JPS58304B2 - Simultaneous purification of lactose and casein - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for efficiently purifying lactose and casein in the same solution.

More specifically, the present invention relates to a method for simultaneously purifying lactose and casein while preventing the Maillard reaction and preventing spoilage when fluid flow is interrupted.

Generally, lactose and casein are found in the same milk and are used together in many foods.

However, lactose and casein are separately separated and purified into separate products that are commercially available.

The lactose and casein produced separately in this way are delivered to users, where they are mixed and used in the production of various foods.

Therefore, there is no problem even if lactose and casein are mixed at a certain ratio, and it can be said that it is rather convenient for the user.

On the other hand, lactose and casein are mostly imported, but they are not yet refined and may have a bad flavor and color.

Therefore, lactose and casein are purified, but conventionally it has been common to purify lactose and casein separately under different conditions.

For example, as a method for purifying casein,
As shown in Japanese Patent Publication No. 616, a method is known in which casein is dissolved in an alkaline solution and treated with granular activated carbon at pH 6.0 to 7.5 and below 40°C. As shown in Publication No. 52-117445,
A method is known in which whey is treated with activated carbon at 70° C. or lower and then treated with an ion exchange electrodialysis device.

Since lactose and casein are often used as a mixture, attempts have been made to mix them before purification and purify them at the same time, but when the two are in a mixed state, the reaction between sugar and protein occurs. A certain Maillard reaction is extremely likely to occur, resulting in browning, and the simultaneous presence of glycoenzyme proteins promotes bacterial growth, making it extremely susceptible to spoilage. It was never made public.

However, the present inventors found that simultaneous purification of lactose and casein
Capital investment for column expansion etc. is halved (2 columns due to 1 column type)
If the amount of activated carbon is the same as that of the tower type, the length of the adsorption zone will be nearly halved, extending the liquid passage time and reducing the regeneration frequency, reducing labor costs and regeneration costs.Extending the time for replacing activated carbon, etc. ) We conducted research on simultaneous refining as it would lead to significant cost savings such as reduced running costs.

Here, in the present invention, a mixed solution of lactose and casein is treated with one or more types of granular activated carbon while maintaining a temperature of 45 to 65 °C, preferably 50 to 60 °C, before and after passing the solution. This enabled simultaneous purification without causing the Maillard reaction.

In addition, in the present invention, the flow of the mixed solution is interrupted as appropriate, and during that time, the lactose solution with a concentration of 30% or more is added, preferably at 45 to 65 °C.
By circulating a lactose solution in the following range, they succeeded in suppressing bacterial growth and completely preventing spoilage.

In this way, spoilage is prevented and the frequency of activated carbon regeneration can be reduced.

In the present invention, first, commercially available crude lactose is 70 to 80%
Dissolved in water at ℃.

The concentration of crude lactose is preferably about 20 to 50%.

This solution is cooled to 45-65°C, but if there is a large amount of insoluble protein, the activated carbon layer will become clogged.
It is preferable to remove dust by adding a filter aid using a filter press, funda filter, etc.

On the other hand, after dissolving commercially available crude alkaline casein with an alkaline agent such as sodium carbonate or potassium carbonate at 80°C,
Cool to 45-65°C.

The concentration of crude alkaline casein may be set as appropriate, but it is between 5 and 13.
Chu level is appropriate.

The crude lactose solution and crude casein solution obtained here are mixed in an appropriate ratio depending on the purpose, and the liquid temperature is adjusted to 45 to 65.
℃, preferably adjusted to 50 to 60℃.

When the temperature of the liquid is lower than 45℃, lactose crystals are likely to form.
As a result, it may cause clogging, which is undesirable.Also, when the temperature is higher than 65°C, the Maillard reaction between lactose and casein tends to occur, which may reduce the adsorption capacity of activated carbon and cause coloration in the purified liquid. Undesirable.

The mixed solution having a liquid temperature of 45 to 65°C is passed through one or more types of granular activated carbon.

One type of granular activated carbon may be used, but two types are preferable.
That is, the granular activated carbon for deodorization and the granular activated carbon for decolorization are used together.

When used in combination, both may be mixed and placed in the same column, or each activated carbon may be placed separately in separate columns.

The mixed solution with a liquid temperature of 45 to 65°C is passed through a column fixed with granular activated carbon, but the liquid temperature is controlled so that it does not fall outside the range of 45 to 65°C during the passage and circulation, and if necessary, it is heated. The temperature of the apparatus must not fall below 45°C, preferably 50°C.

If the liquid temperature is below 45°C, lactose will crystallize and bacteria will proliferate and putrefy, so it must be carried out at a temperature above 45°C.

In the present invention, it is possible to continuously purify a mixed solution having a liquid temperature of 45 to 65° C. up to the breakthrough point of granular activated carbon (the point at which the adsorption capacity of activated carbon decreases).

The breakthrough point is very long and there are usually many pauses between the breakthrough points.

Once the flow of liquid at a temperature of 45 to 65° C. is stopped, bacteria will immediately proliferate and putrefy, necessitating regeneration treatment.

In the present invention, when fluid flow is stopped, 30%
By circulating an aqueous lactose solution of preferably 30 to 50% and at 45 to 65°C, continuous reuse up to the breakthrough point is possible without regeneration treatment.

A 30% or more lactose aqueous solution can suppress the growth of bacteria, and even if a mixture of lactose and casein is directly passed through the product afterwards, it will not cause any problems in the product since it is the same lactose.

Therefore, there is no need for a long period of washing with water, which is common when one liquid flow is interrupted.

Next, test examples and examples of the present invention will be shown.

Test example 1 Purified lactose 40% (W/W), crude casein 10% (W/W)
100 m after mixing the aqueous solution of W) at a weight ratio of 3:1.
The mixture was divided into 3 portions and allowed to stand for 5 to 7 hours in a constant temperature bath adjusted to 80°C, 60°C, and 40°C, and the state of browning was observed every hour.

Coloring is measured by TBA value (E443).

The results are shown in Figure 1, showing that there is no browning at 40°C or 60°C, but there is a rapid browning at 80°C.

Test Example 2 A column (200 ml volume) equipped with a hot water jacket was prepared by filling granular activated charcoal (Atostar BI-L: manufactured by Futamura Chemical Industry Co., Ltd. and Kuraray Coal GLO: manufactured by Kuraray Chemical Co., Ltd., a 2:1 mixture).

On the other hand, make an aqueous solution of 5-40% purified lactose, and
They were prepared by heating them to 7°C and 50°C.

While introducing the above solution with the above device and introducing airborne bacteria,
It was circulated at 2 m/Hr.

For each lactose solution at 50°C, the number of bacteria in the solution was detected after 10 days, and for each lactose solution at 37°C, after 3 days and 6 days.
After a day, the number of bacteria in the solution was detected.

The results are shown in Figure 2, and it can be seen that bacteria are growing at 37°C, but not at all at 50°C.

Example 100 kg of crude lactose was added to 150 kg of 50°C warm water,
After stirring and dissolving at 70 to 80°C, the mixture is cooled to 50°C.

On the other hand, add 10kg of crude casein to 100kg of warm water at 50°C.
After dispersing the mixture, 390 g of potassium carbonate (anhydrous) was added, stirred and dissolved at 80°C, and then cooled to 50°C.

Both were mixed in their entire amounts, and while maintaining the temperature at 50°C, granular activated carbon (Atostar BI-L: Futamura Chemical Co., Ltd., Kuraray Coal GLC, wet type: Kuraray Chemical Co., Ltd. 2:1 mixture) to obtain a purified solution.

A mixed solution of purified lactose and casein was obtained by passing the solution only once.

This solution was completely bleached and deodorized.

Immediately after completing the 4-hour passage, the concentration was 40%, 6
The solution was switched to a lactose solution at 0° C., and the solution was circulated for 20 hours.

The solution of the crude lactose and crude casein was passed through the solution again for purification.

Then, a further 40% lactose solution at 60°C was circulated for 20 hours.

After repeating the above operation for 25 to 30 days, a breakthrough was reached, and a 2% caustic soda solution at 80° C. was passed therethrough for regeneration treatment.

The decolorizing and deodorizing adsorption capacity of the recycled activated carbon product decreased to 85 to 80% compared to fresh carbon, but the adsorption capacity hardly decreased even if the number of regenerations was increased thereafter.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the browning of the casein and lactose mixture in Test Example 1, and FIG. 2 is a diagram showing the degree of aerial bacterial growth in the lactose solution in Test Example 2. A: 10 days after heating at 50°C. B: Shows the results after 3 days at 37°C. C: Shows 6 days at 37°C. (4)

Claims (1)

[Claims] 1. Mix a crude lactose solution and an unpurified casein solution,
A method for simultaneous purification of lactose and casein, which comprises treating with one or more types of granular activated carbon at ~65°C. 2 Mix the crude lactose solution and unpurified casein solution,
Treat with one or more types of granular activated carbon at ~65°C, interrupt the flow of liquid as appropriate, and maintain a 30% (W/W)
) A method for simultaneous purification of lactose and casein, characterized by circulating a lactose solution with a concentration higher than that of the lactose solution. 3. A method for simultaneous purification of lactose and casein according to claim 2, characterized in that the lactose solution with a concentration of 30% (W/W) or more is at 45 to 65°C.