JPH0712277B2 - Instant tea manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing instant tea with low foaming.

Problems to be Solved by the Invention: At present, FD (freeze-dried) instant teas such as black tea, oolong tea, green tea and mate tea are very popular. The biggest problem with these instant teas is that foaming occurs when they are mixed with hot water. The frothy tea blocks the enjoyment of drinkers.

In order to prevent this, a defoaming agent has been conventionally used. However, a large amount of antifoam had to be mixed into the instant tea to completely eliminate the foam. However, the addition of a large amount of defoaming agent naturally lowers the quality of instant tea significantly. In addition, in the production process, the freezing rate of the tea extract or the extract concentrate may be adjusted to reduce foaming. However, in this case, the freezing time may take a long time, which is not always desirable for mass production.

Means for Solving Problems: The present invention relates to FD tea powder by devising the manufacturing process conditions thereof, without using an additive such as an antifoaming agent,
It was discovered to produce FD instant tea that does not generate bubbles. That is, the present inventor uses (i) a liquid containing an extract to concentrate the extract to a concentration of 15 to 60% in a normal method for producing instant tea, and (ii) an ice crystal of 20 to 40% by weight in the concentrated liquid. Surprisingly, it was discovered that the instant tea obtained did not foam when subjected to an operation of generating and (iii) dissolving a part of the ice crystals. The present invention is based on this discovery.

The present invention comprises (a) extracting an extract from tea leaves by a conventional method, and (b) concentrating a liquid containing the extract to obtain an extract concentration of 15 to
Adjusted to 60% by weight, (c) generating 20 to 40% by weight of ice crystals in the concentrated solution before freezing, (d) heating the solution with stirring or with or without stirring To dissolve a portion of the ice crystals,
Preferably, a method for producing instant tea with less generation of bubbles, which comprises dissolving ice crystals to 14 to 25% by weight of ice crystals and (e) lyophilizing a solution containing the ice crystals.

The theoretical reason why the instant tea obtained by obtaining the above operations (i) to (iii) is free of foaming is unknown, but this is the result of an experiment.

In the present invention, the concentration of the liquid containing the extract of tea leaves, the formation of ice crystals, the freeze-drying and the like are carried out by conventionally known methods.

In order to facilitate the drying of the active ingredient of tea, at least one 1 to 100 parts by weight of dextrin and reduced starch decomposition product may be added to 10 parts by weight of the solid content of tea before and / or after the concentration of the extract. it can. These act as dry carriers.

Examples and Controls: Unless otherwise specified, "parts" and "%" mean "parts by weight" and "% by weight", respectively.

Example 1 Black tea leaves were extracted and concentrated by a conventional method, and then 10 parts of dextrin was added to 10 parts of the tea solid content to give a concentration of 25.
% Black tea concentrate was obtained. 10 kg of this solution was put in a 20-liter bowl, stored in a freezer at -40 ° C, and stirred occasionally to adjust the amount of ice crystals to 30% by weight. This liquid was occasionally stirred in the open air (about 25 ° C) to melt the ice crystals to 20% by weight. Again, it was frozen in the freezing room and freeze-dried in the freeze-drying room to obtain FD instant tea.

Example 2 Obtained in the same manner as in Example 1, 50 parts of a reduced starch decomposition product was added to 10 parts of a tea solid content, and a 45% green tea concentrate was passed through a continuous scraping heat exchanger to prepare a solution. 25% by weight of ice crystals were generated therein. Put this liquid in a container and soak it in hot water at 40 ℃,
After stirring for 3 minutes, the ice crystals were thawed to 15% by weight. Freezing was carried out in a freezing room, crushed and sized, and dried to obtain instant tea.

Example 3 An oolong tea concentrate having a concentration of 25% and obtained in the same manner as in Example 1 was passed through a continuous soft ice cream server (scraping heat exchanger) to generate 30% by weight of ice crystals in the solution. This solution was placed in a container and immersed in hot water at 55 ° C. to dissolve the ice crystals in the concentrated solution to 14% by weight. It was frozen in a freezer and freeze-dried to obtain instant tea.

Example 4 Obtained in the same manner as in Example 1, 80 parts of dextrin was added to 10 parts of the tea solid, and the mate tea concentrate having a concentration of 45% was placed in a continuous soft ice cream server (scraping heat exchanger). 40% by weight of ice crystals were generated in the solution. It was put in a double-walled container capable of flowing warm water (about 65 ° C) on the outer wall, and the ice crystals were thawed up to 17% by weight. Freezing was performed in a freezing room, pulverized and sized, and dried to obtain FD instant tea.

Comparative Example 1 After extracting and concentrating the extract of black tea leaves by a conventional method, 10 parts of dextrin was added to 10 parts of the tea solid content to give a concentration of 25.
% Black tea concentrate was obtained. 10 kg of this solution was placed in a 20-liter bowl and stored in a freezer at -40 ° C, and the content of ice crystals was adjusted to 30% by weight while stirring occasionally. The ice crystals were thawed to 10 wt% in 10 minutes in the open air (about 25 ° C). Again, it was frozen in the freezing room, pulverized, sized and dried to obtain FD instant tea.

Control Example 2 Obtained in the same manner as in Example 1, 50 parts of a reduced starch decomposition product was added to 10 parts of the tea solid content, a green tea concentrate having a concentration of 45% was prepared, and then frozen in the freezer as it was, After pulverizing and sizing, it was dried to obtain FD instant tea.

Comparative Example 3 An oolong tea concentrate having a concentration of 25% obtained in the same manner as in Example 1 was passed through a continuous scraping type heat exchanger to form ice crystals in the solution.
Generated by weight%. Freeze in the freezer as it is,
After pulverizing and sizing, it was dried to obtain FD instant tea.

Control Example 4 Black tea leaves were extracted by an ordinary method, and after the extract was clarified and concentrated, 10 parts of dextrin was added to 10 parts of the tea solid content to obtain a concentrated black tea solution having a concentration of 25%. Silicone resin was added to tea solids so as to be 50 ppm, frozen in the freezer as it was, pulverized, sized and dried to obtain FD instant tea.

The results are shown in Table 1.

EFFECTS OF THE INVENTION As can be seen from Examples 1 to 4, once a predetermined amount of ice crystals were generated in the tea concentrate, the ice crystals were dissolved to a certain extent, and then the ice crystals were completely frozen again and ground and sized. After that, FD instant tea obtained by drying can prevent foaming when pouring hot water. Furthermore, it can be applied to the production of all FD instant teas regardless of the type of tea, whether or not dextrin is added.

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Claims (2)

[Claims] 1. An extract is extracted from tea leaves by a conventional method, and (b) a liquid containing the extract is concentrated to obtain an extract concentration of 15 to
Adjusted to 60% by weight, (c) generating 20 to 40% by weight of ice crystals in the concentrated solution before freezing, (d) heating the solution with stirring or with or without stirring A method for producing instant tea with less generation of bubbles, which comprises allowing a part of the ice crystals to be dissolved by leaving it in a room temperature, and (e) freeze-drying the liquid containing the ice crystals. 2. A method comprising the additional step of adding 1 to 100 parts by weight of at least one of dextrin and reduced starch degradation product to 10 parts by weight of tea solid before and / or after concentration containing an extract. The method according to item 1.