JP6224894B2 - Method for stabilizing chlorogenic acids - Google Patents

Description

  The present invention relates to a method for stabilizing chlorogenic acids.

  Chlorogenic acids are polyphenols abundantly contained in green coffee beans and the like, and have various physiological effects such as blood pressure lowering effects, and thus are used in supplements and foods and drinks. However, since chlorogenic acids are antioxidants, they are likely to deteriorate over time due to the influence of oxygen and the like, and the content of chlorogenic acids gradually decreases.

  Conventionally, as a method for suppressing deterioration of chlorogenic acids with time, for example, a method of adding a specific polyphenol fraction derived from a coffee extract in an acidic region around pH 6 has been proposed (Patent Document 1). On the other hand, there is a report that chlorogenic acid is isomerized to neochlorogenic acid having high antioxidant activity when subjected to alkali treatment at pH 10-12 (Patent Document 2).

JP 2011-83254 A JP 2000-63827 A

Coffee compositions containing chlorogenic acids extracted from coffee beans usually have liquidity in the acidic region. For this reason, the purification of chlorogenic acids is usually carried out in the acidic region, but as described above, the content of chlorogenic acids also decreases in the acidic region due to oxidative degradation. When the present inventors refined chlorogenic acids in the neutral region to the alkaline region, it was found that the decrease in the content of chlorogenic acids was more significant than in the acidic region.
Accordingly, an object of the present invention is to provide a method for stabilizing chlorogenic acids in a neutral region to an alkaline region.

  As a result of various studies in view of the above problems, the present inventors have improved the stability of chlorogenic acids in a chlorogenic acid-containing composition having a pH of 7 or more and 9 or less by coexisting chlorogenic acids and a specific organic solvent. I found out.

  That is, the present invention provides a method for stabilizing chlorogenic acids in a chlorogenic acid-containing composition having a pH of 7 or more and 9 or less, wherein chlorogenic acids and ethanol coexist.

  According to the present invention, chlorogenic acids in a chlorogenic acid-containing composition having a pH of 7 or more and 9 or less can be stabilized. Therefore, it is possible to apply a method for preserving chlorogenic acid-containing compositions, a purification method for chlorogenic acids, and the like in a neutral region to an alkaline region having a pH of 7 or more and 9 or less.

In the stabilization method of the present invention, chlorogenic acids and ethanol are allowed to coexist in a chlorogenic acid-containing composition having a pH of 7 or more and 9 or less.
Here, in this specification, “stabilization of chlorogenic acids” means that the decrease in the content of chlorogenic acids contained in the chlorogenic acid-containing composition is suppressed, and the residual rate of chlorogenic acids is increased.
In the present specification, “chlorogenic acids” means 3-caffeoylquinic acid, 4-caffeoylquinic acid and monocaffeoylquinic acid of 5-caffeoylquinic acid, 3-ferlaquinic acid and 4-ferlaquinic acid. And 5-ferlaquinic acid monoferlaquinic acid and 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid dicaffeoylquinic acid Is a general term. In the present invention, at least one of the nine chlorogenic acids may be contained.

  The chlorogenic acid-containing composition used in the present invention is not particularly limited as long as it contains chlorogenic acids. However, since chlorogenic acids are abundantly contained in coffee beans, a coffee extract extracted from coffee beans is used. be able to.

  Examples of coffee bean species used for extraction include arabica species, robusta species, and reberica species. There are no particular restrictions on the coffee beans production area, and examples include Brazil, Colombia, Tanzania, Mocha, Kilimangelo, Mandelin, Blue Mountain and the like. One kind of coffee beans may be used, or a plurality of kinds may be blended.

  The coffee beans used for extraction may be roasted coffee beans or green coffee beans. The roasting degree of roasted coffee beans is not particularly limited, and shallow roasting or deep roasting may be used and can be selected as appropriate. In addition, there is no restriction | limiting in particular in the roasting method of coffee beans, and there is no restriction | limiting also about a roasting temperature and a roasting environment, A normal method can be employ | adopted.

  The coffee extract preferably uses 1 g or more, further 2.5 g or more, and further 5 g or more of coffee beans in terms of green beans per 100 g of the coffee extract. The extraction method and extraction conditions are not particularly limited, and can be performed by known methods and conditions. For example, the method and conditions described in JP-A-2009-153451 can be employed.

  Moreover, what was refine | purified as a coffee extract can also be used. Examples of the purification method include a method of removing turbid components by dispersing in a mixed solvent of an organic solvent and water, a method of contacting with an adsorbent such as activated carbon, acidic clay, activated clay, etc. It is also possible to carry out a combination of two or more. As an organic solvent, a hydrophilic organic solvent is preferable, alcohol is more preferable, and ethanol is still more preferable. The organic solvent used for purification is preferably removed by distillation or the like. For specific purification operations, for example, descriptions in JP-A Nos. 2004-222719 and 2006-174746 can be referred to.

  When a coffee extract is used as the chlorogenic acid-containing composition, various forms such as an aqueous solution, a slurry, and a solid can be used. Among these, an aqueous solution is preferable. In addition, when the organic solvent is contained as a solvent, the said organic solvent can be removed by distillation etc., and a solvent can be substituted for water as needed. In the present invention, as water, for example, ion exchange water, distilled water, natural water, tap water and the like can be appropriately selected and used.

  Moreover, as a chlorogenic acid containing composition, it is possible to use 1 type, or 2 or more types of commercially available chlorogenic acid reagents, and it may mix and use the above-mentioned coffee extract. When using 1 type, or 2 or more types of commercially available reagent, the said reagent can be melt | dissolved and used for water. As a commercially available reagent, for example, 5-caffeoylquinic acid can be obtained from CAYMAN CHEMICAL COMPANY.

  The content of chlorogenic acids in the chlorogenic acid-containing composition is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 7% by mass or more, and 20% by mass or less from the viewpoint of operability. Is preferable, 15 mass% or less is more preferable, and 10 mass% or less is still more preferable. The content of chlorogenic acids is defined based on the total amount of the above nine types, and the analysis of chlorogenic acids follows the method described in “Analysis of chlorogenic acids” in the Examples below.

  The pH (20 ° C.) of the chlorogenic acid-containing composition is 7 or more and 9 or less, but is preferably 7.2 or more, more preferably 7.3 or more, from the viewpoint of further improving the stability of chlorogenic acids. 4 or more is more preferable, and 8.7 or less is preferable, 8.5 or less is more preferable, 8.4 or less is more preferable, and 8 or less is still more preferable.

  In general, alkali can be used to adjust the pH of the chlorogenic acid-containing composition. Examples of the alkali include alkali metal hydroxides and alkaline earth metal hydroxides. Of these, alkali metal hydroxides are preferred. The alkali metal hydroxide is an alkali metal hydroxide such as potassium, lithium, or sodium, and specifically includes potassium hydroxide, lithium hydroxide, sodium hydroxide, or the like.

  In adjusting the pH, the alkali may be used as it is or may be dissolved in water and used in the form of an aqueous solution. In addition, the usage-amount of an alkali can be suitably set so that pH of a chlorogenic acid containing composition may become a desired value.

  In the stabilization method of the present invention, ethanol is allowed to coexist with chlorogenic acids in the chlorogenic acid-containing composition, but ethanol is not particularly limited as long as it is ethanol that is generally used for food industry applications. For example, commercially available products such as industrial alcohol, 99.5 v / v% reagent, 95 v / v% reagent, Japanese Pharmacopoeia standards, and the like can be used, and these can be appropriately selected and used.

  The content of ethanol in the chlorogenic acid-containing composition is preferably 5% by mass or more, more preferably 7% by mass or more, further preferably 10% by mass or more, from the viewpoint of improving the stability of chlorogenic acids, and 70 % By mass or less is preferable, 65% by mass or less is more preferable, and 60% by mass or less is more preferable.

  The temperature when chlorogenic acids and ethanol coexist is preferably 50 ° C. or lower, more preferably 40 ° C. or lower, further preferably 30 ° C. or lower, more preferably 10 ° C. or higher, and preferably 15 ° C. or higher from the viewpoint of operability. More preferred is 20 ° C. or higher.

As preferable embodiments, the following (i) and (ii) can be mentioned.
(I) When the pH of the chlorogenic acid composition is 7 or more and 8 or less, the ethanol content in the chlorogenic acid composition is preferably 10% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 65% by mass or less. 20 mass% or more and 60 mass% or less are still more preferable.
(Ii) When the pH of the chlorogenic acid composition is more than 8 and 9 or less, the content of ethanol in the chlorogenic acid-containing composition is preferably 5% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 40% by mass or less. More preferably, 5 mass% or more and 30 mass% or less are more preferable, 5 mass% or more and 25 mass% or less are more preferable, and 10 mass% or more and 20 mass% or less are still more preferable.

In the stabilization method of the present invention, the form is not particularly limited as long as chlorogenic acids and ethanol coexist in the chlorogenic acid-containing composition having a pH of 7 or more and 9 or less. For example, the following (1) ) To (8).
(1) A method of adding ethanol after adjusting the chlorogenic acid-containing composition to a predetermined pH.
(2) A method in which ethanol is added to a chlorogenic acid-containing composition to adjust to a predetermined pH.
(3) A method in which a chlorogenic acid-containing composition is added to ethanol and adjusted to a predetermined pH.
(4) A method of simultaneously mixing a chlorogenic acid-containing composition and ethanol and adjusting pH.
(5) A method of adding ethanol after dissolving chlorogenic acids in water and adjusting to a predetermined pH.
(6) A method of adjusting chlorogenic acids to a predetermined pH after dissolving ethanol in water and adding ethanol.
(7) A method in which chlorogenic acids, ethanol, and water are simultaneously added and mixed, and then adjusted to a predetermined pH.
(8) A method of simultaneously mixing chlorogenic acids, ethanol and water and adjusting pH.
In the above-described embodiments (1) to (8), hydrous ethanol may be added instead of ethanol.

1. Analysis of chlorogenic acids A sample was diluted with distilled water, filtered through a membrane filter (pore size 0.45 μm), and then a high performance liquid chromatograph (manufactured by Hitachi, Ltd.) was used. The model numbers of the unit units are as follows.
Liquid feed unit (built-in degasser): L-2130
Autosampler (with cooler): L-2200
Column oven: L-2300
Separation column: Cadenza CD-C18, Size: 4.6 mm i. d. × 150mm, 3μm (Intact Corporation)
Detector (UV-visible spectrophotometer): L-2420

  The measurement was performed at a column temperature of 35 ° C. by a gradient method using liquid A and liquid B. The mobile phase A solution was prepared by adding 5% acetonitrile containing 0.05 mol / L acetic acid, 0.01 mol / L sodium acetate, and 0.1 mmol / L HEDPO (1-hydroxyethane-1,1-diphosphonic acid) to the B solution. Was acetonitrile, the sample injection volume was 10 μL, and the UV detector wavelength was 325 nm. The gradient conditions are as follows.

(Retention time of chlorogenic acids)
3-caffeoylquinic acid (3-CQA): 5.2 min,
5-caffeoylquinic acid (5-CQA): 8.7 min.
4-caffeoylquinic acid (4-CQA): 11.2 min.
3-ferlaquinic acid (3-FQA): 12.6 min.
5-ferlaquinic acid (5-FQA): 19.1 min.
4-ferlaquinic acid (4-FQA): 20.9 min,
3,5-dicaffeoylquinic acid (3,5-diCQA): 37.0 min,
3,4-dicaffeoylquinic acid (3,4-diCQA): 37.5 min,
4,5-dicaffeoylquinic acid (4,5-diCQA): 44.8 min
From the area percentage obtained here, chlorogenic acids were quantified using 5-CQA as a standard substance.

2. Analysis of ethanol The analysis of ethanol was performed according to the gas chromatographic method shown below.
GC-14B (manufactured by Shimadzu Corporation) was used as an analytical instrument. The apparatus configuration of the analytical instrument is as follows.
・ Detector: FID
・ Column: Gaskuropack55, 80-100mesh, φ3.2mm × 3.1mm

The analysis conditions are as follows.
・ Temperature: Sample inlet and detector 250 ℃, column 130 ℃
・ Gas pressure: Helium (carrier gas) 140kPa, hydrogen 60kPa, air 50kPa
・ Injection volume: 2μL

A sample for analysis was prepared by the following procedure.
A sample (5 g) was weighed, and water was added thereto to make a constant volume of 25 mL. The solution was subjected to disk filtration to obtain a sample solution. The prepared sample solution was subjected to gas chromatographic analysis.

Production Example 1
Production of Chlorogenic Acids-Containing Composition Robusta coffee beans were extracted with hot water, and the resulting extract was dried to obtain a powdered chlorogenic acid-containing composition A. A chlorogenic acid-containing slurry was obtained by mixing the chlorogenic acid-containing composition A with 4-fold mass of hydrous ethanol. The ethanol concentration in hydrous ethanol was 60.0% by mass. Next, after the chlorogenic acid-containing slurry was filtered with a filter paper, ethanol was distilled off with a rotary evaporator to obtain a chlorogenic acid-containing composition B. The content of chlorogenic acids in the chlorogenic acid-containing composition B was 25.9% by mass, and the pH (20 ° C.) was 5.3.

Example 1
In the chlorogenic acid-containing composition B obtained in Production Example 1, ion-exchanged water and 95 v / v% ethanol (first grade, Kanto) were used so that the chlorogenic acid concentration was 8.5% by mass and the ethanol concentration was 60% by mass. Then, the pH was adjusted to 7.5 with a 30% by mass aqueous sodium hydroxide solution to obtain a chlorogenic acid-containing composition. And the obtained chlorogenic acid containing composition was stirred with the magnetic stirrer at 25 degreeC for 6 hours. After 6 hours, the chlorogenic acid concentration in the chlorogenic acid-containing composition was measured, and the residual ratio of chlorogenic acids was calculated. The evaluation results are shown in Table 2.

Examples 2-4
Evaluation was carried out in the same manner as in Example 1 except that the ethanol concentration shown in Table 2 was changed. The evaluation results are shown in Table 2.

Comparative Example 1
Evaluation was performed in the same manner as in Example 1 except that ethanol was not added. The evaluation results are shown in Table 2.

Example 5
Evaluation was performed in the same manner as in Example 1 except that the pH of the chlorogenic acid-containing composition was adjusted to 8. The evaluation results are shown in Table 3.

Examples 6-8
Evaluation was performed in the same manner as in Example 5 except that the ethanol concentration shown in Table 3 was changed. The evaluation results are shown in Table 3.

Comparative Example 2
Evaluation was performed in the same manner as in Example 5 except that ethanol was not added. The evaluation results are shown in Table 3.

Example 9
Evaluation was performed in the same manner as in Example 1 except that the pH of the chlorogenic acid-containing composition was adjusted to 9. The evaluation results are shown in Table 4.

Examples 10-13
Evaluation was carried out in the same manner as in Example 9 except that the ethanol concentration shown in Table 4 was changed. The evaluation results are shown in Table 4.

Comparative Example 3
Evaluation was performed in the same manner as in Example 9 except that ethanol was not added. The evaluation results are shown in Table 4.

  From Tables 2 to 4, it was found that the stability of chlorogenic acids in a neutral region to an alkaline region from pH 7 to 9 was maintained by allowing chlorogenic acids to coexist with ethanol.

Claims (4)

A method for stabilizing chlorogenic acids in a chlorogenic acid-containing composition having a pH of 7 or more and 9 or less,
A stabilization method in which the pH and the ethanol content of the chlorogenic acid-containing composition are adjusted so as to be any one of the following embodiments, and then allowed to elapse for 6 hours.
(1) when the pH is 7 to 8, the Ru der 10 wt% to 70 wt% content of the ethanol of the chlorogenic acid-containing composition.
(2) When the pH is more than 8 and 9 or less, the content of ethanol in the chlorogenic acid-containing composition is 5% by mass or more and 50% by mass or less .   The stabilization method according to claim 1, wherein the content of chlorogenic acids in the chlorogenic acid-containing composition is 3% by mass or more and 20% by mass or less.   The stabilization method of Claim 1 or 2 whose content of ethanol in a chlorogenic acid containing composition is 15 to 65 mass% when pH is 7 or more and 8 or less.   The stabilization method according to any one of claims 1 to 3, wherein when the pH is more than 8 and 9 or less, the content of ethanol in the chlorogenic acid-containing composition is 5 mass% or more and 40 mass% or less.