JPH06121638A - Method for producing instantly soluble powder - Google Patents

Abstract

PURPOSE:To provide a method for producing the powder of a flavored beverage such as tea or coffee by vacuum lyophilization, capable of instantly dissolving the powder only by pouring hot water or water on the powder. CONSTITUTION:The method for producing instantly soluble powder by vacuum- lyophilizing a solution having a solid content of >=5wt.% comprises adding >=10vol.% of pores to the solution and subsequently vacuum-lyophilizing the solution.

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 an instantly soluble powder. More specifically, the present invention relates to a method for producing a fast-dissolving powder by vacuum freeze-drying.

[0002]

2. Description of the Related Art Conventionally, powdered tea and powdered coffee have been prepared by extracting raw materials such as tea leaves and coffee beans into an extraction tank, extracting them with boiling water, separating the extract, and then extracting the extract from the extract with an appropriate concentration. It was manufactured by concentrating the solution to the above or adjusting the concentration with dextrin or the like, and then drying by spray drying or vacuum freeze drying. However, when pouring hot water into the above powder and drinking it, the one to which dextrin is added has a problem that a flavor different from the original flavor of tea or coffee is imparted, and that dried by spray drying is
There was a flavor problem in that the aroma, which is the life of tea and coffee, was weak, and a particularly light aroma was emitted.

Therefore, in order to solve these flavor problems, the extract is concentrated without using dextrin, or the extract containing concentrated extract is directly freeze-dried into a powder. A method was considered. However, powdered tea and coffee powder obtained by freezing the solution as it is and vacuum freeze-drying tend to cause lumps when pouring hot water into the powder, and it was necessary to stir it in order to completely dissolve it. Furthermore, when water was poured, it was almost insoluble even when stirred.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a powder of a flavored beverage such as tea or coffee by vacuum freeze-drying, which is a method of producing a powder which is quickly dissolved by pouring hot water or water. With the goal.

[0005]

The present invention was made based on the finding that when freeze-drying a green tea extract under vacuum, powder can be easily dissolved in hot water when air bubbles are mixed during freezing.

That is, according to the present invention, when a solution having a solid content of 5% by weight or more is vacuum freeze-dried, 10 bubbles are formed during freezing.
This is a method for producing a fast-dissolving powder, which is characterized by mixing in a volume percentage of at least, and then freeze-drying in vacuum.

Examples of the solution in the present invention include teas such as green tea, black tea, oolong tea and roasted tea, and flavored beverages such as coffee. Preferred solutions are those in which the solid content is dissolved and dispersed in water. Therefore, it is not particularly limited as long as it becomes powder by drying.

When adjusting the concentration of the above solution by concentration or the like, it is preferable that the solid content is 5% by weight or more. When the solid content is less than 5% by weight, the powder state after vacuum freeze-drying becomes like cotton, and when pouring hot water or water, it floats on the surface and becomes difficult to melt.

In the present invention, the method of mixing air bubbles during freezing is not particularly limited, but for example, a concentration-adjusted flavor beverage or the like can be scraped off with a heat exchanger or the like.
It may be cooled and frozen while contacting with air or nitrogen gas. Specifically, there is a method of freezing while mixing air bubbles with an ice creamer, which is an ice cream maker.

When bubbles are mixed in, it is preferable that the amount of bubbles after freezing is 10% by volume or more. This is because, if the amount of bubbles is less than 10% by volume, the effect of easy dissolution cannot be obtained.

As a test example, Table 1 shows the relationship between the air bubble entrainment ratio at the time of freeze-drying and the solubility of the dry powder at each solid content concentration of the green tea extract. In addition, adjustment of air bubble mixing rate is
The procedure was as follows. If you put the green tea extract in a desktop ice creamer (Mr. Chef, manufactured by Aikosha Seisakusho Co., Ltd.) and cool it with stirring, the air bubble inclusion rate will increase with time after ice crystals start to form. went. Air bubble mixing ratio of each sample is 10c
It was filled in a container c and calculated from the weight by the following formula. Then, it was rapidly frozen and freeze-dried to obtain a dry powder. Solution 1 having the same solid content concentration as the sample, with a (%) bubble inclusion rate, b (g) weight per 10 cc of sample
When the weight per 0 cc is c (g),

[0012]

[Table 1]

[0013]

【Example】

Example 1 40 kg of water was added to 3.5 kg of green tea leaves, extracted for 30 minutes, and then squeezed by a press to obtain a solid content concentration of 1.5% (W /
An extract of W) was obtained. After concentrating the obtained extract by reverse osmosis membrane concentration to a solid content concentration of 20% (W / W),
The solution was frozen into an ice cream while mixing 40% (V / V) of air bubbles with a continuous ice creamer (scraping heat exchanger). Then, it was completely frozen in a freezer (-40 ° C), pulverized and sized, and freeze-dried to obtain powder green tea. In a cup containing 0.5 g each of the obtained powdered green tea,
When 80 ml of hot water and 100 ml of water at room temperature (25 ° C.) were poured, respectively, the person who poured the hot water melted immediately, and the person who poured the water also melted relatively easily.

Comparative Example 1 Solid content concentration of 20% (W /
The green tea extract of W) was completely frozen as it was in a freezer at -40 ° C, ground and sized, and then freeze-dried to obtain powdered green tea.
80 cups each containing 0.5 g of the obtained powdered green tea
10 ° C water and room temperature (25 ° C) water each
When pouring 0 ml each, the person who poured hot water was lumpy and did not dissolve unless stirred, and the person who poured water did not dissolve at all.

[0015]

[Effects of the Invention] Conventional powders produced by vacuum freeze-drying are difficult to melt unless they are stirred by pouring hot water. However, the powders produced by the manufacturing method of the present invention are It will dissolve easily just by pouring it, and it will be much easier to dissolve in water than conventional products.

Claims (2)

[Claims] 1. A method for producing a fast-dissolving powder, characterized in that, when a solution having a solid content of 5% by weight or more is vacuum freeze-dried, 10% by volume or more of air bubbles are mixed in at the time of freezing and then vacuum freeze-drying is performed. 2. The solution comprises green tea, black tea, oolong tea,
The method for producing a fast-dissolving powder according to claim 1, wherein the method is a tea such as hojicha or a flavored beverage such as coffee.