JPH1194812A - Detection of diols in beverage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and simply analyze diols such as propylene glycol or the like by supplying a sample of a beverage or the like to a solid phase extraction column and eluting an adsorbing substance by an org. solvent to appropriately treat the same to measure the eluted and treated substance by gas chromatography or the like. SOLUTION: For example, an internal standard or ammonium sulfate is added to beer from which carbon dioxide is preliminarily removed to prepare a sample soln. and, for example, Extrelut (registered trademark) is used to supply the sample soln. After the sample soln. is appropriately held, for example, it is eluted by ethyl acetate/ethanol (80:20) and the eluate is evaporated to dryness to be dissolved in ethanol and this soln. is analyzed by capillary gas chromatography. This method can be adapted to propylene glycol, ethylene glycol, butane diol or the like and, for example, by measuring propylene glycol using ethylene glycol as an internal standard, the mixing with propylene glycol frequently used as a cooling medium in a beer producing process can be accurately inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting diols in a beverage and a method for detecting diols from beer.

[0002]

BACKGROUND ART In addition to decomposing sugars such as glucose to produce ethanol and carbon dioxide, yeast converts a small amount of various substances contained in fermentation products and raw materials by a complex metabolic mechanism. , Giving the brew a unique flavor. Beer yeast fermentation products have an important role in beer flavor and are compounds of interest in beer quality control. Pyruvic aldehyde and hydroxyacetone (acetole) contained in wort are converted to propylene glycol (1,2-
(Propanediol).
(Hardwick, BC, et al: JA)
m. Soc. Brew. Chem. , 34 , 65-67
(1976); Markl, K .; S. and Pala
mand, S.M. R. : J. Am. Soc. Brew. C
hem. , 36 , 56-58 (1976); Gueth
er, V .; H. et al. : Angew. Chem.
95 , 325-326 (1993)).

[0003] On the other hand, propylene glycol is widely used as a refrigerant in a cooling device in various brewing processes including beer. In the beer brewing process, since it is used for cooling the wool cooling plate cooler and fermentation, storage, and filtration tanks, when cracks or pinholes occur in these cooling devices, the refrigerant propylene glycol is used. May leak and mix into beer.

Conventionally, for analysis of propylene glycol mixed in beer, a method has been used in which propylene glycol is extracted from beer and detected by gas chromatography. To extract propylene glycol from beer, beer is saturated with ammonium sulfate, acetone is added, and the organic layer is recovered after shaking and liquid separation.
There is no known method other than concentration.

[0005]

However, in the above method, the extraction operation is not simple, and the extraction efficiency is not always satisfactory. The reason is that it is difficult to extract a water-soluble substance such as propylene glycol from an aqueous solution with an organic solvent. Furthermore, when extracting from a sample containing various components such as beer, it is difficult to extract between an organic solvent layer and an aqueous layer. This is considered to be due to the formation of an emulsion and difficulty in completely separating the two layers. Accordingly, an object of the present invention is a beverage containing diols including propylene glycol,
Particularly, it is an object of the present invention to provide a method for efficiently and easily extracting and detecting diols from beer.

[0006]

Means for Solving the Problems In view of the above situation, the present inventors have conducted intensive studies. As a result, a beverage containing diols was subjected to a solid phase extraction column, and eluted and concentrated with an organic solvent. It has been found that diols can be extracted efficiently and easily, and the present invention has been completed.

That is, the present invention provides a beverage containing a diol, which is subjected to a solid phase extraction column, eluted and concentrated with an organic solvent, and the diol is detected from an extract obtained by concentration. Is a detection method. Further, a method for detecting a diol in a beverage, wherein at least one of diols of propylene glycol, ethylene glycol, and butanediol is detected, a method for detecting a diol in which the beverage is beer, and a method for detecting a diol in a beverage. This is a method for detecting diols in which the phase extraction column is Extrelut (r) Column.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Drinks that can be used in the analysis of the present invention include beer, sake, whiskey, wine and other liquors including liqueurs, fruit juices, carbonated beverages, carbonated beverages containing fruit juices,
Beverages such as coffee beverages. In particular, the present invention is suitable for efficiently and conveniently extracting propylene glycol in beer. Also, not only product beer, wort which is a semi-finished product obtained in the process of beer brewing,
It can also be applied to young beers and the like.

3m beer with degassed carbon dioxide
Take 1 and saturate by adding 2 g of ammonium sulfate.
The addition of ammonium sulfate facilitates separation between the organic solvent and the aqueous phase. 0.5 ml of an ethylene glycol aqueous solution (1500 ppm) was added as an internal standard,
Use as a sample solution. To complete the present invention, in order to study the extraction conditions and the like for obtaining an optimum recovery rate of propylene glycol in beer, 60 μg of propylene glycol was added together with an internal standard to prepare a sample solution, and an addition recovery experiment was performed. Next, the sample solution is applied to a solid phase extraction column, held for 15 minutes, and sufficiently adsorbed to the column carrier.
This was eluted using a predetermined amount of an organic solvent. The obtained eluate is concentrated by a predetermined method, dissolved in an organic solvent, and used as an analysis sample. This analysis sample is analyzed by gas chromatography to measure the amount of propylene glycol in the beer.

Various solid phase extraction columns are commercially available. About 20 cm length molded with glass or porous resin,
A column with a diameter of about 2 cm is uniformly filled with a carrier that has the ability to adsorb organic substances based on silica gel.One of the columns has a narrow mouth, and the elution that has passed through the adsorbent by flowing an organic solvent from the other The liquid falls at a constant speed. There is no particular limitation on the use of a commercially available solid phase extraction column, but particularly preferred is Extre.
lut (registered trademark) Column (manufactured by Merck). Regarding the solid phase extraction method using Extrelut (registered trademark) Column, simultaneous determination of nicotine and cotinine in urine (Hiroshi Mizunuma, Yasuko Hirayama, Satoshi Sakurai, Nobuo Ikegawa: Sanitary Chemistry, 28 , 13-17 (1982)) Determination of D2 nicotine in blood, urine and plasma samples (Eigo Higashi, Fumiko Sashikuma,
Shunro Itani, Hideo Muranaka: Sanitary Chemistry, 32 , 276-28
0 (1986)), determination of diethylene glycol in wine (Uchiyama, S., Kawamura,
Y. , Maitani, T .; Suzuki, T .; , I
Shikawa, T .; , Saito, y. ,: J. Foo
d. Hyg. Soc. Japan. , 28 , 283-2
87 (1986)). Extrelu
t (R) Column is a column packed with diatomaceous earth, which allows the water in the sample to be retained on the porous surface to form a stationary phase, while at the same time retaining many compounds dissolved in water on the column. it can. Next, elution using an organic solvent as a mobile phase enables extraction from the stationary phase, and allows the target compound to be efficiently extracted without involving an emulsion or the like generated during liquid-liquid extraction.

The organic solvent used for eluting the adsorbed components after adsorbing the sample on the solid phase extraction column includes ethyl acetate, diethyl ether, dichloromethane, and chloroform, with ethyl acetate being particularly preferred. Hexane has no extractive power. In addition, by combining the organic solvents described on the left, for example, a mixed solvent of ethyl acetate and diethyl ether can be used. More preferred is a mixed solvent of ethyl acetate and alcohol. Examples of the alcohol include ethanol, propanol, isopropanol, and n-butanol, and ethanol is particularly preferable. Furthermore, the mixing ratio of ethyl acetate and ethanol is 80: 2
0 (V / V) is optimal, indicating the highest propylene glycol recovery. However, if the proportion of ethanol is further increased, water adsorbed on the stationary phase elutes, and does not give a favorable result.

The amount of the eluate is preferably 10 to 30 ml, and most preferably 20 ml. When the liquid volume is less than 10 ml, the recovery rate drops extremely. Concentration of the eluate can be carried out by a conventional method of concentration such as drying under reduced pressure by an evaporator or drying by bubbling nitrogen gas to evaporate. Drying under reduced pressure by an evaporator is preferred. A certain amount of an organic solvent is added to the residue after drying to obtain an analysis sample. As the organic solvent used at that time, ethanol, ethyl acetate,
Diethyl ether, dichloromethane and the like can be mentioned, but ethanol is most suitable.

The measurement of propylene glycol in the analytical sample prepared by the above process can be analyzed by a conventional gas chromatography. Further, capillary gas chromatography using a capillary column coated with a fused silica gel such as DB-WAX is convenient.

Although the embodiment of the present invention has been described above, the compound to be extracted can be applied not only to propylene glycol but also to other glycols such as ethylene glycol and butanediol. In the method of the present invention, ethylene glycol is used as an internal standard,
As described in the Examples, excellent results were obtained in the recovery rate of ethylene glycol as in propylene glycol. It was also confirmed that diols contained in beer such as 1,2-butanediol can be efficiently extracted.

[0015]

By using the method for detecting diols from beverages of the present invention, diols can be efficiently and simply detected from various beverages such as beer. Among them, propylene glycol is frequently used as a refrigerant particularly in the process of producing beer, and the refrigerant may be mixed into products for some reason. From the viewpoint of quality control of beer, discovery of the mixture of refrigerant is an important inspection item, and the method of the present invention is a method that greatly contributes to improving the accuracy of the inspection.

[0016]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Comparative Example Extraction of Propylene Glycol by Acetone Liquid-Liquid Extraction Method (Conventional Method) 10 ml of acetone was added to a sample obtained by adding 2 mg of propylene glycol to 100 ml of beer, and then 50 ppm of an ethylene glycol solution was added as an internal standard, followed by shaking for 5 minutes. did. After standing, 10 ml of the supernatant was collected in a Spitz tube and centrifuged. 4 ml of the supernatant was collected, dried under reduced pressure with an evaporator, redissolved in 2 ml of dichloromethane, and subjected to gas chromatography analysis. Recovery rate 5%
Met. The analysis conditions are shown below. The analysis of propylene glycol in the present invention was all performed by this method. <Measurement of Propylene Glycol by Gas Chromatography> Propylene glycol in the analytical sample prepared by the above method was measured under the following conditions.

Apparatus: Gas chromatograph HP5890 with FID detector (manufactured by Hewlett Packard) Column: DB-WAX (0.25 mm id × 30 m, 0.25 μm FT) (manufactured by J & W) Linear velocity: 38 cm / s (Head pressure 150 KPa) Injection inlet temperature: 230 ° C Detector temperature: 250 ° C Injected sample volume: 2 μl (splitless) Temperature rising condition: After maintaining the sample at 40 ° C for 5 minutes after injection, at 4 ° C per minute The temperature was raised to 150 ° C. Next, the temperature was raised to 230 ° C. at 10 ° C./min and maintained for 10 minutes.

Example 1 Extrelut (registered trademark)
Extraction of Propylene Glycol by Column The examination of the extraction conditions of propylene glycol by Extrelut (registered trademark) Column is described below. (1) Selection of Extraction Solvent First, a solvent that efficiently elutes propylene glycol retained in Extrelut (registered trademark) Column was examined. A known amount (60
μg) of propylene glycol, 2 g of ammonium sulfate, and an ethylene glycol aqueous solution (1500 pp) as an internal standard.
m) 0.5 ml was added to prepare a sample solution. Sample solution E
The sample was subjected to xtrelut (registered trademark) Column for 15 minutes and then eluted with 20 ml of a commonly used solvent, and the recovery of the added propylene glycol was investigated. As a result, the recovery in ethyl acetate was 42%. In order to further increase the elution efficiency, a similar recovery test was performed using a mixed solvent obtained by adding another solvent based on ethyl acetate. As shown in Table 1, ethyl acetate-ethanol (80:20) was used.
The highest recovery rate was 95%. Similarly, the internal standard ethylene glycol was obtained with the highest recovery.
To investigate the optimal composition ratio of ethyl acetate-ethanol,
3 ml of beer to which a known amount (60 μg) of propylene glycol is added is supplied to the column, and various solvents 2 having different composition ratios are added.
After elution with 0 ml, quantification was performed by gas chromatography, and the obtained peak areas were compared. Elution with ethyl acetate-ethanol (65:35) gave the largest peak area. However, when a mixed solvent containing 25% or more of ethanol was used, the stationary phase of Extrelut (registered trademark) Column was obtained together with the target component. It was found that a part of the aqueous phase also eluted. Therefore, ethyl acetate-ethanol (80:20), in which the stationary phase aqueous phase is less eluted and propylene glycol is efficiently recovered, was selected as the elution solvent.

[0019]Table 1 Recovery rate of propylene glycol and internal standard by elution solvent Elution solvent Propylene glycol Internal standard (Ethylene glycol) Recovery rate (%) Recovery rate (%) Hexane 00 chloroform 10 6 dichloromethane 90 diethyl ether 23 16 ethyl acetate 42 22 ethyl acetate-diethyl ether 36 17 (50:50) ethyl acetate-isopropyl alcohol 69 59 (50:50) diethyl ether-ethanol 92 70 (80: 20) Ethyl acetate-diethyl ether 97 95(80:20)

(2) Optimization of elution amount Using the above ethyl acetate-ethanol (80:20),
The elution amount was changed to six stages of 3 to 30 ml, and the recovery rate of propylene glycol retained in the column was examined for each. It was found that almost all of the propylene glycol retained in the column was eluted with 20 ml of ethyl acetate-ethanol (80:20).

(3) Establishment of Extraction Method Based on the results obtained above, a method of extracting propylene glycol from beer using Extrelut (registered trademark) Column was established as follows. Degassing beer 3
ml, 2 g of ammonium sulfate, and 0.5 ml of an ethylene glycol aqueous solution (1500 ppm) as an internal standard were added to prepare a sample solution. The sample solution was transferred to Extrelut (registered trademark) Col.
Then, the mixture is kept for 15 minutes, eluted with 20 ml of ethyl acetate-ethanol (80:20), and the eluate is dried under reduced pressure using an evaporator. 1 ml of the obtained residue in ethanol
And dissolved to obtain an analysis sample.

Example 2 Preparation of propylene glycol standard curve by standard addition method 5 to 2 ml of propylene glycol standard solution was added to 3 ml of beer.
0 ppm was added, and the peak area of propylene glycol relative to the internal standard was determined from the obtained chromatogram. As a result, a linear calibration curve could be created. The regression line of propylene glycol obtained by the least square method is y
= 0.307 × (y: internal standard ratio of propylene glycol to internal standard, x: propylene glycol concentration, r ²
= 0.999). Also, a known amount (60 μg) of propylene glycol was added to 3 ml of beer, and the analysis was repeated (n = 5, 3 days) by this method, and the accuracy was examined. As a result, the daily accuracy was a good 6.8% in terms of variation coefficient. Accuracy was obtained. Similarly, a known amount (60 μg) of propylene glycol was added to 3 ml of wort, and the analysis was repeated (n = 3) by this method. The intra-day precision was 7.1%, which was a good precision with a variation coefficient of 7.1%.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Kaori Kikuchi, Inventor 1-1-21 Midori, Moriya-cho, Kitasoma-gun, Ibaraki Prefecture Asahi Breweries, Ltd. 1-11 Uemaebata, Arai-cho, Amachi-cho Asahi Breweries, Ltd.

Claims (4)

[Claims] 1. A method for detecting diols in a beverage, wherein the diol is detected from an extract obtained by subjecting a beverage containing diols to a solid phase extraction column, eluting and concentrating with an organic solvent. . 2. At least one of diols of propylene glycol, ethylene glycol and butanediol.
The method for detecting a diol according to claim 1, wherein the method comprises detecting a species. 3. The method for detecting diols according to claim 1, wherein the beverage is beer. 4. The method for detecting diols according to claim 1, wherein the solid-phase extraction column is Extrelut (registered trademark) Column.