JP6746672B2 - Method for producing purified pear juice - Google Patents

Description

The present invention relates to a method for producing a purified product of pear juice.

A method for separating a physiologically active substance from a pear plant is disclosed. In Patent Document 1, water is added to a crushed product of pear shoots of Pear for heat extraction, the filtrate is concentrated, ethanol is added and the mixture is centrifuged, and the obtained supernatant is passed through a column to obtain an arbutin fraction. It is described that the profit was obtained. In Patent Document 2, 70% hydrous ethanol solution was added to freeze-dried leaves of pear, homogenized, filtered to remove insoluble matter, and concentrated under reduced pressure to obtain an extract, which produced glutathione. It has been described that it had a promoting action. In Patent Document 3, dried bark or root powder of a pear plant was extracted with ethanol, concentrated under reduced pressure, and then separated by cellulose column chromatography, and the obtained fraction was useful for treating immunodeficiency syndrome. Is listed. In Patent Document 4, a liquid obtained by fermenting pear juice with lactobacillus, removing insoluble matter by filtration, and adding 1,3-butylene glycol had a retinol-related gene expression promoting action. Is listed.

On the other hand, one of the commonly used methods for extracting polysaccharide components from plants and fungi is ethanol precipitation. In Non-patent Document 1, ethanol was added to enzyme-treated fruit juices derived from Japanese pear and Chinese pear to precipitate precipitated polysaccharides, and the inhibitory activity of enzymes such as α-amylase in the aqueous polysaccharide solution was examined. Is listed. In Non-patent Document 2, ethanol is added to fruits such as pears, and the mixture is heated, homogenized and filtered, and an aqueous solution of ethanol is added to the residue, and the mixture is heated and filtered to obtain a residue again, and pectin and hemicellulose are contained. It is described that the polysaccharide was extracted. Non-Patent Document 3 describes that a polymeric substance is ethanol-precipitated from a culture filtrate of pear cells, and an arabinogalactan protein is separated from the obtained precipitate.

Catechins are a kind of polyphenol and have various physiological actions such as antioxidant action. However, a beverage containing a high concentration of catechins may have an unpleasant sensation or aversion, because the astringency derived from catechins is too strong. Conventionally, various means for suppressing the astringency of catechins have been studied. For example, Patent Document 5 describes that the astringency of a beverage containing a gallate-type non-polymer catechin is suppressed by adding fruit juice of a rose family plant such as pear.

JP, 2006-111581, A JP, 2010-105937, A Japanese Patent Publication No. 2017-510288 Japanese Patent No. 6377879 JP, 2018-000192, A

Food Research International, 2017, 102:156-162 Postharvest Biology and Technology, 2006, 40:141-148 Proc. Natl. Acad. Sci. USA, 1994, 91:10305-10309

There is a demand for an astringency inhibitor having a higher astringency suppressing action. Further, conventionally used astringency inhibitors including pear juice and the like (for example, those described in Patent Document 5), when used in a large amount, cause a catechin-containing food to have an unpleasant taste, thereby improving the flavor of the food. May have an adverse effect. There is a need for an astringency inhibitor that has little effect on the flavor of food. The present invention provides a method for producing a purified product of pear juice which has an action of suppressing the astringency of catechins and is less likely to give a harsh taste to foods.

The present inventor has found that a purified product of pear juice obtained by ethanol precipitation of pear juice under specific conditions has a high effect of suppressing the astringency of catechins. Further, the present inventor has found that the purified product of pear juice hardly causes an unpleasant taste when added to foods, and thus is suitable for suppressing the astringency of catechins in foods containing catechins.

Therefore, the present invention
Placing a mixed solution containing pear juice and ethanol at a low temperature to generate a precipitate, and
Collecting the resulting precipitate,
And a method for producing a purified pear juice product, wherein the ethanol concentration of the mixed solution is more than 50 v/v% to 70 v/v %.

According to the method of the present invention, it is possible to extract the astringency-suppressing component of pear juice, which was conventionally known as a catechin astringency suppressor. The purified pear juice obtained by the present invention is excellent in the action of suppressing the astringency of catechins, and is unlikely to cause an unpleasant taste when added to foods. Therefore, the purified pear juice product can suppress the unpleasant flavor of catechins in the food without lowering the flavor of the catechin-containing food.

The present invention provides a method for producing a purified pear juice product. The purified pear juice produced by the present invention is obtained by subjecting the pear juice to ethanol precipitation under specific conditions.

In the present specification, a pear refers to a pear of a species or variety belonging to Pyrus communis, and examples thereof include bartlett pear, Le Lectier, Claude Blanchet, cider pair and the like. Pears are a different species from Japanese pears and Chinese pears (Pyrus pyrifolia, Pyrus bretshneideri, etc.). In the method for producing a purified pear juice of the present invention, the pear juice as a raw material may be a juice of a species or a variety belonging to Pyrus communis, and any one of the species or a variety of juice may be used. A combination of two or more kinds of fruit juices or fruit juices may be used.

The pear juice, which is the raw material, is not particularly limited as long as it is manufactured from pear fruits by a conventional method. For example, the pear juice is juice that is squeezed by crushing or squeezing the pear fruit using a device such as a grinder, a mixer, a juicer, a grater, and a twin-screw extruder. It may be present, or fruit juice obtained by further removing skins and seeds from these juices by lining or the like, or clarified fruit juice may be prepared by a means such as centrifugation or filtration. Alternatively, commercially available pear juice may be used. As these pear juices, those produced by the above-mentioned ordinary method or commercially available products may be used as they are, or may be concentrated or diluted with water before use. For the concentration, it is preferable to use a concentration treatment such as boiling concentration, vacuum concentration, freeze concentration, or membrane concentration for removing water to maintain other components. In the present invention, it is preferable to use concentrated pear juice as the raw pear juice from the viewpoint of improving the yield of the target product of the purified pear juice. For example, the raw pear juice is preferably a pear juice concentrated to have a Brix value of about 60 to 70°Bx.

In the ethanol precipitation of the pear juice, a mixed solution containing the above-mentioned raw material pear juice and ethanol is placed at a low temperature to generate a precipitate, and then the obtained precipitate is recovered. The mixed solution used for the ethanol precipitation also contains water. The water contained in the mixed solution may contain water contained in the raw pear juice or water of an ethanol aqueous solution, or may be water added separately from them. In one example, the mixed solution can be prepared by mixing pear juice as a raw material with ethanol and water. In another example, the liquid mixture may be prepared by mixing raw pear juice with ethanol or an aqueous ethanol solution, and optionally with water. In any case, in the preparation of the mixed solution, it is preferable to sufficiently mix the contained components (raw pear juice, ethanol, and water as necessary) by stirring, shaking, stirring, or the like. The temperature of the liquid during the mixing is not particularly limited, and it is not necessary to heat or cool the liquid. For example, the mixed solution may be prepared at room temperature.

The ethanol concentration in the mixed solution is higher than 50 v/v%, preferably 60 v/v% or more, in order to secure the desired yield of the pear juice purified product. On the other hand, in order to retain the astringency suppressing effect of the purified pear juice product and to suppress the unpleasant taste of foods to which the purified product is added, the ethanol concentration in the mixed solution is 70 v/v% or less. Is preferred. Therefore, the ethanol concentration in the mixed solution is preferably more than 50 v/v% to 70 v/v%, more preferably 60 v/v% to 70 v/v%.

Further, the pear juice concentration in the mixed solution is preferably 5 v/v% to 30 v/v%, and more preferably 10 v/v% to 20 v/v%, in order to ensure the yield of the desired purified product of pear juice. preferable.

In the present specification, volume% (v/v%) represents a value calculated based on the volume at 25°C.

Ethanol precipitation of the pear juice is carried out at a low temperature, preferably at -20 to +5°C. For example, in the ethanol precipitation under the low temperature, the mixed solution is placed in a refrigerator or the like at a low temperature (preferably -20 to +5°C) atmosphere, or the mixed solution is cooled in a thermostat or the like (preferably -). It can be carried out by maintaining the temperature at 20 to +5°C. If the temperature during the ethanol precipitation is too low, the mixed solution may freeze. On the other hand, if the temperature is too high, the rate of precipitation formation may decrease, and a sufficient yield may not be secured.

On the other hand, the ethanol precipitation time is preferably 1 hour or more, and more preferably 24 hours or more in order to secure the desired yield of the purified pear juice product. However, if the time is too long, the taste of the food containing the purified product of the obtained pear juice may increase, so the ethanol precipitation time is preferably 7 days or less, more preferably 5 days or less. is there. Therefore, the ethanol precipitation time is preferably 1 hour to 7 days, more preferably 24 hours to 7 days, and further preferably 24 hours to 5 days. Alternatively, the ethanol precipitation time can be adjusted according to temperature conditions. For example, in consideration of the generation rate of the precipitate (yield of the target product), it can be adjusted to a longer time when the temperature is higher, and a shorter time when the temperature is lower.

Preferred examples of the conditions for ethanol precipitation according to the present invention are described below, but these conditions are merely examples and do not limit the conditions for ethanol precipitation according to the present invention.
Ethanol concentration in the mixture: more than 50 v/v% to 70 v/v%, pear juice concentration in the mixture: 5 v/v% to 30 v/v%, reaction temperature and time: -20 to +5°C for 1 hour to 7 days ,
Ethanol concentration in mixed solution: 60 v/v% to 70 v/v%, pear juice concentration in mixed solution: 5 v/v% to 30 v/v%, reaction temperature and time: -20 to +5°C for 24 hours to 7 days,
Ethanol concentration in mixed solution: 60 v/v% to 70 v/v%, pear juice concentration in mixed solution: 5 v/v% to 30 v/v%, reaction temperature and time: -20 to +5°C for 24 hours to 5 days,
Ethanol concentration in the mixed solution: 60 v/v% to 70 v/v%, pear juice concentration in the mixed solution: 10 v/v% to 20 v/v%, reaction temperature and time: -20 to +5°C for 24 hours to 5 days.
Preferably, the pear juice in the mixture is concentrated pear juice. More preferably, the pear juice in the mixture is concentrated pear juice at 60 to 70°Bx.

A precipitate is generated in the mixed solution by the ethanol precipitation. In the present invention, this precipitate is recovered from the mixed solution. For example, the precipitate may be separated and recovered from the mixed solution by filtration, decantation, centrifugation, or the like. The obtained precipitate may be washed with an aqueous ethanol solution or the like, if necessary. The recovered precipitate can be stored as it is, or can be used as an astringency suppressor described later, but if necessary, it may be prepared in the form of liquid, dried product or the like and stored or used. For example, a liquid obtained by dissolving or suspending the collected precipitate in ethanol or the like may be prepared, or a dried product may be prepared by a means such as freeze-drying.

The target pear juice purified product can be produced by the above procedure. The purified pear juice has an action of suppressing the astringency of catechins, and can be used as an astringency suppressor. In addition, the purified pear juice is less likely to give off taste to foods (including beverages) to which the pear juice is added, as compared with the raw pear juice, which is the original flavor of the food (for example, catechin-containing tea beverages). Tea-like flavor). Therefore, the purified pear juice product obtained in the present invention is suitable as an inhibitor of the astringency of catechins in foods containing catechins.

The "astringency" in the present specification refers to a feeling of numbness in the mouth, which is perceived by contraction of mucous membranes in the entire oral cavity other than taste buds and taste cells. Astringency is a sensation that is not included in the "taste" unlike the bitterness perceived by taste receptors. In fact, when astringent substances are continuously orally ingested, the astringency becomes stronger due to the accumulation of astringency in the oral cavity. On the other hand, bitterness does not occur even if the bitter substance is continuously orally ingested. As described above, it is generally known to those skilled in the art that astringency is a completely different feeling from bitterness.

In addition, the "miscellaneous taste" of the food in the present specification refers to a flavor that impairs the flavor originally required for the food or a flavor different from the flavor originally required for the food. For example, tastes and aromas such as sweetness, saltiness, sourness, bitterness, umami, spiciness, and astringency that are undesirably added to foods may cancel the original flavors of the foods or impart unexpected flavors. Therefore, the food may have a bad taste. In a more specific example, by adding a purified pear juice to a catechin-containing tea beverage, the tea-like flavor of the beverage is impaired, or a flavor different from the tea-like flavor is imparted to the beverage, Tea beverages have a "miscellaneous taste."

Non-polymer catechins are mentioned as the kind of catechins whose astringency is suppressed by the purified pear juice obtained in the present invention, and gallate-type non-polymer catechins are preferable. The "non-polymer catechins" in the present specification include catechin, gallocatechin, epicatechin and epigallocatechin, and their gallates. The “gallate-type non-polymer catechins” in the present specification include catechin gallate, gallocatechin gallate, epicatechin gallate and epigallocatechin gallate. These catechins can be extracted from tea leaves of the genus Camellia or are commercially available.

A catechin-containing beverage is preferable as the catechin-containing food to which the purified pear juice product obtained in the present invention is applied as a catechin-type astringency suppressor. The beverage may be a tea beverage or a non-tea beverage. Examples of tea beverages include green tea beverages, oolong tea beverages, and black tea beverages. Further, as non-tea drinks, for example, carbonated drinks, fruit juice, vegetable juice, sports drinks, isotonic drinks, enhanced water, bottled water, near water, coffee drinks, nutritional drinks, non-alcoholic drinks such as beauty drinks. Examples thereof include beverages and alcoholic beverages such as beer, wine, sake, plum wine, sparkling wine, whiskey, brandy, shochu, rum, gin, and liqueurs. The form of the beverage is not particularly limited, and may be liquid, gel, slurry or the like as long as it is easily ingested.

The content of the purified product of pear juice in the catechin-containing food may be an effective amount for suppressing the astringency of catechins, preferably, the effect of suppressing the astringency of catechins is obtained, and The amount is such that the taste of the purified fruit juice product is not perceived or gives an unpleasant taste. The content of the purified product of pear juice in the catechin-containing food can be appropriately set according to the type of the food and the astringency. In a preferred example, the content of the purified product of pear juice (dry matter conversion) in the catechin-containing food is 2.5 to 50 mass ppm in the total amount of the food, or the catechins 100 in the total amount of the food. It is 0.25 to 5 mass% per mass %. The content of the purified product of pear juice in a food product in terms of a dried product preferably means the mass when the purified product of pear juice is a freeze-dried product. However, as described above, the form of the purified pear juice added to the catechin-containing food is not limited to a freeze-dried product, and the precipitate recovered after the ethanol precipitation may be the precipitate as it is, or a liquid prepared from the precipitate. May be

The following compositions, manufacturing methods, uses or methods are further disclosed herein as exemplary embodiments of the present invention. However, the present invention is not limited to these embodiments.

[1] placing a mixed solution containing pear juice and ethanol at a low temperature to form a precipitate, and
Collecting the resulting precipitate,
A method for producing a purified pear juice product, which comprises:
[2] The ethanol concentration of the mixed solution is
Preferably more than 50 v/v% to 70 v/v%,
More preferably 60 v/v% to 70 v/v%,
The method according to [1].
[3] The method according to [1] or [2], wherein the low temperature is preferably -20 to +5°C.
[4] The time to keep the temperature low is
Preferably from 1 hour to 7 days,
More preferably 24 hours to 7 days,
More preferably 24 hours to 5 days,
The method according to any one of [1] to [3].
[5] The pear juice concentration in the mixed solution is
Preferably 5 v/v% to 30 v/v%,
More preferably 10 v/v% to 20 v/v%,
The method according to any one of [1] to [4].
[6] Preferably, the method according to any one of [1] to [5], wherein the precipitate is formed under the following conditions:
Ethanol concentration in the mixed solution: more than 50 v/v% to 70 v/v%, pear juice concentration in the mixed solution: 5 v/v% to 30 v/v%, reaction temperature and time: -20 to +5°C for 1 hour to 7 days ,
Ethanol concentration in the mixed solution: 60 v/v% to 70 v/v%, pear juice concentration in the mixed solution: 5 v/v% to 30 v/v%, reaction temperature and time: -20 to +5°C for 24 hours to 7 days,
Ethanol concentration in the mixed solution: 60 v/v% to 70 v/v%, pear juice concentration in the mixed solution: 5 v/v% to 30 v/v%, reaction temperature and time: -20 to +5°C for 24 hours to 5 days, Or
Ethanol concentration in the mixed solution: 60 v/v% to 70 v/v%, pear juice concentration in the mixed solution: 10 v/v% to 20 v/v%, reaction temperature and time: -20 to +5°C for 24 hours to 5 days.
[7] The method according to any one of [1] to [6], wherein the pear juice is preferably a concentrated pear juice, more preferably a concentrated pear juice of 60 to 70°Bx.
[8] The method according to any one of [1] to [7], wherein the purified product of pear juice has an action of suppressing the astringency of catechins.
[9] The catechins are
Preferably non-polymer catechins,
More preferably gallate type non-polymer catechins,
The method according to [8].
[10] The method according to any one of [1] to [9], wherein the purified product of pear juice is less likely to cause a peculiar taste in food compared to the pear juice.

Reference Example 1 Measurement of Astringency Intensity By varying the addition concentration of a catechin preparation (Teavigo, manufactured by DSM Nutrition, containing epigallocatechin gallate 94 mass% or more) stepwise as shown in Table 1, different astringency strengths can be obtained. 10 standard aqueous solutions were prepared. Four expert panelists selected a standard aqueous solution recognized by sensory evaluation from 10 types of standard aqueous solutions as having an astringency intensity equivalent to that of the test beverage. Regarding the astringency of the selected standard aqueous solution, the average value among the panelists was calculated and used as the value of the astringency of the test beverage.

Example 1 Preparation of purified pear juice (pear juice)
As the pear fruit juice, 6-fold concentrated pear fruit juice (obtained from Kyoka Inc., Brix 67.0, a product obtained by treating fruit juice with pectinase, filtering and then concentrating under reduced pressure) was used.

(Production Example 1 Production of pear juice 60% ethanol precipitate)
To 30 mL of 6-fold concentrated pear juice, 90 mL of ion-exchanged water and 180 mL of 99.5 v/v% ethanol were added and shaken. The obtained mixed solution was allowed to stand in a freezer at -20°C for 4 days, and then a precipitate was separated by centrifugation. The obtained precipitate was washed with 70 v/v% ethanol, dissolved in ion-exchanged water, and freeze-dried. The yield of the precipitate was 26.5 mg, and the yield was 0.066% by mass.

(Production Example 2 Production of pear juice 65% ethanol precipitate)
To 30 mL of 6-fold concentrated pear juice, 75 mL of ion-exchanged water and 195 mL of 99.5 v/v% ethanol were added and shaken. The obtained mixed solution was allowed to stand in a freezer at -20°C for 4 days, and then a precipitate was separated by centrifugation. The obtained precipitate was washed with 70 v/v% ethanol, dissolved in ion-exchanged water, and freeze-dried. The yield of the precipitate was 74.8 mg, and the yield was 0.19% by mass.

(Production Example 3 Production of pear juice 70% ethanol precipitate-1)
To 30 mL of 6-fold concentrated pear juice, 30 mL of ion-exchanged water and 140 mL of 99.5 v/v% ethanol were added and shaken. The obtained mixed solution was allowed to stand in a refrigerator at 4° C. for 4 days, and then the supernatant was removed by decantation to obtain a precipitate. The obtained precipitate was washed with 70 v/v% ethanol, dissolved in ion-exchanged water, and freeze-dried. The yield of the precipitate was 0.959 g, and the yield was 2.4% by mass.

(Production Example 4 Production of pear juice 70% ethanol precipitate-2)
To 30 mL of 6-fold concentrated pear juice, 30 mL of ion-exchanged water and 140 mL of 99.5 v/v% ethanol were added and shaken. The obtained mixed liquid was allowed to stand in a freezer at -20°C for 4 days, and then the supernatant was removed by decantation to obtain a precipitate. The obtained precipitate was washed with 70 v/v% ethanol, dissolved in ion-exchanged water, and freeze-dried. The amount of the precipitate was 2.75 g, and the yield was 6.9% by mass.

(Production Example 5 Production of 75% pear juice ethanol precipitate)
To 30 mL of 6-fold concentrated pear juice, 20 mL of ion-exchanged water and 150 mL of 99.5 v/v% ethanol were added and shaken. The obtained mixed solution was allowed to stand in a refrigerator at 4° C. for 4 days, and then the supernatant was removed by decantation to obtain a precipitate. The obtained precipitate was washed with 80 v/v% ethanol, dissolved in ion-exchanged water, and freeze-dried. The yield of the precipitate was 3.65 g, and the yield was 9.1% by mass.

(Comparative Example 1 Production of 50% pear juice ethanol precipitate)
To 30 mL of 6 times concentrated pear juice, 120 mL of ion-exchanged water and 150 mL of 99.5 v/v% ethanol were added and shaken. The obtained mixed liquid was allowed to stand in a freezer at -20°C for 5 days. However, no precipitate was produced.

Table 2 shows the production conditions of the precipitates obtained in Production Examples 1 to 5 and Comparative Example 1.

Example 2 Astringency control effect of purified pear juice (preparation of test beverage)
0.10% by mass of a catechin preparation (Teavigo, manufactured by DSM Nutrition, containing 94% by mass or more of epigallocatechin gallate), and the precipitates obtained in Production Examples 1 to 5 were ion-exchanged to 2.5 ppm by mass. It melt|dissolved in water and prepared the test drinks 1-5 as shown in Table 3.

(Measurement of astringency)
According to the procedure of Reference Example 1, the astringency of test beverages 1 to 5 was measured. The results are shown in Table 3. Beverages (Test Beverages 1 to 4) prepared by adding a precipitate of 70% or less of ethanol in Production Examples 1 to 4 had an excellent astringency suppressing effect.

Example 3 Flavor evaluation of beverage containing purified pear juice (preparation of test beverage)
The test beverages 1 to 5 were prepared by dissolving the precipitates obtained in Production Examples 1 to 5 in a green tea beverage (Helsia Green Tea a: Kao Co., Ltd., containing 540 mg of catechins in 350 mL) at a concentration of 25 mass ppm. .. Comparative beverage 1 was prepared by dissolving the 6-fold concentrated pear juice used in Example 1 in the same green tea beverage (Helsia green tea a) so that the concentration was 800 mass ppm.

(Flavor evaluation)
Regarding the test beverages 1 to 5 and the comparative beverage 1, sensory evaluation of astringency and sourness of each beverage was performed by four expert panelists according to the following evaluation criteria.
(astringency)
Each panelist evaluated whether the astringency was suppressed or not compared to Hercia green tea a. When the number of panelists who evaluated that the astringency was suppressed was 4 to 3, it was judged to be A, 2 to B, and 1 to 0 was C.
A: Astringency was suppressed B: Astringency was suppressed a little C: Astringency was not suppressed (miscellaneous)
Each panelist evaluated whether or not it sensed an unpleasant taste (reduction of tea-like flavor) as compared with Hercia green tea a, or not. When the number of panelists who evaluated that they did not feel a taste of miscellaneous taste was 4 to 3, the case was A, the case of 2 was B, and the case of 1 to 0 was C.
A: There is no taste B: There is some taste C: There is taste

The results are shown in Table 4. Tea beverages (test beverages 1 to 4) added with a precipitate of 70% or less of ethanol in Production Examples 1 to 4 are tea beverages (comparative beverage 1) to which pear juice as a raw material is added, and 75% of Production Example 5. The astringency was suppressed and the tea-like flavor was well maintained with less astringent taste, as compared with the tea beverage to which a precipitate due to ethanol was added (test beverage 5).

Claims (4)

Placing a mixed solution containing pear juice and ethanol at a temperature of −20 to +5° C. to form a precipitate, and
Collecting the resulting precipitate,
The method according to claim 1, wherein the pear juice has a Brix value of 60 to 70°, and the mixed solution has an ethanol concentration of more than 50 v/v% to 70 v/v%. The method according to claim 1, wherein the ethanol concentration of the mixed solution is 60 v/v% to 70 v/v%. The method according to claim 1 or 2 , wherein the time for which the temperature is kept at -20 to +5°C is 1 hour to 7 days. The pear juice concentration in the mixed liquid is 5v / v% ~30v / v% , any one method according to claim 1-3.