JP2017195802A - Method for producing component adjusted milk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide component adjusted milk having improved thermal stability and a high Ca/P ratio.SOLUTION: A method for producing component adjusted milk of which a milk fat content is 5.9 g or less per 100 g of the total solid content, a phosphorus content is 20 mmol or less per 100 g of the total solid content, and a Ca/P ratio indicating a molar ratio of a calcium content with respect to the phosphorus content is 1.5 or more includes: a first step of adding hydrochloric acid to a raw material liquid containing a milk solid content to obtain a first treatment liquid; a second step of treating the first treatment liquid with a nano filtration film to obtain a second treatment liquid as a holding liquid which does not permeate the filtration film; a third step of bringing the second treatment liquid into contact with a chloride ion type anion exchange resin to obtain a third treatment liquid; and a fourth step of adding citric acid or citrate to the third treatment liquid, and then adding alkali solution thereto to obtain a fourth treatment liquid.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing ingredient-adjusted milk.

In patients with chronic kidney disease, intake of protein and phosphorus is restricted.
Regarding the intake of protein, in patients with chronic kidney disease, excessive intake increases the risk of end-stage renal failure, but it is also a nutrient necessary for the human body, so a standard for protein intake is set for each stage of chronic kidney disease ing.
The standard is 0.6-0.8 (g / kg body weight / day) for stage 4 patients and 0.9-1.2 (g / kg body weight / day) for dialysis patients. When taking protein within the standard range, it is considered advantageous to take animal protein having a high amino acid score and digestibility, such as meat and milk.

Regarding the intake of phosphorus, in patients with chronic kidney disease, excessive phosphorus intake increases the serum phosphorus content, leading to decreased renal function, cardiovascular disease, etc., so serum phosphorus content in all stages of chronic kidney disease progression It is important to limit the intake of phosphorus so that the amount does not increase. As for phosphorus intake restriction, in patients with kidney disease requiring dialysis, the amount of phosphorus intake (mg / day) is based on protein (g) × 15 or less (Non-patent Document 1).
Regarding intake of calcium, it has been shown that even in patients with chronic kidney disease, it is a policy to compensate up to 600 mg / day, which is the amount of calcium required by Japanese (Non-patent Document 2).
As described above, calcium intake is necessary for patients with chronic kidney disease, and phosphorus and protein need to be restricted.

  Milk, such as skim milk, is a good animal source of protein (Non-patent Document 3), and it is a food that contains a lot of calcium, while it contains a lot of phosphorus. (Non-Patent Document 4).

Patent Document 1 relates to a method for producing low phosphorus whey, and a method of passing a low chlorine whey liquid obtained by desalting a whey liquid as a raw material by a nanofiltration method through a chloride ion-type anion exchange resin. Have been described.
Patent Document 2 relates to a method for producing milk having a low phosphorus content, and describes an example in which lactic acid is added to milk to adjust the pH to 5.5 and then passed through an OH type weakly basic ion exchange resin. Yes.
Patent Document 3 relates to a method for producing skim milk with reduced phosphoric acid and calcium contents. After acidifying to pH 5.5 by adding citric acid to skim milk, OH type weakly basic ion exchange resin is used. An example is described in which the solution is passed through and further neutralized by adding citric acid. This method describes that phosphate ions and calcium ions are retained on an anion exchange resin and removed.

International Publication No. 2011/037155 JP-A-48-33061 JP 60-256342 A

“2014 Dietary Standards for Chronic Kidney Disease”, Nichirenkai, Vol. 56 (5), 553-597, (2014) “Guidelines on Life Guidance and Dietary Therapy for Patients with Kidney Disease” Nichirenkai, Vol. 39 (1), pp. 1-37, (1997) Gertjan Schaafsma, “The protein digestibility-corrected amino acid score” The journal of nutrition, vol. 130, p. 1865S-1867S (2000) “CKD Medical Guide 2012” Nichirenkai, Vol. 54 (8), 1031-1189, (2012)

The inventors focused on non-fat milk (skim milk), which is a high-quality protein source, contains a large amount of calcium (Ca), and has a better flavor than whey. If the component-adjusted milk with a high Ca / P ratio can be produced by reducing the phosphorus (P) content of nonfat milk (skim milk), patients with chronic kidney disease can reduce protein intake and protein It was thought that the food suitable for ingesting can be provided.
Moreover, if the heat stability of the component adjustment milk which raised such Ca / P ratio improved, it thought that industrial utilization could be accelerated | stimulated more.

  The present invention has been made in view of the above circumstances, and the milk fat content is comparable to non-fat milk (skim milk), the phosphorus content is low, the Ca / P ratio is high, and the thermal stability is improved. It aims at providing the manufacturing method of the prepared component milk.

  The present invention that solves the above problems has a milk fat content of 5.9 g or less per 100 g of total solid content, a phosphorus content of 20 mmol or less per 100 g of total solid content, and a mole of calcium content relative to phosphorus content. A method for producing a component-adjusted milk having a Ca / P ratio of 1.5 or more, which includes a milk solid content, wherein the milk fat content is 5.9 g or less per 100 g of the total solid content, and is solid A first step of adding hydrochloric acid to a raw material liquid having a partial concentration of 1 to 25% by mass to obtain a first treatment liquid, and the first treatment liquid is treated with a nanofiltration membrane, and does not pass through the filtration membrane. As a liquid, the chlorine ion concentration is 8 mmol or less per 100 g of the total solid content, and the calcium content per 100 g of the total solid content is 85 to 95 mol% of the calcium content per 100 g of the total solid content in the raw material liquid. A second step of obtaining a second treatment liquid; contacting the second treatment liquid with a chloride ion-type anion exchange resin; and a phosphorus content of 20 mmol or less per 100 g of total solids; A third step of obtaining a third treatment liquid having a P ratio of 1.5 or more; and citric acid or citrate is added to the third treatment liquid, and then an alkaline solution is added to adjust the pH to 6. And a fourth step of obtaining a fourth treatment liquid adjusted to 4 to 6.7.

  In the present invention, the pH of the first treatment liquid at 25 ° C. is 5.5 to 6, and the citrate added to the third treatment liquid is monosodium citrate, citric acid. A preferred embodiment is one or more citrates selected from the group consisting of disodium, trisodium citrate, monopotassium citrate, dipotassium citrate, and tripotassium citrate.

  According to the present invention, it is possible to obtain a component-adjusted milk having a milk fat content comparable to that of non-fat milk (skim milk), a low phosphorus content, a high Ca / P ratio, and good thermal stability.

  Next, a preferred embodiment of the present invention will be described in detail. However, the present invention is not limited to the following preferred embodiments, and can be freely changed within the scope of the present invention. In the present specification, percentages are expressed by mass unless otherwise specified.

<Measurement method>
In the present invention, the following measuring method is used.
(1) Measuring method of total solid content S [unit: g / 100 g] After measuring moisture [unit: g / 100 g] by the loss on drying method, the total solid content is “100 g-water [g / 100 g]”. Calculated.
The total solid content S obtained by this method is the total solid content per 100 g of the sample to be measured, and is equal to the solid content concentration [unit: mass%].
(2) Measurement method of mass-based mineral content A [unit: mg / 100 g] Mass-based calcium (Ca) content, phosphorus (P) content, sodium (Na) content, potassium (K) content Is measured by the ICP method (high frequency inductively coupled plasma method).
(3) Measuring method of mass-based chlorine ion content B [unit: mg / 100 g] The mass-based chlorine (Cl) ion content is measured by potentiometric titration.

(4) Method of measuring each mineral content M [unit: mg / 100 g solid content] based on mass per 100 g of the total solid content Mineral content A obtained by the method (2) above or the method (3) It is calculated by the following formula from the obtained chlorine ion content B and the total solid content S obtained by the method (1).
Mineral content M [mg / 100 g solid content] = (A or B [mg / 100 g]) / S [g / 100 g] × 100
(5) Method of measuring each mineral content [unit: mmol / 100 g solid content] on a molar basis per 100 g of the total solid content Mineral content M [unit: mg / 100 g solid content] obtained in (4) above From the atomic weight of mineral (Na: 22.99, K: 39.10, Ca: 40.08, P: 30.97, Cl: 35.45 [mg / mmol], the following formula is used.
Mineral content [mmol / 100 g solid content] = M [mg / 100 g solid content] / Atomic weight [mg / mmol]
(6) Method for measuring fat content F [unit: mg / 100 g] The fat content is measured by the Gelbel method or the Rosette Gottlieb method.
(7) Measuring method of fat content [unit: mg / 100 g solid content] per 100 g of total solid content The fat content per 100 g of total solid content is the fat content F obtained by the method of (6) and ( It is calculated by the following formula from the total solid content S obtained by the method 1).
Fat content [mg / 100 g solid content] = F [mg / 100 g] / S [g / 100 g] × 100

<Ingredient-adjusted milk>
The component-adjusted milk of the present invention has a milk fat content of 5.9 g or less per 100 g of the total solid content, a phosphorus content of 20 mmol or less per 100 g of the total solid content, and a molar ratio of the calcium content to the phosphorus content. The Ca / P ratio representing is 1.5 or more.
In addition, the amount of precipitate produced when 100 g of the component-adjusted milk of the present invention was heat-treated at 121 ° C. for 1 minute in an autoclave apparatus and then centrifuged at 3000 rpm (centrifugal force 1500 × g) for 5 minutes. Is 1 mL / 100 mL or less, and the component-prepared milk has extremely good heat stability.

Milk fat is fat derived from milk. In this invention, content of solid content other than milk solid content is 10 mass% or less among the total solid content in component adjustment milk.
The fat content of 5.9 g or less per 100 g of the total solid content is the same fat content as “non-fat milk” stipulated by the ministerial ordinance of milk and the like (the ministerial ordinance concerning the component standards of milk and dairy products).
Ingredient-adjusted milk having a low phosphorus content of 20 mmol or less per 100 g of total solids and a high Ca / P ratio of 1.5 or more, which represents the molar ratio of the calcium content to the phosphorus content, restricts the intake of phosphorus. It is useful as a food or ingredient for patients to take milk-derived protein and calcium while suppressing phosphorus intake.
For example, it can be used as a raw material for pudding, milk drink, prepared milk powder, ice cream, or fermented milk.

The sodium content of the component-adjusted milk of the present invention is preferably 1 to 80 mmol, more preferably 1 to 40 mmol, per 100 g of the total solid content. The potassium content is preferably 2 to 90 mmol, more preferably 2 to 70 mmol, and still more preferably 2 to 55 mmol per 100 g of the total solid content.
The form of the component-adjusted milk of the present invention is not particularly limited, and may be a liquid having an arbitrary solid content concentration, or may be a powder that has undergone a drying process such as freeze drying or spray drying.

<Method for producing ingredient-adjusted milk>
The component-adjusted milk of the present invention is produced from the raw material liquid containing milk solids through the following first step, second step, third step and fourth step.
[Raw material]
In the present invention, a raw material liquid containing milk solid content, having a milk fat content of 5.9 g or less per 100 g of total solid content, and having a solid content concentration of 1 to 25% by mass is used. The raw material liquid does not contain solids other than milk solids.
Non-fat milk (skim milk), non-fat milk diluted with water, non-fat milk concentrate, or non-fat milk dry powder (skim milk powder) in water (reduced) Liquid).
It is easy to process in a 2nd process as solid content concentration of a raw material liquid is 1-25 mass%.
The pH of the raw material liquid is preferably 6 to 7, and more preferably 6.4 to 6.8. The pH of nonfat milk (skim milk) is about 6.4 to 6.8.
The value of pH in the present specification and claims is a value at 25 ° C.

[First step]
First, hydrochloric acid is added to the raw material liquid to obtain a first treatment liquid. When an acid is added to the raw material liquid containing milk solids to lower the pH to some extent, a coagulum (curd) is generated.
In this step, it is preferable to add as much hydrochloric acid as possible without causing coagulum (curd). The greater the amount of hydrochloric acid added in this step, the higher the Ca / P ratio of the third treatment liquid obtained in the third step.
The hydrochloric acid added to the raw material liquid is preferably an aqueous solution having a concentration of about 0.5 to 4% by mass (about 0.14N to about 1.1N). The lower the concentration of hydrochloric acid, the less likely it is to form a coagulum (curd) upon addition, but the longer it takes to add.
The amount of hydrochloric acid added is preferably set so that the pH of the first treatment liquid is within the range of 5.5-6. When the pH of the first treatment liquid is not more than the upper limit of the above range, the Ca / P ratio of the third treatment liquid obtained in the third step tends to be higher. When it is at least the lower limit value, a solidified product (card) is hardly generated.

[Second step]
Next, the 2nd process of processing the 1st processing liquid with a nanofiltration membrane and obtaining the 2nd processing liquid is performed.
This step is a step of separating the permeate that has permeated through the filtration membrane and the retentate that does not permeate, and a retentate that does not permeate the filtration membrane is obtained as the second treatment liquid.
As the processing conditions in the nanofiltration membrane, it is preferable to carry out the filtration under the condition that the temperature of the processing liquid is kept at 10 ° C. or less from the viewpoint of preventing the processing liquid from being spoiled.

A nanofiltration (NF) membrane is an intermediate region between an ultrafiltration (UF) membrane and a reverse osmosis (RO) membrane that has a molecular weight of tens to thousands of daltons, that is, a nanometer region when converted to a molecular size. This is a separation membrane to be imaged. Among inorganic substances, carbohydrates, amino acids, vitamins, etc., particles having a low molecular weight and low charge permeate the nanofiltration membrane.
Specific nanofiltration membranes include GE Water Technologies' DL, DK, HL series, Koch Membrane System's SR-3 series, Dow Chemical's DOW-NF series, Nitto Denko's NTR series. (Both are product names) and the like can be exemplified, but are not limited thereto.

A nanofiltration device can be appropriately selected and used.
For example, a membrane module provided with a nanofiltration membrane, a supply pump that sends the first treatment liquid to the membrane module, a means for taking out the permeate that has permeated the nanofiltration membrane from the membrane module, and the nanofiltration membrane did not permeate And a means for taking out the retentate (second treatment liquid) from the membrane module.
The batch type apparatus further includes a stock solution tank that holds the first processing liquid before being supplied to the membrane module, and means for returning the retained solution taken out from the membrane module to the stock solution tank.
The membrane separation operation can be performed using a known method as appropriate.
For example, in addition to the step of taking out the permeate and returning the retentate to the stock solution tank, a method of performing diafiltration (hydrodiafiltration) in which the same amount of water as the taken out permeate is added to the stock solution tank is preferable.

In the nanofiltration membrane treatment, monovalent ions are selectively removed through the nanofiltration membrane. That is, sodium ions (Na ⁺ ), potassium ions (K ⁺ ), and chlorine ions (Cl ⁻ ) in the raw material liquid permeate the nanofiltration membrane and move to the permeate side.
On the other hand, although the amount of divalent mineral cations such as magnesium ions (Mg ²⁺ ) and calcium ions (Ca ²⁺ ) permeates the nanofiltration membrane is small, the second treatment liquid has a calcium content compared to the raw material liquid. Is slightly reduced.
If the solid content concentration of the first treatment liquid to be subjected to the nanofiltration membrane treatment is too high, fouling occurs in the nanofiltration membrane and the membrane function may be deteriorated. If it is too low, the membrane treatment takes time. Therefore, it is preferable to set in a range in which these disadvantages do not occur. For example, 3 to 25% by mass is preferable, and 5 to 15% by mass is more preferable.

In this step, the nanofiltration membrane treatment is performed so that the chlorine ion content of the second treatment liquid obtained as the retentate in the second step is reduced to 8 mmol or less per 100 g of the total solid content. Moreover, it carries out so that the calcium content per 100g of total solid in a 2nd process liquid may be maintained at 85-95 mass% of the calcium content per 100g of total solid in a raw material liquid.
For example, in the method of returning the retentate to the stock solution tank, the chloride ion content and the calcium content decrease as the treatment time increases. Further, the content is less likely to decrease as the process proceeds.

The chlorine ion content of the second treatment liquid is 8 mmol or less per 100 g of the total solid content, preferably 7 mmol or less, and more preferably 5 mmol or less. When the chlorine ion content is not more than the above upper limit, the Ca / P ratio of the third treatment liquid obtained in the third step is sufficiently high.
The lower limit value of the chlorine ion content of the second treatment liquid is not particularly limited, but 3 mmol or more per 100 g of the total solid content is practical in terms of treatment efficiency and the calcium content does not become too low.

If the concentration of the solid content of the second treatment liquid to be passed through the chloride ion type anion exchange resin is too low, a treatment time is required, and if it is too high, the viscosity may increase and precipitation of lactose may occur. Since it becomes difficult, it is preferable to set in a range in which these disadvantages do not occur. For example, the solid content concentration of the second treatment liquid is preferably 1 to 25 mass%, more preferably 2 to 15 mass%, further preferably 3 to 10 mass%.
If necessary, the second treatment liquid obtained in the second step may be diluted with water and brought into contact with the chloride ion-type anion exchange resin.
In the present specification, the second treatment liquid brought into contact with the chloride ion-type anion exchange resin means a liquid that retains the total solid content in the retentate obtained in the second step, and the retentate In addition to the above, the concept includes a dilute solution obtained by diluting the retentate with water, or a concentrate obtained by concentrating part of the water content of the retentate.

[Third step]
By performing the third step of bringing the second treatment liquid into contact with the chlorine ion-type anion exchange resin, the content of phosphate ions in the liquid can be reduced.
The cation content of the divalent mineral is only slightly reduced by contact with the chloride ion type anion exchange resin. Therefore, it is possible to reduce the phosphorus content while suppressing a decrease in the calcium content contained in the second treatment liquid.
In this step, the phosphorus content in the third treatment liquid is 20 mmol or less per 100 g of the total solid content, and the Ca / P ratio representing the molar ratio of the calcium content to the phosphorus content in the third treatment liquid is 1. .5 or more.
The phosphorus content in the third treatment liquid is 20 mmol or less per 100 g of the total solid content, preferably 19 mmol or less, and more preferably 18 mmol or less. The lower limit of the phosphorus content is not particularly limited, but is preferably 15 mmol or more and more preferably 16 mmol or more from the viewpoint of processing efficiency.

In the present invention, all of the calcium in the third treatment liquid is derived from the calcium in the raw material liquid, and the step of increasing calcium in the middle is not performed.
The ratio of the calcium content per 100 g of the total solid content in the third treatment liquid to the calcium content per 100 g of the total solid content in the raw material is preferably 85% by mass or more, more preferably 87% by mass or more, and 90% by mass. % Or more is more preferable. The ratio is preferably as high as possible, but is practically 95% by mass or less.

The phosphorus content and the value of the Ca / P ratio in the third treatment liquid vary depending on the treatment conditions when the second treatment liquid is passed through the chloride ion-type anion exchange resin.
For example, when the exchange capacity of the ion exchange resin is constant and the flow rate of the liquid passed through the ion exchange resin is constant, the smaller the amount of solids passed through the ion exchange resin, the higher the ion exchange efficiency, Reduction amount of phosphorus content by passing liquid increases.
For example, the second treatment liquid in which the volume corresponding to 1.25 equivalents of the ion exchange capacity of the chlorine ion type anion exchange resin to be used is X (unit: liter) and is passed through the chlorine ion type anion exchange resin. When the solid content is Y (unit: kg), when the flow rate is constant, the phosphorus content in the effluent is reduced by decreasing the resin flow solid ratio represented by Y / X. Can be reduced.
The smaller the resin flow solid ratio (Y / X), the lower the phosphorus content can be obtained. On the other hand, in order to increase the processing efficiency, it is preferable that the resin flow solid ratio (Y / X) is large.
The resin flow solid ratio (Y / X) is, for example, preferably 0.2 to 1.5, and more preferably 0.5 to 1.2.

Further, when the resin flow solid ratio (Y / X) is constant, the phosphorus content in the effluent can be reduced by decreasing (slowing) the flow rate.
If the flow rate when the second treatment liquid is passed through the chlorine ion type anion exchange resin is too small, it takes time to pass the liquid and the efficiency deteriorates. If it is too large, the pressure loss becomes too high. It is preferable to set in a range where no inconvenience occurs. It can be within the range of the recommended flow rate of the chlorine ion type anion exchange resin to be used.

Space velocity (SV), for example preferably 2～12Hr ^-1, more preferably 3~10hr ^-1, 3~8hr ^-1 is particularly preferred. The space flow velocity (SV) represents the relative amount of the liquid passed per unit time with respect to the amount of ion-exchange resin (the reciprocal of the time during which the liquid passed per unit time contacts the filtration layer). The flow rate when a treatment liquid having the same volume as the ion exchange resin volume is passed is set to ¹ hr ⁻¹ .

[Fourth step]
A fourth step is performed in which citric acid or citrate is added to the third treatment liquid, and then an alkaline solution is added to obtain a fourth treatment liquid having a pH adjusted to 6.4 to 6.7.
The citrate added to the third treatment solution is selected from the group consisting of monosodium citrate, disodium citrate, trisodium citrate, monopotassium citrate, dipotassium citrate, and tripotassium citrate. It is preferred that the citrate is one or more citrates.
In addition, as an alkaline solution used to adjust the pH to 6.4 to 6.7 after adding citric acid or citrate to the third treatment liquid, a sodium hydroxide solution or potassium hydroxide is used. A solution or the like is preferable, and the concentration of the alkaline solution is preferably 0.5% by mass to 10% by mass. The pH range is preferably pH 12 or higher.
The fourth treatment liquid obtained in this step was subjected to heat treatment at 121 ° C. for 1 minute at 121 ° C. for 1 minute in an autoclave apparatus, and then centrifuged at 3000 rpm (centrifugal force 1500 × g) for 5 minutes. The amount of precipitate produced is 1 mL / 100 mL or less, and it can be provided as a component milk having extremely good heat stability.

<Post-processing>
The fourth treatment liquid (effluent) thus obtained may be used as it is as liquid component-adjusted milk, and if necessary, one or more post-treatments may be performed by a known method.
The post-treatment is preferably a treatment that does not increase the phosphorus content in the liquid. Moreover, it is preferable that it is the process which does not reduce the calcium content in a liquid.
For example, concentrated liquid component-adjusted milk can be obtained by concentrating the fourth treatment liquid. Moreover, after concentrating the obtained 4th process liquid as needed, it is good also as powdery component adjustment milk through drying processes, such as freeze-drying and spray drying. Ingredient-adjusted milk can be used as a raw material for other products.

Furthermore, when a process for treating the fourth treatment liquid (effluent) with a nanofiltration membrane is provided, sodium ions (Na ⁺ ) and potassium in the fourth treatment liquid are maintained while maintaining the value of the Ca / P ratio substantially constant. Ions (K ⁺ ) and chlorine ions (Cl ⁻ ) can be reduced. Thereby, a low salt component-adjusted milk having a high Ca / P ratio value and a low sodium and potassium content is obtained.
In patients with chronic kidney disease, intake restrictions may be imposed on sodium (salt) and potassium in addition to protein and phosphorus, and low-salt component-adjusted milk is desirable.
For example, the phosphorus content is 20 mmol or less per 100 g of the total solid content, the Ca / P ratio is 1.5 or more, the sodium content is 12 mmol or less per 100 g of the total solid content, and the potassium content is per 100 g of the total solid content. A low salt component-adjusted milk reduced to 30 mmol or less can be obtained.

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.
In the examples and comparative examples, the following were used.

Raw material liquid: A skim milk aqueous solution in which skim milk powder (milk fat content 0.7 g / 100 g solid content) is dissolved in water (25 ° C.) so that the solid content concentration is 10% by mass. The pH is about 6.7, the calcium content is about 32 mmol / 100 g solids, the phosphorus content is about 35 mmol / 100 g solids, and the chloride ion content is about 31 mmol / 100 g solids. There is variation.)
Hydrochloric acid aqueous solution: An aqueous hydrochloric acid solution diluted with water so that the concentration of hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) is 2% by mass.
Nanofiltration membrane: NTR7450HG-S2F (product name), manufactured by Nitto Denko Corporation. The blocking rate for 0.2% by mass sodium chloride solution is 40% or more.
Chlorine ion type (Cl ⁻ type) anion exchange resin: IRA402BL (product name), manufactured by Dow Chemical Company.
Aqueous solution of citric acid or citrate: An aqueous solution (pH 8.8) obtained by dissolving 0.6 g of trisodium citrate dihydrate (manufactured by Jungbunzlauer Austria AG) in 5.4 g of water.
Alkaline solution: A sodium hydroxide aqueous solution dissolved in water so that the concentration of sodium hydroxide (manufactured by Kanto Chemical Co., Inc.) is 3.8% by mass.

[Example]
(First step)
A hydrochloric acid aqueous solution was added to the skim milk aqueous solution as a raw material solution while stirring, and then cooled to 10 ° C. to obtain a first treatment liquid. The pH of the first treatment liquid was 5.5 (25 ° C.).
(Second step)
The first treatment liquid was treated with a nanofiltration membrane. In other words, while the retentate that did not permeate the nanofiltration membrane is returned to the stock solution tank and the amount of water that permeates the membrane and is equal to the permeate amount is added to the stock solution tank, the amount of liquid in the stock solution tank is kept constant. Nanofiltration membrane treatment was performed by a filtration (hydrodiafiltration) method. While monitoring the chloride ion content in the retentate, the treatment was performed until the content became 5 mmol / 100 g solids (target value) or less.
The retentate thus obtained was used as the second treatment liquid. The chlorine ion content of the second treatment liquid is 4.7 mmol / 100 g solids, and the calcium content per 100 g of total solids in the second treatment liquid relative to the calcium content per 100 g of total solids in the raw material liquid. The ratio was 90.1 mol% (Ca / Ca of the raw material liquid).

(Third step)
The second treatment liquid containing chloride ions (Cl ^- form) is contacted with an anion exchange resin, the phosphorus content was obtained a third treatment liquid is reduced.
That is, a space velocity (SV) is obtained by adding 400 g of a diluent obtained by adding water so that the solid content concentration of the second treatment liquid is 5% by mass to a column filled with 20 ml of a chloride ion-type anion exchange resin. Liquid feeding was performed under conditions of 7 hr ⁻¹ and a liquid temperature of 5 to 10 ° C. until the resin-flowing solid magnification became 1 to obtain component-adjusted milk (third treatment liquid).
(Fourth process)
Here, the third treatment liquid was freeze-dried (water content 3.6%), and 10 g of the freeze-dried product was dissolved in 84 g (25 ° C.) of room temperature water to obtain a third treatment liquid (reducing liquid). . The third treatment liquid (reducing liquid) was mixed with 6.0 g of an aqueous solution obtained by dissolving 0.6 g of trisodium citrate dihydrate (manufactured by Jungbunzlauer Austria AG) in 5.4 g of water (pH 6.0 at this time). Then, using a 3.8 mass% aqueous sodium hydroxide solution (sodium hydroxide (manufactured by Kanto Chemical Co., Inc.)), a fourth treatment liquid having a pH adjusted to 6.4 was obtained. It was set to 1.
In addition, Example 4 was a fourth treatment liquid obtained by adjusting the pH to 6.7 in the fourth step.

[Comparative example]
In the above embodiment, in the fourth step, 6.0 g of an aqueous solution in which 0.6 g of trisodium citrate dihydrate (manufactured by Jungbunzlauer Austria AG) was dissolved in 5.4 g of water in the third treatment liquid (reducing liquid). A treatment solution that was mixed and the pH was not adjusted thereafter was designated as Comparative Example 1. Furthermore, in the said Example, the processing liquid obtained by adjusting pH to 6.2 at the 4th process was set as the comparative example 2.

[Component measurement method]
Total solid content: Drying loss method Fat content: Rosette Gottlieb method Protein content: Combustion method Na, K, Ca, Mg, P content: ICP method (high frequency inductively coupled plasma method)
Cl content: potentiometric titration Phosphoric acid, citric acid: high performance liquid chromatographic method However, fat, protein, Na, K, Ca, Mg, P, Cl, phosphoric acid, citric acid of Examples 1 and 2 and Comparative Example 2 The acid content was calculated based on the value of Comparative Example 1 from the added amount of 3.8% by mass sodium hydroxide solution.

[Thermal stability test]
About the prepared sample solutions of Examples 1 and 2 and Comparative Examples 1 and 2, 100 g of each was heat-treated at 121 ° C. for 1 minute in an autoclave apparatus. Thereafter, the sample solution was centrifuged at 3000 rpm (centrifugal force: 1500 × g) for 5 minutes, and the amount of the generated precipitate (mL / 100 mL) was measured.
From the measurement result of the precipitation amount, thermal stability was evaluated according to the following evaluation criteria.
(Evaluation criteria for thermal stability)
Precipitation amount after heating and centrifugation is less than 1 mL / 100 mL: ○
Precipitation amount after heating and centrifugation is 1 mL / 100 mL or more: ×

[Test results]
The component measurement results and thermal stability test results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.
From the results shown in Table 1, Examples 1 and 2 and Comparative Examples 1 and 2 obtained component-adjusted milk having a high Ca / P ratio of 1.5 or more, but the Examples were processed by the method of the present invention. In 1 and 2, the precipitation amount was as low as 1 mL / 100 mL or less (Example 1: 0.6 mL / 100 mL, Example 2: 0.5 mL / 100 mL), and the thermal stability was extremely good. On the other hand, in Comparative Example 2, the precipitation amount was 1.3 mL / 100 mL, and the thermal stability was slightly reduced, but in Comparative Example 1, the precipitation amount was 45 mL / 100 mL, which was insensitive to heat. It was found to be stable.

Claims (3)

The milk fat content is 5.9 g or less per 100 g of the total solid content, the phosphorus content is 20 mmol or less per 100 g of the total solid content, and the Ca / P ratio representing the molar ratio of the calcium content to the phosphorus content is 1 A method of producing a component-adjusted milk that is 5 or more,
A first treatment liquid is obtained by adding hydrochloric acid to a raw material liquid containing milk solids, having a milk fat content of 5.9 g or less per 100 g of total solids, and having a solids concentration of 1 to 25% by mass. 1 process,
The first treatment liquid is treated with a nanofiltration membrane, and as a retentate that does not permeate the filtration membrane, the chloride ion concentration is 8 mmol or less per 100 g of the total solid content, and the calcium content per 100 g of the total solid content is the raw material. A second step of obtaining a second treatment liquid that is 85 to 95 mol% of the calcium content per 100 g of the total solid content in the liquid;
A third treatment liquid in which the second treatment liquid is brought into contact with a chloride ion-type anion exchange resin, the phosphorus content is 20 mmol or less per 100 g of the total solid content, and the Ca / P ratio is 1.5 or more. A third step of obtaining
A fourth step of adding a citric acid or citrate to the third treatment liquid and then adding an alkaline solution to obtain a fourth treatment liquid having a pH adjusted to 6.4 to 6.7. The manufacturing method of the component adjustment milk which has.   The manufacturing method of the component adjustment milk of Claim 1 whose pH in 25 degreeC of a said 1st process liquid is 5.5-6.   The citrate added to the third treatment solution is selected from the group consisting of monosodium citrate, disodium citrate, trisodium citrate, monopotassium citrate, dipotassium citrate, and tripotassium citrate. The method for producing an ingredient formula milk according to claim 1 or 2, wherein the formula is one or more citrate salts.