JPH0977793A - Iron-casein complex and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the iron-casein complex not having an astringent taste characteristic to iron even when thermally sterilized, and having a high iron- supplying effect, and to provide a method for producing the same. SOLUTION: This iron-casein complex is produced by mixing (A) a solution containing (i) carbonic acid, (ii) bicarbonic acid or (iii) their mixture, (B) a solution containing iron and (C) a solution containing a casein in a proper order (but the coexistence of only the carbonic acid, the bicarbonic acid and the iron must be avoided). The obtained iron-casein complex contains 1-1,000 atoms of the iron, one or more molecules of the carbonic acid and one or more molecules of the bicarbonic acid per molecule of the casein, does not exhibit an astringent taste, even when thermally sterilized, and shows a higher anemia- preventing effect than those of inorganic iron salts.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a carbonic acid and / or bicarbonate-iron-casein complex and a method for producing the same. Carbonic acid and / or bicarbonate-iron-casein complex of the present invention has a feature that it does not exhibit the astringent taste peculiar to iron even when it is heat-sterilized, so that the prevention or treatment of anemia, a food for the purpose of iron fortification, It is useful as a medicine, feed material, etc.

[0002]

2. Description of the Related Art The iron intake of Japanese people has remained flat at around 100% of the required amount since 1975, and iron is one of the nutrients that must be taken with care in the diet. It can be said to be one. In addition, even in the world, iron is often regarded as a nutrient deficient in industrialized countries, and it is particularly desirable to supply iron-enriched foods and pharmaceuticals for people with anemia and pregnant women. . However, iron salts such as iron sulfate and iron citrate, which are generally used for iron fortification, are added because of the problem that the astringent taste peculiar to iron is felt when added to foods and the side effects such as damage to the gastrointestinal mucosa. There is a limit to the amount. Furthermore, even heme iron, which is an organic iron, has a problem in flavor such as metallic taste and fishy taste, and there are many restrictions on addition to foods and the like. Attempts have been made to add milk casein, amino acids, or casein phosphopeptides (JP-A-59-162843) in order to promote iron absorption. However, these methods cannot eliminate the astringent taste of iron, and cannot reduce the amount of iron added so as to eliminate the astringent taste of iron.

[0003]

The present inventors have already succeeded in developing an iron agent in which the astringent taste peculiar to iron is weakened by binding iron and casein (JP-A-2-8).
3400 publication). However, this iron casein has poor heat resistance, and has a drawback that it exhibits the astringent taste peculiar to iron when subjected to heat sterilization at 90 ° C for 10 minutes, heat sterilization at 120 ° C for 2 to 3 seconds, and retort sterilization. . Therefore, when this iron casein is used for food or the like, it is necessary to take measures such as sterilizing the production line, which causes a problem of increasing the production cost. The reason why iron casein exhibits an astringent taste peculiar to iron due to heat sterilization is that iron is released from casein by heating and iron hydroxide or the like is generated because the binding between iron and casein is weak. it is conceivable that. Therefore, the present inventors cannot develop an iron agent that has heat resistance by strengthening the binding property between iron and casein and that does not exhibit the astringent taste peculiar to iron even when it is sterilized by heating. I thought. It is an object of the present invention to supply an iron agent that does not exhibit the astringent taste peculiar to iron even if it is sterilized by heating and added to foods and the like. That is, an object of the present invention is to provide a carbonic acid and / or bicarbonate-iron-casein complex which does not have an astringent taste peculiar to iron even when heat-sterilized and a method for producing the same.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above-mentioned problems. As a result, a solution containing carbonate ion or bicarbonate ion and a solution containing caseins and iron ions were added and mixed. Then, a carbonate and / or bicarbonate-iron-casein complex is formed, and this carbonate and / or bicarbonate-iron-casein complex has a high iron content but has an astringent taste peculiar to iron. It was found that there is no such a case, and the present invention has been completed.

That is, according to the present invention, carbonic acid and / or bicarbonate containing 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of caseins.
It relates to an iron-casein complex. Such a composite has a feature that it does not exhibit the astringent taste peculiar to iron even when it is heat-sterilized.

Then, such a complex comprises: i) carbonic acid, or ii) bicarbonate, or iii) a solution containing carbonic acid and bicarbonate (solution A), iv) a solution containing iron (solution B1), v)
It is obtained by mixing with a solution containing caseins (B2 solution), and at this time, vi) the molar concentration of iron ions in the B1 solution is equal to the molar concentration of carbonate ions and bicarbonate ions dissolved in the A solution. / 3 or less, preferably 1/10, more preferably 1/30, even more preferably 1/60, and most preferably 1/100, vii) the number of moles of caseins in the B2 solution is the iron ion of the B1 solution. It must be 1 to 1/1000 of the number of moles of. The solution A, the solution B1 and the solution B2 may be mixed at the same time, or the solution B may be mixed with the solution A and then the solution B
You may mix 1 solution. Furthermore, B1 solution and B
After mixing the two solutions, the solution A may be mixed with the solution A, or the solution A may be mixed with the solution A. Furthermore, in order to keep the molar concentration of carbonate ion and bicarbonate ion in the reaction solution at a high level, the solution A may contain in advance an amount of carbonic acid and / or bicarbonate which cannot be completely dissolved. While adding the mixed solution of the B1 solution and the B2 solution, the i) carbonic acid, ii) bicarbonate, iii) carbonic acid and bicarbonate solution may be added. The carbonic acid and / or bicarbonate added in the present invention may be added in the form of acid,
Alternatively, it may be added in the form of a water-soluble salt. Also, iron
It is usually added in the form of a water-soluble salt. Further, in the present invention,
I) carbonate and / or bicarbonate added, ii) iron, and
iii) Caseins may be added as a solution or may be added in a solid state such as salts. In addition, solid state i) carbonates and / or bicarbonates, ii) iron, and iii)
Caseins may be dissolved at the same time. However, procedures that result in the dissolution of only i) carbonates and / or bicarbonates and ii) iron should be avoided.

Caseins which can be used in the present invention include casein, acid casein, sodium caseinate, lactate casein, α-casein, β-casein separated from the secretory fluid of milk or the like of mammals such as humans and cows. , Κ
-Casein etc. can be illustrated. As for these caseins, a large number of methods for separating them in large quantities are already known, but they may be separated by any method. Further, it may be produced from a microorganism, an animal cell or a transgenic animal by genetic manipulation. As the caseins, when a mixture of α-casein such as crude casein, β-casein and κ-casein is used, the average molecular weight is calculated from the composition ratio, and the molar concentration of the dissolved caseins is calculated based on this. It can be calculated.

As the solution A containing carbonic acid or bicarbonate,
Examples include solutions of carbonated water, ammonium bicarbonate, sodium bicarbonate, potassium bicarbonate, sodium carbonate, calcium carbonate and the like, and mixed solutions thereof. Sodium hydroxide, ammonia, potassium hydroxide, hydrochloric acid, citric acid, lactic acid or the like may be mixed and used as a pH adjuster with these solutions. In addition to carbonic acid or bicarbonate, this solution A may contain, for example, sugar, protein, fat or the like.

[0009] However, what is important is that the ratio of the molar concentration of iron ion and the molar concentration of carbonate ion and bicarbonate ion during the reaction is such that the astringent taste peculiar to iron is eliminated. -Influencing the formation of the casein complex. Next, a test example relating to this will be shown.

[0010]

[Test Example 1] (Material) (Solution A) Solution 1 containing sodium bicarbonate of each molar concentration
Liter (B1 solution) 0.2 liter solution containing ferric chloride (B2 solution) 0.8 liter solution containing 1 mmol sodium caseinate (manufactured by Taiyo Kagaku). However, the average molecular weight was used to adjust the molar concentration. In addition, the average molecular weight was calculated from the ratio of α-casein, β-casein and κ-casein determined by urea-sodium dodecyl sulfate (SDS) -electrophoresis and the theoretical molecular weight of each casein. B1
The solution and B2 solution are mixed to form solution B, and solution B is added to solution A.
1 liter of solution was added to make iron bound casein. The B solution used was diluted with deionized water. In addition, when the molar concentration of the final bicarbonate ion is 0.6 or more, sodium bicarbonate is added when the solution A and the solution B are mixed, or a necessary amount of sodium bicarbonate is added to the solution A in advance to form a saturated solution. did. The molecular weight of these solutions is 5000
Carbonic acid and / or bicarbonate-iron-casein complex and aqueous solution were separated by a cut ultrafiltration membrane. When the concentration of iron in the solution that permeated the membrane was measured by an emission spectrophotometer (ICP), it was found that iron was not detected at all and iron became a part of all the complexes. Then, this complex is treated with a buffer solution (simulation buffer solution) that imitates a liquid food product containing 0.05 mol / liter of imidazole and 0.15 mol / liter of salt at pH 7.5.
Dilute to an iron concentration of 3.6 mmol / liter, 90
It heat-sterilized at 10 degreeC for 10 minutes.

The solution thus obtained was subjected to the following sensory evaluation test. A panel of 10 males and 10 females used the simulated buffer solution as a control to determine whether or not each solution had an astringent taste. Each panelist was blindfolded so as not to give a judgment factor based on appearance. As a test for one sample, a control and a sample were tested in this order, and after evaluation of one sample, a test for evaluating the next sample was performed at intervals of at least one day. Moreover, in order to eliminate the daily deviation of sample evaluation, the order of sample evaluation was randomized for each panelist. As a result, Table 1 shows the number of the panelists who felt the astringency among the 20 panelists. In addition, bicarbonate ion in the table /
The minimum molar concentration ratio of iron ion was calculated by dividing the molar concentration of bicarbonate ion after mixing the solution A and the solution B by the molar concentration of iron ion of the solution B.

[0012]

[Table 1] When the B1 solution contains 16 mmol of iron ──────────────────────────────── Molar concentration of carbonate ion I felt an astringent bicarbonate ion ─────────── / Iron solution of A solution AB After mixing the number of panelists Minimum molar concentration ratio ─────────── ────────────────────── 1.0 0.5 0 16.67 0.8 0.4 0 13.33 0.6 0.3 2 10.00 0.4 0.2 4 6.67 0.2 0.1 4 3.33 0.1 0.05 20 1.67 ─── ────────────────────────────

[0013]

[Table 2] When the B1 solution contains 200 mmol of iron, and the B solution is diluted 20 times (the solution B contains 10 mmol / liter of iron) ───── ────────────────────────── Molar concentration of bicarbonate ion Bicarbonate ion with astringent taste ────────── ─── Number of panelists / Iron ion A solution After mixing AB Minimum molar concentration ratio ─────────────────────────────── Saturation ^* Saturation 0 120 or more Saturation 1.2 0 120 Saturation 1.0 0 100 Saturation 0.8 1 80 Saturation 0.7 1 70 1.2 0.6 1 60 1.0 0.5 2 50 0.6 0.3 2 30 0.3 0.15 3 15 ───────────── ─────────────────── ^* Saturated at 30 ℃

As described above, when the iron concentration of the B1 solution is increased, it is necessary to increase the bicarbonate ion concentration. As described above, in the preparation of the carbonic acid and / or bicarbonate-iron-casein complex of the present invention, in the process of adding the solution B to the solution A, at least 3 molecules around one added iron atom, Preferably, 10 or more carbonic acid and / or bicarbonate molecules should always be present. Furthermore, in the case of binding an iron atom in an amount exceeding 200 atoms to one molecule of casein, 30 molecules or more, preferably 60 molecules or more, more preferably 100 molecules or more of carbonic acid around one iron atom and And / or bicarbonate molecules must be present.

Examples of the iron compound which can be used in the present invention include trivalent iron compounds such as ferric chloride, ferric nitrate and ferric sulfate, as well as ferrous nitrate and ferric sulfate. Examples thereof include divalent iron compounds such as ferric iron and iron citrate. The amount of iron added is, as iron ions, preferably 10 mol or more, more preferably 16 mol or more, still more preferably 46 mol or more, and the upper limit is 1000 mol or less, preferably 1 mol or less with respect to 1 mol of caseins. It is 500 mol or less, more preferably 250 mol or less. Next, a test example relating to this will be shown.

[0016]

[Test Example 2] (Material) (Solution A) 1 liter solution containing 1200 mmol / liter sodium bicarbonate (B1 solution) 0.2 liter solution containing ferric chloride at each molar concentration (B2 solution) Casein lactate (New Zealand) -Daily Board) 0.8 liter of a solution containing 1 mmol. However, the molar concentration of lactate casein was calculated by the same method as in Test Example 1. In addition, caseinate lactate was dissolved in a very small amount of 1N sodium hydroxide solution, and this was diluted with deionized water. B1 solution and B2 solution are mixed to prepare B solution, and
1 liter of solution B was added to the solution to prepare iron-bound casein. If necessary, the solution B should be diluted with deionized water so that the final iron ion / casein molar concentration ratio is 100%.
That's it. These solutions were hydrodesalted by an ultrafiltration membrane having a molecular weight of 5000 and further concentrated. Then, it was diluted with a simulated buffer solution to an iron concentration of 3.6 mmol / liter, and sterilized by heating at 90 ° C for 10 minutes. The solution thus obtained was subjected to a sensory evaluation test in the same manner as in Test Example 1. As a result, Table 3 shows the number of the panelists who felt the astringent taste among the 20 panelists.

[0017]

[Table 3]

As described above, the astringent taste of iron may be eliminated depending on the amount of iron bound to caseins. Thus, in the preparation of the carbonic acid and / or bicarbonate-iron-casein complex of the present invention, the amount of iron to be added is preferably 10 mol or more, more preferably 10 mol or more, as iron ion with respect to 1 mol of caseins. 16 mol or more, more preferably 46 mol
It should be at least mol and the upper limit should be at most 1000 mol, preferably at most 500 mol, more preferably at most 250 mol.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

Example 1 1 liter of a solution containing 1.2 mol of sodium bicarbonate and 10 μmol of α-casein (manufactured by Sigma) (solution A), and 1 liter of a solution containing 1.5 mmol of ferric sulfate as iron ion (B). Solution). Then, solution B was added to solution A to prepare iron-bound α-casein. This solution is desalted and concentrated with an ultrafiltration membrane with a molecular weight of 5000 cut, and the iron concentration is 26 mg / 100 with a simulated buffer solution.
After diluting to give ml, seal in a test tube with a screw cap,
Heated at 90 ° C. for 10 minutes. After heating, naturally cool to room temperature,
It was stored at room temperature for 1 month. About this solution, Test Example 1
When a sensory evaluation test was carried out in the same manner as above, none of the 20 panelists who felt an astringent taste was recognized.

[0020]

Example 2 1 liter of a solution containing 0.5 mol / liter of sodium carbonate and 0.5 mol / liter of sodium bicarbonate and adjusted to pH 8.2 with acetic acid (solution A), as iron ions
1 liter of ferric nitrate solution containing 1.5 mmol (B1 solution) and 10 micromoles (B2) of powdered α-casein (manufactured by Sigma) were prepared. Then, add A1 solution to B1 solution and B
2 was added to prepare iron-bound α-casein. This solution was desalted and concentrated with an ultrafiltration membrane with a molecular weight of 5000 cut, diluted with a simulated buffer solution to an iron concentration of 26 mg / 100 ml, then sealed in a test tube with a screw cap, and at 90 ° C. Heated for 10 minutes. After heating, it was naturally cooled to room temperature and stored at room temperature for 1 month. A sensory evaluation test was conducted on this solution in the same manner as in Test Example 1. As a result, none of the 20 panelists who felt an astringent taste was observed.

[0021]

Example 3 1 liter of a solution containing 1.5 mol / liter of sodium carbonate and adjusted to pH 8.0 with hydrochloric acid (solution A), 0.2 liter of an iron citrate solution containing 1.5 mmol of iron ions (solution B1), and κ-casein ( 0.8 liter of a solution (B2 solution) containing 10 μmol was prepared. Then, after mixing the B1 solution and the B2 solution, the A solution was added to this mixed solution to prepare iron-bound κ-casein. This solution is desalted and concentrated with an ultrafiltration membrane with a molecular weight of 5000, and the iron concentration is 26 mg / 100 ml with a simulated buffer solution.
After diluting to 100 ml, seal in a test tube with a screw cap and
Heated at 0 ° C for 10 minutes. After heating, it was naturally cooled to room temperature and stored at room temperature for 1 month. A sensory evaluation test was conducted on this solution in the same manner as in Test Example 1.
None of the 20 people felt an astringent taste.

[0022]

[Test Example 3] The iron concentration of the solution prepared in Example 1 (test group) and the ferrous sulfate solution (control group 1) was 20 mg / 1.
A test sample was prepared by dissolving ascorbic acid and sodium ascorbate in a physiological phosphate buffer (pH 7.2) containing 6.2 mg / 100 g of vitamin C so that the amount of the solution became 00 ml, and heating at 90 ° C. for 10 minutes. In addition, vitamin C as a control group 2
Add physiological phosphate buffer (pH 7.2) containing 6.2mg / 100g at 90 ℃
What was heated for a minute was also used as a test sample.

Immediately after weaning, 21-day-old female Wistar rats (produced by Charles River Japan) with a body weight of 45 to 50 g were selected and subjected to iron removal diet (produced by Oriental Yeast Co., iron content).
0.25 mg / 100 g feed) was given for 2 weeks to prepare anemia rats whose blood hemoglobin level was 7 g / 100 ml or less. Rats were set to 5 to 8 animals per group, and thereafter, the test sample was administered by oral gavage (sonde) at 1 ml / day for 6 weeks while continuing to feed iron-free diet. Then, 6 weeks after the administration of the test sample, blood was collected from the tail vein, and the hemoglobin value was measured with an automatic blood cell counter (Toa Medical Electronics). The results are shown in Table 4.

[0024]

[Table 4]

As described above, the carbonic acid and / or bicarbonate-iron-casein complex of the present invention exhibits an anemia treatment effect, and the effect is superior to that of inorganic iron, ferrous sulfate. Became clear.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Tomizawa 5-3-33 Toyooka, Iruma City, Saitama Arden 710

Claims (7)

[Claims] 1. A carbonate and / or bicarbonate-iron-casein complex exhibiting the following properties. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of caseins, 2) No astringent taste peculiar to iron even when heat sterilized. 2. A solution containing i) carbonic acid, ii) bicarbonate, or iii) carbonate and bicarbonate (A solution), iv) a solution containing iron (B1 solution), and v) a solution containing caseins ( B2 solution)
Carbonic acid and / or bicarbonate-iron-casein complex obtained by mixing and with the following properties 1) and 2). However, at this time, the molar concentration of iron ions in vi) B1 solution is 1/3 or less of the molar concentration of carbonate ions and bicarbonate ions dissolved in A solution, and vii) molar concentration of caseins in B2 solution. The number is 1 to 1/1000 of the number of moles of iron ion in the B1 solution. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of casein, 2) No astringent taste peculiar to iron even when heat sterilized. 3. Mixing a solution containing i) carbonic acid, ii) bicarbonate, or iii) carbonic acid and bicarbonate (A solution) with a solution containing iv) iron and v) caseins (B solution). Carbonic acid and / or
Or bicarbonate-iron-casein complex. However, at this time
vi) The molar concentration of iron ions in solution B is 1/3 of the molar concentration of carbonate ions and bicarbonate ions dissolved in the solution (reaction solution) in which solution A and part or all of solution B are mixed.
Vii) the molar number of caseins in the B solution is B
It is 1 to 1/1000 of the number of moles of iron ion in the solution. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of casein, 2) No astringent taste peculiar to iron even when heat sterilized. 4. A solution (i.e., solution A) containing i) carbonic acid, ii) bicarbonate, or iii) carbonate and bicarbonate, and iv) caseins.
And v) a solution containing iron (solution B), which has the following properties 1) and 2)
Or bicarbonate-iron-casein complex. However, at this time
vi) The molar concentration of iron ions in solution B is 1/3 of the molar concentration of carbonate ions and bicarbonate ions dissolved in the solution (reaction solution) in which solution A and part or all of solution B are mixed.
Vii) the molar number of caseins in the A solution is B
It is 1 to 1/1000 of the number of moles of iron ion in the solution. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of caseins, 2) No astringent taste peculiar to iron even when heat sterilized. 5. A solution containing i) carbonic acid, ii) bicarbonate, or iii) carbonic acid and bicarbonate (A solution), iv) a solution containing iron (B1 solution), and a solution containing caseins (B2 solution). The method for producing a carbonic acid and / or bicarbonate-iron-casein complex exhibiting the following properties 1) to 2), characterized in that However, at this time, the molar concentration of iron ions in vi) B1 solution is 1/3 or less of the molar concentration of carbonate ions and bicarbonate ions dissolved in A solution, and vii) molar concentration of caseins in B2 solution. The number is 1 to 1/1000 of the number of moles of iron ion in the B1 solution. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of caseins, 2) No astringent taste peculiar to iron even when heat sterilized. 6. Mixing a solution containing i) carbonic acid, ii) bicarbonate, or iii) carbonic acid and bicarbonate (A solution) with a solution containing iv) iron and v) caseins (B solution). A process for producing a carbonic acid and / or bicarbonate-iron-casein complex having the following properties 1) to 2), characterized by: However, at this time, vi) the molar concentration of iron ions in solution B is
1/3 or less of the molar concentration of carbonate ion and bicarbonate ion dissolved in a solution (reaction solution) in which a part or all of B solution is mixed, and vii) the number of moles of caseins in B solution is It is 1 to 1/1000 of the number of moles of iron ion in solution B. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of caseins, 2) No astringent taste peculiar to iron even when heat sterilized. 7. A solution (i.e., solution A) containing i) carbonic acid, ii) bicarbonate, or iii) carbonic acid and bicarbonate, iv) caseins,
v) A method for producing a carbonic acid and / or bicarbonate-iron-casein complex exhibiting the following properties 1) to 2), which comprises mixing a solution containing iron (solution B). However, at this time, vi) the molar concentration of iron ions in the B solution is the molar concentration of carbonate ions and bicarbonate ions dissolved in the solution (reaction solution) in which the A solution and a part or all of the B solution are mixed. 1
/ 3 or less, the number of moles of caseins in vii) A solution is
It is 1 to 1/1000 of the number of moles of iron ion in solution B. 1) 1 to 1000 atoms of iron and 1 or more molecules of carbonic acid and / or bicarbonate per 1 molecule of caseins, 2) No astringent taste peculiar to iron even when heat sterilized.