JP2000253820A - Production of instant teas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain instant teas preservable for a long period while scarcely deteriorating the flavor of the teas. SOLUTION: A cyclodextrin is added to an extract liquid of teas so that the ratio of the weight of a cyclodextrin based on the weight of the extract of the teas in the extract liquid is within the range of 0.05-5 when drying and powdering the extract liquid of the teas containing the cyclodextrin added thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing instant teas which can be stored for a long period of time without substantially impairing the flavor of teas such as black tea, oolong tea, green tea and roasted tea.

[0002]

2. Description of the Related Art In the process of producing instant teas (extraction, concentration and drying), there is a problem that the flavor components are lost or volatilized. Particularly, the volatilization of the flavor components during the drying of the tea extract. In general, freeze-vacuum drying or spray drying, which has little loss of aroma components, and vacuum drying at low temperature, etc. are used. However, even if instant teas made in this way are stored for a long time,
There is a problem that the flavor gradually changes, such as generation of an altered odor.

[0003] In order to solve this problem, there is known a storage method in which instant tea is packaged by gas replacement or packaged together with an oxygen scavenger. However, the gas replacement packaging is filled with an inert gas such as nitrogen gas.
By reducing oxygen, oxidation of fragrance components and the like is prevented, and a change in flavor is reduced, but none of these methods has provided a sufficient effect. The cyclodextrin used in the present invention has conventionally been used as a fragrance preserving agent during the drying step (JP-A-6-46794) and as a masking agent for bitter components (JP-A-58-10).
No. 9424, JP-A-54-145268). Also in instant teas, the effect of reducing the deterioration of flavor due to drying and improving the taste is expected, but as in the present invention, the study focused on the problem of storage stability of instant teas Had not been done.

[0004]

SUMMARY OF THE INVENTION According to the present invention, instant teas which have no deterioration in flavor components even when stored for a long period of time and have almost the same flavor as that of a tea bath obtained by a normal coffee method and have excellent storage stability. The purpose is to obtain.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, when the tea extract containing cyclodextrin is dried and powdered, the tea contained in the extract is reduced. By controlling the ratio of cyclodextrin weight to extract weight, that is, the ratio of cyclodextrin weight to tea extract weight in powder,
Even if stored for a long time, fragrance components etc. are kept stably,
The present inventors have found that instant teas having a flavor almost similar to that of a tea ceremony obtained by a normal coffee method can be produced, and have reached the present invention.

That is, in the present invention, when the tea extract to which cyclodextrin is added is dried and powdered, the ratio of the cyclodextrin weight to the tea extract weight in the extract is 0.05 to 5. It is the gist.

[0007]

Next, the present invention will be described in detail.
The instant teas of the present invention can be produced by a tea extraction step, an extract concentration step (in some cases, can be omitted), and a drying step.

[0008] The extraction step is a step of adding an aqueous solvent to tea to obtain an extract. Any tea can be used at this time, for example, black tea such as Ceylon, Assam, Darjeeling, oolong tea, green tea, tea leaves such as Hojicha, wheat, barley, brown rice, soybean,
Grain teas such as buckwheat, dokudami, ganoderma, gymnema, banaba, ginkgo biloba, moroheiya, lakanka, puar, alfalfa, wormwood, mate, gabalone, ginseng,
Healthy teas such as Tochu, Rooibos and Aloe, as well as herbs such as lavender, peppermint, lemongrass and chamomile, perilla and plum. These teas may be used alone or as a mixture of two or more.

The aqueous solvent used for the extraction may be simple tap water, deionized water, or distilled water.
Gelatin, casein, vegetable protein, gum arabic, emulsifiers, alcohols, antioxidants such as ascorbic acid and the like may be appropriately added. The extraction temperature is not particularly limited, but is preferably from 15 ° C to 100 ° C. If the extraction temperature is lower than 15 ° C., the extraction efficiency is remarkably reduced. If the temperature exceeds 100 ° C., unnecessary components are excessively extracted, and a favorable fragrance component is likely to be denatured. One part by weight of tea leaves is immersed in about 30 parts by weight of the solvent 4 or extracted with stirring, and after the extraction, an extract can be obtained by coarse separation. The extract is clarified using a centrifuge if necessary.

The cyclodextrin may be added to the above-mentioned solvent and then subjected to extraction, or may be added to the extract and used later. Also, it may be added to both. However, it is preferable to extract or concentrate after adding the cyclodextrin, since deterioration such as aroma components in those steps can be reduced.

Any cyclodextrin that can be used may be any as long as it has a cyclic structure composed of 6 to 8 glucose units (α-cyclodextrin with 6 glucose units and β with 7 glucose units). Cyclodextrin, eight of which are referred to as γ-cyclodextrin), for example, unbranched cyclodextrin, branched cyclodextrin (glucosyl cyclodextrin, maltosyl cyclodextrin, etc.),
Cyclodextrin derivatives (dimethyl cyclodextrin, trimethyl cyclodextrin, hydroxyethyl cyclodextrin, hydroxypropyl cyclodextrin, etc.) may be used.

When cyclodextrin is added to a tea extract, it is commercially available as a cyclodextrin as exemplified above or a mixture of α, β, and γ-cyclodextrin, for example, a trade name of Dexie Pearl K-
50 (manufactured by Saltwater Port Refining Co., Ltd.) and the trade name Ringdex-PK (manufactured by Mercian Co., Ltd.)
Alternatively, these may be used as a mixture. At this time, α,
Regarding the mixing ratio of β, y-cyclodextrin,
The ratio of the sum of α and β-cyclodextrin weight to the total cyclodextrin weight is preferably 60 to 100%. Within this range, the aroma components of teas are stabilized in a well-balanced manner.

With respect to the amount of cyclodextrin, the ratio of the cyclodextrin weight to the tea extract weight in the extract prepared for dry powdering, that is, the ratio of the cyclodextrin weight to the tea extract weight in the powder, is as follows: It is preferably from 0. 5 to 0.05.
It is necessary to add cyclodextrin so as to be in the range of 1 to 2. If the amount of cyclodextrin added is less than this range, even if the flavor immediately after preparing the instant tea is good, its preservability is likely to deteriorate, and if the amount of cyclodextrin is larger than the above range, it is drunk. When this is done, the sweetness of the cyclodextrin itself becomes noticeable, which is not preferable. To determine the ratio of cyclodextrin weight to tea extract weight, a known method can be used.For example, when a commercially available cyclodextrin preparation is used, cyclodextrin content, water content, etc. described in a catalog or the like Based on the amount of addition, loss rate during each process,
The calculation method is simple in consideration of the amount of tea leaves used and the like. (See Table 1)

[0014]

[Table 1]

Cyclodextrin can be used together with other powdered bases such as dextrin, but it is more economical to produce instant teas. Also, trehalose, which is said to improve the storage stability of the powdered food, may be used in combination. However, if the amount of the powdered base other than cyclodextrin is too large, the content of the tea extract in the powder becomes low, and the taste becomes unfavorably thin.

The concentration step is performed in order to reduce the cost of drying by pre-concentrating the extract, and may be performed as needed. Concentration can be performed by a well-known method such as concentration under reduced pressure, freeze concentration, and reverse osmosis membrane concentration. However, reverse osmosis membrane concentration and freeze concentration with less volatilization and denaturation of aroma components are preferred.

In the drying step, the extract (or concentrate) is dried and powdered. In the present invention, any drying method such as hot air drying, vacuum drying, spray drying, and freeze vacuum drying may be used. However, freeze-vacuum drying or spray-drying, in which the loss of aroma components during drying is small, is preferred. Further, the shape of the obtained dried product may be fine powder, or may be used by molding into a granule, tablet, block, or the like by a known method.

According to the above-mentioned steps, instant teas having excellent storage stability, having no deterioration in flavor components and the like even when stored for a long period of time, and having a flavor almost similar to that of a tea bath obtained by an ordinary coffee method are obtained. be able to.

[0019]

Next, the present invention will be described in detail with reference to Test Examples and Examples.

(Test Example 1) α-cyclodextrin (trade name Celdex A-10, manufactured by Nippon Shokuhin Kako Co., Ltd.)
0), β-cyclodextrin (trade name Celdex B-100, manufactured by Nippon Shokuhin Kako Co., Ltd.) and γ-cyclodextrin (trade name Celdex G-100, manufactured by Nippon Shokuhin Kako Co., Ltd.) Cyclodextrin mixture (α: β: y = 1: 1: 1) and a branched dextrin containing no cyclodextrin (Sanmatsu Kogyo Co., Ltd.)
Was dissolved in 30 kg of hot water at 82 ° C. with the composition shown in Table 2, 1 kg of black tea leaves (Assam) was added, and the mixture was extracted at 80 ° C. for 15 minutes.

[0021]

[Table 2]

Each extract (about 7, 28 kg of Brix) obtained by separating the cake was centrifuged to clarify the liquid, and then heat-sterilized at 95 ° C. for 10 seconds using a plate heat exchanger. . Then, it was spray-dried under the condition of a chamber temperature of 90 ° C. to obtain instant black teas A to J (each,
About 1.8 kg).

When these instant black teas were sealed in aluminum pouches and stored at 25 ° C. for 6 months and tasted (see Table 3), when the ratio of cyclodextrin weight to extract weight was 0.05 to 5, The flavor was almost the same as that of the tea ceremony obtained by the ordinary coffee method, and the storage stability was good. (See Table 4)

[Table 3]

[0024]

[Table 4]

Example 1 Dextrin Pearl SD, a dextrin preparation containing cyclodextrin
2 kg of -20 (manufactured by Saltwater Port Refining Co., Ltd.) and 200 g of β-cyclodextrin (manufactured by Nippon Shokuhin Kako Co., Ltd., trade name: Celldex B-100) were dissolved in 30 kg of 70 ° C. warm water.

To this solution, 2 kg of green tea leaves were added, and the mixture was extracted at 80 ° C. for 10 minutes while stirring, and the cake was separated to obtain 27.3 kg of an extract of Brix 8.9. This extract was clarified by a centrifugal separator, heated to 25 ° C., and concentrated to Brix 20 by reverse osmosis membrane concentration. The obtained concentrate was preliminarily frozen at -40 ° C and then freeze-vacuum dried under the conditions of a vacuum of 1 Torr and a shelf heating temperature of 30 ° C to obtain 1.6 kg of instant green tea A. In the instant green tea A, the ratio of the cyclodextrin weight to the tea extract weight is:
1.2.

(Comparative Example 1) Instead of the cyclodextrin used in Example 1, a branched dextrin containing no cyclodextrin (trade name: BLD, manufactured by Sanmatsu Kogyo KK)
(8)) Using 2.2 kg, 1.6 kg of instant green tea B (freeze-vacuum dried product) was produced in the same manner as in Example 1.

The instant green tea A and the instant green tea B obtained in Example 1 and Comparative Example 1 were packaged normally (air-wrapped) only by enclosing them in an aluminum foil bag, and packaged in a nitrogen gas atmosphere. A 10-point storage test was conducted at 35 ° C. for 5 weeks. Over time, these instant green teas were dissolved in boiling water and tasted. Instant green tea B, even in a nitrogen-gas-substituted packaged product, gradually produced a stuffy, odor-like odor, and had an unpleasant astringency. Although there was a remarkable change in flavor such as increase, instant green tea A had almost the same flavor as that of green tea obtained by a normal café method without any deterioration even in a normal packaged product. (See Table 5)

[0029]

[Table 5]

[0030]

According to the present invention, instant teas that can be stored for a long period of time can be obtained without substantially impairing the flavor of the teas.

Claims (1)

[Claims] When a tea extract to which cyclodextrin is added is dried and powdered, the ratio of the cyclodextrin weight to the tea extract weight in the extract is 0.1%.
The method for producing instant teas, wherein the method is from 05 to 5.