JPH04311348A - Preparation of green tea drink - Google Patents

Abstract

PURPOSE:To obtain a clear green tea drink preservable over a long period by extracting green tea leaf with warm water, adding ascorbic acid to the extract, quenching and filtering the mixture, clarifying the filtrate, adjusting the pH and filling the product in a vessel. CONSTITUTION:Extracted liquid prepared by extracting green tea leaves at a low-temperature zone (50-70 deg.C) is blended with an extracted liquid prepared by extracting at a high temperature (>=80 deg.C) at a ratio of 9:1 to 5:5 to obtain a mixture having a Brix concentration of 0.1-0.7. The mixture is added with ascorbic acid, quenched, filtered by centrifugal separation, etc., added with a filter aid such as diatomaceous earth, clarified by filtration, adjusted to neutral pH and filled in a vessel such as bottle or plastic vessel to obtain the objective drink.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD The present invention relates to a method for producing a clear green tea beverage that does not generate turbidity or sedimentation and has a long shelf life, using green tea (indicating unfermented tea) as a raw material.

0002

[Prior Art] After extracting tea leaves, removing the tea husk using metal nets, cloth, etc., and removing fine tea particles by centrifugation, the tea is extracted into bottles, plastic containers, cans, synthetic paper containers, etc. In recent years, tea beverages packed in and sterilized have been widely consumed and attracting attention. The conventional method for producing green tea beverages involves extracting tea leaves with hot water, separating the tea husks, and if necessary, centrifuging to remove fine tea particles, followed by adding L-ascorbic acid to prevent oxidation. It is manufactured by adding sodium ascorbate and returning the pH to a neutral range with sodium hydrogen carbonate or the like.

[0003] Also, when tea leaf extract is cooled, it becomes cloudy (cloudy or cloudy), and this cloudiness is called creaming or cream-down, a phenomenon that is noticeable in black tea. Although this is not the case, it is widely known that cloudiness is still observed over a long period of time. Suppressing the cloudiness phenomenon is an important issue in the production of tea beverages, and known conventional suppression methods include high-speed centrifugation, tannase treatment, and addition of inorganic salts such as calcium.

0004

[Problems to be Solved by the Invention] However, in the above-mentioned green tea beverage manufacturing method, various polymer compounds, etc., in addition to tea components such as catechin, caffeine, amino acids, and sugars, are dissolved from the green tea raw material. Since these particles combine and precipitate, there is a drawback that turbidity and sludge occur over time after production. Turbidity and sludge, especially when packed in transparent containers such as bottles and plastic containers, give an unpleasant feeling and can be mistaken for spoilage, significantly reducing the value of the product. In order to suppress the occurrence of cloudiness and sludge, some products are excessively diluted, but when diluted excessively, green tea loses its original flavor and color, making it a good green tea drink packed in a transparent container. It was difficult to say.

[0005] Furthermore, methods such as tannase treatment and addition of inorganic salts for suppressing cloudiness have been difficult to call effective treatment methods that sufficiently retain flavor, as these treatments significantly reduce flavor. As described above, with conventional production methods, it has been difficult to preserve the quality of green tea beverages that are clear and have the unique flavor of green tea for a long period of time.

[0006] The present invention provides a green tea beverage that does not change the original concentration, remains clear for a long time, has excellent flavor (flavor, nutritious taste, etc.), can withstand long-term storage, and can be packed in transparent containers such as bottles and plastic containers. It is an object of the present invention to provide a method for producing a green tea beverage particularly suitable for.

[0007]

[Means for Solving the Problems] The present inventors have found that turbidity and sludge are said to be caused by the combination of catechin, caffeine, protein, etc. contained in tea extract, but green tea extract contains oolong tea. It contains more types and contents of polymer compounds (pectin, hemicellulose, polysaccharides, etc.) than tea extracts from tea and black tea. The present invention was developed by rapidly cooling the tea extract of green tea to intentionally generate cloudiness and sludge, and to remove this turbidity.

That is, the present invention extracts green tea with hot water, preferably in hot water of about 40 to 100°C for about 1 to 10 minutes, and then removes the tea husk using a metal net, cloth, etc., and extracts L-ascorbic acid. to adjust the pH of the extract to an acidic range of about 4.0 to 5.0, and then cool it to room temperature or below, preferably 20
The formation of turbidity and sludge is promoted by rapid cooling to below ℃, and after incorporating various polymer compounds into the turbidity and sludge to form particles, the turbidity and sludge containing the particles are removed by centrifugation or other arbitrary means. After removing the slag components,
A filter aid is added to the supernatant liquid and the remaining polymer compounds are removed by filtration through a filter cake, and the pH of the extract is then adjusted to approximately 5.5 to 7.
．． After adjusting the green tea to a neutral range of 0, it is packed into preferably transparent containers such as bottles or plastic containers, and sterilized by a conventional method, thereby producing a green tea beverage that does not become cloudy or stale over time. This is a characteristic feature. In addition,

000
9] The above-mentioned quenching is preferably carried out using a heat exchanger or the like in the production line process. The filter aid should be a material that has little effect on the flavor after processing and has a large precipitation prevention effect.
Diatomaceous earth is preferred. By this filtration, catechins, caffeine, amino acids, sugars, polymer compounds, etc. dissolved in the green tea extract can be effectively removed and clarified. In addition, the pH of the extract that has been subjected to the filtration process is adjusted using sodium hydrogen carbonate, sodium ascorbate, etc., and it is possible to obtain a green tea extract that is clear and has good flavor (flavor, nuttiness, etc.). can.

[0010] Since the extract obtained by the above production method is clear, there is no need for excessive dilution even if it is diluted, and it can be used at the original concentration of the green tea beverage.

[0011] In the production process of the above-mentioned production method, the present invention extracts a liquid obtained by extracting green tea at a low temperature range of about 50 to 70°C and a high temperature range of about 80°C or higher, respectively, at a ratio of about 9:1 to 5:
The manufacturing method is also characterized by mixing in proportions ranging from 5 to 5. The extract in the high temperature range of about 80℃ or higher has a strong aroma and bitter and astringent taste, while the extract in the low temperature range of about 50 to 70℃ has sufficient sweetness and rich taste.By mixing both liquids, it will last for a long time. This is a preserved beverage, and the flavor as a beverage equivalent to the original fresh green tea beverage is preserved.

[0012] A preferable example of the production method using the above mixing method is to add ascorbic acid to the extract obtained by extracting green tea at a low temperature range of about 50° C. to 70° C. to adjust the acidic range, and then rapidly cool the solution, and to add green tea to the extract at a low temperature of about 50° C. to 70° C. After adding ascorbic acid to the extract extracted at a high temperature range of 80°C or higher to adjust it to an acidic range, and mixing this with the rapidly cooled liquid at a ratio in the range of about 9:1 to 5:5, respectively. This is a method in which a green tea beverage is prepared by performing slag filtration using a filter aid, and then using the same method as described above. In this case, filtration by centrifugation or the like may be performed before or after mixing the low-temperature range and high-temperature range extracts.

[0013] In any of the above-mentioned inventions, it is preferable to manufacture the tea leaves so that the concentration of the extract obtained by extracting the tea leaves is within the range of about 0.1 to 0.7 as a Brix value.

[0014]

[Effects of the Invention] In this way, according to the present invention, the green tea beverage remains clear and clear for a long period of time without changing its original concentration.
Moreover, it is possible to provide a green tea beverage that has excellent flavor, endures long-term storage, and is particularly suitable for being packed into transparent containers such as bottles and plastic containers. In the above manufacturing method, diatomaceous earth is used as a filter aid for filter filtration, and an extract mixture of a mixture of a low-temperature extraction and a high-temperature extraction is used as an extract. According to
Further, an optimal green tea beverage can be provided by manufacturing the tea so that the Brix value is within the range of about 0.1 to 0.7.

[0015]

[Embodiment] An embodiment of the present invention will be described below. (Experiment Example 1) Extract 20g of green tea in 400g of warm water at 60°C for 4 minutes,
The tea shell was removed to obtain 305 g of green tea extract. Next, cold water was added to dilute the solution to the liquid weight shown in Table 1, the concentration was adjusted, and the amount of turbidity and ooze produced and flavor after being left at 20° C. for 30 minutes were examined. The results are shown in Table 1.

[0016]

[Table 1]

[0017] As is clear from Table 1, when the amount of dilution is large and the concentration is low, the occurrence of turbidity and sludge becomes less noticeable, but does not disappear, whereas the flavor of green tea is clearly inferior. In fact, the flavor has a Brix value (concentration) of approximately 0.
．． It can be seen that the range of 1 to 0.7 is preferable.

(Experimental Example 2) 5g of green tea was added to 60℃ of warm water at 60°C.
The tea was extracted for 4 minutes in 0 g, and the tea shell was removed to obtain 495 g of green tea extract. The concentration of this extract is Brix 0.26
Met. Next, this extract was divided and diatomaceous earth, cellulose, activated carbon, and bentonite were added to each solution in an amount of 2% by weight, stirred and left to stand, filtered through filter sieve, filled into bottles, and heated to 120°C. The samples were sterilized for 5 minutes, stored in a 35°C environment for 1 to 4 weeks, and the appearance of dregs and flavor were examined. The results are shown in Table 2. As a control, the above-mentioned extract was filled into a bottle without filtration and sterilized under the above-mentioned conditions.

[0019]

[Table 2]

As is clear from Table 2, it was suggested that the occurrence of turbidity and scum over time could be suppressed by performing sieve filtration. Effective filter aids were diatomaceous earth and activated carbon, but activated carbon was found to be unsuitable for practical use because it adsorbed the color and flavor of green tea. It was found that diatomaceous earth had little effect on the flavor of green tea, and the characteristics of green tea were retained. In addition, L, a, and b in the properties represent color tone, L value indicates lightness, a value indicates that the larger the negative value is, the stronger the green color is, the larger the positive value is, the stronger the red color, and the b value is the positive value. The larger the value, the stronger the yellow color.

(Example 1) 1. A liquid obtained by extracting 10 g of green tea with 1 liter of warm water at 80°C for 5 minutes, removing the tea husks, and immediately centrifuging it. (Control group = no treatment) 2. After removing the tea leaves from the extracted liquid in the same manner as the control above, immediately centrifuge the liquid and filter the supernatant through diatomaceous earth. (Comparative Example 1) 3. After removing the tea leaves from the extracted liquid in the same manner as the control, the temperature was increased to 20°C.
The liquid was rapidly cooled (immersion in ice water or ice water bath in small-scale experiments), centrifuged, and the supernatant liquid was filtered through diatomaceous earth. (Comparative Example 2) 4. 0.2 g of L-ascorbic acid was added to the solution extracted in the same manner as the control and the tea leaves were removed, and the pH was adjusted to 4.5.
The liquid was rapidly cooled to below 0°C, centrifuged, the supernatant liquid was filtered through a filter cake using diatomaceous earth, and the pH was then adjusted to 6.0 using sodium hydrogen carbonate. (Present invention)

[
[0022] Fill the above four types of green tea extracts into bottles,
The samples were sterilized at 120°C for 5 minutes, then stored at 35°C for 1 to 4 weeks, and examined for turbidity and ooze formation. The results are shown in Table 3.

[0023]

[Table 3]

As is clear from Table 3, in comparison to the untreated control plot, in Comparative Example 1 in which slag filtration was carried out and in Comparative Example 2 in which a cooling step was further added, turbidity and sludge formation did not occur over time. Although the deviation is suppressed, it is clear that the occurrence occurs over time during long-term storage. On the other hand, the liquid according to the present invention was found to be a clear green tea beverage without any turbidity or sludge even after long-term storage. Furthermore, it is clear from the results shown in Tables 1 and 2 above that the liquid according to the present invention is a green tea beverage with excellent flavor.

(Example 2) 10g of green tea at 30°C to 90°C
After extracting for 4 minutes with 1 liter of hot water in 7 stages with a temperature difference of 10℃ between the two, after removing the tea leaves, L-ascorbic acid was added to adjust the pH to 4.5. 19
It was rapidly cooled to ℃ and centrifuged. Next, the supernatant liquid is filtered through a filter sieve using diatomaceous earth, and then sodium bicarbonate is added to adjust the pH to 6.0.The other is a non-treated area where the pH is adjusted in the same way without filtration. It is divided into
Each of these preparation solutions was packed in a bottle and sterilized at 120° C. for 5 minutes, and a sensory test was conducted on the solution. The results are shown in Table 4. In addition, the Brix (concentration) and L, a, b (color tone) of each of the above sterilizing solutions were tested. The results are shown in Table 5.

[0026]

[Table 4]

[0027]

[Table 5]

In Table 5, for the color difference, the L value of the untreated area at the same temperature extraction is L(1), and the L value of the treated area is L(1).
2) Similarly, let the a values be a(1), a(2), the b values b(1), b(2), and L(1) - L(2).
= △L, a (1) - a (2) = △ a, b (1) - b
(2) Based on the calculated value of =Δb, it is shown by the value calculated by the formula shown in Equation 1.

[0029]

[Math 1]

[0030] As is clear from Tables 4 and 5, when the extraction temperature was below about 40°C, the extraction was insufficient and the original flavor of green tea could not be obtained. By extracting the tea leaves at about 60 to 80°C, it was possible to obtain a tea extract with a rich aroma and a well-balanced flavor of umami and bitterness and astringency. Excessive extraction at an extraction temperature of about 90° C. or higher resulted in a tea extract with a strong aroma and bitter and astringent taste. However, in the treated area where filtration was performed, the extraction at about 60 to 80°C was good, but the light color was a little paler and the flavor was a little weaker than in the untreated area. Therefore, in order to make the extract free from dregs and give it the best flavor by performing filter filtration,
Low temperature range extraction (approx. 50-70℃ extraction) and high temperature range extraction (approx.
It has been found that it is desirable to appropriately combine the various tea extracts (extracted at 0°C).

(Example 3) 10g of green tea in 60°C hot water 1
After extracting for 4 minutes at 1 liter and removing the tea leaves, L-ascorbic acid was added to adjust the pH to 4.5, and this was
Add the extract rapidly cooled to 9℃ and 10g of green tea to 1 liter of warm water at 90℃.
After extracting for 4 minutes at 1 liter and removing the tea leaves, L-ascorbic acid was added to adjust the pH to 4.5, and this was
The extract was rapidly cooled to 9°C and mixed in 9 ratios from 1:9 to 9:1 as shown in Table 6, centrifuged, and the supernatant liquid was filtered through diatomaceous earth. The filtrate was filtered through a sieve, sodium bicarbonate was added to the filtrate, the pH was adjusted to 6.0, the mixture was bottled, and the mixture was sterilized at 120° C. for 5 minutes. A sensory test was conducted for each sterilizing solution. The results are shown in Table 6. In addition,
As a control, 10 g of green tea was extracted with 1 liter of 70°C hot water for 4 minutes, rapidly cooled to 19°C, centrifuged,
A sensory test was also conducted on the bottles filled in bottles and sterilized under the same conditions as above.

[0032]

[Table 6]

[0033] This allows mixing of extracts having different extraction temperatures, that is, approximately 50 to 70°C (including 70°C range).
By mixing the extract at a temperature of about 80°C or higher with the extract at a ratio of 9:1 to 5:5, the flavor that is slightly reduced due to filtration is compensated for, creating a flavorful and refreshing green tea. I was able to get a drink.

Claims (5)

[Claims] [Claim 1] Add ascorbic acid to the extract obtained by extracting green tea with hot water to adjust the acidity range, and then rapidly cool the extract, and then
The extract is filtered by centrifugation, etc., and the extract is clarified by filtering through a filter aid using a filter aid.Then, the pH of the extract is adjusted to a neutral range, and the extract is placed in a bottle or plastic by a conventional method. A method for producing a green tea beverage having a long shelf life, which is packed in a container such as a container. 2. The method for producing a green tea beverage according to claim 1, wherein the filter aid for said slag filtration is diatomaceous earth. [Claim 3] Add ascorbic acid to the extract obtained by extracting green tea with hot water to adjust it to an acidic range, and then rapidly cool it.
The extract is filtered by centrifugation, etc., and the extract is clarified by filtering through a filter aid using a filter aid.Then, the pH of the extract is adjusted to a neutral range, and the extract is placed in a bottle or plastic by a conventional method. A method for producing a green tea beverage which is packed in a container such as a container, wherein in the above production process, a liquid is obtained by extracting green tea at a low temperature range of approximately 50°C to 70°C and a high temperature range of approximately 80°C or higher. A method for producing a green tea beverage having a long shelf life, which comprises mixing the following in a ratio ranging from about 9:1 to 5:5. 4. Green tea is extracted at a low temperature range of about 50°C to 70°C, and ascorbic acid is added to adjust the liquid to an acidic range, and this is rapidly cooled, and green tea is extracted at a high temperature range of about 80°C or higher. Add ascorbic acid to the extracted liquid to adjust it to the acidic range, and then cool the extracted liquid rapidly at a ratio of about 9:1 to 5.
: After mixing at a ratio within the range of 5, filter the extract by centrifugation, etc., or filter each of the extracts with different extraction temperatures by centrifugation, etc., and mix each liquid at the above ratio. This mixed solution is clarified by filtration using a filter aid, and then the pH of this extract is clarified.
A method for producing a green tea beverage having a long shelf life, which comprises adjusting H to a neutral range and filling it into containers such as bottles and plastic containers by a conventional method. 5. The method according to claim 1, wherein the concentration of the extract extracted using the tea leaves is within the range of about 0.1 to 0.7 as a Brix value. Method for producing green tea beverage.