JP7455537B2 - Method for suppressing the growth of Pectinatus bacteria in beer-taste beverages - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) 2019 ASBC meeting presentation summary Date of publication April 12, 2019 Publication address https://asbc. confex. com/asbc/2019/meetingapp. cgi/Paper/1972 (2) Meeting name 2019 ASBC meeting Dates June 24-26, 2019 (Presentation will be made on the 25th) (3) 2019 ASBC meeting Presentation slides Publication date August 6, 2019 Posting address: https://www. asbcnet. org/events/archives/2019meetings/proceedings/Documents/Presentations/28_Takesue. pdf

The present invention relates to inhibiting the growth of bacteria belonging to the genus Pectinatus in beer-taste beverages.

BACKGROUND ART It is known that there are bacteria (beer-turbid harmful bacteria) that proliferate in brewed unheated beer and cause turbidity, etc., which adversely affects its commercial value.
Some lactic acid bacteria are known to be harmful bacteria that cloud beer, but in addition to lactic acid bacteria, Pectinatus is an obligate anaerobic bacterium that has been growing in beer for the past 30 years and has become known to cloud beer. Examples include the genus Bacteria (Pectinatus sp.).
It is known that increasing alcohol concentration and decreasing pH are effective in suppressing the growth of bacteria of the genus Pectinatus. It is also known that the growth of Pectinatus bacteria can be suppressed by adding nisin, which is an antibacterial substance (Non-Patent Document 1).

N.-E. Chihib et al., Nisin, temperature and pH effects on growth and viability of Pectinatus frisingensis, a Gram-negative, strictly anaerobic beer-spoilage bacterium, Journal of Applied Microbiology 1999, 87, 438-446

From the viewpoint of freedom in product design of beer-taste beverages, there is a demand for further options regarding technology that can suppress the growth of Pectinatus bacteria.
An object of the present invention is to provide a novel technique capable of suppressing the growth of bacteria of the genus Pectinatus in beer-taste beverages.

As a result of extensive research, the present inventors have discovered that by adding phytic acid to beer-taste beverages at any stage of their production and adjusting the pH to 3.5 to 4.5, the growth of Pectinatus bacteria can be suppressed. They discovered what they could do and completed the present invention.

The gist of the present invention is as follows.
[1] A method for inhibiting the growth of bacteria belonging to the genus Pectinatus in a beer-taste beverage, which comprises adding phytic acid in the beer-taste beverage production process and adjusting the pH of the beverage to 3.5 to 4.5.
[2] The method for inhibiting the growth of Pectinatus bacteria according to [1], further comprising adjusting the iron concentration in the beer-taste beverage to 20 ppb or less.
[3] The beer-taste beverage has a 600 nm turbidity of 0.2 or less when 1.26 x 10 ³ Pectinatus/ml is inoculated and cultured at 30°C for 10 days, [1] or The method for inhibiting the growth of Pectinatus bacteria according to [2].
[4] The method for inhibiting the growth of bacteria belonging to the genus Pectinatus according to any one of [1] to [3], wherein the content of the phytic acid is 200 to 600 mg/L.
[5] An inhibitor of Pectinatus bacteria in a beer-taste beverage, containing phytic acid.
[6] A beer-taste beverage with a phytic acid content of 200 to 600 mg/L.

According to the present invention, it is possible to provide a novel technique that can suppress the growth of Pectinatus bacteria in beer-taste beverages.

Hereinafter, one embodiment of the present invention will be described in detail.
The present embodiment relates to a method for suppressing the growth of bacteria belonging to the genus Pectinatus in a beer-taste beverage, in which phytic acid is added at any stage of the beer-taste beverage manufacturing process to adjust the pH of the beverage to 3.5 to 4.5. Including adjusting.
Phytic acid refers to myo-inositol 1,2,3,4,5,6-hexaphosphoric acid, which can be synthesized by known methods or extracted from natural products, or can be produced using commercially available products. It's okay.

Bacteria belonging to the genus Pectinatus to be suppressed include, but are not particularly limited to, Pectinatus frisingensis, Pectinatus cerevisiiphilus, Pectinatus haikarae, and the like.
Phytic acid has the effect of chelating iron, and on the other hand, bacteria of the genus Pectinatus are iron-requiring, so it is thought that the iron content in beer-taste drinks is chelated by phytic acid, suppressing the growth of bacteria of the genus Pectinatus. It will be done.

In this specification, beer-taste beverages refer to alcoholic beverages and non-alcoholic beverages that are effervescent due to carbon dioxide gas and have a flavor similar to or similar to beer. Note that whether or not it falls under the category of beer-taste beverage is not limited by the classification under the Liquor Tax Act, the raw materials used, or the amount used.

In the following description, a fermented beer-taste beverage will be exemplified as an example of a beer-taste beverage.
The fermented beer-taste beverage is not particularly limited except that phytic acid is added and the pH is adjusted to 3.5 to 4.5, and for example, it can be a fermented beer-taste beverage produced by a conventional method. .
The alcohol concentration of the fermented beer-taste beverage is not limited, and may be an alcoholic beverage of 0.5% by volume or more, or a so-called non-alcoholic beverage of less than 0.5% by volume. Specific examples include beer, low-malt beer, non-alcoholic beer, and the like.

An example of a process for producing a fermented beer-taste beverage is shown below.
A typical fermented beer-taste beverage can be produced through the steps of preparation (preparation of fermented raw material liquid), fermentation, storage, and filtration.
First, as a preparation step, a fermentation raw material liquid is prepared from one or more raw materials (fermented raw materials) selected from the group consisting of grain raw materials and carbohydrate raw materials. Specifically, first, a mixture containing at least one of a grain raw material and a carbohydrate raw material and raw water is prepared and heated to saccharify the starch such as the grain raw material. Supplementary materials other than grain materials and water may be added to the mixture. Examples of the auxiliary raw materials include hops, dietary fiber, yeast extract, sweeteners, fruit juice, bittering agents, coloring agents, herbs, fragrances, and the like. Furthermore, if necessary, saccharifying enzymes such as α-amylase, glucoamylase, and pullulanase, and enzyme agents such as protease can be added.

The saccharification process is performed using enzymes derived from grain raw materials or separately added enzymes. The temperature and time during the saccharification treatment should be determined based on the type of grain raw materials used, the proportion of grain raw materials in the total fermented raw materials, the type of enzyme added and the amount of the mixture, and the quality of the desired fermented beer-taste beverage. It will be adjusted accordingly. For example, the saccharification treatment can be carried out by a conventional method such as holding a mixture containing grain raw materials at 35 to 70°C for 20 to 90 minutes.

A broth (boiled sugar solution) is prepared by boiling the sugar solution obtained after the saccharification treatment. It is preferable that the sugar solution is filtered before being boiled, and the resulting filtrate is boiled. Moreover, instead of the filtrate of this sugar solution, a mixture of malt extract and warm water may be used and boiled. The boiling method and its conditions can be determined as appropriate.

A fermented beer-taste beverage having a desired flavor may be produced by appropriately adding herbs or the like (for example, hops) before or during the boiling process. The amount of aromatic herbs added, manner of addition (for example, addition in several portions), and boiling conditions can be determined as appropriate.

After the preparation step and before the fermentation step, it is preferable to remove residues such as protein produced by precipitation from the prepared broth. The lees may be removed by any solid-liquid separation process, but the precipitate is generally removed using a tank called a whirlpool. The temperature of the broth at this time only needs to be 15°C or higher, and is generally about 50 to 90°C. The broth (filtrate) after removing the lees is cooled to an appropriate fermentation temperature using a plate cooler or the like. The broth after removing this lees becomes the fermentation raw material liquid.

Next, as a fermentation step, yeast is inoculated into the cooled fermentation raw material liquid and fermentation is performed. The cooled fermentation raw material liquid may be directly subjected to the fermentation process, or may be subjected to the fermentation process after being adjusted to a desired extract concentration. The yeast used for fermentation is not particularly limited, and can be appropriately selected from among the yeasts normally used for producing alcoholic beverages. Although it may be a top-fermenting yeast or a bottom-fermenting yeast, a bottom-fermenting yeast is preferred because it can be easily applied to large-scale brewing equipment.

Furthermore, as a storage process, the obtained fermented liquid is aged in a sake storage tank, and after being stored and stabilized under low temperature conditions of about 0°C, as a filtration process, the fermented liquid after aging is filtered. By removing yeast, proteins, etc. that are insoluble in the temperature range, a fermented beer-taste beverage can be obtained. The filtration treatment may be any method as long as the yeast can be removed by filtration, and examples thereof include diatomaceous earth filtration, filter filtration using a filter with an average pore size of about 0.4 to 0.6 μm, and the like. Further, in order to obtain a desired alcohol concentration, an appropriate amount of water may be added to dilute the solution before or after filtration. Note that, as described later, the filtration step may be omitted in the fermented beer-taste beverage according to this embodiment.

In addition, a fermented beer-taste beverage corresponding to liqueurs under the Liquor Tax Act can also be produced by mixing it with an alcohol-containing distillate in a step after the fermentation step using yeast, for example. The alcohol-containing distillate may be added before or after adding water to adjust the alcohol concentration. The alcohol-containing distillate to be added is preferably barley spirit, since it can produce a fermented beer-taste beverage with a more preferable barley taste.
The obtained fermented beer-taste beverage is usually packed into containers through a filling process.

In this embodiment, the process for making the fermented beer-taste beverage contain phytic acid is not particularly limited, and phytic acid may be added at any stage of the manufacturing process. For example, addition of phytic acid to the obtained fermented beer-taste beverage can be exemplified.
Specifically, for example, phytic acid may be mixed into the fermented beer-taste beverage to adjust the pH to 3.5 to 4.5 before filling the obtained fermented beer-taste beverage into a container.
The amount of phytic acid added is not particularly limited, but the content is preferably 200 to 600 mg/L from the viewpoint of further suppressing the growth of bacteria belonging to the genus Pectinatus.

In addition, in the fermented beer-taste beverage according to the present embodiment in which phytic acid is added, the iron concentration in the fermented beer-taste beverage is preferably adjusted to 20 ppb or less in order to further suppress the growth of Pectinatus bacteria. preferable.
Note that in this specification, the iron concentration refers to the concentration of the entire iron component dissolved in the beer-taste beverage. The iron concentration can be measured, for example, by inductively coupled plasma mass spectrometry (ICP-MS) after wet ashing the sample with nitric acid or the like.
The method for adjusting the iron concentration is not particularly limited, and for example, it can be done by adjusting the amount of phytic acid added, or by selecting diatomaceous earth used for filtration.

Although this embodiment has been described above, the present invention is not limited to this embodiment.
For example, in the present embodiment, a fermented beer-taste drink has been described as an example of the beer-taste drink, but the invention is not limited to this, and a non-fermented beer-taste drink may be used.
A non-fermented beer-taste beverage refers to a beer-taste beverage produced without fermentation. Non-fermented beer-taste beverages are produced, for example, by mixing raw materials such as malt extract, hop extract, acidulant, and sweetener, and introducing carbon dioxide gas into the resulting liquid mixture.

The non-fermented beer-taste beverage may be an alcoholic beverage containing alcohol (ethanol), or may be a so-called non-alcoholic beverage or low alcoholic beverage with an alcohol content of less than 1% by volume.
Specific examples of non-fermented beer-taste drinks include beer-taste drinks such as low-malt beer, low-alcohol sparkling drinks, and non-alcoholic beer. In addition, liqueurs obtained by mixing a beverage produced without going through a fermentation process with an alcohol-containing distillate and carbon dioxide gas may also be used. The alcohol-containing distilled liquid is a solution containing alcohol obtained by a distillation operation, and spirits and other liquids that are generally classified as distilled spirits can be used.

The non-fermented beer-taste beverage can be made from malt or barley, or may not be made from malt or the like, and is not particularly limited.
Here, "the raw material contains malt" means that a substantial amount of malt-derived components are blended into the non-fermented beer-taste beverage. For example, if malt is used as a raw material for flavoring, etc., and a small amount of malt is added as a flavoring agent to a non-fermented beer-taste beverage, it does not fall under "the raw material contains malt." On the other hand, if malt, etc. is specified as an ingredient when being sold as a product, it falls under the category of ``the ingredient contains malt.''

There are no particular limitations on the treatment for making the non-fermented beer-taste beverage into a state containing phytic acid, as long as phytic acid is added at any stage of the manufacturing process. For example, before filling the resulting non-fermented beer-taste beverage into a container, phytic acid may be mixed with the non-fermented beer-taste beverage to adjust the pH to 3.5 to 4.5. The amount of phytic acid added is preferably 200 mg/L to 600 mg/L for the same reason as in the fermented beer-taste beverage. Further, for the same reason as the fermented beer-taste beverage, the iron concentration is preferably adjusted to 20 ppb or less.

According to the present invention, it is possible to provide a novel technique that can suppress the growth of Pectinatus bacteria in beer-taste beverages. For example, when a beer-taste beverage is inoculated with 1.26 x 10 ³ Pectinatus fricingensis cells/ml and cultured at 30°C for 10 days, the turbidity at 600 nm can be 0.2 or less. In order to make the turbidity 0.2 or less, as mentioned above, add phytic acid to adjust the pH to 3.5 to 4.5, and adjust the iron concentration as necessary. do it.
Note that in this specification, turbidity refers to absorbance at a wavelength of 600 nm, and can be measured with a spectrophotometer (for example, Hitachi U-3900 model).
Further, as another aspect of the present invention, the present invention relates to a beer-taste beverage having a phytic acid content of 200 to 600 mg/L.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

[Test example 1]
Commercial beer A (pH 4.4) was used as a control. In addition, beer A whose pH was lowered to 4.1 with 5N-HCl (Comparative Example 1) and beer A whose pH was lowered to 4.1 with 50% phytic acid (Example 1, amount of phytic acid added: 295 mg/L) was prepared.
Each of the above beers was inoculated with Pectinatus frisingensis (inoculated so that the initial number of bacteria was 1.26×10 ³ cells/ml). The growth of Pectinatus frisingensis after 11 days at 30°C was compared by measuring turbidity at 600 nm (measured using Hitachi U-3900).

The results are shown in Table 1.
As can be seen from Table 1, it can be seen that the growth of Pectinatus frisingensis is greatly suppressed when phytic acid is added, compared to when it is not added or when hydrochloric acid is added.

[Test example 2]
0.25 g of each of five commercially available diatomaceous earths (A to E) was suspended in 100 ml of Asahi Super Dry (manufactured by Asahi Breweries, Ltd.), filtered through a 0.45 μm membrane, and the iron concentration in beer was determined by ICP-MS. (7800 manufactured by Agilent Technologies). Pretreatment and analysis were carried out by a conventional method (wet oxidation with nitric acid). Beer filtered through diatomaceous earth A had an iron concentration of 20 ppb or less. In addition, when the filtered beer was inoculated with Pectinatus frisingensis and cultured in the same manner as in Test Example 1 except that the culture time was changed to 10 days, beer filtered with diatomaceous earth A had a turbidity of 600 nm after 10 days of culture. At 0.2 or less, growth was suppressed compared to other diatomaceous earth-filtered beers.

Claims (4)

Adding phytic acid in the manufacturing process of beer-taste drinks,
Including adjusting the pH in the beverage to 3.5 to 4.5,
A method for inhibiting the growth of Pectinatus bacteria in a beer-taste beverage, further comprising adjusting the iron concentration in the beer-taste beverage to 20 ppb or less. Pectinatus according to claim 1, wherein the beer-taste beverage is inoculated with 1.26 x ¹⁰³ Pectinatus/ml and has a 600 nm turbidity of 0.2 or less when cultured at 30°C for 10 days. A method for inhibiting the growth of bacteria of the genus. The method for inhibiting the growth of bacteria belonging to the genus Pectinatus according to claim 1 or 2, wherein the content of phytic acid in the beer-taste beverage is 200 to 600 mg/L. An inhibitor of Pectinatus bacteria in beer-taste beverages containing phytic acid.