JP4119440B2 - Iron-added whey protein concentrate and method for producing the same - Google Patents

Description

  The present invention relates to an iron-added whey protein concentrate (hereinafter sometimes abbreviated as WPC), more specifically, iron useful as a raw material for foods, pharmaceuticals and the like for the purpose of prevention and improvement of iron deficiency anemia and iron fortification. The present invention relates to an added WPC and a method for producing the same.

In recent years, many women have developed anemia due to insufficient iron intake. This trend is particularly noticeable in adolescent girls and young women. The most common cause of iron deficiency anemia is due to dietary habits, but women suffer from iron deficiency due to bleeding due to menstruation, increased demand due to pregnancy, and insufficient iron intake due to excessive dieting. The environment is prone to anemia.
In general, about 50% of women are said to be somehow iron deficient. In order to eliminate this iron deficiency, iron-enriched foods for people who are anemic and for pregnant women are being sold, and many products with enhanced iron content in milk and soft drinks are also on sale. . For example, as iron additives to be added to soft drinks, water-soluble organic acid iron salts such as iron lactate, sodium ferrous citrate, and iron iron citrate are used. There is a problem that it is not possible to use a large amount at a time because of a strong taste problem. Moreover, organic iron heme iron also has a flavor problem such as iron taste and bloody odor derived from blood, and its addition to foods and drinks is restricted. When water-insoluble and poorly soluble iron salts such as ferric pyrophosphate are used, the iron taste is improved, but the specific gravity is as high as 2.75 or more, and when dispersed in soft drinks, etc., it is short in the liquid. It settles over time and there is a problem with suspension stability. Furthermore, for the purpose of promoting iron absorption, a complex of iron and lactoferrin is prepared in the presence of carbonate ions and added to food (see Patent Documents 1 and 2). However, lactoferrin is expensive as a food material and has a problem in terms of cost.
On the other hand, whey is a by-product of manufacturing cheese and casein, and is rich in protein, minerals, lactose and the like. WPC that concentrates whey protein from cheese whey and isolated whey protein (WPI) that is concentrated and dried after the ion exchange resin adsorption method has superior amino acid composition and high nutritional value compared to casein. Widely used as an inexpensive food material. However, in recent years, whey production has increased as cheese consumption has increased, and further development of methods of use is required from the viewpoint of environmental protection and effective use of resources.
As an iron agent using whey, a complex of whey protein hydrolyzate obtained by hydrolyzing whey protein with a protein hydrolase and iron has been proposed (see Patent Document 3).
Japanese Patent Publication No.6-21077 JP-A-7-304798 JP 2000-50812 A

  An object of the present invention is to provide an iron-added WPC excellent in iron absorption and anemia improvement effects and a method for producing the same, by effectively using whey produced as a by-product of cheese and casein.

The inventors of the present invention have been studying a new utilization technology of whey produced when producing cheese and casein. Even without treatment with protein hydrolase, iron-added whey protein concentrate (WPC) It has been found that the iron agent is excellent in iron absorption and anemia improvement effects, and that the iron-added WPC does not have iron astringency even though it contains iron in a high ratio. It came to be completed.
That is, the present invention
(1) An iron-added whey protein concentrate containing 0.001 to 0.05 parts by weight of iron per part by weight of whey protein and having no iron astringent taste,
(2) The concentrate according to (1) above, which is a liquid having a pH of 5.5 or higher or a dried product thereof,
(3) The concentrate according to the above (1), which is for iron absorption and anemia improvement effect,
(4) The iron-added whey protein concentrate according to (1) above, wherein the whey and an aqueous solution containing iron ions are mixed and ultrafiltered, or the ultrafiltered whey and iron ions are mixed. Manufacturing method,
(5) The production method according to the above (4), wherein the weight of iron ions is 1/20 or less of the protein in whey, and the pH of the liquid mixture of whey and iron ions obtained is 5.5 or more. is there.

  The iron-added WPC of the present invention can be produced by a simple method of mixing whey and iron. The obtained iron-added WPC forms an iron-whey protein complex, has excellent solubility, and has a unique astringent taste of iron. Therefore, it is useful as a raw material for foods, pharmaceuticals, feeds, etc. for the purpose of preventing or improving iron deficiency anemia and strengthening iron.

The iron-added WPC of the present invention contains 0.001 to 0.05 parts by weight, preferably 0.005 to 0.03 parts by weight of iron per 1 part by weight of whey protein. It was found that such iron-added WPC has no astringent taste unique to iron and is excellent in iron absorption and anemia improvement effects.
The whey to be used is not particularly limited, and the whey produced during cheese and casein production may be reconstituted by dissolving the dried whey again in water.
As the iron source, iron compounds such as ferric chloride, ferric nitrate, and ferric sulfate can be usually used. For example, these are used in the form of an aqueous solution.

The iron-added WPC of the present invention can be produced by mixing whey and a solution containing iron ions, that is, an iron source, and concentrating by ultrafiltration using a conventional method. Alternatively, whey may be preliminarily concentrated by ultrafiltration and then mixed with iron ions, that is, an iron source.
At this time, the weight of the iron ions to be mixed is 1/20 or less, preferably 1/250 or less of the protein contained in the whey.
Solutions containing iron ions, whey and / or whey after mixing with iron ions, ie, liquid iron-added WPC, is adjusted to pH using sodium hydroxide, potassium hydroxide, hydrochloric acid, citric acid, acetic acid, etc. In general, the obtained liquid iron-added WCP is adjusted to have a pH of 2 to 9, preferably 5.5 or more. The obtained liquid iron-added WPC may be used as it is, or may be dried and pulverized by freeze-drying, spray-drying or the like according to a conventional method.
The obtained iron-added WPC does not have iron astringent taste, and has excellent iron absorption and anemia improvement effects. Therefore, foods and pharmaceuticals for the purpose of preventing and improving anemia and strengthening iron It is useful as an iron preparation for iron reinforcement added to feed and the like.
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

As whey, mozzarella cheese whey was used. This rennet whey was ultrafiltered with a GP81PP membrane (manufactured by DOW DANMARK A / S, cutoff 10 kDa) and concentrated to 1/5 to obtain a whey protein concentrate (WPC). This was centrifuged at 2500 × g for 15 minutes to remove fat. Iron was added FeCl ₃ · 6H ₂ O as a 10 mg / 100 mL thereto. The pH of the obtained liquid mixture was 5.73. This mixture was freeze-dried to obtain iron-added WCP.
The obtained sample was dissolved in water, ultrafiltered at a cutoff of 10 kDa, and iron in the filtrate was measured. The value obtained by subtracting the iron content in the filtrate from the iron content in the stock solution was defined as the protein iron content. 90% of the added iron was bound. In order to clarify the relationship between protein and iron in iron-added WPC, the elution pattern of iron-added WPC was examined by gel filtration using Sephadex G-50. Atomic absorption spectroscopic analysis was performed by SDS-PAGE. FIG. 1 shows the results of scanning the protein eluted by gel filtration at an absorbance of 280 nm and measuring the iron content in the eluate. SDS-PAGE results and elution patterns were compared. Peak 1 was bovine serum albumin (BSA) and lactoferrin (Lf), peak 2 was β-lactoglobulin (β-Lg), and peak 3 was α-lactalbumin (α- Lg). When this result was compared with the elution pattern of iron, it was found that iron was bound to a large amount of β-Lg and α-La.

The iron deficient state improving effect of the iron-added WPC prepared in Example 1 using an anemia model rat was compared with other iron reinforcing agents (FeSO ₄ ). Three-week-old Wistar male rats were fed an iron-deficient diet for 3 weeks to be anemic. Thereafter, feeds each consisting of iron-added WPC and FeSO ₄ were given for 3 weeks, and the anemia-improving effect was compared. As a control group, a non-anemic group in which a commercially available solid diet was given without giving an iron-deficient diet, and an iron-deficient group in which an iron-deficient diet was given during the test diet administration period were used. FIG. 2 shows the serum iron concentration after administration of the test meal, and FIG. 3 shows the liver iron content after administration of the test meal.
In the figure, a and b indicate significant differences at the 1% level.
The serum iron concentration after administration of the test diet tended to be higher in the iron-added WPC diet group than in the FeSO ₄ diet group. The liver iron content after administration of the test meal was significantly higher in the iron-added WPC diet group than in the FeSO ₄ diet group. From these facts, it can be said that iron-added WPI has a higher iron content accumulated in the rat body than FeSO4. Therefore, iron-added WPC is useful as a food material for improving anemia.

In order to evaluate the absorbability of iron-added WPC prepared in Example 1, an in vivo test using Caco-2 cells was performed. A 6-well plate was seeded with Caco-2 cells at a concentration of 50,000 cells / cm ² and cultured in DMEM containing 10% FCS for 14 days. The iron absorption test was performed using MEM serum-free medium. Iron-added WPC artificially digested with pepsin and pancreatin was added to a MEM serum-free medium so that the iron concentration was 50 μM and 100 μM, cultured for 24 hours, washed twice with PBS, and cells were detached with a rubber policeman. The collected cells were sonicated and the ferritin content was measured. Since lactoferrin (LF) contained in WPC is known to have a cell growth promoting action, the protein content was measured. The result of correcting the ferritin content by the protein content is shown in FIG.
In the figure, Blank represents an iron-deficient group, FeSO ₄ represents a ferrous sulfate-added group, Whey Fe represents an iron-added WPC-added group, and ** represents a significant difference at a 1% level.
The ferritin content of Caco-2 cells was significantly higher in iron-added WPC than in FeSO ₄ at any iron concentration. From this, it is considered that the iron in the iron-added WPC is superior in absorbability compared to FeSO ₄ . It is considered that the improvement of anemia of iron-added WPC observed in animal experiments is a result of reflecting this easy absorption.

  A sensory test was performed on the iron-added WPC prepared in Example 1 dissolved in water so that the iron concentration was 10 mg%. Panelists of 5 males and 3 females were asked to determine whether they felt the astringent taste of iron. In addition, the sensory test was similarly performed about the ferrous sulfate aqueous solution whose iron concentration is 10 mg% as a sample which feels the astringency of iron. As a result, all panelists determined that the ferrous sulfate aqueous solution felt the astringent taste of iron, whereas iron-added WPC determined that all panelists did not feel the astringent taste of iron.

  According to the present invention, when using iron which is a water-insoluble or sparingly soluble mineral to be added to foods and drinks, feeds, etc., it has a property that it is extremely soluble in water, does not show astringent taste unique to iron, and absorbs -It is possible to provide an iron preparation for an iron-enhancing material that is excellent as an anemia-improving effect and is useful as a raw material for foods, pharmaceuticals, feeds, etc., for the purpose of iron strengthening and prevention or treatment of anemia.

It is a graph which shows the gel filtration elution pattern of the iron addition WPC prepared in Example 1, and the iron concentration in the eluate. It is a graph which shows the serum iron density | concentration after administering the iron addition WPC prepared in Example 1 to an anemia model rat. It is a graph which shows the liver iron density | concentration after administering the iron addition WPC prepared in Example 1 to an anemia model rat. It is a graph which shows the influence of iron addition WPC on the ferritin content of Caco-2 cell.

Claims (3)

Contains 0.001-0.05 parts by weight of iron per 1 part by weight of whey protein, whey protein and iron form a complex, does not have iron astringent taste, and is enriched with α-lactalbumin An iron-added whey protein concentrate for improving iron absorptivity and anemia, characterized by being not liquid and having a pH of 5.5 or higher or a dried product thereof. 2. The method for producing an iron-added whey protein concentrate according to claim 1, wherein whey and an aqueous solution containing iron ions are mixed and subjected to ultrafiltration, or ultrafiltered whey and iron ions are mixed. The method according to claim 2, wherein the weight of iron ions is 1/20 or less of the protein in whey, and the pH of the resulting liquid mixture of whey and iron ions is 5.5 or more.

Images