JP2011078388A - Method for producing oolong tea - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a packaged oolong tea beverage. <P>SOLUTION: The method for producing a packaged oolong tea beverage containing caffeine of not less than 180 ppm, and having a ratio of (tannin-catechin)/tannin of 0.05-0.5, includes an extraction step of extracting oolong tea leaves with warm water, a pH adjustment step of adjusting obtained tea extract to a pH of 6.05-7.0, a sterilization step, and a container packaging step. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a oolong tea beverage in which secondary cotton-like floats and / or precipitates are suppressed during storage.

  In tea beverages filled in containers such as plastic bottles, floating and white turbidity that occurs over time during long-term storage after beverage production, apart from primary sedimentation that occurs immediately after beverage production. In some cases, secondary floats and / or precipitates (hereinafter collectively referred to simply as “floc”) in the form of flocs (cotton) or precipitates may be formed. The flocs increase in size and quantity over time, and finally grow into macromolecules of about several millimeters and can be visually observed, especially filled in transparent containers such as PET bottles and bottles. In tea beverages, this type of flock is an important issue as it loses its commercial value.

  Occurrence of flocs is found in tea beverages in general, but since it is a phenomenon that is particularly likely to occur in green tea, various techniques for suppressing flocs have been reported for green tea beverages. For example, a green tea extract is enzymatically treated with an enzyme having hemicellulase activity to decompose components that are considered to be floc-causing substances (Patent Document 1), and a green tea extract is fractionated by ultrafiltration. , A method of physically removing high molecular components with molecular weight of about 10,000 or more, which is considered to be the cause of flocs (Patent Document 2), adjusting green tea extract to an acidic region and rapidly cooling to promote flocs , A method of removing the generated precipitate by filtration (Patent Document 3), a method of adding aluminum which is a component that suppresses the generation of flocs (Patent Document 4), and a content of strictinin that is one of the components causing flocs generation There is a method for preventing the occurrence of flocs using a raw material with a small amount (Patent Document 5).

JP-A-8-228684 JP-A-4-45744 JP-A-4-31348 JP 2005-143331 A JP 2003-235451 A

As described above, a technology for suppressing flocs for green tea beverages has been reported, but a technology for suppressing flocs for oolong tea beverages has not been disclosed.
Unlike green tea, which is heated immediately after picking tea leaves to make tea, oolong tea is heated during fermentation to stop fermentation and semi-fermented to make tea. The oolong tea beverage is characterized by containing a polymer of catechins produced during the fermentation process (polymerized catechin, also called oolong tea polymerized polyphenols (OTPP)), and this polymerized catechin is a oolong tea beverage. Has a great influence on the flavor and physiological activity. Therefore, there is a problem that the flavor inherent to oolong tea is reduced when the polymer component that is considered to cause flocs is decomposed or removed as in the above-described floc control technology for green tea beverages.

  Also, in container-packed beverages, oxidation is accelerated during heat sterilization and long-term storage, and the pH of the beverage is lowered. Therefore, an antioxidant such as ascorbic acid is added, and the pH is adjusted by a pH adjuster such as sodium bicarbonate. Has been. On the other hand, it is necessary to foster a refreshing feeling of the aftertaste unique to oolong tea beverages. Therefore, the pH of oolong tea drinks is usually set lower (for example, pH 5.9 or lower) than that of green tea drinks. In this way, the required flavor differs between green tea drinks and oolong tea drinks, and there are differences in the quality of flocs due to different component compositions, etc., and the above floc control technology of green tea drinks can be directly transferred to oolong tea drinks is not.

  In recent years, so-called high-quality oolong tea with high rare value such as large red rice cake has been distributed. High-grade oolong tea is characterized by a light brown color and a refreshing sensation, with a rich and strong floral scent and a crisp taste. In this oolong tea beverage with a light brown color, the occurrence of flocs is easily recognized visually, so the occurrence of flocs particularly reduces the commercial value, but in order to maintain the characteristic strong floral aroma and crisp taste, Development of a technique for generating flocs without removing molecular components has been desired.

  The present invention provides a method for producing a container-packed oolong tea beverage that maintains the inherent flavor of oolong tea (especially a oolong tea beverage having a light brown color) and suppresses the occurrence of flocs during long-term storage. There is.

  As a result of intensive studies to solve the above problems, the present inventors have adjusted the pH of the oolong tea leaf extract to 6.05 to 7.0 and control caffeine to be 180 ppm or higher. Thus, it was found that the oolong tea beverage satisfying the flavor of oolong tea and suppressing the occurrence of flocs during storage can be easily produced, and the present invention has been completed.

Although not necessarily limited, this invention includes the following aspects.
Aspect 1
Extraction process of extracting oolong tea leaves with warm water, pH adjustment process of adjusting the pH of the obtained tea extract to 6.05-7.0, sterilization process and container filling process, including caffeine 180 ppm or more A method for producing a stuffed oolong tea beverage containing (tannin-catechin) / tannin of 0.05 to 0.5.
Aspect 2
The manufacturing method of aspect 1 whose temperature of the warm water in an extraction process is less than 100 degreeC from the temperature over 85 degreeC.
Aspect 3
The manufacturing method according to aspect 1 or 2, wherein a part or all of the oolong tea leaves are large red rice cakes.
Aspect 4
Adjusting pH to 6.05-7.0, The method to suppress generation | occurrence | production of the flock in a container stuffed oolong tea drink characterized by the above-mentioned.

  A oolong tea beverage in which the occurrence of flocks is easily suppressed can be produced using existing production equipment without requiring any special equipment or complicated processes. Moreover, in the manufacturing method of this invention, since the important components (for example, polymeric component etc.) which determine the flavor of oolong tea drink are not removed, the flavor which oolong tea originally has can be maintained, and the oolong tea drink which can fully satisfy also in flavor aspect. Can be manufactured.

Hereinafter, although the best embodiment for carrying out the present invention is described, the embodiment of the present invention is not limited to the following examples.
In this embodiment, an extraction step of extracting oolong tea leaves with warm water, a coarse filtration step of removing extraction residues from the obtained tea extract, and a pH adjuster added to the tea extract to adjust the pH of the tea extract to 6. A oolong tea beverage packed in a container through a pH adjustment step adjusted to 05 to 7.0, a preparation step where necessary to prepare a caffeine content of 180 ppm or more based on the whole beverage, a sterilization step, and a container filling step. Manufacturing.

  However, the said manufacturing process is an example, the order of each process may be replaced and another process may be added between each process. The coarse filtration step and the caffeine content preparation step are optional steps performed as necessary.

(Raw tea)
Oolong tea leaves used as a raw material are Camellia genus such as C.I. sinensis, C.I. The assamica or their hybrids are generally dried and shaded (withered) after the above-mentioned raw material leaves are oxidatively fermented by shaking the tea leaves inside a bamboo basket, etc., and the oxidative fermentation proceeds to about 30% to 70%. In the meantime, the fermentation is stopped by heat treatment in a kettle, and then subjected to twisting, hot air drying and the like. The varieties, parts (leaves, stems), production area, picking time, picking method, cultivation method, etc. of the oolong tea of the present invention are not particularly limited, and any one such as iron kannon, color type, golden katsura, wushuiwa tea, etc. It may be used as a mixture of two or more. However, when oolong tea leaves having a low fermentation degree are used, the characteristic composition of the oolong tea beverage of the present invention (caffeine can be used without adding caffeine). Content of 180 ppm or more) is preferable. Moreover, as will be described later, the present invention is suitable for producing a oolong tea beverage having a light brown liquid color in which precipitation is easily recognized visually. It is preferable to select tea leaves having a low fermentation degree from the viewpoint of tea leaves whose liquid color is light brown.

  As a specific variety of tea leaves having a low fermentation degree, large red rice cake can be exemplified. Daimoku is a tea cultivar that has a particularly high quality and is called “Chao” among the “Wuyi Iwacha” made in and around Mt. Its taste is called “Iro-Ryo” and is characterized by a rock-like powerful, deeply balanced flavor and a lingering scent like a flower. As the large red rice cake, tea leaves that have undergone rough tea processing may be used, or commercially available tea leaves that have been finished may be used.

(Extraction process)
Oolong tea leaves are extracted with warm water. The oolong tea of the present invention contains a specific amount of caffeine, and the temperature of hot water exceeds 85 ° C. for the purpose of efficiently extracting caffeine and the purpose of efficiently extracting the original aroma components of oolong tea. The temperature is less than 100 ° C, preferably 90 ° C to 95 ° C. The mixing ratio of tea leaves and warm water is about 1:15 to 1:40, preferably about 1:15 to 1:20, and generation of floc can be suppressed by the amount of hot water to be extracted.

  Extraction water used for extraction can be exemplified by pure water (including hard water, soft water, ion-exchanged water, natural water, etc.), ascorbic acid-containing aqueous solution, pH-adjusted water, etc. According to the report, it has been found that flocs are likely to occur when extracted with warm water in an alkaline region. Therefore, the pH of the extracted water is neutral or weakly acidic, specifically about pH 5.0 to 7.0, preferably about pH 5.5 to 6.5.

(Coarse filtration step)
The coarse filtration step is a step of removing extraction residues such as large fine powder from tea leaves. For example, a metal mesh, flannel cloth, ceramic membrane, diatomaceous earth, centrifugal separation or the like is used. In addition, since a rough filtration process is a process of removing a big extraction residue, you should avoid the process conditions which affect the flavor of a tea drink. Since rough filtration in the acidic region removes polymer components and the like, the pH of the extract in the coarse filtration step is about 5.0 to 6.0. Moreover, when using centrifugation, from a viewpoint which prevents removal of an excessive polymer component, the rotation speed is 1000-10000 rpm, Preferably it is 3000-8000 rpm, Processing time is 1-30 minutes, Preferably it is 5-15 minutes. Degree.

(Formulation and pH adjustment process)
In the preparation, ascorbic acid is added for the purpose of preventing the oxidation of the oolong tea beverage and / or enhancing the fragrance. Ascorbic acid is added so as to have a concentration of 100 ppm or more, preferably 300 ppm or more, more preferably 400 ppm or more in the preparation solution. If ascorbic acid is blended at 100 ppm or more, there is no substantial upper limit to the blending amount, but if the blending amount is too large, the taste of ascorbic acids may affect the flavor of oolong tea beverages. The upper limit is about 1000 ppm, preferably about 800 ppm.

  In addition, as ascorbic acid in this specification, 1 type (s) or 2 or more types in ascorbic acid, its isomer, those derivatives, and those salts can be used. Specific examples of ascorbic acid that can be incorporated into beverages include ascorbic acid; isomers of ascorbic acid such as erythorbic acid; 2,6-dipalmitate ascorbic acid, 6-stearate ascorbate, sodium ascorbate-2 phosphate, ascorbine 2-sodium acid-2sulfate, 2-glucoside ascorbate, glucosamine ascorbate, L-dehydroascorbic acid, 6-palmitate ascorbate, L-ascorbine tetraisopalmitate, ascorbyl tetra-2-hexyldecanoate, L-ascorbyl magnesium phosphate Derivatives of isomers of ascorbic acid such as; salts with alkali metals such as sodium and potassium; salts with alkaline earth metals such as calcium, magnesium and barium; basic amino acid salts such as arginine and lysine Examples include ammonium salts, ammonium salts such as tricyclohexylammonium salts; salts of ascorbic acid and derivatives thereof such as alkanolamine salts such as monoisopropanolamine salt, diisopropanolamine salt, triisopropanolamine salt, among others, ascorbic acid, Erythorbic acid and salts thereof, more preferably sodium ascorbate and sodium erythorbate are preferably used.

  The oolong tea beverage of the present invention is characterized by containing caffeine of 180 ppm or more, preferably 200 ppm or more with respect to the whole beverage. Due to the presence of the above-mentioned amount of caffeine, it is microbially stable and has a refreshing aftertaste peculiar to oolong tea even though the pH is higher than that of a normal oolong tea beverage. Beverages containing caffeine in the above range when using an extract obtained by extracting with 15-40 times the amount of warm water (90-95 ° C.) using tea leaves with a low fermentation degree such as Daikon Is easy to prepare. When performing other tea leaves, extraction processing, etc., selection of raw tea leaves, setting of extraction conditions, etc. are performed so that caffeine is in the above range. Alternatively, natural or synthetic caffeine is added. Here, the caffeine concentration in the beverage can be quantified by a known measurement method by HPLC.

  Furthermore, when the oolong tea beverage of the present invention contains catechins of 300 ppm or more, preferably 350 ppm or more with respect to the whole beverage, a refreshing feeling of the aftertaste of the oolong tea beverage having a high pH, in addition and / or synergistically with caffeine. Can be improved. In the preparation step of the present invention, the amount of catechin may be adjusted as necessary.

  In the preparation process of the present invention, in addition to the above ascorbic acid and caffeine, water (hard water, soft water, ion-exchanged water, natural water and others), sugars, dextrins, fragrances, emulsifiers, stabilizers, and other taste materials However, in the method for producing the oolong tea beverage of the present invention, the pH of the preparation liquid is 6.05 to 7.0, preferably 6.10 to 6.50, more preferably 6.10 to 6 It is important to strictly control so that. By adjusting the pH of the preparation liquid to the above range, generation of flocs during long-term storage after filling the container can be suppressed. For adjusting the pH, known pH adjusting agents, for example, organic acids such as citric acid and DL-malic acid and salts thereof, carbonates such as sodium carbonate, phosphoric acids such as phosphoric acid, and the like can be used.

Moreover, it is good to prepare Bx of a preparation liquid to about 0.25-0.35 which is a drinking density | concentration.
(Sterilization and container filling)
The container-packed oolong tea beverage of the present invention is produced by sterilizing the above-mentioned preparation liquid and filling the container, or filling the container and sterilizing. The term “container” in the present specification is not particularly limited as long as it is a container used as a single-strength oolong tea beverage, that is, a container that can be used as it is without being diluted after being opened, and filled with oolong tea. Known containers that are generally used for this purpose, such as PET bottles, cans (aluminum, steel), paper, retort pouches, bottles (glass) and the like are used.

  If it is a can beverage, if it is a can beverage, it is reheated (hot-packed) and then filled as necessary, and then retort sterilized (for example, 1.2 mmHg, 121 ° C., 7 minutes), PET bottle, paper pack, bottle beverage In this case, for example, UHT sterilization that is held at 120 to 150 ° C. for 1 to several tens of seconds is performed.

(Packed oolong tea drink)
The oolong tea beverage obtained by the production method of the present invention is less likely to generate flocs and has an influence on the flavor even during long-term storage, for example, storage at room temperature for 6 months or more, preferably storage at room temperature for 3 months or more. Advantages of maintaining the flavor (including the clean feeling of the aftertaste) of oolong tea because it does not decompose or remove polymer components such as polymerized catechin and contains a specific amount of caffeine, preferably catechin Have

  The present invention is a oolong tea beverage having a light brown liquid color in which occurrence of floc is easily recognized visually. Specifically, the value of (tannin-catechin) / tannin is 0.05 to 0 using tannin and catechin in the beverage as indices. .5 oolong tea beverages are eligible. Here, tannin is a value measured by the FOLIN-DENIS method, and catechin is a method of Goto et al. (T. Goto, Y. Yoshida, M. kiso and H. Nagashima, Journal of Chromatography A, 749 (1996) 295- 299) represents a total amount of non-polymerized catechins (catechin, gallocatechin, epicatechin, epigallocatechin, catechin gallate, epicatechin is a rate, gallocatechin gallate, epigallocatechin gallate) in a measured value based on an HPLC method in accordance with (299).

  The oolong tea beverage of the present invention is a highly clarified beverage in which the occurrence of floc is suppressed, and its absorbance at 660 nm (OD660 nm) is 0.06 or less, preferably 0.05 or less, more preferably 0.04 or less, Particularly preferred is a oolong tea beverage that is 0.03 or less.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.
A container-packed oolong tea beverage was produced with the formulation shown in Table 1. That is, 10 g of oolong tea leaves (Daikoku) were added to 15 to 20 times the amount of warm water (80, 85 or 90 ° C.), extracted for 5 minutes with stirring, and oolong tea leaves were separated with a 150 mesh stainless steel filter. Subsequently, after centrifugation (6000 rpm, 9 minutes), the mixture was filtered with a filter to obtain an oolong tea extract. Add 400 ppm ascorbic acid to oolong tea extract, add sodium bicarbonate (sodium bicarbonate) to adjust pH, add water to make Bx 0.3, perform hot-pack sterilization and fill the container (bottle) did.

  Sensory evaluation of oolong tea drinks was conducted by five specialized panelists. The evaluation was performed according to an agreement on the taste of oolong tea (richness of flavor, clean feeling of aftertaste, etc.) based on a three-step evaluation of ○, Δ, and ×. In addition, the occurrence of flocs was observed visually when the packaged oolong tea beverage was stored at room temperature for 2 weeks. Flock occurs in 8 stages (level 0: no agglomerates are observed even when light from the projector is applied, level 1: poor projection when exposed to the light from the projector, level 2: extremely fine when light from the projector is applied Level 3: Sandy when exposed to natural light-A small amount of ultrafine particles (less than 0.5 mm) is observed, Level 4: Sandy when exposed to natural light- Fine particles (less than 1 mm) exist, visually confirmed as particles Level 5: small amount of fine particles (1-2 mm) in the presence of sandy to fine particles (less than 1 mm) when exposed to natural light Existence, Level 6: Small amount of fine particles (about 1 mm) are present, and can be confirmed even in a stationary state, Level 7: Evaluation is made with very fine to massive large particles (3 mm or more), Level 0 2 ○, levels 3-4 and △, and determine the level 5-7 and ×.

  The results are shown in Table 1. By adjusting the pH of the preparation liquid to 6.05 or more, generation of flocs during storage (storage) could be suppressed. In addition, the extraction temperature of oolong tea leaves is also related to the occurrence of flocs, suggesting that extraction at a temperature exceeding 85 ° C. (especially 90 ° C. or more) is advantageous for suppressing flocs. From the viewpoint of the flavor of oolong tea beverages, extraction at a temperature exceeding 85 ° C. (especially 90 ° C. or higher) suggests that the beverage has a refreshing aftertaste even if the pH is 6.05 or higher, and is a preferable beverage. It was done. In Examples 1 to 3, the tannin content was 665 ppm, the caffeine content was 210 ppm, and the catechin (non-polymerized catechin) content was 395 ppm. From this, the (tannin-catechin) / tannin in Examples 1 to 3 was calculated to be 0.41. Further, the absorbance was measured using an absorptiometer (Shimadzu Corporation, UV-1600). The beverages of Examples 1 to 3 were OD660 = 0.029 to 0.031.

  From the above results, even in a oolong tea beverage with a light brown color and a refreshing sensation, a specific amount of caffeine is contained and the pH is adjusted to 6.05 or more, so that the refreshing feeling of the aftertaste is not impaired. It was found that a highly transparent oolong tea beverage with suppressed generation can be produced.

Claims (4)

Extraction process of extracting oolong tea leaves with warm water, pH adjustment process of adjusting the pH of the obtained tea extract to 6.05-7.0, sterilization process and container filling process, including caffeine 180 ppm or more A method for producing a stuffed oolong tea beverage containing (tannin-catechin) / tannin of 0.05 to 0.5. The manufacturing method of Claim 1 whose temperature of the warm water in an extraction process is less than 100 degreeC from the temperature over 85 degreeC. The production method according to claim 1 or 2, wherein a part or all of the oolong tea leaves are large red rice cakes. Adjusting pH to 6.05-7.0, The method to suppress generation | occurrence | production of the flock in a container stuffed oolong tea drink characterized by the above-mentioned.