JP3225081B2 - Method for producing a composition having a high content of kappa-casein glycomacropeptide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a composition having a high content of κ-casein glycomacropeptide from milky whey.

[0002]

BACKGROUND OF THE INVENTION κ-Casein glycomacropeptide is
It is a sialic acid-binding peptide that is produced when renento or pepsin is allowed to act on κ-casein of milk, and it is conventionally known that it is contained in cheese whey and rennet casein whey.

Hitherto, as a method for producing a κ-casein glycomacropeptide, in the laboratory, after dissolving κ-casein isolated from milk in deionized water, pepsin is allowed to act on the solution, and then trichloroacetic acid is produced. In addition, a para-κ-casein fraction is precipitated, and then the resulting supernatant is dialyzed against deionized water and freeze-dried (Seo et al., Jo).
urnal of Food Science 53 ,
80 (1988)) or after dissolving the above κ-casein in deionized water and adjusting the pH of the solution to 6.7,
A rennet was allowed to act, and then the pH was further adjusted to 4.6 to precipitate and remove para-κ-casein. The resulting supernatant was subjected to dialysis, desalted, and lyophilized. The method of preparation (“Milk Protein” PP200 issued by Academic Press) and the like have been performed. However, these methods are not suitable for mass production on an industrial scale because they are preparation methods in a laboratory.

On the other hand, since the industrial utility of κ-casein glycomacropeptide has not been known,
The method of mass production has not been sufficiently studied.

However, recently, κ-casein glycomacropeptide has an effect of reducing the appetite of dogs (Stan et al., Bullutin of Explorer).
imment Biology and Medicin
e 96 , 889 (1983)), indicating that it can be used as a food material for preventing obesity.

[0006] Thereafter, the κ-casein glycomacropeptide has an effect of preventing Escherichia coli from adhering to the intestinal tract and preventing influenza virus infection (Japanese Patent Application Laid-open No. Sho 63).
-284133) and an antiplaque effect (JP-A-63-233)
No. 911), the production on an industrial scale has been strongly desired.

Under such circumstances, a method for preparing κ-casein glycomacropeptide from rennet casein whey (JP-A-63-284199) has been developed.
This method can be used as a food material because it does not use conventionally used trichloroacetic acid, and can be mass-produced. However, when rennet casein is not widely used and a large amount of rennet casein is to be obtained, κ-
This raises the cost of producing casein glycomacropeptide and is not practical.

Japanese Patent Application Laid-Open No. 2-276542 discloses a method for purifying κ-casein glycomacropeptide by combining pH adjustment of a milk material containing κ-casein glycomacropeptide and ultrafiltration membrane treatment. ing. By this method, mass production has become possible at lower cost than ever before, and it has become possible to use it as a pharmaceutical material. However, for use as a food material, the development of a technology that can be more easily and cheaply produced is desired.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a method for inexpensively producing κ-casein glycomacropeptide, which has recently been found useful, from milky whey on an industrial scale. is there.

[0010]

The molecular weight of κ-casein glycomacropeptide is about 9,000, and it is said that it exists as a monomer below pH 4 and as a polymer above pH 4 as a polymer (molecular weight of about 45,000). However, the denaturation and the change in morphology (apparent molecular weight) due to the heat treatment are not disclosed. What is important here is that membrane separation of a specific component from a multi-component system is different from membrane separation of a component from a single-component system, and the interaction between components has a large effect. For example, a single component system does not transmit through the membrane, whereas a multicomponent system may transmit the same membrane.

[0011] Since the κ-casein glycomacropeptide has a unknown portion in terms of its own membrane permeability, the behavior of κ-casein glycomacropeptide in milk whey is almost unknown. Unknown. Therefore, although the permeability of the membrane of κ-casein glycomacropeptide due to the heat treatment has not been clarified, the present inventors have focused on the relationship between the heating conditions and the permeability of the membrane, and as a result of intensive research. A phenomenon in which the membrane permeability of κ-casein glycomacropeptide in milk whey is reversed by specific heating and pH conditions, and by utilizing such a phenomenon, κ-casein glycomacropeptide is effectively concentrated and recovered at a high concentration. It has been found that this is possible and the present invention has been completed. That is, the present invention has a pH of 6.0.
The milk whey prepared above and heat-treated at 40 to 79 ° C. is subjected to membrane treatment to remove whey protein from the permeate, and κ-
The casein glycomacropeptide is recovered in a concentrated solution, the obtained concentrated solution is adjusted to pH 5.5 or less, and then subjected to membrane treatment again to recover the κ-casein glycomacropeptide in a permeate. -A method for producing a composition having a high content of casein glycomacropeptide.

Further, the present inventors have found that the permeability of κ-casein glycomacropeptide changes extremely sharply at pH 6 by using a specific membrane material. That is, in a preferred embodiment of the present invention,
The membrane used for the membrane treatment may be a microfiltration membrane having a pore size of 0.5 μm or less or an ultrafiltration membrane having a molecular weight cut off of 500,000 Da or more, and the membrane may be an inorganic alumina membrane.

The present invention also relates to a method for preparing a permeate recovered by the above-mentioned production method, wherein the permeate is adjusted to a pH of 4 or less, and then a molecular weight cut off of 1 is obtained.
Concentration using an ultrafiltration membrane of 000 Da or less,
Alternatively, a composition having a high κ-casein glycomacropeptide content, wherein the recovered permeate is adjusted to pH 4 or higher, and then concentrated using an ultrafiltration membrane having a molecular weight cutoff of 10,000 to 50,000 Da. It is a manufacturing method of.

The content of κ-casein glycomacropeptide in the composition obtained according to the present invention is approximately 1000 to 3000 mg / 100 g in terms of sialic acid content in the solid content.
And more than 50% of the kappa-casein glycomacropeptide per protein is present in the raw milk whey.
The content of casein glycomacropeptide is considerably higher than that of 10%.

In the present invention, the membrane permeability of κ-casein glycomacropeptide changes drastically depending on the pH of milk whey and the heating conditions, and the separation from contaminating whey proteins and the like becomes possible depending on the processing conditions. The interaction and morphology of whey protein, fat, and kappa-casein glycomacropeptide have been altered, and this is thought to be due to a difference in their fractionation characteristics, but it is not always clear.

Hereinafter, the present invention will be described in detail.

The milky whey which is a raw material of the present invention is a by-product of producing cheese or rennet casein from milks such as cow's milk, goat's milk and sheep's milk, and is κ-casein glycomacropeptide. As long as it is contained, it can be used. Also, whey protein concentrate obtained by concentrating these whey using an ultrafiltration membrane can be used. Furthermore, reduced whey obtained by re-dissolving the powder obtained by spray-drying these whey and whey protein concentrate in water can also be used.

After the above whey is adjusted to pH 6 or more, preferably to pH 6 to 8, it is added at 40 to 79 ° C., preferably 45 to 79 ° C.
Heat treatment at 70 ° C. The processing time is preferably about 2 to 30 minutes. Under stronger heating conditions, β-lactoglobulin, the main whey protein in whey, self-associates or associates or aggregates with other whey proteins, fat globule membrane substances, etc., and these contaminants are less likely to penetrate the membrane Result
This is because it becomes difficult to separate from the κ-casein glycomacropeptide during the membrane treatment. Therefore, it is important that the heat treatment is performed to such an extent that the whey protein does not undergo irreversible denaturation, and the above-mentioned heating conditions are necessary. For example, under a heating condition of 80 ° C. or more, whey protein associates to a state close to particles due to interaction between protein and fat, and cannot pass through the membrane.

On the other hand, the target substance κ-casein glycomacropeptide has the property that it does not associate with whey protein, exists as an oligomer by self-association, and changes the permeability during membrane treatment due to the difference in membrane material. Has been made clear by the present invention.

At pH 6 or above, which is the above pH adjustment range, the permeability of κ-casein glycomacropeptide membrane is low, and it is difficult to separate κ-casein glycomacropeptide as a concentrate and other contaminants as a permeate. It is a suitable range. The pH may be adjusted by any alkali agent or acid, and examples thereof include sodium hydroxide, sodium carbonate, potassium hydroxide, hydrochloric acid, sulfuric acid, acetic acid, lactic acid, and citric acid.

Next, the above-mentioned heat-treated whey is subjected to a membrane treatment. Any means capable of effectively separating whey protein from κ-casein glycomacropeptide can be employed without any limitation. Those having an excellent fractionation ability and suitable for industrial-scale processing include a microfiltration membrane having a membrane material of alumina having a pore size of 0.5 μm or less or a molecular weight cut off of 500,
It is an ultrafiltration membrane of 000 Da or more. If membrane filtration is performed using these membranes, most of the whey proteins can be separated and removed from the permeate side, and the κ-casein glycomacropeptide can be concentrated. Here, pore size 0.5
With a microfiltration membrane exceeding μm, the associated κ-casein glycomacropeptide is permeated and the molecular weight cut off is 5
In an ultrafiltration membrane having a molecular weight of less than 00000 Da, whey protein is partially concentrated, and the concentration efficiency of κ-casein glycomacropeptide is reduced. Further, as a film material, pH 6
It is preferable that the fractionation of κ-casein glycomacropeptide changes sharply in the vicinity. This means that the pH of the concentrate is adjusted again in the next step, this time not on the concentrate side,
This is because it is convenient to perform a membrane treatment to recover the κ-casein glycomacropeptide on the permeate side. This second
In the second membrane separation, fat is removed from the concentrate. The same membrane is used for the first and second membrane treatments,
If the κ-casein glycomacropeptide can be fractionated only by the above adjustment, the membrane treatment operation is extremely easy.
From this viewpoint, an alumina film is optimal. However, for example, in a membrane using zirconia carbon, the permeability of κ-casein glycomacropeptide is low and constant, and it is difficult to efficiently collect the κ-casein glycomacropeptide in the permeate after re-adjusting the pH. FIG. 1 shows an example of the pH-dependent transmittance of the alumina film and the zirconia-carbon film. Zirconia carbon has only a few percent difference in transmittance due to changes in pH. Since there is no significant difference in membrane permeability between the first and second membrane treatments, it is difficult to selectively fractionate κ-casein glycomacropeptide.

However, in the first and second film treatments, it is not necessary to use an alumina film, for example, a titania film or the like, as long as a film material having an appropriate fractionation property is used.

In the first membrane treatment, whey protein,
Lactose and minerals can be removed on the permeate side. The obtained concentrated liquid is adjusted to a pH of 5.5 or less, preferably 3.5 to 5.0.
After treatment with a microfiltration membrane having a pore size of 0.5 μm or less or an ultrafiltration membrane having a molecular weight cut off of 500,000 Da or more, κ-casein glycomacropeptide can be recovered on the permeate side. . Such changes in fractionation properties involve interactions between components and have not been fully elucidated.

The reason why the lower limit value of the microfiltration membrane and the upper limit value of the ultrafiltration membrane are not set is that each fractionation characteristic is evaluated by the pore size of the microfiltration membrane and the molecular weight cut off of the ultrafiltration membrane. Because it is. That is, the boundary between the microfiltration membrane having a small pore size and the ultrafiltration membrane having a large molecular weight cut-off is not clearly defined.

At this time, the material of the film may be any material, but it is simple and efficient to use the alumina film which has been treated first. By this membrane treatment, the fat is concentrated in the concentrated solution, and the permeated solution recovers the κ-casein glycomacropeptide composition containing less fat, whey protein and the like.

Further, in order to remove whey proteins, lactose and minerals remaining in the permeate, the pH of the permeate is adjusted.
Is 4 or less, it can be concentrated using an ultrafiltration membrane having a molecular weight cut-off of 10,000 Da or less. After adjusting the obtained permeate to pH 4 or higher, the molecular weight cut off was 10,10.
It can also be concentrated using a 000-50,000 Da ultrafiltration membrane. The kappa-casein glycomacropeptide has a pH of 4 or lower and a monomer below it (molecular weight 9,9).
000), and beyond that the polymer (molecular weight 45,000)
0), and the membrane permeability changes. Further, the fraction obtained here can be dried and powdered if necessary.

The content of κ-casein glycomacropeptide in the powder varies depending on the milky whey and the processing conditions, but is approximately 1000 to 30 in terms of sialic acid content.
00 mg / 100 g.

When granules or powders are formed by a conventional method, oils and fats, vitamins, milanel, taste components, pigments, fragrances, sugars, etc. are added as necessary to obtain products according to the intended use. It is also possible.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. Example 1 100 kg of cheddar cheese whey (protein 0.6%) whose pH was adjusted to 7.0 was heated and maintained at 50 ° C. for 10 minutes, and then this whey was subjected to a microfiltration membrane having a pore size of 0.1 μm (Nippon Gaishi Co., Ltd.). Using CEFILT-MF, alumina membrane, membrane area of 4 m ² ) and an average flux of 150 l / m ² hr
To obtain 10 kg of a concentrated solution. This concentrated solution is adjusted to pH5.
After adjusting to 0, membrane filtration was performed using the same membrane, and 10 kg of permeate was
I got This permeate was concentrated and dried to 0.5 kg of powder,
It contained 1000 mg / 100 g in terms of sialic acid in κ-casein glycomacropeptide, and the κ-casein glycomacropeptide was 50% by weight per protein. Example 2 100 kg of Gouda cheese whey (protein 0.7%) adjusted to pH 8.5 was heated at 75 ° C. for 1 minute, cooled to 50 ° C., and the whey was subjected to microfiltration with a pore size of 0.5 μm. Average permeation flux of 120 l / m using a membrane (SCT MEMBRALOX, alumina membrane, membrane area 5 m ² )
^The mixture was concentrated for ² hours to obtain 10 kg of a concentrate. This concentrated solution is p
After adjusting to H5.0, membrane filtration was performed using the same membrane to obtain 12 kg of permeate. This permeate was subjected to a cut-off molecular weight of 50,000 D.
a ultrafiltration membrane (CEFILT-UF manufactured by NGK Insulators, Ltd.
The solution was concentrated using an alumina membrane with a membrane area of 4.0 m ² ) at an average permeation flux of 40 l / m ² hr. 0.1 kg of the dried powder of this concentrated liquid contained 3000 mg / 100 g in terms of sialic acid in κ-casein glycomacropeptide, and contained 80% by weight of κ-casein glycomacropeptide per protein. Example 3 100 kg of rennet casein whey (protein 0.8%) whose pH was adjusted to 6.5 was heat-treated at 60 ° C. for 5 minutes, cooled to 10 ° C., and the whey was subjected to a molecular weight cutoff of 50%.
Ultrafiltration membrane of 000 Da (CEFI manufactured by NGK Insulators, Ltd.)
LT-UF, membrane area 8 m ² ) and average permeation flux 30
The mixture was concentrated at 1 / m ² hr to obtain 10 kg of a concentrate. After adjusting this concentrated solution to pH 3.5, the solution was subjected to membrane filtration using the same membrane to obtain 15 kg of a permeate. This permeate was subjected to fractionation molecular weight 8,
000 Da ultrafiltration membrane (HFK-1 manufactured by Nippon Abco Co., Ltd.)
31, an alumina membrane and a membrane area of 5.0 m ² ) at an average flux of 25 l / m ² hr. 0.2 kg of the dried powder of this concentrated liquid contained 1600 mg / 100 g in terms of sialic acid in κ-casein glycomacropeptide, and κ-casein glycomacropeptide was 60% by weight per protein.

[0030]

As described above, according to the present invention, milk whey containing κ-casein glycomacropeptide is heat-treated and filtered through a membrane made of a specific material to obtain a κ-casein glycomacropeptide content. Can be easily and efficiently produced on a commercial scale at a low cost. The composition having a high content of κ-casein glycomacropeptide thus obtained can be used as a food material or a pharmaceutical raw material, and is extremely useful for the industry.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a change in the transmittance of κ-casein glycomacropeptide with respect to pH in an alumina membrane and a zirconia-carbon membrane.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukio Uchida 5270-1 Kitano, Tokorozawa-shi, Saitama 1082-204 (72) Inventor Yoshihiro Kawasaki 4881-21 Kasawa, Kawagoe-shi, Saitama (56) References JP JP-A-63-284199 (JP, A) JP-A-2-276542 (JP, A) JP-A-3-294299 (JP, A) Nippon Gijutsu Kyokai, Vol. 40 (1990) pp. 117-129 Biochi. Biotechnol l. Biochem. , Vol. 56, No. 1 (1992-Jan) p. 140-141 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07K 14/47 A23C 21/00 A23J 1/20 C07K 1/14-1/36 BIOSIS (DIALOG) CA (STN) JICST file ( JOIS) JAFIC file (JOIS) MEDLINE (STN) WPI (DIALOG)

Claims (5)

(57) [Claims] 1. A milk whey that has been adjusted to a pH of 6.0 or more and heat-treated at 40 to 79 ° C. is subjected to a membrane treatment to remove whey protein from the permeate, and the κ-casein glycomacropeptide is recovered in a concentrate. After adjusting the pH of the obtained concentrated solution to 5.5 or less, the solution is again subjected to membrane treatment, and the κ-casein glycomacropeptide is recovered in the permeate.
A method for producing a composition having a high casein glycomacropeptide content. 2. The membrane used for membrane treatment has a pore size of 0.5
Microfiltration membrane of μm or less or molecular weight cut off 500,000
The production method according to claim 1, wherein the ultrafiltration membrane is a Da or more ultrafiltration membrane. 3. The method according to claim 2, wherein the film is an alumina film made of an inorganic material. 4. The κ-casein glycomacropeptide-containing solution, wherein the permeate recovered in claim 1 is adjusted to pH 4 or less and then concentrated using an ultrafiltration membrane having a molecular weight cut-off of 10,000 Da or less. A method for producing a high-volume composition. 5. After adjusting the pH of the permeated liquid recovered in claim 1 to 4 or more, the molecular weight cut off is 10,000 to 50,000.
Κ characterized by being concentrated using an ultrafiltration membrane of Da
-A method for producing a composition having a high content of casein glycomacropeptide.