JPS6240260A - Decoloration of liquid food - Google Patents

Abstract

PURPOSE:To enable the decoloration of a liquid food in high efficiency at an arbitrary degree of decoloration using an ultrafiltration membrane, a reverse osmosis membrane having low salt rejection, etc., by adding fine particles of a polymeric substance or a hardly soluble substance to stock liquid and decoloring the liquid with a membrane. CONSTITUTION:A liquid food to be decolored is added with 0.01-1.0wt% additive consisting of one or more kinds of particles of a polymeric substance having a molecular weight of >=5,000 (e.g., gelatin, soybean protein, albumen, etc.) or a hardly soluble substance (e.g., amino acid, organic acid, inorganic acid, etc.) having particle size unable to pass through the membrane used in the present process. The obtained liquid is decolored with a membrane such as an ultrafiltration membrane having a critical molecular weight of >=5,000 or a reverse osmosis membrane having an NaCl rejection of <=30% etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for efficiently decolorizing liquid foods at any degree of decolorization using an ultrafiltration membrane, a reverse osmosis membrane with a low salt rejection rate, or the like.

[Conventional technology]

Decolorization is important in refining liquid foods.For example, in acid-decomposed solutions of vegetable proteins and soy sauce, the color increases due to oxidation during storage and the quality deteriorates significantly, so color stability is important. Decolorization is generally performed for the purpose of increasing the color.

Conventional methods for decolorizing liquid foods include removing pigments using adsorbents such as activated carbon and ion exchange resins, or
There are known methods of separating pigments using an ultralacrimal membrane that can block pigments or a reverse osmosis membrane that has a low salt rejection rate. However, in the method using an adsorbent, since the adsorbent adsorbs not only the dye but also the target substance to be purified to some extent, the yield of the target substance is inevitably reduced. Another disadvantage is that a large amount of waste liquid is produced when the adsorbent is regenerated. On the other hand, methods using membranes have the disadvantage that there is no membrane that can achieve the desired decolorizing property, or that once the membrane is determined, the decolorizing property is automatically determined and cannot be changed freely. Was.

This drawback exists regardless of the type of membrane, such as ultraviolet hyperemia or reverse osmosis membranes.

[Problem that the invention seeks to solve]

The present invention solves the disadvantages of conventional membrane decolorization methods, namely, that the decolorization property is determined by the selection of the membrane, and it is not always possible to obtain a membrane that provides the desired decolorization property. This solution solves the problem of the difficulty in setting flexible targets and the low yield and quality stability of the resulting product, and allows the decolorization to be set and changed arbitrarily even when using a membrane with low salt rejection. The aim is to develop a decolorization method that can obtain liquid foods with high quality stability.

[Means to Solve All Problems] As a result of extensive research into solving the problems in decolorizing liquid foods using the above-mentioned membrane, the present inventors discovered that fine particles of polymeric substances or acidic substances The present invention was completed by discovering that by adding additives to the stock solution in advance and then decolorizing the membrane, arbitrary decolorizing properties can be obtained depending on the type and concentration of the additive.

The membrane used in the present invention is an ultrafiltration membrane with a molecular fractionation of 1i5000 or more, a reverse osmosis membrane with a salt rejection rate of 30% or less, or a membrane with a molecular fractionation it of 5,000 or more or a salt rejection rate of 30% or less. Specific examples of such membranes include UM-10, P
M-10, UM-20E (manufactured by Amicon), HFA-1
80 (manufactured by Bio Engineering Co., Ltd.), G-10T (manufactured by Nippon Vacuum Technology Co., Ltd.), NTU-3502 (manufactured by Nitto Denko Corporation)
, 5IP-3013 (Asahi Kasei Inu, PBIL-TL-23
0 (manufactured in large quantities), etc. Molecular weight cut off is s, ooo
In the case of a membrane with a very small salt rejection rate or a salt rejection rate of more than 30%, the addition of additives will have little effect on changing the decolorization property, and there is a risk that the decolorization efficiency will deteriorate significantly due to a decrease in permeation flux. be. Therefore, in order to fully exhibit the effects of the present invention, the molecular weight cutoff of the membrane must be s, o o o or more or the salt rejection rate of the membrane must be 30% or less, and the upper limit of the molecular weight cutoff is 1 molecule fraction: Amount: 300. OOO'5
- Those exceeding - have poor decolorizing properties and are not suitable as objects of the present invention.

The polymer substance to be added has a molecular weight of 5,000 or more,
For example, gelatin, soy protein, egg white, pectin, agar,
These include gum, dextran, and sodium polyacrylate.

In addition, poorly soluble substances include those with a molecular weight of s, ooo or less, and have a particle size that does not pass through the membrane used.The required particle size varies depending on the type of membrane used, but specific Examples include amino acids, organic acids, inorganic substances, and salts thereof. One type or a combination of two or more of these polymeric substances and poorly soluble substances are added to the stock solution, but generally, 2 or more of the molecular weight cutoff of the membrane used is
edible polymeric substance or tyrosine,
It is desirable to add crystals of poorly soluble amino acids such as cystine.

The amount of the polymeric substance or acidic 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 amount added according to these conditions, but generally, the target decolorization property can be sufficiently obtained by adding 0.01 to 1% by weight to the stock solution.

The membrane treatment method follows conventional methods, except that the above substances are added to the stock solution in advance and then supplied to the membrane treatment equipment.
(You can do it.

The liquid food that is the object of the present invention is, for example, a plant ′
Protein hydrolyzate (HVP), animal protein hydrolyzate (H
Examples include proteolytic solutions such as AP), fermentation solutions such as soy sauce, extracts such as meat extract, fish and shellfish extract, and wildflower extract. Manufactured: □It is necessary to acquire the product 1 (VP,,
It is highly useful in decolorizing RAP and other methods because it eases restrictions on the selection of a vinyl film and allows multiple desired decolorizing properties to be achieved with one or two types of films.
-1. Hereinafter, the present invention will be further explained with reference to Examples. .

Example 11: A soybean protein hydrolyzate (hereinafter referred to as HVP liquid) was prepared using a mother yral type ultrafiltration membrane (molecular weight cut off: 6000, membrane
r (Area: 0.25m", Material: Polysulfone)
i:? .

It was bleached. For the experiment, prepare 201% of the supply solution and concentrate it.
[Perform the number of lines and return all the permeated liquid to the supply liquid tank.]
It was. The operating conditions for the ultrafiltration device are a pressure of 10 kgf.
The Δml temperature was 40° C., and the circulation flow was m 311 /min. Additives include 41J sodium acrylate (average molecular weight 200,000), 0.05t, gelatin (average molecular weight 110
0.05% and 0.4% tyrosine microcrystals were used to compare the permeation flux and decolorization properties with those without additives. Results first
Shown in the table.

Table 1 Absorption value of this supply liquid at 532 nm: 0.95 Example 2 Soy sauce? The membrane was decolorized under the same conditions as in Example-1.

Gelatin (average molecular weight 100,000) 0.05 as an additive
% was used to compare the permeation flux and decolorization with those without additives.

The results are shown in Table 2.

Table 2 Absorption value at 532 nm of this supply solution: 4.25 Example 3 The same treatment as in Example 2 was carried out using a PBIL reverse osmosis membrane (name: TL-230, salt rejection rate 10 cm) manufactured by Yodai Co., Ltd. The permeation flux and decolorization properties of the gelatin-added area and the gelatin-free area were compared. The results are shown in Table 3.

Table 3

Claims (1)

[Claims] 1. When decolorizing liquid foods using a membrane with a molecular weight cut-off of 5,000 or more or a salt rejection rate of 30% or less, in advance,
A method for decolorizing liquid foods, which comprises adding particles of a polymer substance having a molecular weight of 5,000 or more or a poorly soluble substance having a particle size that does not pass through a membrane, and supplying the particles to a membrane treatment device. 2. The polymer substance or poorly soluble substance selected from gelatin, soybean protein, egg white, pectin, agar, gum, dextran, sodium polyacrylate, poorly soluble amino acids, organic acids, inorganic substances, and their salts. A method for decolorizing a liquid food according to claim 1, characterized in that one or more types are added. 3. The method for decolorizing a liquid food according to claim 1, characterized in that 0.01 to 1.0% by weight of a polymeric substance or a poorly soluble substance is added to the stock solution.