JPH0687759B2 - Decolorization method for liquid foods - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for efficiently decolorizing liquid foods at an arbitrary degree of decolorization using an ultrapermeation membrane, a reverse osmosis membrane having a low salt rejection rate, or the like.

[Conventional technology]

Decolorization is important for refining liquid foods.For example, in acid decomposed solution of vegetable protein, soy sauce, etc., the color is increased due to oxidation during storage, and the quality is significantly deteriorated. Decolorization for the purpose is generally performed.

As a conventional decolorization method of liquid foods, a method of removing a pigment using an adsorbent such as activated carbon or an ion exchange resin, or
There is known a method of separating dyes using an ultrapermeable membrane capable of blocking dyes or a reverse osmosis membrane having a low salt rejection. However, in the method using the adsorbent, the adsorbent adsorbs not only the dye but also the target substance to be purified to some extent, so that the yield of the target substance cannot be reduced. Further, there is a drawback that a large amount of waste liquid is produced when the adsorbent is regenerated. On the other hand, the method using a film has the drawback that there is no film that can obtain the target decolorizing property, or that once the film is set, the decolorizing property is automatically determined and cannot be freely changed. Was. This defect exists regardless of the type of membrane such as ultrapermeabilization membrane or reverse osmosis membrane.

[Problems to be solved by the invention]

The present invention has a drawback of the conventional film decolorizing method, that is, the decolorizing property is determined by the selection of the film, and the film having the target decolorizing property cannot always be obtained. It is difficult to set a flexible target, and the problem that the yield and the quality stability of the obtained product are low is solved, and even if a membrane with a low salt rejection rate is used, the decolorizing property can be set and changed arbitrarily, The purpose is to develop a decolorization method that can obtain a liquid food with high quality stability.

[Means for solving problems]

The present inventors have conducted intensive research on solving the problems in decolorizing liquid foods using the above-mentioned film, and after decolorizing the film after adding fine particles of a polymer substance or a poorly soluble substance to the stock solution in advance, The present invention has been completed by finding that any decolorizing property can be obtained depending on the kind and concentration of the additive.

The membrane used in the present invention includes an ultrapermeaion having a molecular weight cutoff of 5000 or more, a reverse osmosis membrane having a salt inhibition rate of 30% or less, and a molecular weight cutoff of 5,00.
It is a membrane with 0 or more or a salt inhibition rate of 30% or less. Specific examples of such a membrane include UM-10, PM-10, UM-20E (manufactured by Amicon), HFA-180 (manufactured by Bioengineering), G-1.
0T (Nippon Vacuum Engineering Co., Ltd.), NTU-3502 (Nitto Denko), SI
P-3013 (manufactured by Asahi Kasei), PBIL / TL-230 (manufactured by Teijin) and the like can be mentioned. Fractionated molecular weight is less than 5,000 or salt rejection is 3
In the case of a film of more than 0%, the effect of changing the decolorizing property by adding the additive is small, and the decolorizing efficiency may be significantly deteriorated due to the reduction of the permeation flux. Therefore, in order to fully exert the effect of the present invention, the molecular weight cutoff of the membrane is 5,000 or more or the salt inhibition rate of the membrane is 30% or less,
Regarding the upper limit of the molecular weight cutoff, those having a molecular weight cutoff of more than 300,000 have poor decolorization properties and are not suitable for the present invention.

The polymer substance added has a molecular weight of 5,000 or more, for example, gelatin, soybean protein, egg white, pectin, agar, gum, dextran, sodium polyacrylate and the like. Further, as the poorly soluble substance, including those having a molecular weight of 5,000 or less, those having a particle size that does not pass through the membrane to be used, and the required particle size varies depending on the type of the membrane to be used. , Amino acids, organic acids, inorganic substances and salts thereof, and the like. Of these polymeric substances and sparingly soluble substances, one kind alone or a combination of two or more kinds is added to the stock solution, but generally, it is twice the molecular weight cutoff of the membrane to be used.
It is desirable to add about 60 times the edible polymer substance or the hardly soluble amino acid crystals such as tyrosine and cystine.

The amount of the polymer substance or the hardly soluble substance added to the stock solution varies depending on the type of the added substance and the target decolorizing property. Therefore, it is necessary to set the addition amount according to these conditions, but generally, by adding 0.01 to 1% by weight to the stock solution, a sufficient target decolorizing property can be obtained.

The membrane treatment method may be carried out according to a conventional method, except that the above substance is added to the stock solution in advance and supplied to the membrane treatment apparatus.

The liquid food subject to the present invention includes, for example, a proteolytic solution such as a vegetable protein hydrolyzate (HVP) and an animal protein hydrolyzate (HAP), a fermented solution such as soy sauce, a meat extract, a seafood extract, and a vegetable extract. There are no particular restrictions on the type of extract such as HVP, HAP that requires the acquisition of various decolorizing products.
In bleaching, etc., the restrictions on the selection of the film are eased,
Moreover, it is highly useful in that a plurality of desired decolorizing properties can be obtained with one type of film.

The present invention will be further described below with reference to examples.

Example 1 A soybean protein hydrolyzed solution (hereinafter referred to as HVP solution) was decolorized using a spiral ultrafiltration membrane (molecular cutoff: 6000, membrane area: 0.25 m ² , material: polysulfone type). The experiment was carried out by preparing 20 supply solutions and returning all the concentrated solution and the permeated solution to the supply solution tank. The operating condition of the ultrafiltration device is a pressure of 10 kg.
The f / cm ² , the temperature was 40 ° C, and the circulation flow rate was 3 / min. As an additive, sodium polyacrylate (average molecular weight 200,000) 0.05
%, Gelatin (average molecular weight 100,000) 0.05%, and tyrosine fine crystals 0.4% were used to compare the permeation flux and decolorization property with no addition. The results are shown in Table 1.

Example 2 Soy sauce was subjected to film decolorization under the same conditions as in Example-1. As an additive, 0.05% gelatin (average molecular weight 100,000) was used, and the permeation flux and the decolorizing property were compared with those without addition. The results are shown in Table 2.

Example 3 The same treatment as in Example 2 was carried out using a Teijin Ltd. PBIL reverse osmosis membrane (name TL-230, salt inhibition rate 10%), and the permeation flow of the gelatin 0.05% addition group and non-addition group The bleaching and decolorizing properties were compared. The results are shown in Table 3.

Claims (3)

[Claims] 1. A molecular weight cutoff of 5,000 or more or a salt inhibition rate of 30%
When decolorizing liquid foods using the following membranes, in advance in the undiluted solution, add a high molecular weight substance of 5,000 or more or particles of a poorly soluble substance having a particle size that does not pass through the membrane, and supply it to the membrane treatment device. A characteristic method for decolorizing liquid foods. 2. A gelatin or soybean protein, egg white, pectin, agar, gum, dextran, sodium polyacrylate, a sparingly soluble amino acid, an organic acid, an inorganic substance or a salt thereof as a polymer substance or a sparingly soluble substance. The method for decolorizing liquid foods according to claim 1, characterized in that one or more selected from the above are added. 3. The method for decolorizing a liquid food according to claim 1, wherein 0.01 to 1.0% by weight of the high molecular weight substance or the hardly soluble substance is added to the stock solution.