JPH01202247A - Preparation of canned oolong tea - Google Patents

Abstract

PURPOSE:To enable stable preservation of quality even under warming conditions for a long period, by extracting oolong tea by a conventional method and regulating characteristic values, such as pH, within a prescribed range, sterilizing the extract solution and canning the sterilized extract solution. CONSTITUTION:For example, an adequate amount of deionized water is added to an extract solution of oolong tea, which is then regulated to 0.2-0.4 Brix, pH5-7, 81-85 (L) value, 3-9 (a) value and 34-42 (b) value. The resultant regulated extract solution is subsequently sterilized in an instantaneous type sterilizer at 130-145 deg.C for 2-30sec, then cooled to 90-95 deg.C, filled in a can and seamed. The obtained canned extract solution is subsequently sterilized at 100-109 deg.C for 1-10min to prepare the aimed canned oolong tea.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing canned oolong tea, and more particularly to a method for producing canned oolong tea, which has a good flavor, is prevented from breeding microorganisms, and is stable for long-term storage. This invention relates to a method for producing infused oolong tea with a short final sterilization time.

Conventional technology and its problems Conventionally, canned oolong tea is produced by heat-sealing the extract in a container and then sterilizing it for 11 minutes using a high-temperature and high-pressure sterilization pot (retort device).
It has been manufactured by sterilizing it at 0 to 125°C for 15 to 30 minutes. However, since the sterilization time is relatively long, the productivity is low. To improve productivity,
It was necessary to shorten the sterilization time or install additional sterilization equipment.

For oolong tea in paper containers or bottled bottles, a combination of short-term sterilization at high temperatures and hot filling (82-86°C) is carried out. However, canned oolong tea has a wide range of uses, and can be used in hot venders (approximately 55℃) in winter.
), so the same sterilization process as for oolong tea in paper containers or plastic bottles was not sufficient.

Problems to be Solved by the Invention Since sterilization of canned oolong tea is carried out at high temperature and high pressure for a relatively long period of time as described above, the flavor and color tone change significantly, making it difficult to obtain a high-quality product. In addition, since retort sterilization takes a long time, excessive equipment was required to increase production capacity.

The present invention aims to provide a method for producing high-quality canned oolong tea with high productivity using labor-saving equipment.

Means to solve the problem Generally, canned oolong tea is heated in a hot vender (approximately 55℃).
), it is necessary to sterilize heat-resistant bacteria. Sterilization of heat-resistant bacteria in oolong tea extract is
Almost complete sterilization can be achieved by instantaneously sterilizing the extract at high temperature for a short period of time. However, considering the possibility of bacterial contamination during the subsequent process of filling the extract liquid into the can and sealing the can lid, sterilizing the can itself after filling the extract liquid and sealing the can lid is effective in sterilizing heat-resistant bacteria. It is an effective method.

In the present invention, oolong tea is extracted, and an appropriate amount of deionized water is added to the extract to obtain Br1x 0.2-0.4,
pH5-7. L value 81-85. a value 3-9. A liquid preparation having a b value of 34 to 42 is prepared, and this liquid is sterilized using an instant sterilizer at 130 to 145°C for 2 to 30 seconds, preferably at 135 to 142°C for 5 to 10 seconds. Next, the mixture is cooled to 95°C or less, preferably 90-95°C, filled into a can, sealed, and then heated at 100-109°C for 1-10 minutes, preferably at 105-109°C for 5-10 minutes. 9
By sterilizing for minutes, it is possible to obtain a product that is rich in flavor and stable against modification by microorganisms and flavor deterioration.

The present invention uses a liquid preparation of oolong tea extract having the above-mentioned specific properties, sterilizes this liquid under specific conditions, fills it into a can, seals it, and then sterilizes the liquid in the can under specific conditions. By doing so, you can obtain the desired desired results for the first time.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example: Extract 13 kg of oolong tea from Baijian Province, China with 400 g of boiling water of 90°C or higher for about 4 minutes, remove the used tea leaves, filter, and add both ion exchange treated water for a total of 1000, Q
And so. Brix (Brlx) OJ; pH5
, 9; L value 83.2. a value 4.5. The b value was 37.3. Using an instant sterilizer, this mixture was heated to 140
The mixture was sterilized at .degree. C. for 8 seconds, cooled to 91.degree. C., filled into cans, and sealed with a can lid. After tightening, sterilization was performed at 105° C. for 8 minutes to obtain canned oolong tea (Product A).

Comparative Example As in Example 1, the oolong tea preparation was filled into a can and sealed, and the can was then sterilized at 121° C. for 20 minutes to obtain a can of oolong tea (Product B).

It was prepared in the same manner as in Example 1, filled into cans, sealed with a can lid, and then cooled without sterilization to obtain canned oolong tea (Product C).

Prepared in the same manner as in Example 1 (A), sterilized at 140°C for 8 seconds, filled into cans at 91°C and cooled to obtain canned oolong tea (
Product D) was obtained.

Comparative test The flavor of sample products A, B, C, D was sensory tested,
Furthermore, storage tests were conducted at room temperature, 37°C, and 55°C. Three hundred samples were used for each temperature, and the storage period was one month.

The results are shown in the table below.

*Samples A and B had no deterioration or putrefaction caused by microorganisms, but samples C and D were confirmed to have viable bacteria, and a few samples were found to be close to deterioration.

Effects of the Invention According to the method of the present invention, high-quality canned oolong tea with excellent flavor can be produced with high productivity, and the product of the present invention can be maintained for a long period of time even at elevated temperatures of, for example, 55°C. It is extremely stable without being degraded or spoiled by microorganisms even after long periods of storage.

Claims (1)

[Claims] Extract oolong tea using a conventional method, and make the extract at a Brix of 0.2~
0.4 at pH 5-7, L value 81-85, a value 3-9, b
Prepare the product to a value between 34 and 42, and use an instant sterilizer to bring the product temperature to 1.
Sterilize at 30-145°C for 2-30 seconds, and Fo=
After increasing the temperature to 3.2 or higher, the temperature of the extract is increased to 90°C or higher9.
After lowering the temperature to below 5℃, filling the can and sealing it, the temperature is 100~
A method for producing canned oolong tea, characterized by further sterilizing it at 109°C for 1 to 10 minutes.