JP3119968B2 - Tea beverage manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of producing a tea beverage using unfermented tea such as green tea, and more particularly, to a transparent bright red color similar to black tea without using unfermented tea. The present invention relates to a novel method for producing a tea beverage in a sealed container capable of maintaining the color tone for a long period of time.

[0002]

2. Description of the Related Art In recent years, low-sugar and non-sugar beverages have been favored as beverages as the sweetness of consumers has increased, and the market for tea beverages such as green tea, oolong tea and black tea has been remarkably expanding. It is in. Among these tea beverages, the market for green tea beverages is a particularly remarkable market recently. In general,
The types of green tea, such as sencha, hojicha, and bancha, are well known, and the tea leaves are generally manufactured as follows. That is, first, the tea leaves are steamed in the first stage of production or roasted in a kettle to inactivate the oxidase in the tea leaves, and then, through several kneading steps such as kneading, the moisture and shape are reduced. After adjustment, it is manufactured by dry-burning. As described above, green tea does not undergo fermentation like oolong tea and black tea, and is therefore called unfermented tea. Green tea hardly undergoes oxidation during production, so it retains green color, has little change in components, and has a unique blue flavor.

[0003] Green tea beverages obtained using the above-mentioned tea leaves are filled and sealed in a sealed container such as a can for the long-term distribution and distributed. However, at that time, to perform retort sterilization,
A unique germicidal smell (retort smell) is generated, and there is a problem that the blue smell is emphasized and the original flavor of green tea is impaired, and the color tone changes from green to yellow-brown.

[0004] By the way, when oolong tea is extracted, it is extracted with an aqueous solution of sodium carbonate, cooled rapidly, adjusted in color tone with ascorbic acid, and then neutralized with an acid.
A method of adjusting the pH to 6.0 to 6.5 with sodium hydrogen carbonate has been proposed (JP-A-60-192548). According to this method, the tea component is easily eluted in a short time, and the extraction efficiency can be increased. Therefore, a slight improvement in the retention of the fragrance and the retention of the color tone can be seen. However, although the oolong tea beverage obtained by the above method has a good flavor in the state of the extract immediately after extraction, when it is subjected to retort sterilization treatment, the pH is less than 7.0, so that the retort odor still remains. I will join. In addition, when the above method is used not for oolong tea but for green tea having a more delicate flavor than oolong tea, the effect of retaining flavor is further reduced.

[0005] As another method for extracting tea beverages, extraction is performed with an aqueous solution to which sodium or potassium carbonates or phosphates are added, and the extract is adjusted to pH with ascorbic acid.
A method of adjusting the value to 6.0 to 7.0 has been proposed (JP-A-57-16649). Further, as another method for extracting tea beverages, a method for producing instant powdered tea in which tea leaves are extracted with water containing a metal salt having a higher ionization voltage than iron such as sodium polyphosphate and a chelating agent such as alum is proposed. (Japanese Patent Publication No. 39-21643). However, when these methods are applied to green tea beverages, the flavor of green tea is good in the state of the extract, but when this extract is placed in a sealed container and sterilized by retort, a retort odor still occurs, In addition, the color tone changes to yellow-brown.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to maintain the original good flavor of a green tea beverage even after retort sterilization. Another object of the present invention is to provide a method for producing a novel tea beverage which exhibits a blackish, transparent, reddish color that is not present in conventional green tea beverages and can maintain the color tone.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to reduce the buffer capacity.
Using an aqueous medium having a pH of 7 or more containing a pH adjustor , extracting a tea extract from unfermented tea, and then, while maintaining the pH at 7 or more, filling the extract containing the tea extract into a container, This is achieved by a method for producing a tea beverage, which is characterized in that it is sealed and heated at 100 ° C. or higher.

That is, the present inventors have conducted a series of studies on extraction conditions and heat treatment conditions of a green tea beverage having a high aroma and a beautiful color while preventing the generation of a blue odor due to a retort odor. As a result, buffering capacity non 醗酵茶(green tea)
After extraction with an alkaline aqueous medium containing a pH adjuster having a pH adjuster , the retort odor is obtained by performing a high-temperature heat treatment while adjusting the pH of the obtained extract to neutral or weakly acidic while maintaining the alkalinity. The present invention has been found to be able to prevent the occurrence of whitening, and to show that the color tone of the extract has a transparent and bright red color like black tea.

Next, the present invention will be described in detail. Examples of the unfermented tea used in the present invention include those commonly used in the production of tea beverages. Among them, the most fragrant first tea (new tea or spring tea) obtained by collecting sprout and growing young shoots in spring is preferable. It is. In a normal sealed container-filled green tea beverage, high-grade green tea such as the first tea has a remarkable loss of aroma due to retort sterilization, but according to the method of the present invention, high-grade tea retains aroma. The effect is high and suitable. In addition, in addition to the above, lower-grade tea and Chinese green tea, such as second tea, third tea (summer tea), fourth tea (autumn tea), and autumn tea, which are plucked after the first tea,
In addition, non-fermented products of various plants such as young leaves of coffee tree may be used. These may be used alone or in combination.

Next, the method for producing the tea beverage of the present invention using the above-mentioned unfermented tea is carried out, for example, as follows. That is,
First, a tea extract is extracted from unfermented tea using an aqueous medium having a pH of 7 or more containing a pH adjuster having a buffering capacity .

[0011] The pH of the aqueous medium is adjusted to 7 or more, more preferably 7.5 to 9.0. If the pH is less than 7,
A tea extract-containing extract with good flavor cannot be obtained. Also,
When the pH exceeds 9.0, the agitation characteristic of the alkaline aqueous solution tends to be felt.

When adjusting the pH of the extraction solvent used for extraction to 7 or more, potassium dihydrogen phosphate-disodium hydrogen phosphate buffer, disodium hydrogen phosphate-citrate buffer, sodium carbonate-hydrogen carbonate It is necessary to use a buffer such as a sodium buffer in order to maintain the pH at 7 or more even after the extraction and heating in the subsequent step.

The extraction temperature varies depending on the type of tea leaves, extraction concentration, etc., but is preferably 75 to 100 ° C, more preferably 80 to 90 ° C. In addition, the extraction time is preferably 2 to 4 minutes, and most preferably about 3 minutes, in terms of maintaining the scent. The extraction method may be performed, for example, by immersing unfermented tea in an extraction solvent and stirring as necessary.

The extraction concentration of the extract containing the tea extract obtained in this extraction step is usually desirably such that the soluble solid content is 0.8 to 1.7% by weight in terms of flavor. Further, the color tone of the extract is slightly yellowish green.

Next, the extract is filled and sealed in a container such as a can or a bottle while maintaining the pH at 7.0 or higher.
Heat treatment. By adjusting the pH to 7.0 or more, the original fragrance of the green tea beverage can be maintained, and the extract becomes transparent and bright red during the heat treatment. Further, the heat treatment is performed at 100 ° C. or more, preferably at 115 to 121 ° C., for 5 to 2 hours.
The treatment for 0 minutes is preferable in that the bright red color of black tea can be best developed. The tea beverage thus obtained, despite being subjected to heat treatment,
Maintains the original flavor of green tea, and has a beautiful bright red color like black tea by heat treatment.

[0016]

As described above, according to the method for producing a tea beverage of the present invention, the unfermented tea is extracted with an alkaline aqueous medium containing a pH adjuster having a buffering ability, and then the pH is adjusted. A novel tea that retains the original aroma of a green tea beverage that has a deep, transparent, reddish red color like black tea that is not available in conventional green tea beverages and has no blue odor even after retort sterilization You can get a drink. Moreover, the color tone does not deteriorate during the long-term storage.

Next, a specific description will be given with reference to examples. (Example 1) As a green tea, a commercially available Japanese tea (Ichibancha) was used, and 3 tea leaves were added to a 5 mM potassium dihydrogen phosphate-disodium hydrogen phosphate buffer (pH 7.7) heated to 85 ° C.
After soaking for 1 minute, the tea leaves were separated by filtration to obtain an extract. This extract was filled in a can, sealed, and heated at 121 ° C. for 5 minutes to obtain a tea beverage product.

Example 2 Example 1 was the same as Example 1 except that a heat treatment was performed at 100 ° C. for 40 minutes.

Example 3 The procedure of Example 1 was repeated except that tea leaves were immersed in a sodium carbonate-sodium bicarbonate buffer (pH 9.0) heated to 85 ° C.

Comparative Example 1 A tea beverage product was obtained in the same manner as in Example 1 except that the pH of the extraction medium was changed to 6.1.

Comparative Example 2 A tea beverage product was obtained in the same manner as in Example 1 except that the extract was not heated after the extraction.

Comparative Example 3 A tea beverage was obtained in the same manner as in Example 1 except that the pH of the aqueous extraction medium was adjusted to 7.7 by adding sodium bicarbonate. Since sodium bicarbonate alone does not have a buffering capacity, the final pH was 6.6.

The tea beverage product obtained as described above was evaluated. The presence or absence of blue odor was evaluated by sensory evaluation by 20 specialized panelists. The color tone was measured with a color difference meter manufactured by Nippon Denshoku Industries Co., Ltd. Furthermore, the color tone after storage at 40 ° C. for one month was evaluated by visually observing the degree of black change in comparison with a sample stored at 5 ° C. for one month. Table 1 shows the results.

[0024]

[Table 1]

As is clear from Table 1, the tea beverage product of Example 1 exhibited the deepest red color, showed almost no blue odor, and was the best. Example 2
The tea beverage product of No. 3 also exhibited a tea-like bright red color. on the other hand,
The tea beverage product of the comparative example had a poor color tone and a blue smell, and a satisfactory product was not obtained.

Claims (1)

(57) [Claims] Claims: 1. A pH containing a pH adjuster having a buffering capacity
Extract the tea extract from unfermented tea using an aqueous medium of 7 or more, then, while maintaining the pH at 7 or more, fill the extract containing the tea extract into a container, seal the container, and heat at 100 ° C. or more. A method for producing a tea beverage.