JP3417513B2 - How to prepare whey - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to white whey, its powder, and a method for producing powdered milk using them.
The whey protein in the white whey obtained by the present invention forms a casein micelle-like aggregate, and in particular,
It has excellent thermal stability and high solubility. Whey and milk powder containing such micellar whey protein are widely applicable as food materials.

[0002]

Whey proteins are defined as milk proteins that are soluble in water under acidic conditions. Whey is obtained as a by-product in the production of cheese and casein, but it is extremely important to develop whey protein as a food material for the purpose of environmental protection and effective use of resources. Whey protein generally denatures when heated above 60 ° C, and easily gels when heated in the presence of salts under certain conditions (Kamiya Takamoto, Jpn. J. Dairy.
Food Sci., 29, A15-A25, 1980). Such gelling is
It is considered that the higher-order structure changes with heat denaturation, and the protein molecules form a three-dimensional network structure due to the increase in the hydrophobic region and the increase in the reactivity of the disulfide bond.

Since whey protein has a high nutritional value, it is used as a raw material for highly nutritious foods such as powdered milk for child-rearing, and the heat gelling property of whey protein as described above, binding property, emulsifying property, etc. Since it also has functional properties, it is used as a meat binder, fat substitute, etc. (Shunichi Dosako, Science of Food Protein p10
1-118). As described above, various uses of whey protein have been considered, but they are still used only in a limited number of fields as auxiliary materials for food processing.

Although whey is produced in large quantities as a by-product during cheese production, whey after removing casein has a transparent yellow green color. This is because the protein in whey is dissolved in water. When this whey is heated, the whey protein gels or precipitates as described above. Therefore, in order to powder whey, a high technique is required, and usually whey is used as a whey powder by adjusting its pH to around neutral, then concentrating and spray-drying. However, since such an operation has a high production cost and requires a large-scale facility, most whey produced during cheese production is often discarded as it is.

Furthermore, in order to utilize whey, a solution of casein is added to whey or reduced whey in which whey powder is dissolved, or fat is further added to carry out an emulsification treatment, which is then subjected to spray drying or the like. Drying is often performed to produce milk powder. However, the milk powder produced using whey as a raw material in this way lacks thermal stability as compared with the milk powder produced by the usual production method, and when reduced whey in which whey powder is dissolved is used, A defect called whey odor appears.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances of the prior art, and it is an object of the present invention to provide a method for treating whey for effectively utilizing it. In particular, the whey obtained by the present invention does not exist in the dissolved state of proteins as in conventional whey, but is dispersed in water in a micelle state, and therefore the whey solution has a white milk-like state. Present. Further, there is no need to separate and process whey protein, and the utility of whey can be enhanced by a very simple operation. Further, it is an object of the present invention to provide a method for preparing powdered milk having a high thermal stability, which uses this whey solution as a raw material.

[0007]

The present invention determines the pH of whey.
This is a method for preparing white whey, which comprises adjusting the whey protein to 5.5 to 6.5 and then heating it to 90 ° C. or higher to make the whey protein present in the whey into micelles. Further, the present invention is a method for producing a dry whey powder, which comprises heating the whey to pH 5.5 to 6.5 and then heating it to 90 ° C. or higher to micelle the whey protein present in the whey, and then drying the whey protein. is there. Furthermore, the present invention is characterized in that after the pH of whey is adjusted to 5.5 to 6.5, it is heated to 90 ° C. or higher, the whey protein present in the whey is micellar, and then a solution of casein is added. And its preparation method. Furthermore, the present invention provides 90% whey pH after adjustment to 5.5-6.5.
This is a method for preparing powdered milk, which comprises heating to a temperature of not lower than 0 ° C. to micelle the whey protein present in whey, and then adding a casein solution and drying.

The whey as a raw material of the present invention is produced as a by-product during cheese production or casein production. The whey used as the raw material of the present invention is a powder obtained by concentrating these whey and spray-drying them, or desalting these whey and spray-drying them (whey powder) or a powder by another method at 0.1-10%. Reduced whey obtained by dissolving in water to a certain concentration may be used. The main component composition of whey is about 0.6-0.8% protein, about 4.5% lactose, about 0.6 ash.
%, Fat about 0.3%, water about 93%. Whey powder is about 12 to 13% protein, about 65 to 75% lactose, and about 9 ash.
~ 10%, fat about 0.5-0.9%, water about 5-7%.

The pH of whey is usually pH 6.0-6.5,
Further, reduced whey in which whey powder is dissolved usually shows a neutral value around pH 7. At such pH, the protein in the whey is in a dissolved state and has a pale yellowish green color as described above.

The pH of this whey is weakly acidic, especially pH 5.5-
Adjust to 6.5 and then heat under conditions such that the whey protein will be heat denatured. When the whey protein is heat-denatured, heating is usually carried out at a heat denaturation temperature of the whey protein of 55 to 60 ° C., but the object of the present invention is completely achieved.
That is, in order to micelle the whey protein,
It is preferable to heat at 90 ° C. or higher. The heating time varies depending on the protein concentration in the whey that is the raw material, but for example, when using whey during cheese production, 12
It may be heated at 0 ° C. for 2 to 5 seconds. By such heat treatment, the protein in whey changes from the dissolved state to the micellar state. Incidentally, the micelle state in the present invention, as shown by casein which is a kind of milk protein,
It is a state in which a whey protein complex containing β-lactoglobulin as a main component is in the form of colloidal particles, as in the state of colloidal particles having a particle size distribution of 20 to 600 nm. These micelles have the property of scattering light, and the formation of whey protein micelles causes the whey to change dramatically from the original yellow-green color of whey to a milky-white color.

Furthermore, the milk protein micelle solution obtained by associating this micellar whey protein with a specific amount of casein exhibits milk-like whiteness like the whey solution containing the micellar whey protein and is excellent in heat stability. Does not cause gelation or precipitation by heating. Therefore, it can be used as a milk-like beverage or the like, or can be used as it is as a food material for various purposes. In addition, since the whey protein molecule is micellar and polymerized in the solution, it can be concentrated using, for example, a membrane having a cut-off molecular weight of 50,000 Da or more, and can be easily separated from low-molecular substances such as lactose in whey. .

The whey solution containing the above-mentioned micellar whey protein can be dried and powdered. Since the whey protein in the form of micelle has excellent thermal stability and the like, its solution can be easily made into a highly storable powder by freeze-drying, spray-drying, etc. , Unlike ordinary whey powder, the solubility does not decrease. Therefore, this powder can be used as an easily soluble powdered beverage or the like which is dissolved at the time of eating and drinking by performing a granulation process or the like.

In this way, the pH of whey is adjusted to 5.5 to 6.5.
It has not been known so far that the whey protein becomes micelles and the whey has a white color by adjusting to a weakly acidic region of and heat treatment. Further, it has not been known that the whey prepared in this way is powdered to improve the solubility and thermal stability. Further, this whey or whey powder is also characterized in that the conventional whey odor has disappeared.

Furthermore, after the pH of the whey is adjusted to 5.5 to 6.5, the whey protein is heated to 90 ° C. or more to micelle the whey protein present in the whey, and then the solution containing casein solution is also stable to heat and white. Stable powder can be prepared by drying it.

As mentioned above, it is known in the art to re-add casein removed during whey production to produce a dairy product called reconstituted milk. However, the dairy products thus produced are not always satisfactory because the heat stability of whey protein is poor and the whey odor is strong. However, in the method of the present invention, whey obtained by micelleizing whey protein is used as a raw material, casein is added thereto, and fat is added as necessary, and spray drying and other drying operations are performed to provide heat stability. It is possible to obtain milk powder without whey odor. The milk powder thus prepared has a very good flavor without the whey odor of conventional reconstituted milk and is also excellent in heat stability.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The white whey obtained by the method of the present invention is characterized in that the protein forms a micellar structure similar to casein micelles. In the present invention, the micelle structure, the micelle state described above,
That is, the state where the whey protein complex is a colloidal particle, such as the state where the whey protein complex has a particle distribution of 20 to 600 nm as shown by casein which is a kind of milk protein. . The whey micelles are in the form of irregularly shaped particles in appearance, and when they scatter light, they become white, and the internal structure of the particles is not particularly specified. The size of the whey micelle particles in the present invention is about 30 to 700 nm, preferably 50 to 600 nm.
It is a degree. The whey micelles are stably dispersed in the solution to form a cloudy solution. This micellar solution is extremely stable without precipitation or gelation even when heated. The particle size of the particles can be easily measured by a known laser scattering method or the like.

The whey used as a raw material for carrying out the present invention is particularly preferably one produced in association with the production of cheese. A method using this will be described. The whey obtained during production of Gouda cheese was adjusted to pH 5.5 with an aqueous lactic acid solution.
Adjust to ~ 6.5. After adjustment, using a plate type sterilizer,
Hold at 90 ° C for 3-6 seconds and cool to 5 ° C. By performing this operation, the whey that was initially yellowish green changes to milky white. This solution can maintain a stable state without precipitation even when heated or stored for a long period of time. Casein is then added to this white whey. As casein, commercially available acid casein is used, and it is about 5-10.
Dissolve to a concentration of 10%, treat with activated carbon to remove the casein odor, mix both to obtain the desired solid content, add water as necessary, and further homogenize. . If the casein added at this time is 1/20 weight or more with respect to whey protein, it becomes a stable suspension.
A whey powder can be obtained by heating at 0 ° C. or higher and spray drying. Furthermore, casein was added to whey protein in an amount of 1/3 or more by weight, which was dried, especially
A powder equivalent to skim milk powder can be obtained by heating at 120 ° C and spray drying.

Examples are shown below, but the present invention is not limited thereto.

Example 1 Generation of whey protein micelles (hereinafter abbreviated as WPM)
Preparation of whitened whey by (1) WPM preparation method Unsterilized cheese whey (containing 0.71% whey protein)
After incubation at 37 ° C, lactic acid was added to adjust the pH to 6.0. Then, this cheese whey at 90-120 ℃ for 2-4
After heating for 2 seconds, it was immediately cooled to 4 ° C. By this treatment, the morphology of protein in whey was changed into micelles, and the transparent and yellowish color peculiar to whey was changed to a milky white suspension.

(2) WPM characteristics The turbidity of heat-treated whey and unheated whey is 600 nm.
It was shown by measuring the absorbance. The color was measured using a color difference meter (CR200, manufactured by Minolta). Table 1 shows the measured values of turbidity and color of the whey protein micelle solution prepared by heating at pH 6.0 and 120 ° C. for 2 seconds according to the examples.

[0020]

[Table 1]                   Turbidity and color change by heat treatment of whey           ─────────────────────────                             WPM untreated whey           ─────────────────────────                 Turbidity 0.870 0.408                 L value 53.98 44.93                 a value -3.40 -2.09                 b value 0.50 1.28           ─────────────────────────

The heat treatment after pH adjustment markedly increased the turbidity of whey. As for the color, the L value showing whiteness was remarkably increased, and the b value showing yellowness was also decreased. Next, the heated whey was centrifuged at 3000 × G for 5 minutes to try to separate the substance causing white turbidity. However, almost no precipitate of the heat-treated whey of the present invention was observed, and the white turbidity did not disappear.
From this, it was confirmed that the whitening of the whey of the present invention was due to the formation of a stable suspension by the protein colloid.

[0022]

Example 2 By adding milk protein micelles (hereinafter abbreviated as MPM)
Preparation of whitened whey (1) Method for preparing MPM To 1400 ml of the whey protein solution prepared in Example 1, 10
% Acid casein solution 1, 2, 5, 10, 20 ml each,
An MPM solution was prepared.

(2) Characteristics of MPM The MPM solution of each concentration prepared in (1) above was stirred at 50 ° C. for 1 hour and then centrifuged at 3000 × G for 5 minutes to confirm the stability. As in the case of Example 1 (2), almost no precipitate was observed even after centrifugation, and the white color did not disappear. From this, it was confirmed that the whitening of the whey of the present invention was due to the formation of a stable suspension by the protein colloid. The color of the casein solution added with 10 ml was measured using a colorimeter (CR200, manufactured by Minolta). The results are shown in Table 2. The MPM solution also showed whiteness similar to WPM.

[0024]

[Table 2]

(3) Thermal stability of MPM The MPM solution of each concentration prepared in (1) above was dispensed and sealed in 2 ml aliquots in a 3 ml ampoule bottle. 120 these ampoules
It was heated in an oil bath at ℃, the time until the coagulation was generated was measured, the relationship between the amount of casein added and the time required for coagulation was examined, and the value is shown in Table 3.

The casein addition amount in the table is It is represented by.

[0027]

[Table 3] Thermal stability of MPM ──────────────────── Casein addition amount Coagulation time [ml] [%] ^* [min] ─────── ────────────── 0 0.0 0.8 1 1.0 5.3 2 2.0 8.2 5 5.0 54.5 10 10.0 120.0 20 20.0 126.5 ────────────────── ── ^* Per amount of protein in WPM

The thermal stability of the MPM solution prepared by adding the acid casein solution to the WPM solution is high, and this depends on the concentration of casein, and the amount of casein added to the protein amount of WPM is 5% by weight. Above all, a particularly high stability was shown.

(3) MPM protein composition The MPM solution added with 10 ml of acid casein prepared in Example 2 and the WPM solution prepared in Example 1 were each 0.22 μm.
After passing through a pore size membrane filter of m, the permeate was subjected to gel filtration chromatography (Superose12HR
Column, manufactured by Pharmacia) and separated at a flow rate of 0.5 ml / min, and the WPM and MPM eluted at the exclusion volume were respectively collected. Each recovered micelle was subjected to SDS-PAGE under reducing conditions, and constituent components were identified and quantified by densitometry. The SDS electrophoresis pattern is shown in FIG. 1, and the densitometry result is shown in Table 4.

[0030]

[Table 4]                     Protein composition of WPM and MPM           ────────────────────────────                 Protein composition WPM (%) MPM (%)           ────────────────────────────             α-lactalbumin 7.7 7.5             β-lactoglobulin 92.3 81.5             α-casein 0.0 5.3             β-casein 0.0 1.6             κ-Casein 0.0 4.1           ────────────────────────────

It was confirmed that the main constituent of WPM is β-lactoglobulin. On the other hand, MPM is β-
It was confirmed that α-casein, β-casein and κ-casein were contained together with lactoglobulin.

Next, the particle diameters of WPM (pH 6.0) and MPM were measured by a laser particle size measuring system PAR-3 (manufactured by Otsuka Electronics). As a pretreatment, filtration was performed with a membrane filter having a pore size of 5 μm, and the particle size of micelle particles contained in the filtrate was measured. The measurement results are shown in Table 5.

[0033]

[Table 5]                       Comparison of particle size between WPM and MPM       ─────────────────────────────                                 WPM MPM       ─────────────────────────────         Average particle size (nm) 547.07 ± 2.43 669.03 ± 6.01         Polydispersity index 0.1299 ± 0.0098 0.1661 ± 0.0165       ─────────────────────────────

It was confirmed that the particle size of WPM in the whitened whey obtained by the method of the present invention has a particle size substantially the same as that of MPM and is about 500 nm to about 700 nm.

[0035]

[Example 3] Method for producing skim milk-like modified milk drink (1) Deodorization treatment of casein 3.5 kg of acid casein acid was dissolved in 20 kg of warm water heated to 50 ° C. Next, a column packed with activated carbon (inner diameter 50 mm, height
The odor peculiar to casein was removed by passing through 500 mm). At this time, the total recovered solid amount was adjusted to 3.0 kg, and the total recovered liquid amount was set to 30 kg or less. Next, skim milk powder
1.67 kg was added and dissolved by stirring to obtain a raw material mix solution.

(2) Preparation of white whey solution 10.0 kg of whey powder (12.7
% Whey protein) and dissolve with stirring to pH 6.0.
Was adjusted with lactic acid. Then, the plate type heat exchanger was heat-treated at 120 ° C. for 2 seconds and cooled to 50 ° C. to prepare a whitened whey solution. As a result, the total solid amount is 8.7k.
It was g and the liquid volume was 110 kg.

(3) Production of non-fat modified milk beverages The total amount of the deodorized casein solution prepared in (1) above and the above (2)
The whole amount of the whitened whey solution prepared in 1 above was mixed, the pH was adjusted to 6.5 with sodium hydroxide, and the insoluble matter was removed with a clarifier. Next, 0.2 kg of unsalted butter was added, and then water was added so that the total amount became 150 kg. Further, homogenization was carried out using a homogenizer at a homogenization pressure of 150 kg / cm ² , and finally heat treatment was carried out at 120 ° C. for 2 seconds to produce a skim milk-like modified milk drink.

(4) Component composition Table 6 shows the component composition of the skimmed milk-like modified milk drink obtained.
As a control, the composition value of skim milk is shown. As shown in Table 6, a formula having almost the same nutritional components as skim milk could be produced.

[0039]

[Table 6]                         Composition of skim milk-like modified milk drink       ──────────────────────────────                       Non-fat milk-like modified milk beverage (the present invention) non-fat milk       ──────────────────────────────             Total solid 8.95% 8.52%             Protein 3.10% 3.02%             Fat 0.38% 0.07%             Sugar 4.90% 4.71%             Ash 0.57% 0.72%       ──────────────────────────────

(5) Color measurement The color of the skimmed milk-like prepared milk beverage and skim milk obtained was measured using a color difference meter (CR200, manufactured by Minolta), and Table 7 shows the measurement results. Both showed substantially the same value, and milk having the same color tone as skimmed milk could be prepared by the present invention. The color difference between the skim milk-like modified milk beverage of the present invention and the skim milk shown as a control is represented by ΔE.

[0041]

[Table 7]                   Color measurement of skim milk-like modified milk drink       ─────────────────────────                   Non-fat milk-like modified milk drink Non-fat milk       ─────────────────────────           L value 81.67 84.65           a value -4.35 -4.85           b value 3.12 2.51           ΔE value 3.08 0.0       ─────────────────────────

[0042]

[Example 4] Method for producing skim milk-like modified milk powder (1) Heat treatment of whey Unpasteurized cheese whey (containing 0.9 whey protein)
200 kg was kept at 30 ° C. in the tank until a pH of 6.2 was reached. After reaching pH 6.2, use a plate heat exchanger at 120 ° C for 2
After heat treatment for seconds, it was cooled to 50 ° C. to prepare a whitened whey solution.

(2) Casein Deodorization Treatment Acid casein (3.5 kg) was dissolved in hot water (28 kg) at 50 ° C., and the mixture was passed through a column (inner diameter 50 mm, height 500 mm) packed with activated carbon for deodorization. The total amount of solids recovered at this time was 3.0 kg.

(3) Formulation, concentration and spray drying To 150 kg of the whitened whey solution prepared in (1) above,
The whole amount of the deodorized casein solution recovered in (2) was added and mixed, the pH was adjusted to 6.5 with sodium hydroxide, and the insoluble matter was removed with a clarifier. Next, 0.2 kg of unsalted butter was added and mixed, and further homogenized with a homogenizer at a homogenizing pressure of 150 kg / cm ² , and then at 120 ° C for 2 hours.
Second heat treatment was performed. After heating, the mixture was vacuum concentrated until the solid concentration reached 38%, filtered through a 100-mesh filter cloth, and spray-dried to produce a modified milk powder.

(4) Component composition Table 8 shows the composition of the skimmed milk powder-like prepared milk powder produced and general skim milk powder. No significant difference was observed between the two, and it was confirmed that there was almost no loss of protein due to heat treatment of whey.

[0046]

[Table 8]                         Composition of non-fat dry milk powder       ──────────────────────────────                       Nonfat dry milk-like modified milk powder Nonfat dry milk       ──────────────────────────────           Moisture 3.8% 3.6%           Protein 31.0% 34.8%           Fat 4.0% 0.8%           Carbohydrate 54.2% 52.8%           Ash 7.0% 8.0%       ──────────────────────────────

(5) Physical Properties of Formulated Milk Powder The amount of insolubles in the skim milk-like powdered milk powder prepared in Example 4 was quantified by the ADMI method. As a result, the precipitation amount is 0.1 ml
Below, it was confirmed that the amount was similar to that of normal skim milk powder. Moreover, the following measurement was implemented as a heat resistance test.
Adjust the final solid concentration to 15% with a powdered milk solution pH of 6.1 to 6.
It was adjusted to 0.1 in the range of 7 and then 2 ml was dispensed and sealed in a 3 ml ampoule bottle. The ampoule was heated in an oil bath at 120 ° C., and the time until a solidified product was generated was measured for each sample having each pH value. Similar measurements were carried out for skim milk powder, and the amounts of precipitates generated in both were compared. As a result, the skimmed milk powder-like modified milk powder of Example 4 was most stable at pH 6.6. At this time, the formation of coagulation was observed after 205 minutes.
In the case of pH 6.1, the coagulate was generated earliest and the time was 130 minutes. The pH immediately after dissolving this modified milk powder was 6.43, and when this solution was heated, coagulation was observed after 190 minutes.

On the other hand, the heat stability of normal skim milk powder is low, and the pH around 6.4 is the most stable, but it solidifies in 67 minutes and the pH
It solidified in 10 minutes at 6.1 and 20 minutes at pH 6.7. In addition, a solution of skim milk powder solution that is only dissolved in water but not pH adjusted
The pH value was 6.56, and the coagulation start time at this time was 30 minutes.
The skimmed milk powder-like prepared milk powder prepared by the method of the present invention has extremely high thermal stability as compared with normal skim milk powder, and the pH at the time of dissolution can be set in advance to a stable pH.

The dispersibility and wettability of the modified milk powder were not significantly different from those of skim milk powder, and the results were almost the same. Further, the color of the prepared milk powder aqueous solution dissolved to have a solid content concentration of 10% was measured using a color difference meter. The results are shown in Table 9. As shown in Table 9, no difference was found between the skim milk powder and the skim milk powder.

[0050]

[Table 9]                       Color measurement of skimmed milk powder           ─────────────────────────                       Nonfat dry milk-like modified milk powder Nonfat dry milk           ─────────────────────────               L value 83.06 84.22               a value -4.47 -4.30               b value 4.64 3.59               ΔE value 1.57 0.0           ─────────────────────────

(6) Sensory evaluation The flavors of skimmed milk powder prepared by the method of the present invention dissolved in a solid content concentration of 8.8% and commercially available skimmed milk powder were compared by a sensory test. A two-point discriminant test was conducted by a panel of 39 people. When those having a more preferable flavor were selected, 21 of 39 panelists judged that the flavor of the skim milk powder-like prepared milk powder according to the method of the present invention was preferable.

[0052]

INDUSTRIAL APPLICABILITY The present invention provides white whey, whey powder, and infant formula. The dairy product provided by this method has characteristics such as high heat stability and no whey odor, and can enhance the utilization of whey that has been conventionally disposed of. Further, whey micelles provided by the method of the present invention, a solution containing a specific amount of whey micelles and casein associates has excellent thermal stability and does not cause gelation or precipitation, so that it can be used as a beverage, etc. Can be used for various purposes. In addition, since whey protein molecules are micelles and polymerized in the solution, they can be concentrated using, for example, a membrane having a cut-off molecular weight of 50,000 Da or more, and can be easily separated from low-molecular substances such as lactose.

Furthermore, since whey micelles and whey micelles and casein-aggregates are excellent in thermal stability, their solutions can be easily freeze-dried and spray-dried to obtain highly storable powders. Since the solubility does not deteriorate even if it is redissolved, it can be used as a powdered beverage or the like.

[Brief description of drawings]

FIG. 1 shows an SDS gel electrophoresis pattern of constituent proteins of WPM and MPM according to the present invention.

[Explanation of symbols]

Lane 1 WPM Lane 2 MPM

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Ishii 16-1-13 Kita 8 Higashi, Higashi-ku, Sapporo, Hokkaido (13) (72) Inventor Masakazu Horikawa 4-18 10-102 Yamanote, Nishi-ku, Sapporo, Hokkaido 2-18-102 (56 ) Reference JP-A-63-24857 (JP, A) JP-A-7-213232 (JP, A) JP-A-7-75498 (JP, A) JP-A-3-87148 (JP, A) JP-B 45-20537 (JP, B1) Special table HEI 5-500163 (JP, A) Special table HEI 7-507452 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A23C 1/00 -23/00 A23J 1/00-7/00

Claims (6)

(57) [Claims] 1. A method for preparing white whey, which comprises adjusting the pH of whey to 5.5 to 6.5 and then heating it to 90 ° C. or higher to micelle the whey protein present in the whey. 2. A method for preparing a dry whey powder, which comprises heating the whey to pH 5.5 to 6.5 and heating it to 90 ° C. or higher to micelle the whey protein present in the whey, and then drying. 3. A white whey characterized in that after the pH of the whey is adjusted to 5.5 to 6.5, the whey protein is heated to 90 ° C. or higher to micelle the whey protein present in the whey, and then a casein solution is added. Preparation method. 4. The method for preparing white whey according to claim 3, wherein the amount of casein added is 1/20 weight or more based on the amount of whey protein. 5. The pH of whey is adjusted to 5.5 to 6.5 and then 90 ° C.
White whey powder obtained by heating to the above temperature to make the whey protein present in whey into micelles, adding a casein solution, and drying. 6. The pH of whey is adjusted to 5.5 to 6.5 and then heated to 90 ° C. or higher to micelle the whey protein present in the whey, and then the casein solution is added to the whey protein in an amount relative to the whey protein mass. A method for preparing milk powder, which comprises adding 1/3 by weight or more and drying.