed, and an aqueous dextrin solution with a concentration of about 5 to about 30% by weight, which has been heated in advance to about 80°C or higher, preferably about 90°C or higher, is fed from the top or bottom of the column, preferably from the bottom. For example, SV
Extraction is performed by pumping the liquid at a flow rate of about 1 to about 50%.

The concentration of dextrin is about 5 to about 30% by weight as described above.
For example, if the concentration is less than about 5%, the swelling suppressing effect of the tea of the present invention will be insufficient, and if the concentration is more than about 30%, the viscosity of the dextrin solution will affect the workability. and a decrease in the extraction rate, making it impossible to obtain favorable results.

It is preferable to connect a plurality of nine columns filled with the above-mentioned tea products in series, so that a concentrated extract can be obtained all at once. The amount of the dextrin aqueous solution used for tea extraction can be arbitrarily selected, and for example, about 5 to about 20 parts by weight can be used for 1 part by weight of tea.

Further, the above-mentioned extraction column can be heated, insulated, or heated by hot water, steam, etc. via a jacket, if desired. Furthermore, in the present invention, the tea extract obtained as described above is immediately cooled to, for example, about 30°C or less by a cooler connected to the column outlet, thereby producing a flavor rich in palatability peculiar to tea. And the color tone can be stably maintained.

According to the method of the present invention, by simply employing an extremely simple method of using an inexpensive and easily available dextrin aqueous solution when extracting tea with hot water, the tea can have the same favorable flavor balance as ordinary drinking tea. The extract can be obtained industrially with great advantage, and the resulting tea extract has almost negligible sweetness compared to conventional tea extracts that use monosaccharide or oligosaccharide aqueous solutions. ,
The extraction rate improves because the components inside the strips are effectively extracted by the osmotic pressure effect, and it also emulsifies, adsorbs, and clathrates the extracted aroma components, tannins, amino acids, caffeine, and pigments. This protects and stabilizes the extract, prevents the extract from changing over time, and provides a highly palatable tea extract with excellent clarity, aroma, flavor, color tone, and stability.

Furthermore, by using a dextrin aqueous solution containing about 5 to about 30% by weight of dextrin, it is possible to suppress swelling of tea products due to water absorption, and it is possible to reduce the size of the equipment, increase the amount of preparation, and further reduce the amount of extraction solvent used. In addition, by maintaining multiple extraction vessels or columns, it became possible to obtain an extract with a higher concentration. Moreover, the obtained extract already contains about 5 to about 30% by weight of dextrin in addition to tea soluble components, and the concentration operation that is essential for conventional water-extracted extracts can be omitted. It becomes possible to immediately dry it by spray drying or other means and turn it into powder or granules, thereby minimizing the loss of aroma components.

The present invention has many excellent effects as described above, and is particularly suitable for extracting not only black tea but also green tea, oolong tea, etc., which do not require sweetness or are inconvenient if sweetness is present. The tea extract obtained by the present invention can be added to beverages such as Japanese and Western confectionery, chanterelles, frozen desserts, instant tea, and health drinks, in addition to being used as a raw material for producing instant teas. These foods and drinks can be given the same desirable and highly palatable tea flavor as other decoctions.

Some embodiments of the present invention will be explained in more detail with reference to Examples below.

Example 1 Dextrin (N5DXDE 1o.

22) Dissolve 24ON in 2,161' demineralized water to 10%
A dextrin aqueous solution was prepared, commercially available black tea 2001 was added thereto, and the mixture was stirred and extracted at 90'-95@1'C for 30 minutes.

After the extraction was completed, the mixture was cooled to 30°C, centrifuged, and filtered through a bleached cloth to obtain black tea extract λ1001.

Comparative Example 1 1.980 g of black tea extract rough was obtained under the same conditions as in Example 1 except that 4400 g of demineralized water was used instead of the dextrin aqueous solution.

Comparative Example 2 Black tea extract 061' was obtained under the same conditions as in Example 1 except that the extraction temperature was 25 to 30°C.

Comparative Example 3 In Example 1, 2,400 ml of demineralized water was used instead of the dextrin aqueous solution. 2020 g of black tea extract was obtained under the same conditions except that F was used and the extraction temperature was 25L and 30°C.

[Analysis results and sensory evaluation]

Example 1 and Comparative Examples 1 to 3'c The obtained black tea extracts were analyzed for Br1z, pH, tannin content, and caffeine content. Furthermore, the amount of precipitate formed after these extracts were stored at about 25° C. for 12 hours was visually observed. These results are shown in Table 1.

Table 1 *Note) -2 Precipitates were not observed, +: Precipitates were clearly observed, ++: A large amount of precipitate was formed and a precipitate layer was formed.Example 1 and Comparative Example 1 Hot water 502 was added to each 10F of the extract obtained in 3 to 3 to dilute it, and the light color, aroma, taste, and overall evaluation were performed by sensory evaluation. The sensory test was conducted by a panel of 20 experts, who asked them to select the one they liked the most in terms of color, aroma, taste, and palatability. The results are shown in Table 2.

As shown in Table 2, the black tea extract of the present invention obtained in Example 1 was outstanding in both flavor and color, and was outstanding in terms of palatability.

Example 2 Three jacketed glass columns with an inner diameter of 45 sq., a height of 300 ml, and a capacity of about 480 ml were connected in series, and a total of 1,501 soybeans of black tea were charged into each column. Steam was passed through the jacket of each column to keep it warm, and a 10 weight aqueous solution of dextrin (N5DXDE, manufactured by Nippon Shokuhin Co., Ltd., approximately 10) previously heated to 90 to 95° C. was fed from the bottom of the first column at an SV of approximately 6. The extract flowing out from the top of the first column is led to the bottom of the second column for granular extraction, and a cooling pipe is attached to the top outlet of the third column to cool the extract flowing out by about 30"CJK. 690y of extract having a refractive sugar content Br1z of about 20° was obtained.

This extract was directly spray-dried by a conventional method to obtain powdered black tea 120I having good flavor, color tone, and solubility.

Claims (1)

[Claims] 1. When producing a tea extract by water extraction of tea, using an aqueous dextrin solution in which about 5 to about 30% by weight of dextrin is added and dissolved in advance, and about 80% by weight of dextrin is used.
A method for producing a tea extract characterized by extraction processing at an extraction temperature of ℃ or higher. 2. The manufacturing method according to claim 1, wherein the extraction process is performed by column extraction.