JP5389844B2 - Production method of brown rice tea - Google Patents

Description

  The present invention relates to a method for producing a brown rice tea beverage having an excellent flavor.

  Traditionally, brown rice tea beverages that take advantage of the flavor of brown rice have been favored and drunk by many people. Brown rice tea drinks are generally mixed with steamed, dried, and roasted rice (referred to as “brown rice tea” in this specification for convenience) and green tea. A product obtained by extracting a product with hot water or the like, and a harmonious scent of brown rice and the flavor of green tea are known as highly-preferred brown rice tea beverages.

  The types of brown rice tea are classified according to the type of green tea, for example, Sencha brown rice tea, Gyokuro brown rice tea, roasted brown rice tea, and the like. In addition, in order to obtain a brown rice tea beverage having a high palatability unlike conventional ones, a brown rice tea using fermented brown rice in which the sweetness and scent of rice bran is added to brown rice has also been proposed (Patent Document 1).

JP 08-275742 A

  In container-packed brown rice tea beverages, the starch contained in the raw brown rice tends to be eluted during extraction and storage, and there is also the effect of heat history such as heat sterilization and storage in the refrigerated state, and the harmony of the flavor tends to be lost. have.

  The present invention relates to a method for producing brown rice for brown rice tea, in which the fragrance, sweetness and richness are enhanced, and the original aroma of brown rice is harmonized in a balanced manner. The purpose is to provide.

  The flavor of brown rice tea is determined by the type of green tea, and brown rice is only positioned as a blend material for producing a fragrant scent. In order to solve the above-mentioned problems, the present inventors have intensively studied the processing method of brown rice in order to characterize the flavor of brown rice, and as a result, at least 1 selected from the group consisting of a specific amino acid (leucine, valine and isoleucine) in brown rice. After impregnating an aqueous solution containing amino acids of at least seeds, roasting at a temperature of 100 to 200 ° C., the flavor of brown rice can be characterized, and the brown rice tea has a higher taste than conventional. Has been found, and the present invention has been completed.

That is, the present invention includes, but is not limited to, the following inventions.
(1) A step of impregnating brown rice with an aqueous amino acid solution containing at least one amino acid selected from the group consisting of leucine, valine and isoleucine, and roasting the brown rice subjected to infiltration treatment at a temperature of 100 to 200 ° C. The manufacturing method of the brown rice for brown rice tea including a process.
(2) The production method according to (1), wherein 45 mg or more of amino acid (A) is added per 1 kg of raw brown rice.
(3) The production method according to (1) or (2), wherein the aqueous amino acid solution is an extract of green tea leaves.
(4) The production method according to (3), wherein the green tea leaf extract is subjected to an enzyme treatment.
(5) A step of impregnating raw rice with an aqueous amino acid solution containing at least one amino acid (A) selected from the group consisting of leucine, valine and isoleucine, roasting the brown rice subjected to infiltration treatment at a temperature of 100 to 200 ° C 5 to 150 parts by weight with respect to 1 part by weight of the step of treating, the step of mixing roasted brown rice and green tea in a weight ratio of 2: 8 to 8: 2, and the mixture of roasted brown rice and green tea A method for producing a brown rice tea beverage, comprising a step of extracting with water.

  By using the brown rice for brown rice tea of the present invention, a brown rice tea beverage having an excellent flavor can be produced.

It is a flowchart which shows the example of a manufacturing process of the brown rice for brown rice tea of this invention. It is a flowchart which shows the example of a manufacturing process of the brown rice for brown rice tea of this invention. It is a flowchart which shows the example of a manufacturing process of the brown rice for brown rice tea of this invention. It is a figure which shows the amino acid composition of the tea extract analyzed in Example 2.

  As described above, in the present invention, brown rice is impregnated with an aqueous solution containing a specific amino acid (at least one amino acid selected from the group consisting of leucine, valine and isoleucine), and then at a temperature of 100 to 200 ° C. Roast. From one point of view, the present invention is a method for producing brown rice for brown rice tea, and from another point of view, the present invention is a method for producing brown rice tea using the brown rice for brown rice tea thus obtained.

(Method for producing brown rice for brown rice tea)
In the present invention, the raw rice is impregnated with an aqueous solution containing a specific amino acid (at least one amino acid selected from the group consisting of leucine, valine and isoleucine), but the type of raw rice is not limited. For example, japonica Type rice, indica type rice and its intermediates, uruchi rice, glutinous rice, and the like can be used according to a desired flavor. Use of glutinous rice is preferable because the effects of the present invention are remarkably exhibited.

  Hereinafter, examples of specific embodiments of brown rice for brown rice tea using amino acids according to the present invention will be described with reference to the drawings. 1-3 is a flowchart which shows the manufacturing process example of the brown rice for brown rice tea concerning this embodiment, and passes through a whitening process, a soaking process, a steaming process, a drying process, a mixing process, a roasting process, a cooling process, and brown rice Brown rice for tea is produced.

  First, in the whitening process of Step 1, the rice husk is removed from the grain of the carefully selected brown rice, and the brown rice is shaved until white to obtain white rice. The degree of milling is not particularly limited, but so-called white rice that has been milled more than 9 minutes is suitably used. In the dipping process of Step 2, the white rice obtained in Step 1 is dipped in water to facilitate steaming. Preferable immersion conditions are about 1 to 24 hours, preferably about 1 to 3 hours in water at 10 to 40 ° C. White rice is taken out after the immersion, and in the steaming step of Step 3, steam is steamed at about 100 ° C. for 10 to 120 minutes, preferably about 10 to 30 minutes. After the steaming process, the rice is dried while being loosened in the drying process of Step 4 so that the grains of rice do not stick to each other. Drying is performed at a temperature of about 120 to 180 ° C. until the water content of the rice reaches about 0.1 to 10%.

  In the present invention, an aqueous solution containing at least one amino acid selected from the group consisting of leucine (Leu), valine (Val), and isoleucine (Ile) as an amino acid (hereinafter also referred to as amino acid (A)) is used. Impregnate rice. The amino acid aqueous solution as used in the present invention means a liquid containing amino acids and includes a suspension of amino acids. From the viewpoint that amino acids can be uniformly mixed with brown rice as a raw material, amino acids It is preferable to use it as an aqueous solution.

  1-3, the aqueous amino acid solution is prepared in Step 8 in parallel with the step of processing the raw rice. In a preferred embodiment, the aqueous amino acid solution is prepared so that the total amount of amino acid (A), that is, leucine, valine and isoleucine is 0.01 to 10% by weight, preferably 0.1 to 2% by weight in the aqueous amino acid solution.

  In addition, the starch in brown rice elutes during extraction and may give a paste-like feeling. However, one or more amino acids selected from the group consisting of phenylalanine, glutamic acid, glycine, proline and theanine (hereinafter referred to as amino acids (B) )) In combination with the amino acid (A) is preferable because it has an effect of remarkably improving the glue feeling. When these amino acids (B) are used in combination, the total amount of amino acids (B) is the total amount of amino acids contained in the aqueous amino acid solution (specifically, aspartic acid, glutamic acid, serine, glycine, histidine, arginine, threonine, alanine). , Proline, theanine, tyrosine, valine, methionine, isoleucine, leucine, lysine, phenylalanine), preferably 10 to 80% by weight, and preferably 15 to 25% by weight. It is more preferable to prepare so that.

  In the mixing process of Step 5 shown in FIG. 1 and FIG. 3, rice (hereinafter referred to as “raw brown rice”), which is obtained by steaming the amino acid aqueous solution obtained in Step 8 above to the extent that it can penetrate the water obtained in Step 4. Mixed) and impregnated.

  In the present invention, the method for impregnating the aqueous amino acid solution is not particularly limited as long as the amino acid can permeate or adhere to the raw brown rice. For example, a method of spraying, spreading or applying an amino acid aqueous solution to raw brown rice, a method of immersing raw brown rice in an aqueous amino acid solution, and the like can be mentioned. From the viewpoint of uniformly impregnating raw brown rice with amino acids, a method of spraying an aqueous amino acid solution onto raw brown rice is preferable.

  In this invention, it is preferable to impregnate 45 mg or more of amino acids (A) with respect to 1 kg of raw material brown rice. In the case of 45 mg or more, the fragrant aroma characteristic of the present invention can be sufficiently enhanced, and a brown rice tea drink in which the fragrant aroma, sweetness and richness are harmonized can be produced. Therefore, in the present invention, the total amount of leucine, valine and isoleucine is preferably about 0.005 to 0.25% by weight, and about 0.05 to 0.1% by weight, based on 100 parts by weight of the raw large brown rice. It is more preferable that

  Next, in this invention, it roasts at the temperature of 100-200 degreeC with respect to the brown rice impregnated with said amino acid aqueous solution. It is thought that 2-butanal and / or 3-butanal, which is a fragrant scent of brown rice tea, can be enhanced in a state containing a little moisture than that during drying. When the degree of heating is deep, simple incense, i.e., a scent close to a burning odor, becomes strong and may inhibit the perception of preferred fragrances such as 2-butanal and / or 3-butanal. Accordingly, it is preferable that 2-methylbutanal and / or 3-butanal is 0.5 to 2,5- (or 2,6-) dimethylpyrazine (2,5 (6) -dimethylpyrazine), which is an incense. It is desirable to roast so as to contain 50 times, more preferably 1 to 30 times. Here, the 2-butanal, 3-butanal content and 2,5- (or 2,6-) dimethylpyrazine content in the roasted brown rice can be measured by gas chromatography.

  As a roasting method in which 2-butanal and / or 3-butanal content and 2,5- (or 2,6-) dimethylpyrazine content are within the above ranges, specifically, the temperature of brown rice impregnated with amino acids is The method of heating to 100-200 degreeC, Preferably it is 110-170 degreeC, More preferably, it reaches 130-150 degreeC is mentioned. The apparatus and method for roasting are not particularly limited, and methods that are usually used for roasting brown rice for brown rice tea, such as roasted roasted burdock, roasted kataka and the like, can be mentioned.

  1-3, the rice is roasted in step 6 and the roasted rice in step 7 is cooled. The cooling of step 7 is mainly intended to prevent this ignition because the raw material may ignite when it is taken out of the kettle after roasting.

The water content of the roasted brown rice obtained by roasting in this way is preferably 5% or less, more preferably about 1% or less.
In the present invention, the brown rice may be impregnated with a specific amino acid in the step of immersing the polished brown rice in Step 2. In the embodiment shown in FIG. 2, an amino acid aqueous solution is used instead of water, and brown rice refined in the amino acid aqueous solution is immersed to impregnate the brown rice with amino acid. However, in this case, since it is difficult to impregnate the amino acid and it takes a long time to immerse, it is preferable to impregnate the steamed and softened rice with the aqueous amino acid solution as shown in FIG. 1 or FIG.

  In the present invention, brown rice may be impregnated with amino acids in multiple stages, for example, a method in which polished brown rice is immersed in an aqueous amino acid solution, then steamed and softened, and further impregnated with an aqueous amino acid solution and roasted. Are also included in the present invention.

  In the present invention, by impregnating raw brown rice with the above-mentioned specific amino acid aqueous solution and roasting under specific conditions, the fragrant fragrance of brown rice tea is enhanced, and as a result, the fragrant fragrance is not accompanied by burnt odor and miscellaneous taste. An enhanced brown rice tea beverage can be produced. According to the study by the present inventors, this fragrant scent is expressed when an aqueous solution containing at least one amino acid selected from the group consisting of leucine, valine and isoleucine is used. In particular, leucine has an effect of enhancing not only a fragrant scent but also sweetness and richness. Accordingly, one preferred embodiment of the present invention is one in which the amino acid-containing solution contains leucine and further contains valine and / or isoleucine. The details of the reason why the fragrant aroma of brown rice tea is enhanced by the present invention is not clear, and the present invention is not limited to the following assumptions, but when the raw material brown rice is impregnated with a specific amino acid and then roasted. It is speculated that this is because 2-methylbutanal and / or 3-methylbutanal, which are fragrant scents, are enhanced.

  The flavor improving action expressed by using leucine, valine and / or isoleucine is one selected from the group consisting of phenylalanine (Phe), glutamic acid (Glu), glycine (Gly), proline (Pro), and theanine (Theanine) By using the above amino acids in combination, a greater effect is obtained, and particularly effective for enhancing richness and sweetness. When one or more amino acids selected from the group consisting of phenylalanine, glutamic acid, glycine, proline and theanine are added without using leucine, valine and isoleucine, the effect of improving flavor is not obtained. It is considered that a specific amino acid (leucine, valine, isoleucine: amino acid A) and a specific amino acid (phenylalanine, glutamic acid, glycine, proline, theanine: amino acid B) function cooperatively.

  As the aqueous amino acid solution prepared in Step 8, a purified amino acid dissolved in water (or suspended) may be used, or a plant extract containing an amino acid may be used as it is or purified (crude). (Including purification). In the embodiment shown in FIG. 3, the green tea extract is used as an amino acid-containing solution, and the green tea extract is filtered and concentrated before impregnating brown rice. Here, a green tea extract is preferably exemplified as a plant extract containing amino acids. Usually, the green tea extract contains many amino acids such as theanine, glutamic acid, aspartic acid, and methionine. The amino acid (A) valine, leucine, and isoleucine, which are the active ingredients of the present invention, are compatible with these amino acids (A). It is known that the contents of amino acids (B) phenylalanine, glycine, and proline that act additively or synergistically to improve the starch-like glue feel are low. Therefore, when using a green tea extract, it is preferable to perform a treatment that increases the concentration of amino acid (A) or amino acid (B) by applying a physical or chemical treatment. Here, examples of the physical or chemical treatment include enzyme treatment, acid treatment, high-temperature and high-pressure treatment, miniaturization treatment, and ultrasonic treatment. Of these, enzyme treatment is preferable from the viewpoint of selectively controlling the reaction of amino acids.

  As the enzyme treatment of the green tea extract, any method can be used as long as the enzyme acts on proteins and fibers in the green tea leaves and / or tea extract to increase the amino acid concentration in the extract. But you can. For example, enzyme extraction (a method of extracting green tea leaves mixed with enzymes with water (hot water) or a method of extracting green tea leaves with water added with enzymes (hot water)), or green tea is more water (hot water) The method of adding and mixing an enzyme with the green tea extract extracted by (1) is mentioned. As the enzyme, protease, α-amylase, cellulase, hemicellulase, pectinase, protopectinase, glutaminase and the like can be used singly or in combination. The conditions for the enzyme treatment may be appropriately selected in view of the optimum conditions for the enzyme used.

  When a green tea extract is used as an aqueous amino acid solution, if a green tea extract containing a large amount of catechins is used, bitterness and astringency may be generated in the roasting process of the present invention, or a taste may be generated during heat sterilization in tea beverage production. There is a case. Therefore, the green tea extract used in the present invention is preferably subjected to a catechin removal process. Here, the catechins in the present specification represent a generic name of catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate. Specifically, in the green tea extract, the ratio of the total amount of catechins to the tea leaf-derived solid content is 15.0 wt% or less, preferably 13.5 wt% or less, more preferably 10.0 wt% or less, It is particularly preferably removed so as to be 8.0% by weight or less. In addition, the Brix (soluble solid component amount) of the tea extract is usually about 0.2 to 20%, preferably 5 to 20%, more preferably 10 to 20%. The method for removing catechins is not particularly limited. For example, a method for removing catechins from a green tea extract by resin (adsorption), an aqueous solvent is brought into contact with green tea leaves to obtain a green tea leaf extract, and then the extract is used. The method of removing (disposing) is mentioned. In particular, since catechins have the property of being easily extracted at high temperatures, a method of obtaining a high temperature extract by bringing high temperature water into contact with green tea leaves and removing (discarding) the high temperature extract is suitable.

(Manufacturing method of brown rice tea beverage)
The brown rice tea drink as used in this specification means the drink containing the extract obtained by extracting from the brown rice for brown rice tea obtained by this invention. A preferable embodiment includes a beverage obtained by mixing brown rice for brown rice tea obtained in the present invention with green tea and extracting it with water or warm water. At this time, the mixing ratio of brown rice and green tea is about 2: 8 to 8: 2, preferably 3: 7 to 8: 2, and more preferably about 4: 6 to 8: 2 in weight ratio.

  The brown rice used as a raw material for extracting brown rice tea beverages may be all of the brown rice subjected to the amino acid impregnation treatment of the present invention, or a portion of the brown rice subjected to the amino acid impregnation treatment, You may mix and use the thing which is not processing. Specifically, the brown rice for brown rice tea of the present invention is blended so as to be 10 to 100% by weight, preferably 50 to 100% by weight, based on the total amount of brown rice as an extraction raw material.

The green tea mixed with the brown rice for brown rice tea of the present invention is not particularly limited, and may be appropriately selected according to the desired flavor. Specifically, sencha, gyokuro, topped tea, roasted tea, deep-steamed tea, kettle roasted tea, tama green tea, strawberry tea, stem tea, matcha tea, powdered tea, and the like are selected.
Obtaining a brown rice tea beverage by extracting an extraction raw material in which brown rice and green tea are mixed with any water such as tap water or deionized water, preferably at an extraction water temperature of 75 to 100 ° C., preferably 80 to 95 ° C. Can do. At the time of extraction, it may or may not be stirred. The extraction ratio (weight ratio) is 5 to 150 parts, preferably 5 to 30 parts, of extraction water with respect to 1 part by weight of the extraction raw material. Moreover, although the extraction time in this invention is based also on extraction temperature, Preferably it is 3 to 60 minutes, More preferably, it is about 5 to 30 minutes.

  In a preferred embodiment, the extracted brown rice tea extract is immediately filtered in a stepwise manner using a wire mesh to remove residues such as tea husks, and the temperature is 10 to 40 ° C., for example, using a plate-type exchanger. Cooling. Furthermore, it is preferable to remove insoluble components using a continuous centrifugal separator or flannel filtration, and the centrifugal conditions are usually 4000 to 9000G. The centrifugal separator may be of any type, but preferably a three-phase centrifugal separator is preferable because oil components floating on the upper layer of the brown rice tea extract can be removed. Further, flannel filtration may be performed, for example, by using flannel cloth or the like.

  Thereafter, if necessary, an antioxidant or a pH adjuster such as L-ascorbic acid or sodium bicarbonate may be added to the obtained filtrate to adjust the pH to 5.0 to 7.0. The pH-adjusted extract may be diluted so that the soluble solid content (Brix) of the final preparation solution becomes a desired value (0.1 to 0.5) to adjust the solid content concentration.

  In a preferred embodiment, the sterilization treatment is performed on the preparation liquid thus obtained in order to improve the storage stability. The sterilization treatment may be performed after the preparation liquid is filled into a sealed container, or may be filled into the container after sterilization. A container is not specifically limited, A paper pack, a bottle, a can, a plastic bottle etc. are used. Sterilization may be appropriately selected according to the type of container and storage conditions, such as UHT sterilization, retort sterilization, and plate sterilization. Specifically, if the container can be sterilized by heating after filling into a container such as a can or bottle, retort sterilization is adopted under the sterilization conditions stipulated in the Food Sanitation Law, and retort sterilization is performed like a plastic bottle or paper pack. For those that cannot, pre-sterilization conditions similar to the above, for example after sterilization at high temperature and short time in a plate heat exchanger, cooled to a certain temperature, and filled into a container by a method such as hot pack filling or aseptic filling Such a method is adopted.

  It is known that brown rice tea beverages have a problem of having a paste-like texture as the starch component is extracted. In particular, in container-packed brown rice tea beverages that are refrigerated and stored at room temperature or lower (preferably 20 ° C. or lower, more preferably 15 ° C. or lower, particularly preferably 10 ° C. or lower), starch-derived stickiness is prominent. There is a problem that the taste and the aftertaste (clean taste) after drinking are impaired. On the other hand, the present inventors have found that 2-methylbutanal and / or 3-butanal has an effect of improving a sticky feeling (stickiness) derived from starch in beverages. In the brown rice for brown rice tea of the present invention, since 2-methylbutanal and / or 3-butanal is enhanced, the tea beverage of the present invention obtained by extracting this can be stored in a refrigerated state as a container-packed beverage. Even when it is drunk, the starch-derived glue-like sensation is reduced without deteriorating the fragrant fragrance, and it is produced as having an excellent flavor.

  This glue-like improvement effect is greater when one or more amino acids selected from the group consisting of phenylalanine, glutamic acid, glycine, proline and theanine are used in combination in the amino acid impregnation step in the production of brown rice for brown rice tea. Play. From the viewpoint of reducing the glue-like feeling derived from starch of this brown rice tea extract, in the amino acid impregnation step, in addition to at least one amino acid (A) selected from the group consisting of leucine, valine and isoleucine, phenylalanine and glutamic acid The raw brown rice is preferably impregnated with an aqueous solution containing one or more amino acids (B) selected from the group consisting of glycine, proline and theanine.

  Furthermore, the present inventors have found that 2-methylbutanal and / or 3-butanal has an action capable of masking an unfavorable flavor resulting from heat sterilization of a green tea extract. The brown rice tea beverage obtained by extracting from brown rice tea obtained by mixing 2-methylbutanal and / or 3-butanal-enhanced brown rice tea and green tea according to the present invention can be stored for a long period of time. Thus, it becomes a tea beverage having an excellent flavor masked with off-flavors such as a heated odor.

  From one viewpoint, the present invention can be understood as a method for improving the flavor of brown rice tea or brown rice for brown rice tea, and a method for reducing the sticky feeling of brown rice tea.

  EXAMPLES Hereinafter, although an Example is shown and the detail of this invention is demonstrated concretely, this invention is not limited to this. Unless otherwise specified in the present specification, the concentration and the like are based on weight, and the numerical range is described as including the end points.

Example 1. Production of Brown Rice Tea Beverage-Addition of Amino Acid Commercially available polished rice was used, soaked in water for 40 minutes, and steamed for 30 minutes in order to facilitate the penetration of moisture. This was sprayed with 1% aqueous solution of various amino acids so that the weight ratio of brown rice: amino acid aqueous solution was 0.2: 1 and then impregnated, and then a roasting machine (IC Electronics Co., Ltd. TORNADE KING TypeT) was used. It was roasted at 150 ° C. for 15 minutes to obtain brown rice for brown rice tea (roasted brown rice). Here, the amount of amino acid added to the brown rice is about 2000 mg / kg. As amino acids, (i) aspartic acid (Asp), (ii) glutamic acid (Glu), (iii) serine (Ser), (iv) glycine (Gly), (v) histidine (His), (vi) arginine ( Arg), (vii) threonine (Thr), (viii) alanine (Ala), (ix) proline (Pro), (x) theanine (xi) tyrosine (Tyr), (xii) valine (Val) (Xiii) Methionine (Met), (xiv) Isoleucine (Ile), (xv) Leucine (Leu), (xvi) Lysine (Lys), (xvii) Phenylalanine (Phe) L type). As a control, roasted brown rice was obtained in the same manner except that the amino acid impregnation step was not performed, that is, the amino acid aqueous solution was not sprayed.

  17 g roasted brown rice sprayed with amino acids and 2 g of roasted brown rice for comparison (no amino acid added) were lightened and extracted with 200 g of hot water (95 ° C.) for 5 minutes to extract (Brix: approx. 0.15) was obtained.

  As a result of sensory evaluation, it was found that Val, Ile, and Leu, which are neutral amino acids having an alkyl chain of 100 or more molecular weight, can enhance a fragrant fragrance that is perceived as preferable without a burning odor or miscellaneous taste. In particular, Leu became a brown rice tea extract with an excellent harmonious flavor with enhanced sweetness and richness as well as a fragrant scent. On the other hand, Phe was given a floral sweet scent, and Asp, Glu, Ser, Gly, His, Arg, Thr, Ala, Pro, Theanin, Tyr, and Lys were not different from the controls. In addition, Met developed a potato odor and became a less preferred flavor than the control.

Example 2 Manufacture of brown rice tea beverage-impregnation of tea extract (1) Manufacture of tea extract An extract containing an amino acid at a high concentration was manufactured by the following method. First, 10 g of green tea leaves (heating degree: medium) were sealed in an airtight container with a stirrer, and 180 mL of 40 ° C. ion exchange water was added to immerse the green tea leaves. Thereto was added 0.2 g of protease preparation (Mitsubishi Chemical Foods Co., Ltd. “Coclase P”), and the mixture was stirred for 16 hours while being kept at 40 ° C. to perform enzyme treatment. Thereafter, the obtained enzyme-treated solution was heated at 90 ° C. for 10 minutes to deactivate the enzyme to obtain an enzyme extract (sample A: with enzyme). Further, a green tea extract (tea extract) was similarly obtained except that no enzyme was added (sample B: no enzyme).

  The amino acid composition of Sample A and Sample B was analyzed by HPLC. Specific measurement conditions are as follows, and 18 kinds of amino acids (arginine, lysine, histidine, phenylalanine, tyrosine, leucine, isoleucine, methionine, valine, alanine, glycine, proline, glutamic acid, serine, threonine, asparagine as standard substances. Acid, tryptophan, cystine) and theanine were used.

  Table 2 and FIG. 4 show the amino acid analysis results of the tea extract. As is clear from FIG. 4, the ratio of Val, Ile, and Leu is increased in the tea extract (sample A) that has been subjected to enzyme treatment, compared to the tea extract that has not been subjected to enzyme treatment (sample B). When the ratio [(Val + Ile + Leu) / (Met)] with the amino acid Met expressing an unfavorable flavor in Example 1 was calculated, 0.16 was obtained when the enzyme treatment was not carried out, and 1.47 when the enzyme treatment was carried out. It became.

(2) Production of brown rice for brown rice tea impregnated with tea extract The tea extract (sample A) produced in (1) was converted into 17 kinds of amino acids (Asp, Glu, Ser, Gly, His, Arg, Thr, Concentrate under reduced pressure so that the total amount of Ala, Pro, Theanin, Tyr, Val, Met, Ile, Leu, Lys, Phe is 1% by weight with respect to the whole extract, and then concentrate the tea extract (Sample A ') Was prepared.

  Commercially available polished rice was prepared, immersed in water, drained after about 4 hours, and steamed with steam for 30 minutes. The steamed rice was sprayed with a concentrated tea extract (sample A ') at a weight ratio of 0.2: 1. At this time, the total amount of amino acids (the above 17 types) added to brown rice was 2000 mg / kg, of which the total amount of valine, isoleucine and leucine (Val + Ile + Leu) was 460 mg / kg.

After the amino acid impregnation step by spraying the tea extract, roasting was performed at 150 ° C or 230 ° C. As a control, roasted brown rice was produced in the same manner except that the tea extract was not sprayed. The roasting treatment conditions are as follows. In addition, the firing time refers to the time from when the amino acid-impregnated brown rice is put into the quenching machine until it is removed, and the firing temperature refers to the atmospheric temperature in the kettle of the firing machine.
・ Fire Maker: IC Electronics Co., Ltd. TORNADE KING TypeT
・ Taking time: 10 minutes ・ Taking temperature: 150 ℃, 230 ℃
(3) Manufacture of brown rice tea beverage 2 g each of roasted brown rice and control brown rice obtained by impregnating and roasting tea extract (sample A), and measuring 200 g For 5 minutes to obtain a brown rice tea beverage.

  Sensory evaluation was performed on a brown rice tea beverage at about 60 ° C. The fragrance, sweet scent (sweet scent), and dark odor are evaluated in four stages, and the evaluation criteria are as follows: No feel (0 points), Somewhat feel (1 point), Feel (2 points), Strongly feel (3 points) did. The results are shown in Table 3. In the control method, a sweet scent stands at a low firing temperature, but the fragrance is weak, and a high scent tends to give a burnt odor instead of a strong scent. could not. On the other hand, the method of the present invention, that is, roasted with the addition of the enzyme-treated green tea extract, is a large brown rice that has both aroma and sweet scent while having a small burnt odor, and has an excellent flavor. It became a drink.

Example 3 FIG. Production of Container-packed Brown Rice Tea Beverage Brown rice tea for brown rice tea obtained in Example 2 (2) (impregnated with a tea extract (sample A) as an amino acid and roasted) was used to prepare a container-packed brown rice tea beverage. Manufactured. That is, 7 g of a mixture of brown rice for brown rice tea obtained in Example 2 (2) and green tea (sencha) in a ratio of 5: 5 was weighed and extracted with 250 g of hot water for 5 minutes. After cooling to below ℃ and clarified by centrifugation, L-ascorbic acid is added to the obtained filtrate as an antioxidant and sodium bicarbonate is added as a pH adjuster to adjust the pH to 6.0. did. Thereafter, the pH-adjusted extract was made up to 1 L so that the soluble solid content (Brix) of the final preparation was 0.15. The obtained preparation was filled in a can, retort sterilized at 130 ° C. for 1 minute, and cooled in a refrigerator at 5 ° C. to obtain a container-packed brown rice tea beverage. In addition, a container-packed beverage was produced in the same manner using the control of Example 2 (2) as a control (roasted brown rice made in the same manner except that the tea extract was not sprayed).

  The container-packed brown rice tea beverage of the present invention is a brown rice tea beverage whose fragrance, sweetness and richness are enhanced even after sterilization, and the original fragrance of brown rice is balanced in a balanced manner. It has an excellent flavor that cannot be felt. In addition, brown rice tea beverages did not exhibit a paste-like texture (tackiness) even after refrigerated storage, and maintained excellent flavor and mouthfeel and aftertaste (clean taste) even after storage .

Claims (5)

A step of impregnating brown rice with an aqueous amino acid solution containing at least one amino acid (A) selected from the group consisting of leucine, valine and isoleucine, and a step of roasting the permeated brown rice at a temperature of 100 to 200 ° C. ,
A method for producing brown rice for brown rice tea. Raw brown rice 1kg per 45mg or more amino acids (A) Ru is impregnated into raw brown rice method according to claim 1.   The production method according to claim 1 or 2, wherein the aqueous amino acid solution is an extract of green tea leaves.   The production method according to claim 3, wherein the extract of green tea leaves is subjected to protease treatment. A step of impregnating raw brown rice with an aqueous amino acid solution containing at least one amino acid (A) selected from the group consisting of leucine, valine and isoleucine,
Roasting the osmotically treated brown rice at a temperature of 100 to 200 ° C.,
The step of mixing roasted brown rice and green tea in a weight ratio of 2: 8 to 8: 2, and the step of extracting with 5 to 150 parts by weight of water with respect to 1 part by weight of the mixture of roasted brown rice and green tea ,
A method for producing brown rice tea beverages.