JPH0655124B2 - Filtering raw sake - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for filtering sake.

[0002]

2. Description of the Related Art Conventionally, as a method of filtering sake, there is a method of filtering with diatomaceous earth, cotton or the like, and filtration with an ultrafiltration membrane has also been proposed.

[0003]

However, in the method using diatomaceous earth and cotton, filtration fractionation, that is, filtration of minute components is not sufficient, and further disposal after use is a difficult problem, which is a big problem. In addition, the method using an ultrafiltration membrane, as described in the "Fermentation Engineering Society of Japan" Autumn Meeting 1976, Abstracts, p. 47, greatly improves the fractionation property, but circulates the liquor to be treated. However, since there is concern that the quality of liquor may be altered and a large amount of residual liquid is produced, its treatment is also a problem. In terms of practical use, the equipment and operating costs are large, which is not desirable.

[0004]

The present invention is an improvement over these drawbacks. After adding a protein flocculant to sake,
It is a filtration method for sake which is characterized by filtering through a fine porous hollow fiber membrane having an average pore diameter of 0.01 to 0.2 µ.

According to the present invention, the fractionation property (removal property of minute components) is far superior to that of diatomaceous earth and cotton and almost corresponds to the boundary region between the ultrafiltration membrane and the microfiltration membrane, Furthermore, the liquidity of the filtered sake is good. In addition, the filtration method can be either full filtration or circulation type, and since the circulation liquid is completely unnecessary in the full filtration method, the equipment and operating costs can be greatly reduced, and even in the circulation type, an ultrafiltration membrane can be used. Since the amount of permeated liquid is large, the various expenses can be reduced. As an unexpected effect, the pore size is 0.01 to 0.
It can be said that the liquid property called "terri" of sake was improved by filtering with a 2 µ microporous hollow fiber membrane. "Teri" is different from mere transparency, and refers to the gloss that the liquid produces when it is exposed to light, and is one of the desirable liquid properties in sake. In the conventional sake filtration using diatomaceous earth and ultrafiltration membrane, the generation of "terri" is insufficient.

[0006] In the present invention, a protein aggregating agent is added to raw sake filtered with a microporous hollow fiber membrane, and this is refiltered with a microporous hollow fiber membrane having an average pore diameter of 0.01 to 0.2 µ. Methods are also included. According to this two-stage filtration method, since it is not necessary to leave still after adding the protein coagulation treating agent to the sake, a large-capacity tank for still standing is not required. Further, in the present invention, the alcohol obtained by filtering through such a microporous hollow fiber membrane is water-diluted to adjust the alcohol concentration to a desired value (15 to 17%), and then the average pore diameter is further adjusted to 0.01 to 0. It also includes a method of re-filtration with a 2 μ microporous hollow fiber membrane.

Further, according to the method of the present invention, the average pore size is 0.
By using a fine porous hollow fiber membrane of 01 to 0.2μ, it is far superior to the conventional method in terms of filtration efficiency, especially in terms of sterilization property, and the hollow fiber membrane has a pore size of filtration of sake. The molecular weight used as 190000 (about 0.0
(It corresponds to 05μ) It is not an extremely fine membrane like the conventional ultrafiltration membrane that removes the following substances, but has a certain size, so the pores of the hollow fiber membrane are clogged and the filtration capacity is Even when dropped, the filtration capacity can be regenerated by backwashing the filtrate. Therefore, the life of the hollow fiber membrane is long and it is not necessary to replace it for 6 months to 2 years. In addition, since the hollow fiber membrane can be washed with a chemical solution, the SS portion that could not be completely removed by backwashing the filtrate is completely removed to regenerate the membrane, and the raw solution side and the filtrate side are separated. There is no problem of microbial contamination because it can be sterilized in an emergency.

It is essential that the hollow fiber membrane used in the present invention has an average pore diameter of 0.01 to 0.2 μm.
If it is less than μ, clogging is likely to occur, the flux is lowered, and the refining efficiency is significantly deteriorated. On the other hand, if it exceeds 0.2 μm, it is impossible to completely remove the SS content and the bacteria. The average pore diameter is 0.02 to more completely remove SS and bacteria without lowering the flux.
0.2μ is preferable. The average pore size referred to herein means the particle size of the reference substance such as colloidal silica, emulsion and latex, 90% of which is excluded when various reference substances of known particle size are filtered through a hollow fiber membrane. Further, it is preferable that the pore diameter is uniform.

As hollow fiber membranes, cellulose acetate type, polyacrylonitrile type, polymethacrylic acid type,
Polyamide-based, polyester-based, polyvinyl alcohol-based, ethylene-vinyl alcohol copolymer-based, polyolefin-based, polysulfone-based materials, etc. are formed into films by ordinary spinning methods (wet method, dry method, dry-wet method, melt method, etc.). The ones that have been made are listed.

Here, the term "system" refers to a copolymer obtained by copolymerizing 30 mol% or less than 20 mol% of other materials, or a blend of 30 wt% or less than 20 wt% of other materials. Means to include. Of these, polyvinyl alcohol-based hollow fiber membranes
It is preferable for the reason that it is stable over the pH range. Further, if the filtration temperature in the filtration step is raised to a high temperature, the treatment rate is increased, so that a hollow fiber membrane that can withstand hot water of 50 to 90 ° C. is more desirable.

For this reason, among polyvinyl alcohol type hollow fiber membranes, JP-A-52-21420 and JP-A-54-21520.
-Polyvinyl alcohol hollow fibers crosslinked with polyhydric aldehydes such as glutaraldehyde, which have heat resistance and excellent mechanical properties as described in JP-A-117380, or monoaldehydes such as formaldehyde. A cross-linked polyvinyl alcohol-based hollow fiber with a polyvalent aldehyde such as glutaraldehyde is effective.

The outer diameter of the hollow fiber membrane is 200 to 3000.
μ, preferably 500 to 2000 μ, film thickness 50 to 50
It is 0 μ, preferably 100 to 400 μ. Further, in the present invention, the hollow fiber membrane is modularized and used in the filtration step. As the module type, a large number (several tens to several hundreds of thousands) of hollow fiber membranes are bundled into a U-shape in the module, or one end of the hollow fiber bundle is collectively sealed with an appropriate sealing material. Alternatively, one end of each hollow fiber membrane is sealed in a free state with a suitable sealing material, or both ends of the hollow fiber membrane are opened. Among these, one with one end sealed in a free state is preferable. Sake is filtered by flowing it either inside (internal pressure type) or outside (external pressure type) of the hollow fiber membrane, but the external pressure total filtration type is most suitable.

The protein aggregating agent added to liquor for decolorizing liquor obtained by filtering raw liquor includes activated carbon, kakishibu, gelatin, zeolite and the like which are commonly used. The amount of addition is, for example, in the case of activated carbon, the amount usually used is 0.5 to 2.0 g / 1 (sake). In the present invention, it is best from the point of rationalization to add these protein aggregating agents to liquor and then immediately filter through a porous hollow fiber membrane without allowing it to stand as it is, but allow some standing time. However, after standing still for a while, only the supernatant liquid can be filtered through a porous hollow fiber membrane. Water was added to the sake thus filtered to obtain a desired alcohol concentration (15 to 17%), and then the average pore diameter was adjusted to 0.
It may be filtered through a fine porous hollow fiber membrane of 01 to 0.2 μm. In this case, the same porous hollow fiber membrane used for the first stage filtration may be used, or a different one may be used. Porous hollow fiber membranes may be used. The liquor thus obtained is sent to a bottling process to be a product.

Further, in the present invention, the SS which is adhered to the hollow fiber membrane by backwashing the filtration step with the hollow fiber membrane with the filtrate.
Minutes can be removed. In addition, after the filtration step using the hollow fiber membrane or after the backwash step, the hollow fiber membrane can be washed with a chemical solution to remove organic substances and / or inorganic substances attached to the hollow fiber membrane. Here, the chemical cleaning is a method of treating with caustic soda to remove adhered organic substances and / or inorganic substances, or an acid (inorganic acid such as hydrochloric acid or sulfuric acid, or formic acid, oxalic acid, citric acid) to remove adhered metals. An acid, an organic acid such as succinic acid, and sulfamic acid: preferably hydrochloric acid), a method of treating with caustic soda and then an acid, or a method of treating with an acid and then caustic soda. In particular, it is extremely effective to regenerate the film with a hot alkaline solution at 50 to 90 ° C. Further, it is of course possible to wash the filtration step using the hollow fiber membrane with water.

Washing such as back washing with a filtrate, washing with a chemical solution or washing with water can be appropriately performed by sequence control or the like. For example, after backwashing with the filtrate a plurality of times, washing with water is also performed once or a plurality of times if necessary, and a series of washing steps of performing chemical washing once are continuously repeated by the sequence control, whereby the hollow fiber membrane is used. It is possible to stably operate for a long period of time by alternately repeating the filtration process and the filtration line cleaning process. Further, the filtration step and the backwashing step can be continuously repeated by sequence control, and chemical washing can be carried out manually when clogging becomes large, and stable operation can be performed for a long time by a so-called select switch system.

[0016]

The present invention will be further described with reference to Examples.

EXAMPLE 1 Activated carbon powder 0.8 g / 1 (sake) and Kakishibu 0.7 ml / 1 (sake) were added to raw sake, stirred for 10 minutes, and cross-linked with glutaraldehyde and formaldehyde as it was to obtain. , A module using a heat-resistant polyvinyl alcohol-based hollow fiber membrane (average pore size 0.04μ, uniform fine structure, outer diameter 800μ, inner diameter 400μ) (one end of a hollow fiber bundle is sealed in a free state, external pressure type module ). The filtration conditions and results are shown in Table 1.

[0017]

Comparative Example 1 0.8 g / 1 of activated carbon powder and 0.7 ml / 1 of kakishibu (sake) were added to sake and allowed to stand for a day, and the supernatant was filtered through diatomaceous earth. The filtration conditions and results are shown in Table 1.

[0018]

[0019]

INDUSTRIAL APPLICABILITY As described above, the present invention is excellent in filtering ability and removal of bacteria and yeasts by filtering raw sake with a fine porous hollow fiber membrane having an average pore size of 0.01 to 0.2μ. Not only that, it can greatly improve the quality of sake, especially "terri".

Claims (1)

[Claims] 1. A method for filtering sake which comprises adding a protein aggregating agent to sake and then filtering through a fine porous hollow fiber membrane having an average pore diameter of 0.01 to 0.2 μm.