JPH0147980B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing instant tea with excellent flavor in good yield. Instant tea is obtained by extracting the active ingredients such as aroma and flavor components from raw tea such as green tea, hojicha, oolong tea, black tea, etc. using warm water, etc., drying, and powdering it, just add hot water. It is a growing product whose demand is rapidly increasing because it can be consumed immediately and does not produce waste such as tea leaves. Important issues to consider when commercializing instant tea are preserving the aroma and improving the yield of extracted solids. When extracting the active ingredients of tea from raw tea using hot water, it is necessary to extract at the lowest temperature possible for a short time in order to capture the weak and unstable aroma components of tea without escaping into the atmosphere. Furthermore, in order to increase the yield of extracted solids, it is necessary to perform extraction at as high a temperature as possible for a long time. In other words, for these contradictory reasons, when producing instant tea industrially, in order to obtain a product with excellent flavor, extraction is performed at a low temperature and for a short time, resulting in a decrease in extracted solid content and a decrease in product yield. On the other hand, when high-temperature, long-term pressure extraction is performed to increase the yield of the product, the aroma components dissipate and change, and the taste becomes decocted, which impairs the flavor of the product. There was an unavoidable problem. As a result of various studies to solve the problems of conventional methods for producing instant tea, the present inventors first extracted aroma components from raw tea at low temperature and in a short period of time under normal pressure, and then removed these aroma components. We have discovered that instant tea with excellent flavor can be produced in good yield by extracting solids under pressure from raw tea at high temperatures and for a long period of time. That is, the present invention includes a first step of adding 5 to 15 times the amount of water to raw tea, extracting it under normal pressure at a temperature of 20 to 70°C for 1 to 10 minutes, and then separating the extract. Add 5 to 15 times the amount of water (based on anhydrous) to the obtained tea extraction residue, extract under pressure for 5 to 30 minutes under a steam pressure of 0.5 to 3.0 Kg/ ^cm2 , and then separate the extract. This is a method for producing instant tea, which comprises a second step of mixing the extract obtained in the first step and the extract obtained in the second step, followed by drying and powdering. As the raw material tea used in the method of the present invention, all kinds of tea can be used, such as green tea, hojicha, oolong tea, and black tea. When extracting the active ingredients of tea from raw tea, the amount of water added to raw tea is 100% of raw tea.
The appropriate amount is 500 to 1500 parts by weight, that is, 5 to 15 times the amount.If the amount added is less than this, the fluidity of the tea liquid will be lost and the extraction rate will be reduced; When added, the extraction rate improves slightly, but it is not preferable because it increases the cost of drying the tea active ingredient extract. In the first step of the method of the present invention, the extraction temperature is set to 20
The reason why we set the temperature and extraction time to ~70℃ and 1 to 10 minutes is that these extraction conditions are suitable for extracting and retaining the aromatic components of tea. If the amount is more than this, the aroma components of tea cannot be extracted sufficiently, and on the other hand, if the amount is more than this, the aroma components tend to dissipate into the atmosphere, which is not preferable. In addition, in the second step of the method of the present invention, the extraction pressure was set to a vapor pressure of 0.5 to 3.0 Kg/cm ² and the extraction time was set to 5 to 30 minutes. This is because it is necessary to maximize the Even if implemented, not only can no improvement in effectiveness be expected, but
On the contrary, the solid content of tea extraction may change in quality,
This results in drawbacks such as reduced productivity of instant tea products. The tea active ingredient extract obtained in the first step and the second step is preferably cooled and then mixed, and if necessary, white dextrin, β-cyclodextrin, waxy seed starch decomposition product, methyl cellulose, gum substance, etc. , a powdering aid such as a food-grade emulsifier is added, and the product is dried and powdered by a drying method such as spray drying, freeze drying, or fluidized bed drying to obtain an instant tea product. According to the method of the present invention, aroma components are first extracted from raw tea at a low temperature in a short period of time, and then aroma components are extracted from the raw tea from which the aroma components have been removed at a high temperature (i.e., a vapor pressure of 0.5
~3.0Kg/cm ² ), and uses a two-stage extraction method that extracts the solid content over a long period of time, so it can be used at low temperatures (20 to 40℃) or It has become possible to obtain both aroma and solid content at the same time, which was not possible with the method of extracting the active ingredients of tea using medium-high temperatures (50-90℃).
As a result, instant tea with excellent flavor can be produced with good yield. Next, the effects of the present invention will be explained by giving examples and comparative examples of the present invention. Example 1 Add warm water 2 to 200 g of green tea (third-heated tea),
After extraction at 70°C for 2 minutes with stirring, the mixture was filtered. This resulted in approximately 1600ml of primary extract (solid content 2.4
%) was obtained. Next, 1600 ml of warm water was added to the green tea after the primary extraction, and the mixture was extracted in an autoclave for 15 minutes with stirring at a steam pressure of 1.5 Kg/cm ² , and then rapidly cooled to below 70° C. and filtered. Approximately 1,400 ml of secondary extract (solid content: 3.1%) was obtained by this pressure extraction. Mix the primary extract and secondary extract, and add 120g of enzyme-modified dextrin and 2.4g of gum arabic to this mixture.
g and 0.24 g of sugar ester were added, stirred, and then spray-dried at an inlet temperature of 160°C and an outlet temperature of 90°C to obtain an instant green tea product 177 according to the method of the present invention.
I got g. Control example 1 Add 3600 ml of warm water to 200 g of the same green tea as in Example 1,
After extraction at 70° C. for 17 minutes with stirring, the mixture was filtered. Approximately 3200ml of extract liquid (solid content 1.5%)
I got it. Using this extract, 144 g of instant green tea product was obtained by the control method in the same manner as in Example 1. Control example 2 Add 3600 ml of warm water to 200 g of the same green tea as in Example 1,
After extracting in an autoclave for 17 minutes with stirring at a vapor pressure of 1.5Kg/ ^cm2 , it was rapidly cooled to below 70℃.
Filtered. Approximately 3200ml of extracted liquid is obtained by this pressure extraction.
(solid content 2.6%) was obtained. Using this extract, 178 g of instant green tea product was obtained by the control method in the same manner as in Example 1. In order to clarify the effects of the method of the present invention, the instant green tea products obtained in the above Examples and Control Examples were dissolved in hot water at 70°C, and a sensory evaluation was conducted on the aroma and taste. The sensory evaluation was conducted by a panel of 20 experts (10 men and women aged 20 to 50) using a 5-point scoring system. The results of these sensory tests and the extraction rate of green tea solids are shown in the table below.

【table】

[Table] From the above results, it can be seen that the instant green tea produced by the method of the present invention has excellent aroma and taste, and also has an excellent extraction rate of green tea solid content.

Claims (1)

[Claims] 1 Add 5 to 15 times the amount of water to the raw tea, extract at normal pressure for 1 to 10 minutes at a temperature of 20 to 70°C, and then separate the extract liquid. Add 5 to 15 times the amount of water to the extraction residue, and add 0.5 to 3.0 times the amount of water.
After pressure extraction for 5-30 minutes under steam pressure of Kg/ ^cm2 ,
Production of instant tea, which consists of a second step of separating the extract, and a third step of mixing the extract obtained in the first step and the extract obtained in the second step, followed by drying and powdering. Method.