JP3044487B2 - Method for producing a composition containing sialic acids and having a high α-lactalbumin content - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing a composition containing sialic acids and having a high α-lactalbumin content from milky whey.

[0002]

2. Description of the Related Art Sialic acids present in milk include, for example, sialic acid-linked oligosaccharides linked to sugars such as sialyl lactose (SL), κ-casein glycomacropeptide (GMP) linked to peptides, and lipids. It is conventionally known that there is a ganglioside bound thereto. GMP
Is a sialic acid-binding peptide produced when rennet or pepsin is allowed to act on κ-casein of milk,
Included in cheese whey and rennet casein whey.

In recent years, it has been known that sugar chains contained in complex carbohydrates such as glycoproteins and glycolipids play an important role in intercellular discrimination in living organisms. It has been recognized that it is particularly important as a necessary component for a receptor to perform. In addition, sialic acids are contained in breast milk in an amount about 3 to 5 times that of cow's milk, and these sialic acids are also considered to function as one of the protective factors for infection of infants. In particular, GM
P has an effect of preventing Escherichia coli from adhering to intestinal cells and protecting against influenza virus infection (JP-A-63-284).
133), anti-plaque effect (JP-A-63-233911) and anorexia (Bulletin of Experimental Biology and Medication)
cine 96,889 (1983))
There has been a strong demand for industrial-scale production for utilizing these as foods and pharmaceutical materials such as breast milk substitutes and functional foods.

As a technique for separating sialic acids in milk, a method for preparing a sialic acid binding protein (Japanese Patent Publication No.
21234), a method for preparing a sialic acid-linked oligosaccharide (JP-A-59-184)
197) and a method for preparing sialic acid-binding peptide (GMP) (JP-A-63-284199). On the other hand, whey protein is known to be used as a protein source in breast milk substitutes or nutritional compositions because it has higher nutritional value and protein utilization efficiency than casein and soy protein. In particular, when used as a substitute for breast milk, β-lactoglobulin, which is the main component of whey protein in milk, is a protein that does not exist in breast milk and acts as an allergen for infant allergies, containing α-lactalbumin. It is said that it is preferable to use a high amount of material.

As a method for separating and recovering a fraction having a high α-lactalbumin content from whey, there have been proposed, for example, Kuwata et al. (J. Food Sci., 50 (1985)) and Pierce (Aust. D.
airyTechnol., 42 (1987)) and Mowwa et al.
No. 494) is disclosed. However,
These methods aim at separating sialic acids and α-lactalbumin individually, and do not show a method for simultaneously and efficiently recovering sialic acids and α-lactalbumin contained in milk. In addition, these methods have economical problems, such as complicated processes in industrial production, large capital investment and high operating costs.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to sialic acids and α-alpha acids which have recently been found to be useful.
To provide a method for simultaneously separating and producing lactalbumin efficiently and simultaneously from milky whey such as cheese whey or rennet casein whey.

[0007]

According to the present invention, milk whey is cooled, after adding Ca and / or Mg, the pH is adjusted to 6 to 9, and after heating and holding at 40 to 60 ° C. for 10 to 20 minutes , A method for producing a composition containing sialic acids and having a high α-lactalbumin content, which comprises removing a formed precipitate.
More particularly, the present invention relates to milk whey,
Cool to 10 ° C. and reduce the Ca and / or Mg content preferably from 0.6 to
After adjusting to 2.0 g / kg and adding, adjust the pH to 6-9 and add 40-60
After heating at 10 ° C. for 10 to 20 minutes, the formed precipitate is removed. When removing the formed precipitate, microfiltration is performed using a membrane having a pore size of 1 μm or less.
Alternatively, ultrafiltration can be performed using a membrane having a molecular weight cut-off of 50,000 or more.

Further, the filtrate obtained by the membrane treatment can be concentrated and / or desalted, and if necessary, can be made into a dry powder. After adjusting the pH to 4 or more during the concentration and desalting, ultrafiltration can be performed using a membrane having a molecular weight cut off of 50,000 or less. More preferably, in order to increase the α-lactalbumin content, the concentrated solution obtained by the ultrafiltration treatment is adjusted to pH 3.0 to 5.0, and then heated and maintained at 40 to 55 ° C., preferably for 30 to 60 minutes. The resulting precipitate is obtained. Also,
Further, after adjusting the pH to 6 to 8 and dissolving the precipitate, it can be concentrated, desalted, and dried to a powder as required.

The whey containing sialic acids as a raw material of the present invention is produced as a by-product when producing cheese or rennet casein from milk such as cow's milk, goat's milk and sheep's milk. Since a small amount of curd or fat often remains in these whey, they are generally removed with a cream separator or a clarifier. However, according to the present invention, without performing such treatment, fat is removed by performing treatment with a microfiltration membrane or ultrafiltration membrane, and β-lactoglobulin is simultaneously removed by removing β-lactoglobulin. α-lactalbumin content can be increased. The permeate thus obtained contained sialic acids and α-lactalbumin at a high concentration.

In the present invention, the substance used for adjusting the Ca and Mg concentrations may be any water-soluble salt such as CaCl ₂ or MgCl _2, and the substance used for adjusting the pH may be, for example, an acid such as hydrochloric acid, sulfuric acid or acetic acid. And sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, and the like when they are alkalis. The reason for using Ca and / or Mg is to associate and agglutinate β-lactoglobulin in the subsequent heating and holding step, so that the content of Ca and / or Mg is 0.6 to 2.0 g.
The reason for adjusting to / kg is that if the ionic strength of free Ca and / or Mg is lower than 0.6 g / kg, the association / aggregation does not proceed sufficiently, and if it exceeds 2.0 g / kg and the ionic strength is higher. This is because the association and aggregation of β-lactoglobulin is reduced.

Then, the pH is adjusted to 6 to 9 and the temperature is adjusted to 10 at 40 to 60 ° C.
Heat for ~ 20 minutes, but if the pH is less than 6 or greater than 9,
-Lactoglobulin association / aggregation does not occur sufficiently.
Further, if the heating time and temperature exceed the above range, due to the thermal denaturation of α-lactalbumin, etc., it remains in the concentrate together with β-lactoglobulin in the subsequent microfiltration or ultrafiltration treatment step, and the permeated liquid contains the target composition. Can not get.

The substances removed in this microfiltration or ultrafiltration step are mainly fats and β-lactoglobulin, and some serum albumins and immunoglobulins are also removed. The components of the resulting composition consist mainly of α as whey protein.
-Lactalbumin and also contains sialic acids, including GMP, lactose and ash. The thermal stability of whey proteins according to Ca and Mg concentrations has already been determined by the method of SUNISA VARUNSATIAN et al. (J. Food
Science, 48 (1983)), and the method of JNdeWIT et al. (J. Dairy Science, 67 (1984)). As a fractionation method, the supernatant and the precipitate are separated by centrifugation. Draw
It merely shows the composition of the fraction, but does not describe separation and fractionation using an industrial membrane. on the other hand,
Mulwa (JLMAUBOIS) et al. (Bulletin of the IDF212 (1
987)) shows a method for removing lipoprotein by a microfiltration membrane, but does not mention the change in β-lactoglobulin content by this operation.

[0013] The composition thus obtained comprises a whey protein concentrate (WPC) having a high lactose content and an increased protein content.
If used, the protein content can be adjusted to the required protein content by performing an ultrafiltration treatment. In the ultrafiltration treatment, it is preferable to use a membrane having a molecular weight cut-off of 50,000 or less after adjusting the pH to 4 or more in order to efficiently recover sialic acids into a concentrated solution. That is, GMP (molecular weight of about 9000), which is a main component of sialic acids, exists as a polymer (molecular weight of 50,000) at pH 4 or higher, while at a pH of less than 4,
Polymerization is preferred for efficient recovery in a concentrated solution since it exists as a monomer.

The concentrate obtained in this manner is adjusted to pH 3.0 to 5.0 in order to further increase the α-lactalbumin content, and then heated at 40 to 55 ° C., preferably for 30 to 60 minutes, to obtain a precipitate. Generate The precipitate can be adjusted to pH 6 to 8 and dissolved, and then, if necessary, concentrated, desalted, and dried to a powder. In this precipitation generation step, outside the above range, sialic acids and α-lactalbumin cannot be simultaneously and efficiently recovered as a precipitate.

Incidentally, the precipitation fractionation operation has already been described by Pierce (RJPEARCE) et al. (JP-A-2-503425) and Chihara et al.
As disclosed in Japanese Patent Application Laid-Open No. 63-268138, these methods aim at separating and recovering only α-lactalbumin. Further, the method according to the present invention is different from these methods in the pretreatment, and by these steps, sialic acid is contained and α-lactalbumin can be recovered simultaneously and efficiently.

[0016]

According to the present invention, a composition containing sialic acids from whey and a high concentration of α-lactalbumin can be produced on an industrial scale at low cost, easily and efficiently. . The composition thus obtained can be used as a food material or a pharmaceutical material, and is extremely useful for industry.

[0017]

Next, the present invention will be specifically described based on examples. Example 1 100 kg of cheddar cheese whey was sterilized and cooled to 2 ° C.
Adjust the Ca concentration to 1.2 g / kg with CaCl ₂ . Then NaOH
After adjusting the pH to 7.3 using a, and heating at 50 ° C for 10 minutes, the resulting precipitate was filtered using a microfiltration membrane (TECH-SEP CARP
This was removed using BOSEP M20), and 100 kg of a permeate was obtained, which was filtered at a concentration ratio of 20 times and an equivalent water ratio of 1 time. The obtained permeate is solid 5.1 g / 100 g, protein 0.4 g / 100 g, α-lactalbumin 0.08 g / 100 g, β-lactoglobulin 0.07 / 100
g, sialic acid 12 mg / 100 g.

Example 2 100 kg of the permeate obtained in Example 1 was converted to pH 5.5 using HCl.
After that, ultrafiltration was performed at a concentration of 15 times using a membrane having a molecular weight cut-off of 20,000 Da (DDS GR61PP) to obtain 6.7 kg of a concentrated solution. The resulting concentrate is a solid 12.1 g / 100 g, protein 5.0
g / 100 g, α-lactalbumin 1.2 g / 100 g, β-lactoglobulin 1.0 g / 100 g, and sialic acid 175 mg / 100 g.

Example 3 6.7 kg of the concentrate obtained in Example 2 was treated with HCl at pH 3.7.
Then, the mixture was heated at 55 ° C. for 30 minutes, and the formed precipitate was separated and collected by centrifugation. The resulting precipitate was washed with NaOH
It was adjusted to pH 7 and dissolved to obtain 7.0 kg of the composition. The obtained composition is solid 2.6 g / 100 g, protein 2.0 g / 100 g, α-lactalbumin 1.0 g / 100 g, β-lactoglobulin 0.3 g / 100 g.
Sialic acid at 70 mg / 100 g.

This composition was concentrated and dried by a conventional method to obtain 200 g of a powder.

Example 4 100 kg of rennet casein whey was sterilized, cooled to 2 ° C., and the Mg concentration was adjusted to 0.8 g / kg with MgCl ₂ . Then KO
After adjusting the pH to 7.3 with H and heating at 50 ° C for 10 minutes, the resulting precipitate was filtered through a 0.5 μm pore microfiltration membrane (NGK CEFILT-
MF) and filtered at a concentration ratio of 25 times and an equivalent water ratio of 3 times to obtain 108 kg of a permeate. The obtained permeate contained 6.0 g / 100 g of solid, 0.5 g / 100 g of protein, 0.10 g / 100 g of α-lactalbumin, 0.09 / 100 g of β-lactoglobulin, and 16 mg / 100 g of sialic acid.

Example 5 108 kg of the permeate obtained in Example 4 was converted to pH 5.5 using HCl.
After adjusting to 8000 Da membrane (KOCH ABCOR HFK131)
Ultrafiltration treatment of 10 times the concentration using a concentrated solution 10.8
kg gained. The resulting concentrate is 12.1 g / 100 g solid, protein
5.0 g / 100 g, α-lactalbumin 1.0 g / 100 g, β-lactoglobulin 0.9 g / 100 g, and sialic acid 150 mg / 100 g.

Example 6 10.8 kg of the concentrate obtained in Example 5 was subjected to pH 4.0 using HCl.
After heating to 55 ° C. for 30 minutes, the resulting precipitate was separated by centrifugation. The resulting precipitate was adjusted to pH 7 with NaOH and dissolved to obtain 10.0 kg of a composition. The resulting composition is solid
2.4g / 100g, protein 1.8g / 100g, α-lactalbumin
It contained 1.0 g / 100 g, β-lactoglobulin 0.25 g / 100 g, and sialic acid 60 mg / 100 g.

This composition was concentrated and dried by a conventional method to obtain 250 g of a powder.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makihiro Sugawara 5-11-3 Shinjuku-cho, Kawagoe-shi, Saitama Snow Brand Milk Industry Co., Ltd. Single dormitory (72) Inventor Yasuhiro Matsuoka 1-6, Miyamoto-cho, Tokorozawa-shi, Saitama 2 Canadian Heights 201 (56) References JP-A-1-165343 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A23J 3/08 A23C 9/142 A23J 1/20

Claims (2)

(57) [Claims] 1. Cooling milk whey, adding Ca and / or Mg, adjusting the pH to 6 to 9, heating and holding at 40 to 60 ° C. for 10 to 20 minutes , and using a membrane having a pore size of 1 μm or less, Perform microfiltration
The resulting precipitate was removed, and the resulting filtrate was adjusted to pH 4
After adjustment as above, use a membrane with a molecular weight cut off of 50,000 or less,
Perform filtration and adjust the resulting concentrate to pH 3.0 to 5.0
Thereafter, after heating and holding at 40 to 55 ° C for 30 to 60 minutes, the formed precipitate is removed.
And further adjusted to pH 6-8, and after dissolving the precipitate,
A method for producing a composition containing sialic acids and having a high content of α-lactalbumin at the same time , characterized in that the composition is concentrated, desalted and dried to obtain a powder . 2. Milk whey is cooled, and Ca and / or Mg is added.
After addition, adjust the pH to 6-9 and heat at 40-60 ° C for 10-20 minutes
After retention, use an ultrafiltration
The resulting precipitate was removed by filtration and the resulting filtrate was filtered.
After adjusting the pH to 4 or more, use a membrane with a molecular weight cut off of 50,000 or less.
Ultrafiltration was performed, and the resulting concentrated solution was adjusted to pH 3.0 to 5.
After adjusting to 0, heating and holding at 40-55 ° C for 30-60 minutes,
The precipitate obtained was adjusted to pH 6-8, and the precipitate was dissolved.
Afterwards, if necessary, it is concentrated, desalted, and dried into powder
Α-lactalbumin containing sialic acids
A method for producing a composition having a high content .