WO2010137195A1 - Silica gel for beer stabilization and method for beer stabilization - Google Patents

Abstract

A silica gel for stabilizing beer which has a Darcy coefficient that shows the filtration performance of 0.29 to 1.0, and a 1 wt% aqueous slurry of which shows a transmittance of 50% or higher after allowing to stand for 2 hours.

Description

Silica gel for beer stabilization treatment and beer stabilization treatment method

The present invention relates to a silica gel for beer stabilization treatment used for improving the turbidity stability of beer and a beer stabilization treatment method.

Conventionally, in order to improve the turbidity stability of beer, a technique for removing proteins contained in beer using silica gel is known (for example, see Patent Document 1). In a large domestic brewery, the beer stabilization silica gel as described above is brought into contact with beer to adsorb the protein contained in the beer onto the silica gel, and then the mixture containing the beer and the silica gel is mixed with diatomaceous earth. By introducing it into the filter, silica gel is removed from the beer.

When unnecessary protein contained in beer is removed by such a process, polyphenol contained in beer does not bind to protein, so the generation of turbidity-causing substances is suppressed and the turbidity stability of beer can be improved. it can.

However, if a diatomaceous earth filter as described above is used, a large amount of diatomaceous earth sludge is inevitably generated. Although this diatomaceous earth sludge is reused as a by-product, it requires significant costs. In addition, the diatomite filter has a problem that a loss when switching products is large.

Therefore, considering the cost and environmental issues, the beer industry is currently considering the use of a filtration system that is different from the diatomaceous earth filter. One of the promising candidates is cross-flow membrane filtration. The machine is attracting attention.

In the cross flow membrane filter, the pre-filtration liquid is circulated at high speed in the inner flow path of the tubular membrane module, and the filtrate is obtained in a direction perpendicular to this flow. The permeation flow rate and the transmembrane pressure between the non-filtrate side and the filtrate side (hereinafter referred to as transmembrane differential pressure) are maintained due to the scraping effect of the membrane surface by circulation, and filtration is possible for a long time.

Japanese Patent Laid-Open No. 09-025114

However, when beer stabilization processing is performed using silica gel as described above, the cross-flow membrane filter cannot be used as a simple alternative to the diatomaceous earth filter.

Specifically, when conventional silica gel for stabilizing beer is passed through a cross-flow membrane filter together with beer, membrane pores are clogged in a very short time, resulting in an immediate increase in transmembrane pressure difference. There was a problem that it could not withstand the use of time.

On the other hand, cross-flow membrane filters have already begun to spread in the beer industry in some overseas countries. However, overseas, polyvinylpolypyrrolidone (hereinafter abbreviated as PVPP) is generally used as a stabilizing treatment agent.

When PVPP is used as a stabilizing treatment agent, polyphenols contained in beer are removed, and as a result, proteins contained in beer do not bind to polyphenols, thereby suppressing the generation of turbidity causing substances.

However, when polyphenol is removed by PVPP in this way, there is a problem that the characteristic of beer taste finally obtained is changed from the conventional method of removing protein by silica gel. Therefore, in order to maintain the same taste as existing beer, there has been a problem that PVPP cannot simply be used as an alternative to silica gel.

In other words, if you want to produce beer with the same taste as before, it is essential to use silica gel as a stabilizing agent, but using silica gel makes it difficult to use a cross-flow membrane filter. It was.

The present invention has been made to solve the above problems, and its purpose is to remove unnecessary proteins as in the case of conventional products and to beer that can be used for a long time with a crossflow membrane filter. The object is to provide a silica gel for stabilization treatment and a beer stabilization treatment method using the silica gel for beer stabilization treatment.

The characteristic configuration employed in the present invention will be described below.
The silica gel for beer stabilization treatment according to the first aspect of the present invention has a Darcy coefficient of 0.29 to 1.0 indicating filtration performance and a transmittance of 50% or more after leaving a 1% strength by weight water slurry for 2 hours. It is characterized by being.

The silica gel for beer stabilization treatment of the second aspect of the present invention is the same as the silica gel for beer stabilization treatment of the first aspect, with a specific surface area of 700 to 1000 m ² / g and a pore volume of 1.1 to 1.6 ml / g. The average pore diameter is 6 to 10 nm.

The beer stabilization treatment method of the third aspect of the present invention is to separate the silica gel by crossflow membrane filtration after contacting the beer silica gel for beer stabilization of the first aspect or the second aspect with the beer. Features.

The silica gel for beer stabilization treatment of the present invention configured as described above is compatible with cross-flow membrane filtration while maintaining the same protein removal performance that causes cold turbidity, and stable filtration for a long time. It is a new one that makes possible.

In general, the Darcy coefficient is one of the indexes of filtration performance, and is also noted in the above-mentioned Patent Document 1. However, in the case of crossflow membrane filtration, a filter aid such as diatomaceous earth is not used, so there is no precoat layer. Filtered through a membrane. Therefore, even if the physical properties are optimized by paying attention only to the Darcy coefficient, clogging of the membrane may be significant, and the crossflow membrane filtration may not be performed normally.

Therefore, the present inventors have found that the cross flow membrane filtration can be normally performed by controlling the transmittance simultaneously with the Darcy coefficient and simultaneously optimizing these parameters, and have completed the present invention. .

In addition, in order to ensure excellent adsorption performance during such studies, the specific surface area is 700 to 1000 m ² / g, the pore volume is 1.1 to 1.6 ml / g, and the average pore diameter is 6 It was also confirmed that ˜10 nm is preferable.

More specifically, as a result of experimental confirmation by the inventors of the present invention, when both the Darcy coefficient and the transmittance are low, or when either of them is low, such silica gel has a high differential pressure increase rate, which is practical. It was unbearable. Specifically, when the Darcy coefficient is less than 0.29, or when the permeability after leaving a 1 wt% water slurry for 2 hours is less than 50%, the cross-flow filtration membrane is likely to be clogged with silica gel. Since the transmembrane pressure difference tends to increase excessively, there is a tendency that stable treatment over a long time cannot be performed.

In addition, silica gel with a high Darcy coefficient has a good differential pressure increase rate, but in analysis of filtered beer, it was confirmed that the value of sensitive protein was high and the adsorption performance and filtration effect were inferior. That is, when the Darcy coefficient is 1.0 or more, the adsorption performance cannot be maintained, which is also undesirable.

∙ The increase in filtration differential pressure and quality are in a contradictory relationship, and the physical properties of silica gel must be in an appropriate range. More preferably, the silica gel has a low sensitivity protein and a low differential pressure increase rate. However, if the Darcy coefficient is low, the sensitivity protein tends to be low. Therefore, it can be said that silica gel having a slow differential pressure increase and a low Darcy coefficient as much as possible is more desirable.

Furthermore, in order to maintain the same or better adsorption performance as that of the conventional product, the specific surface area is preferably 700 m ² / g or more. When the specific surface area is less than 700 m ² / g, the same or better adsorption performance as that of the conventional product is maintained. It tends to be difficult to do. On the other hand, the larger the specific surface area of silica gel is, the more desirable, but those having a specific surface area exceeding 1000 m ² / g are not realistic because industrial production becomes difficult.

On the other hand, if the average pore size is less than 6 nm, it is not preferable because a significant decrease in adsorption performance is observed. On the other hand, if it exceeds 10 nm, it is difficult to maintain a large surface area of 700 m ² / g or more. It is not preferable.

In addition, since the specific surface area, pore diameter, and pore volume in silica gel have a subordinate relationship with each other, with respect to the pore volume, when the specific surface area and pore diameter are controlled in the above-described range, 1.1 to 1 A range of about 6 ml / g is reasonable.

The silica gel of the present invention as described above has excellent adsorption performance equivalent to that of silica gel used in conventional diatomaceous earth filter machines, and can be effectively stabilized by contacting with beer. is there. Moreover, unlike silica gel that has been used in conventional diatomaceous earth filter, even if it is used in a cross-flow membrane filter, the filtration performance is not impaired over a long period of time. Such an effect will be more specifically clarified in embodiments described later.

Next, an embodiment of the present invention will be described with an example.
[1] Method for Producing Silica Gel First, a silica hydrosol is produced by reacting a silicate and an inorganic acid so that the SiO ₂ concentration is 10 to 20% by weight, and the silica hydrosol is gelled. As the silicate, sodium silicate, potassium silicate, ammonium silicate and the like can be used, but sodium silicate is often used industrially. As the inorganic acid, sulfuric acid, nitric acid, hydrochloric acid and the like can be used, but generally sulfuric acid is used.

Next, when the obtained silica hydrogel is washed with water, the inorganic acid salt contained in the silica hydrogel is removed. By performing hydrothermal treatment on this silica hydrogel, the specific surface area, average pore diameter and pore volume of the silica gel can be adjusted.

Specifically, when silica gel is hydrothermally treated with water having a pH of 2 to 10 and a temperature of 20 to 100 ° C., the pore diameter and pore volume tend to increase while the specific surface area tends to decrease. At this time, the specific surface area, pore diameter, and pore volume of the silica gel are adjusted according to the pH and temperature settings of the water used for hydrothermal polymerization.

Next, the silica hydrogel is pulverized with a fine pulverizer such as a rod mill, ball mill, jet mill or the like so as to have an average particle size of 10 to 30 μm, and dried at a temperature of 100 to 1000 ° C. for 1 to 100 seconds. Classification is performed using a classification or centrifugal classification type dry classifier or sieving classifier. Here, since the pulverization and classification steps are important factors for determining the Darcy coefficient and permeability, which are indicators of filtration performance, by controlling both, the Darcy coefficient is 0.29 to 1.0, the concentration is 1 It is possible to obtain physical properties of a transmittance of 50% or more after allowing the weight% water slurry to stand for 2 hours.

[Table 1] shows the powder physical properties of the silica gels (Examples 1 to 7 and Comparative Examples 1 to 3) obtained by the above procedure. [Table 1] also shows the powder physical properties of a commercially available silica gel (Comparative Example 4) for diatomaceous earth filter.

　上記［表１］において、シリカゲルの各物性値の測定・算出は、以下のように行った。

In [Table 1] above, each physical property value of silica gel was measured and calculated as follows.

(Specific surface area)
The silica gel sample was oven-dried at 180 ° C. and determined by a simple nitrogen adsorption method (rapid surface area measuring device SA-1000, manufactured by Shibata Kagaku Kogyo Co., Ltd.).

(Pore volume)
Silica gel samples were oven dried at 180 ° C. and determined by water titration. In general, the pore volume is often obtained from a nitrogen adsorption isotherm, but when the pore diameter of silica gel is large, an accurate pore volume cannot be obtained from the nitrogen adsorption isotherm. Therefore, 5 g of the dried sample was weighed into an approximately 100 ml mayonnaise bottle, and the pore volume was defined as the end point where the powder no longer floated by dripping water.

(Pore diameter)
It was determined by the following formula.
Pore diameter (APD) = (4000 × pore volume) / specific surface area (average particle diameter)
Measurement was performed with a laser diffraction particle size distribution analyzer (SALD-2200, manufactured by Shimadzu Corporation).

(Darcy coefficient)
20 g of silica gel is dispersed in 500 ml of deionized water, and filtered using a wire mesh having a mesh size of 33 μm and a diameter of 60 mm and a suction pressure of 40 cmHg. At this time, the time required for filtration from 400 ml to 150 ml is measured. After that, all are filtered, the deposited silica cake is taken out, and the thickness is measured. The Darcy coefficient indicating the filtration characteristics was calculated by the following equation.

Darcy coefficient = (cake thickness [cm] × filtration amount per hour [250 ml] × water viscosity [mPa · s]) / (filtration time [sec] × filtration area [cm ² ] × (suction pressure [cmHg] / 76)).

(Transmittance)
1 g of silica gel and 99 g of distilled water are placed in a 100 ml screw cap bottle and stirred for 1 minute. Immediately weigh 4 ml of the slurry and pour it into a quartz cell (size: 10 × 10 × 45 mm). The sample was mounted on an ultraviolet-visible spectrophotometer (V-550, manufactured by JASCO Corporation) and allowed to stand, and the transmittance (wavelength 350 nm) after 2 hours was measured.

[2] Stabilization with silica gel and separation / removal by cross-flow membrane filtration The above-described silica gel was body-fed to the test beer produced by the pilot plant at a rate of 300 g per kiloliter of beer. After contacting silica gel and beer for a certain period of time, about 1500 L of test beer was filtered using a cross flow membrane filter with a filtration flow rate of 15 L / min.

[Table 2] shows the transmembrane pressure increase rate of the cross flow membrane filter and the characteristics of the filtered beer when each silica gel is used.

　上記［表２］において、濾過性能および吸着性能は以下の方法により評価した。

In the above [Table 2], filtration performance and adsorption performance were evaluated by the following methods.

(Transmembrane differential pressure increase rate)
The increase in transmembrane pressure difference during filtration expressed per unit time. If the rate of increase in transmembrane pressure is 0.65 kPa / min or less, practical use with a cross-flow membrane filter is possible.

(Sensitive protein)
Measurement with a tanometer (manufactured by Pfeuffer).
From the results of [Table 2], silica gel having a Darcy coefficient in the range of 0.29 to 1.0 and a transmittance of 50% or more after standing for 2 hours with a 1 wt% water slurry (Example 1 to Regarding Example 7), it was confirmed that the rate of increase in transmembrane pressure difference and the physical properties of filtered beer were also good.

On the other hand, the silica gel comparative example 1, comparative example 2 and comparative example 4, both of which have low values of Darcy coefficient and transmittance, had a high rate of increase in transmembrane pressure difference and were not practical. In addition, the silica gel comparative example 3 having a Darcy coefficient exceeding 1.0 has a good rate of increase in the transmembrane pressure difference, but in the analysis of the filtered beer, it was confirmed that the value of the sensitive protein was high and the adsorption performance was poor.

[3] Long-term operation test of crossflow membrane filtration In order to confirm the possibility of practical use of the silica gel of Example 2 in which good results were obtained in the test of [2] above, I drove for a long time. The method of cross flow filtration is the same as the test of [2] above. The operation time was 6 hours and about 5400 L of beer was processed. The results are shown in [Table 3].

　上記［表３］において、ビールの特性は以下のように測定した。

In the above [Table 3], the characteristics of beer were measured as follows.

(PH) ......... Measurement with a pH meter.
(Alcohol): Conforms to EBC (European Brewery Convention) law.
Measurement is by SCABA Automatic Beer Analyzer.

(Raw wort extract): Conforms to EBC (European Brewery Convention) method.
Measurement is by SCABA Automatic Beer Analyzer.
(External appearance extract): Conforms to EBC (European Brewery Convention) method.

Measurement is by SCABA Automatic Beer Analyzer.
(Chromaticity) ………… According to EBC (European Brewery Convention) method.
Measurement is by SCABA Automatic Beer Analyzer.

(Cold turbidity) ... Conforms to EBC (European Brewery Convention) method.
(Bubble holding time): According to EBC (European Brewery Convention) law.
Use NIBEM-T meter for measurement.

From the results of [Table 3], according to the silica gel of Example 2 above, there is no problem with the transmembrane pressure difference in the operation in the cross flow membrane filtration for 6 hours, and the physical properties of the filtered beer are stable. It turns out that it is obtained.

On the other hand, the commercially available silica gel for the diatomaceous earth filter (silica gel of Comparative Example 4) reached the limit point of the transmembrane pressure difference in about 1 hour and 15 minutes, resulting in the inability to use.
[4] Modifications The embodiment of the present invention has been described above, but the present invention is not limited to the specific embodiment described above, and can be implemented in various other forms.

For example, in the above embodiment, seven types of silica gels having specific numerical values are exemplified as Examples 1 to 7 with respect to the Darcy coefficient indicating the filtration performance and the transmittance after leaving the water slurry having a concentration of 1 wt% for 2 hours. However, the present invention is not limited to these specific examples.

As a result of confirmation by the inventors, when the Darcy coefficient is less than 0.29, the silica gel tends to be clogged in the cross-flow filtration membrane, and the transmembrane pressure difference tends to increase excessively. There was a tendency that stable treatment over a long time was impossible. On the other hand, when the Darcy coefficient was 1.0 or more, there was a tendency that the adsorption performance could not be maintained. Therefore, it is considered preferable to adjust the Darcy coefficient within the range of 0.29 to 1.0.

In addition, when the transmittance after leaving a 1 wt% water slurry for 2 hours is less than 50%, the cross flow filtration membrane tends to be clogged with silica gel, and the transmembrane pressure rises excessively. It becomes easy. For this reason, there is a tendency that stable treatment over a long period of time cannot be performed. Therefore, it is considered preferable to adjust the transmittance to 50% or more.

That is, if the Darcy coefficient is in the range of 0.29 to 1.0 and the transmittance is 50% or more, the silica gel is suitable for use in crossflow membrane filtration.
Further, in the above embodiment, seven types of silica gel having specific numerical values for the specific surface area, pore volume, and average pore diameter of silica gel are exemplified as Examples 1 to 7, but these parameters are also described in the above embodiment. It is not limited to the values of Examples 1-7.

As a result of confirmation by the inventors, when the specific surface area is less than 700 m ² / g, it tends to be difficult to maintain adsorption performance equal to or higher than that of conventional products. On the other hand, the larger the specific surface area of silica gel is, the more desirable, but those having a specific surface area exceeding 1000 m ² / g are not realistic because industrial production becomes difficult.

Moreover, when the average pore diameter was less than 6 nm, a significant decrease in adsorption performance was observed. On the other hand, when the average pore diameter exceeded 10 nm, it was difficult to maintain a large surface area such as a specific surface area of 700 m ² / g or more.

Furthermore, since the specific surface area, pore diameter, and pore volume in silica gel have a subordinate relationship with each other, when the specific surface area and pore diameter are controlled in the above-mentioned range, 1.1-1. A range of about 6 ml / g was found to be reasonable.

Therefore, considering these matters, the specific surface area, pore volume, and average pore diameter of the silica gel are within the range of 700 to 1000 m ² / g and the pore volume is 1.1 to 1.6 ml / g. If the average pore diameter is in the range of 6 to 10 nm, the silica gel is suitable for use in crossflow membrane filtration.

Claims (3)

A silica gel for beer stabilization treatment, wherein the Darcy coefficient indicating filtration performance is 0.29 to 1.0, and the permeability after standing for 2 hours with a water slurry having a concentration of 1% by weight is 50% or more. ^{2. The} silica gel for beer stabilization treatment according to claim 1, wherein the specific surface area is 700 to 1000 m ² / g, the pore volume is 1.1 to 1.6 ml / g, and the average pore diameter is 6 to 10 nm. . A silica gel for beer stabilization treatment according to claim 1 or claim 2 and beer are contacted, and then the silica gel is separated by cross-flow membrane filtration.