JP2003111558A - Method for producing tea extract - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing clear tea extract having flesh flavor peculiar to raw tea leaves, and strong palatability. SOLUTION: The method for producing tea extract excellent in flavor and taste from juice obtained by steaming raw tea leaves to inactivate enzyme followed by cooling the resultant enzyme, and compressing the cooled enzyme, comprises the following processes: (A) a first process of making pectinase act to the juice to obtain an enzyme treating solution, and (B) a second process of making the enzyme treating solution come in contact with polyvinyl polypyrrolidone (PVPP) to obtain the extract.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tea extract having a rich aroma and enhanced umami. [0002] In recent years, products filled with green tea drinks in cans or plastic bottles have been provided, and the amount of production has been steadily increasing with the strong support of consumers for their sweetness. I have. Green tea used as an extraction raw material in such a green tea beverage has been subjected to a general tea-making process. That is, the harvested raw tea leaves are first steamed with steam to inactivate oxidases contained in the raw tea leaves, and then the rough tea is produced through a series of processes such as rough rubbing, rough twisting, medium twisting, spinning, and drying. Tea and sencha, which has been further burned, are used as extraction raw materials. Conventionally, the above-mentioned green tea, which has been used as an extraction raw material for green tea beverages, loses a fresh aroma due to thermal deterioration during the tea-making process, and has a strong astringency. [0003] On the other hand, the use of raw tea leaves as an extraction raw material has been studied so far mainly for instant powdered tea. For example, raw tea leaves are steamed to deactivate enzymes, then cooled, and preheated at a specific temperature. And filter the extract with warm water,
A method for producing an instant green tea having an excellent flavor by heating a soluble powdered tea obtained by concentration and drying (Japanese Patent Publication No. 60-48)
No. 138), a tea leaf obtained from a juice of tea leaves and containing amino acids, catechin, caffeine, and vitamin C in a weight ratio of 3 to 19: 9 to 22: 1 to 6: 1 to 4 Extract powder (Japanese Patent Application Laid-Open No. 9-275903), a step of steaming fresh tea leaves, a step of grinding and pressing the tea leaves after this step, ultrafiltration of the pressed liquid obtained in this step, and reverse osmosis. A method for producing powdered teas, which comprises a step of concentrating and a step of adding a cyclic dextrin to the concentrated liquid obtained in this step and drying the same, has been proposed (Japanese Patent Application Laid-Open No. H11-56243). . [0004] The raw tea leaf juice has little thermal degradation during the tea-making process, has a fresh aroma similar to that of fresh tea leaves and a strong umami, but has a strong turbidity and is transparent as it is. It is not suitable as a drink. Accordingly, an object of the present invention is to provide a method for producing a clear tea extract having a fresh aroma and a strong umami from a fresh tea leaf juice. Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, this time, a fresh tea leaf juice was obtained by applying pectinase to the fresh tea leaf juice. Of the enzyme-treated solution can be easily clarified by centrifugation or the like. Further, by contacting this enzyme-treated solution with polyvinylpolypyrrolidone (PVPP), it has a fresh aroma, The inventors have found that a strong and clear tea extract can be obtained, and have completed the present invention. [0007] Thus, according to the present invention, the raw tea leaves are steamed to inactivate the enzyme, then cooled and pressed to produce a tea extract from the squeezed liquid obtained. A first step of obtaining an enzyme-treated solution by allowing pectinase to act, and (b) a second step of obtaining an extract by subjecting the enzyme-treated solution to contact treatment with polyvinylpolypyrrolidone (PVPP). The present invention provides a method for producing a tea extract having an excellent flavor. Hereinafter, the present invention will be described in more detail. DETAILED DESCRIPTION OF THE INVENTION The raw tea leaves used in the present invention may be of any varieties, and may be either cultivated for gyokuro or tencha or cultivated in open-air for sencha. It may be. In addition, plucking time is also the best tea,
Any of the second and third teas can be used. Such raw tea leaves are steamed with saturated steam at about 100 ° C. using a general steaming device. By this steaming, the activity of oxidizing enzymes such as peroxidase and oxidase contained in the raw tea leaves is lost and the tea leaves are softened. After cooling, the green tea leaf juice can be obtained by squeezing with a suitable squeezing device. [0010] The first step of the present invention is a step in which pectinase is allowed to act on the juice of fresh tea leaves to obtain an enzyme-treated solution. Pectinase is polygalacturonase,
Pectic enzyme, polymethylgalacturonase,
It is also called pectin depolymerase and is an enzyme that hydrolyzes α (1-4) bond such as pectinic acid, pectin and pectic acid. Pectinase is used in bacteria, mold, yeast,
It is known that it is contained in higher plants, snails and the like, and in the present invention, pectinase obtained from such and other organisms can be widely used. Also,
A commercially available pectinase preparation may be used. Commercially available pectinase preparations include, for example, sucrase (manufactured by Sankyo Co., Ltd.), Pectinex Ultra SP-L (manufactured by Novo Nordic A / S), and mecerase (Meiji Seika Co., Ltd.)
), Ultrazyme (Novo Nordics A / S),
Neulase F (manufactured by Amano Enzyme Co., Ltd.) can be exemplified. [0012] The amount of pectinase to be added is set within a range that can reduce the viscosity of the raw tea leaf juice. Although it varies depending on the enzyme activity and the like, for example, a range of 0.005 to 0.5% by weight based on the weight of the raw tea leaf juice can be exemplified. The method of treating the raw tea leaf juice with pectinase is carried out at a temperature of about 0 ° C.
A method of operating at a temperature range of about 55 ° C. for about 10 minutes to about 24 hours can be exemplified. After completion of the enzymatic reaction, for example, in a temperature range of about 70 ° C. to about 100 ° C. for about 1 second to about 3 seconds.
The enzyme is inactivated by heating for 0 minutes. The enzyme-treated solution can be subjected to the second step of the present invention as it is, or can be a separated solution treated by using an appropriate separation means such as centrifugation. Next, as a second step, the enzyme-treated solution obtained in the first step is treated with polyvinylpolypyrrolidone (PVP).
Contact treatment with P) to obtain a tea extract. The amount of polyvinylpyrrolidone added is preferably 0.1 to 10% by weight, more preferably 1 to 8% by weight, based on the enzyme treatment. If it is less than 0.1% by weight, the effect of improving the taste can hardly be expected, and if it exceeds 10% by weight, the flavor of the tea itself may be impaired, which is not preferable. Although the treatment with polyvinylpolypyrrolidone cannot be said unconditionally depending on the flavor of the desired tea extract, for example,
A method of performing a stirring treatment at a temperature range of about 0 ° C. to about 50 ° C. for about 10 minutes to about 3 hours can be exemplified. afterwards,
By using an appropriate separation means such as centrifugation or filtration, a clear tea extract can be obtained. The obtained tea extract can be in the form of a concentrated liquid by employing an appropriate concentration means if desired. The tea extract of the present invention is usually used as it is in a liquid form, but if desired, an excipient such as dextrin, modified starch, cyclodextrin, or gum arabic can be added to the extract to form a powder. . The tea extract obtained by the present invention can be sterilized by heating after filling or before filling the container, if desired. More desirably, it is possible to maintain the excellent flavor of the teas of the present invention for a long period of time by freezing after freezing after instantaneous high-temperature sterilization by a heat exchanger. Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples. EXAMPLE 1 Raw tea leaves (first tea) are steamed and pressed to obtain a raw juice extract (Bx: 10 °, tannin: 1.39%, caffeine: 0.41%). , Amino acid: 0.90% (theanine:
0.37%)) 1000 g of sucrase N (Sankyo Co., Ltd.)
(Pectinase) (0.5 g) was added, and a stirring reaction was performed at 42 ± 2 ° C. for 2 hours. After the enzyme reaction, the mixture was heated to 90 ° C. to inactivate the enzyme, cooled, centrifuged, and subjected to an enzyme treatment solution (Bx: 10 °, tannin: 1.51%, caffeine: 0.46%, Amino acid: 1.04% (theanine:
0.43%)) 853 g was obtained. 29.8 g of Daigaban F (PVPP manufactured by BASF) was added to the separated solution, and the mixture was stirred at 22.5 ° C. ± 2.5 ° C. for 1.5 hours.
An extract clarified by centrifugation and diatomaceous earth filtration (invention product 1) (Bx: 8 °, tannin: 0.66%, caffeine: 0.45%, amino acid: 1.01% (theanine:
0.43%)) 820 g were obtained. The extract was sterilized at 90 ° C. and stored frozen. (Comparison of the components of the product of the present invention and the comparative product) Changes in components such as amino acids during the production of the product of the present invention (raw tea leaf juice, enzyme-treated solution, product of the present invention) and green tea infusion as a comparative product (Comparative product 1) Table 1 shows a comparison of components such as amino acids of the gyokuro leaching solution (Comparative product 2). The product of the present invention is Bx0.3 °
(Drinking concentration). The preparation methods of the green tea infusion and the gyokuro infusion are shown below. Preparation method of green tea and gyokuro leaching solution 500 g of hot water at 85 ° C. was poured into 5 g of tea leaves, immersed for 5 minutes, separated, and Bx was adjusted to 0.3 °. Table 1: Comparison of component amounts between the product of the present invention and a comparative product (unit:
mg%) As is clear from the results in Table 1, the product of the present invention shows that the tannin which is a bitter component is reduced by the pectinase treatment and the PVPP treatment, and the ratio of the amino acid (theanine) which is the umami component is increased. Proven. In addition, the ratio of amino acids / tannin was higher than that of green tea infusion and gyokuro infusion, indicating that the product of the present invention has low bitterness and strong umami. In addition, the measuring method of each component in a table | surface was measured by the method shown below. Tannin: Measured by the iron tartrate method. Caffeine: High Performance Liquid Chromatography (HPLC)
It was measured by the method. Amino acid (theanine): Measured by an automatic amino acid analyzer. (Sensory evaluation) For the product of the present invention and the comparative product shown above,
Sensory evaluation was performed by 10 well-trained panelists. Table 2 shows the average sensory evaluation of the ten panelists. Table 2: Sensory evaluation of the product of the present invention and the comparative product According to the present invention, it is possible to provide a method for producing a clear tea extract having a strong flavor and a fresh aroma unique to fresh tea leaves.

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Claims (1)

Claims 1. A tea extract is steamed from raw tea leaves to inactivate enzymes, then cooled and pressed to produce a tea extract from the squeezed liquid obtained. A first step of obtaining an enzyme-treated solution by allowing pectinase to act, and (b) a second step of obtaining an extract by subjecting the enzyme-treated solution to contact treatment with polyvinylpolypyrrolidone (PVPP). Production method of tea extract with excellent flavor.