AU2010201649C1 - Method for producing a tea extract - Google Patents

Abstract

An object of the present invention is to provide a method for producing a tea extract, the method being 5 capable of producing a tea extract that is particularly superior in flavour by carrying out extraction without imparting unwanted astringency and acrid taste included in tea leaves. The method for producing a tea extract according to the present invention includes: an extraction 10 step for extracting a tea leaf with warm water; a first recovery step including carrying out a solid-liquid separation treatment for separating a tea extract and a tea dreg obtained in the extraction step to recover the tea extract; and a second recovery step including adding 15 to the tea dreg subjected to the solid-liquid separation treatment, water in an amount 0.5 to 10 times by mass of the tea leaf, the water having a temperature lower than that of the warm water used in the extraction step, and thereafter recovering the added water together with the 20 tea extract which failed to be recovered in the first recovery step. 2256934_1 (GHMatters) 23/04/10

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant(s): ASAHI SOFT DRINKS CO., LTD. and ASAHI BREWERIES, LTD. Invention Title: Method for producing a tea extract The following statement is a full description of this invention, including the best method for performing it known to me/us: - 2 METHOD FOR PRODUCING A TEA EXTRACT This application is based on and claims the 5 benefit of priority from Japanese Patent Application No. 2009-106708, filed on 24 April 2009, the content of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 10 Field of the Invention The present invention relates to a method for producing a tea extract, and particularly relates to a method for producing a tea extract having superior 15 flavour. Related Art Conventionally, when tea such as green tea or black tea is prepared in a teapot, the last one drop 20 poured from the teapot is referred to as a best drop or golden drop, which has been known as an important drop for preparing good tea. However, due to time constraints, it is not easy to industrially pour completely to take the last one drop. Moreover, since industrial scale methods 25 employ a large amount of tea leaf, even completely pouring out to take the last one drop is not easy in technical aspects. Thus, industrially adopted methods include, for example, a method of compressing tea dreg obtained after 30 the extraction, a method of squeezing with a screw decanter, and the like. However, according to these methods, unwanted astringent components are recovered together, leading to failure in obtaining a tea extract 2256934_1 (GHMattere) 23/04/10 -3 having superior flavour. For example, a method for producing a tea extract was proposed including: a first extraction step of 5 extracting tea leaf with warm water of 55*C to 80*C to obtain an extract A and a tea dreg B; a second extraction step of extracting the tea dreg B with warm water having a temperature no lower than that of the warm water used in the first extraction step for an extraction time period no 10 longer than the extraction time period in the first extraction step to obtain an extract C and a tea dreg D; and a step of mixing the extract A and the extract C (see Japanese Unexamined Patent Application, First Publication No. 2008-131932). According to this method, components 15 included in the tea leaf can be reportedly extracted sufficiently as a result of extraction carried out in two steps. However, the method of Japanese Unexamined Patent 20 Application, First Publication No. 2008-131932 is characterized by a finding that pharmacologic effects can be improved by suppressing thermal isomerization of catechins, and no consideration was made with respect to flavour. Thus, the tea extract obtained by the production 25 method of Japanese Unexamined Patent Application, First Publication No. 2008-131932 contains a large amount of catechins that are predominant astringent components, and is thus the tea extract has a far from superior flavour. 30 SUMMARY OF THE INVENTION According to a first broad aspect, the present invention provides the following. 2256934_1 (GHMatters) 23/04/10 -4 The method for producing a tea extract according to the present invention includes: an extraction step for extracting a tea leaf with warm water with agitation; a 5 first recovery step including carrying out a solid-liquid separation treatment for separating a tea extract and a tea dreg obtained in the extraction step to recover the tea extract; and a second recovery step including adding to the tea dreg subjected to the solid-liquid separation 10 treatment, water in an amount 0.5 to 10 times by mass of the tea leaf, the water having a temperature lower than that of the warm water used in the extraction step, and thereafter recovering the added water without agitation together with the tea extract which failed to be recovered 15 in the first recovery step. In the method according to the present invention, the amount of water added in the second recovery step is 20 preferably a mass 1 to 4 times the mass of the tea leaf. In the method according to the present invention, the temperature of water added in the second recovery step is preferably 10 0 C to 40 0 C. 25 It is preferred that the method according to the present invention further includes a mixing step of mixing the tea extract recovered in the first recovery step with the tea extract recovered in the second recovery step. 30 According to a second broad aspect, there is provided a tea extract prepared according to the method described above. 3174676_1 (GHMatters) P83973.AU 29/02/12 -5 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a view illustrating analytical results of flavouring components. 5 DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present invention are explained in detail. 10 The method for producing a tea extract according to this embodiment includes an extraction step, a first recovery step, and a second recovery step. Hereinafter, each step is explained in detail. 15 [Extraction Step] In the extraction step, a tea leaf is extracted under extraction conditions conventionally employed, in 20 general. Variety, production region, picking season, picking process, cultivation method of the tea leaf are not limited. The type of the tea leaf is not also limited particularly, and any tea which has been universally drunk can be used in the present invention such as green tea, 25 oolong tea, black tea or grain tea. For example, a blend tea including Coix seed, barley, brown rice, Cassia obtusifolia, black bean, Japanese medlar leaf, tangle weed, sasa veitchii, sesame, persinmon leaf, Gynostemma, mulberry leaf, Reishi mushroom (Ganoderma lucidum), 30 mandarin orange peel, du zhong (Eucommia ulmoides) leaf, Japanese basil leaf may be used. By applying the method for production of the present invention to such a tea leaf, a tea extract that is particularly superior in 2256934_1 (GHMatters) 23/04/10 - 6 flavour can be obtained. The extraction rate, which is a ratio of an amount of the water added to an amount of the tea, is 5 preferably regulated depending on the type of the tea leaf. For example, the extraction is preferably carried out by adding warm water in an amount of 3 to 50 times the mass of the tea leaf (dry tea leaf), and more preferably, the extraction rate is 5 to 40 times. When the extraction 10 rate falls within the range of 3 to 50 times, the components included in the tea leaf can be sufficiently extracted without generating poor flavour as if brewed with used leaves. 15 The temperature of the warm water used for the extraction is preferably adjusted appropriately depending on the type of the tea leaf, and it is preferred that the temperature be adjusted to, for example, 35 to 100 0 C. When the temperature of the warm water is no lower than 20 35*C, the components included in the tea leaf can be sufficiently extracted. Whereas, when the temperature of the warm water is no higher than 100*C, preparation of a tea extract having strong astringency and/or acrid taste can be avoided. 25 The extraction time is not particularly limited, and may be predetermined appropriately depending on the tea leaf type and the extraction method. In addition, the pH of the warm water used in the extraction is not also 30 limited particularly, and may be adjusted appropriately depending on the type of the auxiliary extraction agent used in the extraction, and the type of the intended components to be extracted. 2256934_1 (GHMatters) 23/04/10 - 7 It is to be noted that the extraction is preferably carried out while stirring the tea leaf with a kneader or a multifunctional extractor except for the case 5 of dripping extraction. Accordingly, the extraction efficiency is improved, and thus a tea extract having even superior flavour can be obtained. In addition, upon extraction, an auxiliary 10 extraction agent may be also added. The auxiliary extraction agent is not particularly limited, and a conventionally well-known auxiliary extraction agent e.g., an anti-oxidizing agent such as sodium L-ascorbate or L ascorbic acid, a pH adjuster such as sodium bicarbonate or 15 potassium carbonate can be used. Moreover, these auxiliary extraction agents may be added in an amount of 0.1 to 10% by mass of the tea leaf. [First Recovery Step] 20 In the first recovery step, a solid-liquid separation treatment is executed for separating a tea extract and a tea dreg obtained in the extraction step to recover the tea extract. In the solid-liquid separation 25 treatment, for example, a pot in which the extraction is carried out is tilted gently to allow only the tea extract to flow out on the filter and be recovered. Thus, a tea extract can be recovered without imparting astringency and acrid taste. Alternatively, the tea extract may be gently 30 flowed out and recovered from the bottom portion of the pot in which the extraction is carried out to a filter or the like. It is to be noted that the recovery of the tea extract may be carried out after completing the solid 2256934_1 (GHMattere) 23/04/10 - 8 liquid separation treatment, or during the solid-liquid separation treatment. Also in the solid-liquid separation treatment, 5 the filter may be vibrated to allow the solid-liquid separation and the like to efficiently proceed. However, squeezing with a screw decanter, or compression of the tea dreg obtained after the extraction is not preferred since unwanted astringent components are recovered as well, 10 leading to difficulty in obtaining a tea extract having superior flavour. In addition, a time period required for the solid-liquid separation treatment is not particularly 15 limited, and may be predetermined appropriately in range such that unwanted astringent components are hardly extracted, and the tea dreg and the tea extract can be sufficiently separated. 20 [Second Recovery Step] In the second recovery step, after adding water having a temperature lower than the warm water used in the extraction step to the tea dreg after subjecting to the 25 solid-liquid separation treatment in an amount of 0.5 to 10 times the mass of the tea leaf (dry tea leaf), the added water is recovered together with the tea extract which failed to be recovered in the first recovery step. Accordingly, a sufficient amount of recovery of active 30 ingredients such as tannin, amino acids and flavouring components which failed to be recovered in the first recovery step is enabled without imparting astringency and acrid taste, and thus a tea extract having a high soluble 22569341 (GHMattere) 23/04/10 - 9 solid content and a pleasant taste can be obtained. The second recovery step is preferably carried out as soon as possible following completing the first 5 recovery step. Thus, proceeding of extraction, with the tea extract, of astringent components and acrid taste components which failed to be recovered in the first recovery step can be inhibited. 10 The method of addition of water to the tea dreg subjected to the solid-liquid separation treatment is not particularly limited. However, water is preferably added at a hydraulic pressure of a level not applying a great pressure to the tea dreg since astringent components and 15 acrid taste components may also be recovered when the great pressure is applied to the tea dreg. In addition, after adding water to the tea dreg, avoiding carrying out a stirring treatment using a kneader 20 or the like is preferred. Thus, recovery of astringent components and acrid taste components by applying a great pressure to the tea dreg can be inhibited. However, stirring may be also carried out in the range less likely to result in extraction of the astringent components and 25 acrid taste components in order to, for example, discharge the tea dreg in recovery. The added water may be recovered, similarly to the solid-liquid separation treatment carried out in the 30 above first recovery step, together with the tea extract that failed to be recovered in the first recovery step and thus remained by adhesion or the like to the tea dreg. 2256934_1 (GHMatters) 23/04/10 - 10 The amount of water added in the second recovery step is 0.5 to 10 times the mass of the dry tea leaf used in the extraction step. When the amount of water added in the second recovery step is no less than 0.5 times the 5 mass of the tea leaf used in the extraction step, the tea extract which failed to be recovered in the first recovery step can be sufficiently recovered. In addition, by using water in an amount of no greater than 10 times, generation of poor flavour as if brewed with used leaves can be 10 avoided. More preferable amount of water is a mass 1 to 4 times the mass of the tea leaf used in the extraction step. The temperature of water added in the second 15 recovery step is predetermined to be lower than the temperature of the warm water used in the extraction step, and specifically, temperatures of 10 0 C to 40*C are preferred. When the temperature of added water is no lower than 10*C, components of extract failed to be 20 recovered by adhering to the tea dreg can be recovered, whereas a tea extract having superior flavour can be obtained with less astringency and acrid taste imparted when the temperature of water is no higher than 40*C. More preferred temperature of water is 15 to 40*C. 25 In addition, the method of the present invention may further include a mixing step of mixing the tea extract recovered in the second recovery step with the tea extract recovered in the first recovery step. The tea 30 extract obtained by mixing both tea extracts in the mixing step has a high soluble solid content, contains a large amount of active ingredients such as tannin, amino acids and flavouring components, and is superior in flavour; 22569341 (GHMatters) 23/04/10 - 11 therefore, it can be suitably used as a material for the production of tea beverages. The present invention is not limited to the 5 embodiments described in the foregoing, and alteration, modification and the like in the scope enabling achieving the object of the present invention falls within the scope of the present invention. 10 EXAMPLES Hereinafter, the present invention is explained by way of Examples, but the present invention is not limited to these Examples. 15 Black tea: Examples 1 to 3, and Comparative Example 1 Example 1 As a black tea leaf, CEYLON BLEND was used. To 75 g of the black tea leaf (dry tea leaf) placed in a 20 given vessel was added 2,250 g of warm water, and an extraction treatment was carried out in the presence of sodium L-ascorbate corresponding to an amount of 4% by mass of the black tea leaf (dry tea leaf) (extraction step). This step was carried out with the warm water 25 having a temperature of 60"C for an extraction time set to be 6 min, while stirring. After completing the extraction treatment, the vessel was tilted to allow the black tea extract to flow out gently on the filter to execute a solid-liquid separation treatment (first recovery step). 30 A 80 mesh filter was used as the filter, and the solid liquid separation time in the first recovery step was 0 min. 2256934_1 (GHMatters) 23/04/10 - 12 Next, to the tea dreg obtained after the solid liquid separation treatment was immediately added 75 g of water (water temperature: 25*C) in an amount corresponding to an equivalent mass to the tea leaf used in the 5 extraction. After adding water, the vessel was tilted again to allow the black tea extract to flow out gently on the filter to execute a solid-liquid separation treatment (second recovery step). A 80 mesh filter was used as the filter, and the solid-liquid separation treatment time in 10 the second recovery step was 2 min. A black tea extract obtained by mixing the black tea extract obtained in the first recovery step with the black tea extract obtained in the second recovery step was 15 filtrated by passing through a filter paper No. 2. The recovery amount and the recovery rate of thus obtained extract were as shown in Table 1. Example 2 20 An extract was obtained by carrying out a similar operation to Example 1 except that 187.5 g of water (water temperature: 25*C) corresponding to 2.5 times the mass of the tea leaf used in the extraction was added to the tea 25 dreg obtained after the solid-liquid separation treatment. The recovery amount and the recovery rate of the extract of Example 2 were as shown in Table 1. Example 3 30 An extract was obtained by carrying out a similar operation to Example 1 except that 300 g of water (water temperature: 25*C) corresponding to 4 times the mass of 2256934_1 (GHMattere) 23/04/10 - 13 the tea leaf used in the extraction was added to the tea dreg obtained after the solid-liquid separation treatment. The recovery amount and the recovery rate of the extract of Example 3 were as shown in Table 1. 5 Comparative Example 1 An extract of Comparative Example 1 was a black tea extract obtained according to the extraction step and 10 the first recovery step of Example 1 except that the second recovery step of Example 1 was not carried out. However, the solid-liquid separation time in the first recovery step was 2 min. The recovery amount and the recovery rate of the extract of Comparative Example 1 were 15 as shown in Table 1. Green tea: Example 4, and Comparative Example 2 Example 4 20 As a green tea leaf, a blend of three different green teas from Kagoshima Prefecture was used. An extract was obtained by carrying out a similar operation to Example 1 except that: sodium L-ascorbate as an auxiliary 25 extraction agent was not used; the temperature of the warm water was 75*C; the extraction time was 5 min; and the amount of water added in the second recovery step was 225 g corresponding to 3 times the mass of the green tea leaf used in the extraction. The recovery amount and the 30 recovery rate of the extract of Example 4 were as shown in Table 1. Comparative Example 2 2256934_1 (GHMatters) 23/04/10 - 14 An extract of Comparative Example 2 was a green tea extract obtained according to the extraction step and the first recovery step of Example 4 except that the 5 second recovery step of Example 4 was not carried out. However, the solid-liquid separation time in the first recovery step was 2 min. The recovery amount and the recovery rate of the extract of Comparative Example 2 were as shown in Table 1. 10 Oolong tea: Example 5, and Comparative Example 3 Example 5 15 As an oolong tea leaf, Donding oolong tea from Taiwan was used. An extract was obtained by carrying out a similar operation to Example 1 except that: sodium L ascorbate as an auxiliary extraction agent was not used; the temperature of the warm water was 85 0 C; the extraction 20 time was 10 min; and the amount of water added in the second recovery step was 225 g corresponding to 3 times the mass of the oolong tea leaf used in the extraction. The recovery amount and the recovery rate of the extract of Example 5 were as shown in Table 1. 25 Comparative Example 3 An extract of Comparative Example 3 was an oolong tea extract obtained according to the extraction step and 30 the first recovery step of Example 5 except that the second recovery step of Example 5 was not carried out. However, the solid-liquid separation time in the first recovery step was 2 min. The recovery amount and the 22569341 (GHMatters) 23/04/10 - 15 recovery rate of the extract of Comparative Example 3 were as shown in Table 1. Blend tea: Example 6, and Comparative Example 4 5 Example 6 As materials of a blend tea, a blend of Coix seed, barley, brown rice, Cassia obtusifolia, black bean, 10 Japanese medlar leaf, tangle weed, sasa veitchii, sesame, persimmon leaf, Gynostemma, mulberry leaf, Reishi mushroom, mandarin orange peel, du zhong leaf, and Japanese basil leaf (hereinafter, blend tea leaf) was used. To 200 g of the blend tea leaf (dry blend tea leaf) 15 placed in a given vessel was added 4,700 g of warm water, and an extraction treatment was carried out (extraction step). Since immersion dripping extraction using a glass column was employed, the extraction treatment also serves as the extraction step and the first recovery step. 20 Details of the warm water in an amount of 4,700 g used for extraction were: 500 g of filled hot water; 600 g of primary showered warm water with a holding time of 10 min; and 3,600 g of secondary showered warm water. In the extraction treatment, the warm water had a temperature of 25 90 0 C, and the extraction time was 31.35 min. After completing the extraction treatment, a tea extract was obtained by carrying out a similar operation to Example 1 except that the amount of water added in the second recovery step was 800 g corresponding to four times the 30 mass of the blend tea leaf used in the extraction. The recovery amount and the recovery rate of the extract of Example 6 were as shown in Table 1. 2256934_1 (CGHMatters) 23/04/10 - 16 Comparative Example 4 An extract of Comparative Example 4 was a blend tea extract obtained according to the extraction step and 5 the first recovery step of Example 6 except that the second recovery step of Example 6 was not carried out. The recovery amount and the recovery rate of the extract of Comparative Example 4 were as shown in Table 1. Evaluations 10 With respect to each tea extract obtained in Examples and Comparative Examples, six expert panelists evaluated the flavour. The evaluation of the flavour was made on a five-grade rating of "5" for the best evaluation 15 to "1" for the worst evaluation, and represented by an average. In the evaluation, number of experiment was 2 (n=2). The results are shown in Table 1. The black tea extract obtained in Examples 1 to 20 3, and Comparative Example 1 was subjected to determination of flavouring components by GC/MS measurement. GC/MS measurement was performed under the following conditions. The measurement results are shown in Fig. 1. 25 (GC/MS Measurement Conditions) Instrument: GC/MS system 6890/5973 manufactured by Agilent Technologies 30 Column: DB-FFAP 30 m (length) x 0.25 mm (internal diameter) x 0.25 pm (membrane thickness) 22569341 (GHMatters) 23/04/10 - 17 Column temperature elevation condition: 40 0 C to 250 0 C Extraction solvent: dichloromethane 5 Concentration rate: 10 times Quantitative procedure: internal reference method 10 (Method of Analyzing Measurement Results) Fifteen components that are main flavouring components included in black tea extract were classified into the following five groups based on features of the 15 flavour, and a total value of results derived by dividing the content of each component by a threshold value was determined as a flavouring strength index on each group. Next, a relative value of each Example relative to Comparative Example 1 assumed to be 1 was determined on 20 each group. Green, minty: (E)-2-Hexenal(trans-2-), 1-Hexanol, (Z)-3-Hexen-1-ol(cis-3-), Methyl salicylate; 25 Sweet, floral, leafy: Linalool oxide I, II, III, IV, Linalool; Floral: Benzaldehyde, Geraniol, Benzyl Alcohol, P-Phenylethyl Alcohol (Penethyl Alcohol); 30 Sweet, honey-like: Phenylacetaldehyde; and Woody: P-Ionone 22569341 (GHMatters) 23/04/10 - 18 After each tea extract obtained in Examples and Comparative Examples was mixed with pure water to give a preparation of 3,000 g (only Example 6 and Comparative 5 Example 4, mixed with pure water to give a preparation of 6,000 g), and Brix (soluble solid content) was measured with a digital differential refractometer DD-7 manufactured by Atago Co., Ltd. The results are shown in Table 1. 10 Each tea extract obtained in Examples and Comparative Examples mixed with pure water to give a preparation of 3,000 g was further diluted with pure water to 3.33 times (w/v), and thereafter the pH was measured. 15 In addition, the absorbance at wavelengths of 420 nm and 720 nm was measured using a spectrophotometer U-1500 manufactured by Hitachi High-Technologies Corporation to examine the liquid color and turbidity of each tea extract. Furthermore, contents of tannin, caffeine, 20 catechins, and amino acids were determined. The results are shown in Table 1. However, since the blend tea did not contain almost all of these components, this determination was not performed. The measurement of each component was carried out as in the following. 25 (Tannin) A tartaric acid iron (II) salt assay was performed for determination. Specifically, using ethyl 30 gallate as a standard substance, the absorbance at 540 nm of each measurement sample prepared under a specified condition was measured to determine the tannin content. 22569341 (GHMatters) 23/04/10 - 19 (Caffeine and Catechins) A UPLC assay was performed for determination. Specifically, the content of caffeine and catechins was 5 determined by measurement under the following conditions. Instrument: Acquity UPLC SYSTEM manufactured by Waters Corporation 10 Detection wavelength: 280 nm Column: Acquity UPLC BEHC 1.7 pm 2.1 x 100 mm Mobile phases: A buffer, 0.5% formic acid; and B 15 buffer, 0.5% formic acid/methanol, which are used as gradient (Amino Acids) 20 An HPLC assay was performed for determination. Specifically, the content of amino acids was determined by measurement under the following conditions. Instrument: fully automated amino acid analyzer 25 JLC-500/V manufactured by JEOL, Ltd. Detection wavelengths: 440 nm, 570 nm and 690 nm Detection method: ninhydrin colorimetric assay 30 2256934_1 (GHMatters) 23/04/10 -20 0 L C4- z 0 00 E x 0 LU . e In 0InN . )C 0 0 0 n C, co 0 E - ) -D 0 z m cca m0 I ) Ca 0 -q 0 Z w - au I 0 In o. i 0 . E n U) 02 In In 0 n 0 0 4 C C- Go - = 0 0) 0- 0 N I- CL WI 0 I n 0 to to . .1 o 0 r- E t o C4~ N 0LoN 0) (I0 - 0 , c E xJ a. 0 '- LI E w In) 0 n I nON I m N, .) li rOD C N = 0 0) 4 I l toI 0 In 0L o 4 0 0 4 10 N o In a. o aE' m~ N- V~ W0 0o 0N 0 0 0 N~ 0 Z E f E' "U r- OD N CD C,4 00 Nm x N CL Z 0 N 0" -4 - m - a. n N a. 0 I D . ciC 0 CL C 0 a-. M ~ E E E M 00 , 0 0 0u 0 x C 0I ~ ~ M CL 0 .) 0 0 E 0 0 a.E00C . a 0 0 M- m . > o - E 0- > 0 0 0 0 a.c 0 0 a. x- a 0 , 1C 0 0 O i-I~ ~ 0 ~ . - 0 o 0>- I *~0 0 0 0 0 0 4-~~ CL 4)~E C 0 00 0 0 C 0 0 E 0C 0 . 0 C 0)- .2 < .0 o * C 7 0 c 00 HC 0 C 0 0 0 -m c C > 0 M m 0 0 > m 0 1 0~~~~ CL 0 CL.0~ 0~ .0 a U ~ 00 E -'x~ LiW E 00 -0 0 Eo ! E oC/3. <. 4 Ix L < < 0 1 2256934_1 (O~mattere) 23/04/10 - 21 04 N o o J C.4 on 0 0 0 m Cq -~ m In 0 0 ') U- - U. 4 f - I -0 CD -0 0 C.) C-iCi04- i (o 0 C') Cl 0 O M1 .eC. 0 0 0 0- 0 i* 00 Co9 CD~C 01r C 'I 0 r 0n 00 0 0 H.

-; U) (K Cl) 00 a .00 0) 0(0 LeL) 0C3 Cl)) *r En 00 ~~o 0 c:-~ ' Nx 0 0Q 1f) CD U) -~ -- E 4; .0 0 0 C~ L to 0 0, 0 ol1 > n m 00 - ) In - - - o to 5, . .> U)s a) a 7,* Ca * c~ ~ 41' E ~ Z CCS) o co M ) L o E M ) co C 0 WE 0 0 E ... ES b0 > C 0 0 0 0 50 - <. < . m . m) 04 > . 5 o0 0 6<02 S.-''..-*2256934_C 4) CS SC erSo 23/04/10 - 22 Results of Evaluation As shown in Table 1, it was proven that in any case of black tea (Examples 1 to 3, Comparative Example 5 1), green tea (Example 4, Comparative Example 2), oolong tea (Example 5, Comparative Example 3), and blend tea (Example 6, Comparative Example 4), the solid content and the recovery rate of active ingredient (tannin, catechin, caffeine, and amino acids (however, blend tea excluded)) 10 were improved, and the flavour was also improved, as compared with Comparative Examples. Specifically, as a result of sensuous evaluation, pleasant taste increased as compared with Comparative Examples, and appreciated as being aromatic, thick in taste and the like. 15 In addition, A720 (absorbance at a wavelength of 720 nm) that is a marker of turbidness which matters in quality of tea beverages hardly varied, and thus it was revealed that any of tea extracts obtained in the present 20 Examples can be suitably used as an ingredient of tea beverages. From the foregoing results, it was ascertained that the tea extract obtained by the method for production 25 of the present invention exhibited improved soluble solid content and recovery rate of active ingredients (tannin, total catechins, caffeine, amino acids), and was superior in flavour, as compared with tea extracts obtained by conventional methods for production. 30 In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary 22569341 (GHMatters) 23/04/10 - 23 implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further 5 features in various embodiments of the invention It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part 10 of the common general knowledge in the art, in Australia or any other country. 2256934_1 (GHMatters) 23/04/10

Claims (7)

1. A method for producing a tea extract comprising the steps of: 5 an extraction step for extracting tea leaf with warm water under agitation; a first recovery step including carrying out a solid-liquid separation treatment for separating a tea extract and a tea dreg obtained in the extraction step to 10 recover the tea extract; and a second recovery step including adding to the tea dreg subjected to the solid-liquid separation treatment, water in an amount 0.5 to 10 times by mass of the tea leaf, the water having a temperature lower than 15 that of the warm water used in the extraction step, and thereafter recovering the added water without agitation together with the tea extract which failed to be recovered in the first recovery step. 20

2. A method as claimed in claim 1, wherein the amount of water added in the second recovery step is a mass 1 to 4 times the mass of the tea leaf.

3. The method as claimed in either claim 1 or 2, 25 wherein the temperature of water added in the second recovery step is 10 0 C to 40 0 C.

4. A method for producing a tea extract as claimed in any one of claims 1 to 3, further comprising a mixing 30 step of mixing the tea extract recovered in the first recovery step with the tea extract recovered in the second recovery step. 3174676_1 (GHMatters) P83973.AU 29/02/12 - 25 5. A tea extract prepared according to the method of any one of the preceding claims.

5

6. A method for producing a tea extract substantially as herein described with reference to Examples 1 to 6.

7. A tea extract substantially as herein described 10 with reference to Examples 1 to 6. 2256934_1 (GHMatters) 23/04/10