JP2009067688A - Iron absorption promoter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly safe iron absorption promoter having suitability to food processing and excellent activity for promoting iron absorption. <P>SOLUTION: The iron absorption promoter contains an acidic xylooligosaccharide having at least one uronic acid residue in one molecule as a side chain as an active ingredient. Preferably, the iron absorption promoter contains the acidic xylooligosaccharide having 2.0-15.0 average polymerization degree. Also preferably, the uronic acid is glucuronic acid or 4-O-methyl-glucuronic acid. The iron absorption promoter preferably contains an iron compound. The iron compound is preferably one or more kinds selected from the group consisting of iron chloride, ferrous sulfate, ferrous citrate, iron ammonium citrate, iron glucuronate, ferric glucuronate, iron and sodium succinate citrate, iron lactate, iron chondroitin sulfate, ferrous fumarate and iron pyrophosphate in the iron absorption promoter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an iron absorption promoter and a food or beverage containing the iron absorption promoter. Specifically, the present invention relates to an iron absorption promoter containing acidic xylo-oligosaccharide as an active ingredient, and a food or beverage containing the iron absorption promoter.

  Iron is an essential element for all living organisms and an important component of hemoglobin. Iron deficiency is a serious nutritional disorder worldwide, with mild to moderate anemia in the initial onset, and if the deficiency persists, worsening anemia, headache, loss of appetite, pain, stomatitis, etc. Develops.

  In recent years, the iron intake per capita in Japan has been declining, and it cannot be said that both men and women have satisfied iron intake in all age groups, and the prevalence of iron deficiency and iron deficiency anemia. An increase is feared. In particular, the situation in which prevalent women and growing children are increasingly prone to iron deficiency is regarded as a problem.

  There are 2.3 to 3.8 g of iron in the adult body, about 70% of which is present in erythrocytes as hemoglobin, and 20 to 30% is in the liver, bone marrow, etc. as ferritin or hemosiderin as stored iron To do. Iron other than the above functions as metalloenzymes such as myoglobin and cytochrome, which are iron pigment proteins in muscle. Heme iron is known to have a higher absorption rate from the intestinal tract than non-heme iron. Most of the iron contained in food is non-heme iron and the content of heme iron is low. Although heme iron is easily absorbed, absorption is enhanced by vitamin C present in food and is inhibited by phosphate, phytate, and the like. Iron is an essential component of cells and is supplied from iron contained in foods. Iron has a high absorption rate when the required amount of iron in the living body is high, and conversely, when the required amount is low, the absorption rate decreases. When iron intake is low or there is bleeding, iron stored in the body is deficient, leading to the development of anemia (Non-patent Document 1).

Recently, many iron-enriched foods and supplements have been developed around the world for the purpose of preventing or improving iron deficiency. For example, iron compounds, seasonings added with iron absorption promoters, rice, bread, cereal, etc. It is on the market. In this way, iron-enriched foods and drinks and supplements that can be easily ingested have been developed, and development of products that are more excellent in iron absorption effect is desired.
As an example of the iron absorption accelerator, there is Patent Document 1 and the like.

"Health and Nutrition Food Advisory Staff Textbook" Kazuhiko Yamada, Yasuhiro Matsumura, 1st Publication: p34-35, 2005 Japanese Unexamined Patent Publication No. 7-97323 JP 2003-183303 A JP 2003-055331 A JP 2004-059481 A JP 2003-221339 A

  An object of the present invention is to provide an iron absorption promoter having high safety, excellent iron absorption promoting action, and food processing suitability.

  As a result of intensive studies to solve the above problems, the present inventors have found that an acidic xylo-oligosaccharide composition to which a uronic acid residue has been added has an excellent iron absorption promoting effect, leading to the completion of the invention. It was.

In addition, this applicant has reported about the manufacturing method of acidic xylo-oligosaccharide, and physiological effects, such as an enteral nutrient, a histamine release inhibitor, and an anti-inflammatory agent (refer patent documents 2-5).

That is, the present invention employs the following configuration.
The first of the present invention is an iron absorption promoter containing acidic xylo-oligosaccharide having at least one uronic acid residue as a side chain in one molecule as an active ingredient.

  2nd of this invention is an iron absorption promoter as described in 1st of this invention whose average degree of polymerization of acidic xylo-oligosaccharide is 2.0-15.0.

  3rd of this invention is the iron absorption promoter in any one of 1-2 of this invention whose uronic acid is glucuronic acid or 4-O-methyl- glucuronic acid.

  4th of this invention is the iron absorption promoter in any one of 1st-3rd of this invention containing an iron compound.

  In the fifth aspect of the present invention, the iron compound is iron chloride, ferrous sulfate, ferrous citrate, ammonium iron citrate, iron glucuronic acid, ferric glucuronic acid, sodium iron citrate succinate, iron lactate, The iron absorption promoter according to the fourth aspect of the present invention, which is at least one selected from the group consisting of iron chondroitin sulfate, ferrous fumarate, and iron pyrophosphate.

  A sixth aspect of the present invention is the iron absorption promoter according to any one of the fourth to fifth aspects of the present invention, wherein the iron compound is chelate-bonded to the acidic xylooligosaccharide.

  7th of this invention is the foodstuff or drink containing the iron absorption promoter described in any one of 1st-6 of this invention.

  According to the present invention, it is possible to provide an iron absorption promoter having high safety and an excellent iron absorption promoting action. Such an iron absorption enhancer can be used as an iron absorption enhancer after improvement of anemia, etc., after blood donation, after surgery and after delivery. Moreover, the iron absorption promoter of the present invention can be easily added to foods and beverages and is excellent in food processing suitability. Furthermore, the iron absorption promoter of the present invention can also be used as an iron agent having an excellent effect by adding iron.

  Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

The iron absorption promoter of the present invention contains acidic xylo-oligosaccharide as an active ingredient.
The xylooligosaccharide is a xylose polymer which is a dimer of xylose, a xylotriose which is a trimer, or a tetramer to 20-mer xylose polymer.

  The acidic xylo-oligosaccharide which is an active ingredient of the iron absorption promoter in the present invention refers to one having at least one uronic acid side chain in one molecule of the xylo-oligosaccharide. The number of uronic acid residues in one molecule is preferably 1 to 5 on average and more preferably 1 to 2 on average.

The degree of polymerization of the xylo-oligosaccharide used in the present invention is preferably 3.5 to 20 and more preferably 5 to 10 in the case of a xylo-oligosaccharide having a single polymerization degree.
In the present invention, the acidic xylooligosaccharide may be a mixed composition of oligosaccharides having different degrees of polymerization of xylose. In general, since an acidic xylo-oligosaccharide is produced from a natural product, it is often obtained as such a mixed composition.

  The degree of polymerization of the mixed composition is indicated by the average degree of polymerization of the xylose chain length. The average degree of polymerization is an average value of the xylose chain length of the acidic xylooligosaccharide having a normal distribution, and the average degree of polymerization of the acidic xylooligosaccharide used in the present invention is preferably 2.0 to 15.0, and 7.0. ~ 13.0 is more preferred. The difference between the upper limit and the lower limit of the xylose chain length is preferably 10 or less, and more preferably 6 or less.

Further, the uronic acid side chain of the acidic xylooligosaccharide of the present invention is known in nature as a component of a polysaccharide having various physiological activities such as pectin, pectinic acid, alginic acid, hyaluronic acid, heparin, chondroitin sulfate, dermatan sulfate. ing.
The uronic acid in the present invention is not particularly limited, but glucuronic acid or 4-O-methyl-glucuronic acid is preferable.

  Various methods can be used as the method for producing the acidic xylo-oligosaccharide of the present invention. (1) A method of extracting xylan from wood and enzymatically decomposing it (Cellulase Research Report Vol. 16, 2001) June 14, p17-26) and (2) Lignocellulosic material is treated enzymatically and / or physicochemically to obtain a complex of xylooligosaccharide component and lignin component, which is then subjected to acid hydrolysis Examples of the method include obtaining a xylooligosaccharide mixture by treatment, and separating the xylooligosaccharide mixture having at least one uronic acid residue as a side chain in one molecule from the obtained xylooligosaccharide mixture.

  In particular, the method (2) is preferable because it can produce a large amount of a polymer having a relatively high degree of polymerization, such as a 5-10 mer, at a low cost.

The acidic oligosaccharide composition can be obtained through a hydrolysis process, a concentration process, a dilute acid treatment process, and a purification process using a lignocellulosic material derived from chemical pulp as a raw material.
In the hydrolysis process, xylan in lignocellulose is selectively hydrolyzed with dilute acid treatment, high-temperature and high-pressure steam (cooking / explosion) treatment, or hemicellulase, and a high molecular weight complex composed of xylooligosaccharide and lignin is intermediated. Get as a body.

  For the production of the xylo-oligosaccharide of the present invention, for example, a commercially available hemicellulase or a microorganism-derived hemicellulase can be used. Examples of the commercially available hemicellulase include, for example, the brand name Cartozyme (manufactured by Clariant), the brand name Eco Pulp (manufactured by Rohm Enzyme), the brand name Sumiteam (manufactured by Shin Nippon Chemical Industry Co., Ltd.), and pulpzyme (manufactured by Novo Nordics), Examples include Multifect 720 (Genencore). Examples of microorganism-derived hemicellulases include Trichoderma genus, Thermomyces genus, Aureobasidium genus, Streptomyces genus, Aspergillus genus, Clostridium genus, Bacillus genus, Thermotoga genus, Thermoscus genus, Cardocera genus, Thermomonospora genus, etc. And xylanase produced by these microorganisms.

  In general, the enzyme reaction temperature in the enzyme treatment is preferably in the range of 10 to 90 ° C, more preferably in the range of 30 to 60 ° C. 3-10 are preferable and, as for pH of the reaction solution at the time of an enzyme treatment, the range of 5-9 is more preferable.

  In the concentration step, the xylooligosaccharide-lignin-like substance complex is concentrated by a reverse osmosis membrane or the like, and oligosaccharides having a low polymerization degree, low-molecular impurities, and the like can be removed. In the concentration step, a reverse osmosis membrane is preferably used, but ultrafiltration membrane, salting out, dialysis and the like are also possible.

  A lignin-like substance is released from the complex by the diluted acid treatment step of the obtained concentrated liquid, and a diluted acid-treated liquid containing acidic xylo-oligosaccharides and neutral xylo-oligosaccharides can be obtained. As a method for adjusting the pH of the sugar solution, a mineral acid (for example, hydrochloric acid, sulfuric acid, nitric acid, etc.) or an organic acid (for example, p-toluenesulfonic acid, acetic acid, trifluoroacetic acid, etc.) is appropriately added to the sugar solution. In general, the pH of the liquid is adjusted to around 3.5. For example, the sugar solution can be prepared using a cation exchange resin (ion exchange resin) such as Amberlite 200C (trade name, manufactured by Rohm & Haas). It is also possible to lower the pH by treatment.

  Thereafter, the sugar solution whose pH has been adjusted is heated in the range of 105 ° C. to 150 ° C., preferably in the range of 110 ° C. to 130 ° C., to perform acid hydrolysis. The treatment time is preferably 15 minutes or more, and more preferably 30 to 60 minutes. If the treatment time for acid hydrolysis is set to 90 minutes or longer, the decomposition of oligosaccharides into monosaccharides proceeds, which is not preferable. In the acid hydrolysis treatment, lignin-like organic substances are decomposed and removed from the xylooligosaccharide-lignin complex, and converted into acidic xylooligosaccharide and xylooligosaccharide. The conversion efficiency from the xylooligosaccharide complex to acidic xylooligosaccharide and xylooligosaccharide (neutral xylooligosaccharide) when the sugar solution is hydrolyzed at 121 ° C. for 60 minutes (pH 3.5) is about 95%. Since the lignin-like substance separated from the complex by the acid hydrolysis treatment is condensed and precipitated under acidic conditions, it can be removed by filtration using a ceramic filter or filter paper. Further, as an alternative to the dilute acid treatment step, for example, a method by enzymatic decomposition using a lignin degrading enzyme can also be performed.

The purification process includes an ultrafiltration process, a decolorization process, and an adsorption process. After the dilute acid treatment, a part of the lignin-like substance remains in the sugar solution as a soluble polymer, but is removed by an ultrafiltration step (for example, using a UF membrane having a fractional molecular weight of 20000 or less).
Although an ultrafiltration membrane is preferably used in the ultrafiltration step, a reverse osmosis membrane, salting out, dialysis, or the like can also be used. Further, most of impurities such as coloring substances are removed by a decoloring process using activated carbon.
Acid xylo-oligosaccharides and neutral xylo-oligosaccharides are dissolved in the sugar solution thus obtained. Only an acidic xylo-oligosaccharide can be extracted from this sugar solution by an adsorption process using an ion exchange resin. First, the sugar solution is treated with a strong cation exchange resin to remove metal ions in the sugar solution. Next, sulfate ions and the like in the sugar solution are removed using a strong anion exchange resin. In this step, it is possible to remove a part of the organic acid, which is a weak acid, and the coloring component simultaneously with the removal of sulfate ions. The sugar solution treated with the strong anion exchange resin is treated again with the strong cation exchange resin to further remove metal ions. Finally, it is treated with a weak anion exchange resin to adsorb acidic xylo-oligosaccharides to the resin.

By eluting the acidic xylo-oligosaccharide adsorbed on the resin with a low-concentration metal salt (NaCl, CaCl ₂ , KCl, MgCl ₂ or the like), an acidic xylo-oligosaccharide solution free from impurities can be obtained. From this solution, for example, a powder of a white acidic xylo-oligosaccharide composition can be obtained by spray drying or freeze-drying treatment.

  The merit of the above-mentioned production method of acidic xylooligosaccharide composition using chemical pulp-derived lignocellulose as a raw material and high molecular weight complex consisting of xylooligosaccharide and lignin as an intermediate is economical and acidic with high average polymerization degree of xylose. The xylo-oligosaccharide composition is easily obtained. The average degree of polymerization can be adjusted, for example, by adjusting dilute acid treatment conditions or treating with hemicellulase again. In addition, by changing the salt concentration of the eluate used for elution of acidic xylo-oligosaccharide adsorbed on weak anion exchange resin, an acidic xylo-oligosaccharide composition in which the number of uronic acid residues bonded per molecule is different is obtained. You can also. Furthermore, it is also possible to obtain an acidic xylo-oligosaccharide composition in which the uronic acid binding site is limited to the terminal by acting an appropriate xylanase or hemicellulase.

The acidic xylo-oligosaccharide of the present invention exhibits an effect of promoting iron absorption when taken orally, thereby exhibiting an improvement effect such as anemia.
The acidic xylo-oligosaccharide can be used alone or in combination with a known excipient (solid or liquid). Moreover, an iron compound and additives (antioxidants, dyes, fragrances, tastes, enzymes, etc.) as necessary can be added to the composition and used as an iron absorption promoter.

  Examples of solid excipients include lactose, sucrose, glucose, corn starch, gelatin, dextrin, and starch. Examples of the liquid excipient include water, glycerin, fatty oil, sorbitol and the like.

The iron absorption promoter of the present invention may further contain an iron compound.
Iron compounds include iron chloride, ferrous sulfate, ferrous citrate, ammonium iron citrate, sodium iron citrate succinate, iron lactate, chondroitin iron sulfate, ferrous fumarate, and iron pyrophosphate, others Any one of inorganic or organic iron compounds or a combination of these may be used as appropriate.
Thus, the iron absorption promoter of this invention can be used also as an iron agent which has the outstanding effect by containing an iron compound.
The compounding ratio of the acidic xylooligosaccharide and the iron compound in the iron absorption promoter is not particularly limited as long as the iron absorption promotion effect is obtained.
In the present invention, the iron compound may be chelated with an acidic xylooligosaccharide.

  The iron absorption promoter of the present invention can be used in a powder form, or can be used in a liquid state after being dissolved in a liquid. Moreover, it can be processed into any form such as powder, granule, tablet, capsule and the like.

  The iron absorption promoter of the present invention can be used for foods, animal foods (feed, pet food, etc.), pharmaceuticals, quasi drugs and the like. The above-mentioned foods, animal foods, pharmaceuticals, and quasi-drugs can be used for humans or livestock (cattle, horses, pigs, sheep, goats, etc.), pets (eg, dogs, cats, etc.), etc. .

  Examples of food include health foods, breads, confectionery, processed cereals such as cookies and biscuits, dairy products such as milk, yogurt and ice cream, carbonated drinks, soft drinks, soft drinks with fruit juice, and drinks with fruit juice. , Drinks such as medicinal drinks, prepared foods using soybeans, fish meat, livestock meat, processed foods, and the like.

  Examples of animal foods include general livestock feed, pet food (including premium pet food), and supplements.

  When the acidic xylo-oligosaccharide of the present invention is used in combination with foods, livestock foods, etc., the content of the acidic xylo-oligosaccharide is 0.01 to 30% by mass, although it varies depending on the type of target human or animal. It is preferable that it is 0.1 to 5% by mass.

  The amount of acidic xylo-oligosaccharides contained in the iron absorption enhancer of the present invention to humans or animals varies depending on the type of human or animal of interest, but is 0.1 mg to 5000 mg / kg per body weight as acidic xylo-oligosaccharides. It is preferably 2 mg to 100 mg / kg.

  The iron absorption promoter of the present invention has a slight salty taste, and when added to food, does not impair the taste of the added food, and is also excellent in acid and heat resistance. Excellent processability. Therefore, by adding it to various foods, animal foods, pharmaceuticals, quasi drugs, etc. that are taken orally by humans and animals, the acidic xylooligosaccharide having an iron absorption promoting action of the present invention can be used in a normal diet. There is a merit that it can be ingested easily, and iron deficiency anemia and the like can be routinely prevented and alleviated.

  Hereinafter, the present invention will be described in detail with reference to examples.

<Preparation of acidic xylooligosaccharides>
Hereinafter, preparation examples of acidic xylo-oligosaccharide which is an active ingredient of the present invention will be shown.
Oxygen delignified pulp slurry (kappa number 9.6, pulp viscosity 25.1 cps) was obtained from mixed hardwood chips (domestic hardwood 30%, eucalyptus 70%) as a raw material through kraft cooking and oxygen delignification processes.
After the pulp was filtered and washed from the slurry, the pulp slurry prepared to a pulp concentration of 10% and pH 8 was subjected to enzyme treatment with xylanase as follows.

  After adding xylanase conch (manufactured by Advanced Biochemicals) to 50 units / g of pulp, it was treated at 60 ° C. for 120 minutes. Thereafter, the pulp residue was removed by filtration to obtain 1000 L of an enzyme treatment liquid.

Next, the obtained enzyme treatment solution was subjected to a concentration step, a dilute acid treatment step, and a purification step in this order.
In the concentration step, a concentrated solution (40-fold concentration) was prepared using a reverse osmosis membrane (Nonto Denko Corporation, RONTR-7410). In the dilute acid treatment step, the pH of the obtained concentrated solution was adjusted to 3.5 and then heat-treated at 121 ° C. for 60 minutes to form precipitates of polymer contaminants such as lignin. Further, the precipitate was removed by ceramic filter filtration to obtain a diluted acid treatment solution.

In the purification step, the obtained diluted acid treatment solution was subjected to an ultrafiltration / decolorization step and an adsorption step in this order. In the ultrafiltration / decolorization step, after passing the dilute acid treatment solution through an ultrafiltration membrane (Osmonics, molecular weight cut off 8000), addition of 770 g of activated carbon (Wako Pure Chemical Industries, Ltd.) and ceramic filter filtration To obtain a decolorization treatment solution.
In the adsorption process, the decolorization treatment solution was used as a strong cation exchange resin (PK218 manufactured by Mitsubishi Chemical Corporation), a strong anion exchange resin (PA408 manufactured by Mitsubishi Chemical Corporation), or a strong cation exchange resin (Mitsubishi Chemical Corporation). PK 218) Each was sequentially passed through a column packed with 100 kg, and then subjected to a column packed with 100 kg of weak anion exchange resin (WA30 manufactured by Mitsubishi Chemical Corporation).
By spray-drying the solution eluted with NaCl solution (75 mM) from the weak anion exchange packed column, acid xylo-oligosaccharide powder (total sugar amount 12.7 kg, recovery rate 13.9%) is obtained. It was. Hereinafter, this acidic xylo-oligosaccharide is referred to as UX10.
UX10 obtained by the above-mentioned method was a sugar composition compound having an average degree of polymerization of 10.2, a difference between the upper limit and the lower limit of the xylose chain length of 10, and one uronic acid residue per molecule of acidic xylooligosaccharide. (Analytical measurement method will be described later).

<Analytical measurement of xylooligosaccharides>
(1) Quantification of total sugar content:
The total sugar amount was prepared using a calibration curve using D-xylose (manufactured by Wako Pure Chemical Industries, Ltd.) and quantified by the phenol sulfate method (quantitative method for reducing sugar, published by the Academic Publishing Center).
(2) Quantification of reducing sugar amount:
The amount of reducing sugar was prepared by using D-xylose (manufactured by Wako Pure Chemical Industries, Ltd.) with a calibration curve, and quantified by the Sommoji-Nelson method (quantitative method for reducing sugar, published by Academic Publishing Center).
(3) Determination of uronic acid content:
Uronic acid was prepared by using D-glucuronic acid (manufactured by Wako Pure Chemical Industries, Ltd.) with a calibration curve, and quantified by the carbazole sulfate method (reducing sugar quantification method, published by Academic Publishing Center).
(4) Method for determining the average degree of polymerization:
The sample sugar solution was kept at 50 ° C. and centrifuged at 15,000 rpm for 15 minutes to remove insoluble matter, and the total sugar amount in the supernatant was divided by the reducing sugar amount (both converted to xylose) to determine the average degree of polymerization.
(5) Method for analyzing acid xylo-oligosaccharides:
The oligosaccharide chain distribution was analyzed using an ion chromatograph (Dionex, analytical column: Carbo Pac PA-10). A 100 mM NaOH solution is used as a separation solvent, and sodium acetate is added to the above-mentioned separation solvent so as to have a concentration of 500 mM as an elution solvent, so that the separation solvent: elution solvent = 10: 0 to 4: 6 in a solution ratio. A simple linear gradient was combined and separated. From the obtained chromatogram, the difference between the upper limit and the lower limit of the xylose chain length was determined.
(6) Determination of the number of uronic acid residues per molecule of oligosaccharide The sample sugar solution was kept at 50 ° C. and centrifuged at 15000 rpm for 15 minutes to remove insoluble matters, and the amount of uronic acid in the supernatant (D-glucuronic acid) (Converted) was divided by the amount of reducing sugar (converted to xylose) to determine the number of uronic acid residues per oligosaccharide molecule.
(7) Definition of enzyme titer:
Kabikilan (manufactured by Sigma) was used to measure the activity of the xylanase used as the enzyme. The enzyme titer is defined by measuring the reducing power of reducing sugar obtained by xylanase degrading xylan using the DNS method (quantitative method for reducing sugar, published by Academic Publishing Center), and 1 micromole of xylose per minute. The amount of enzyme that generates a reducing power corresponding to 1 was defined as 1 unit.

  The iron absorption promoting action of the acidic xylo-oligosaccharide (UX10) obtained by the method described above was examined by the following method.

<Iron absorption promotion test>
12 SD rats (7 weeks old, male: purchased from Japan SLC Co., Ltd.) were fed with normal xylo-oligosaccharides or cellulose from the experimental diet of Example 1 or Comparative Example 1 described in Table 1 described later. Excluded composition) was given for 3 days and preliminarily reared. The breeding was carried out from the breeding to the end of breeding in a breeding room adjusted to a temperature of 23 ± 2 ° C., a humidity of 50 ± 2%, and a 12-hour light / dark cycle (lights on from 6:00:00 to 18:00). Rats were kept in individual stainless cages, and body weight and food intake were measured every day at the same time zone.
After the preliminary breeding, 12 rats were randomly divided into 1 group and 2 groups of 6 animals each, and the experimental diet of Example 1 was divided into 1 group, and the experimental diet shown in Comparative Example 1 was divided into 1 group for 1 week. Ad libitum.
In addition, as drinking water for rats, distilled water was freely ingested from the preliminary breeding to the end of the breeding. As a result of measuring the iron content in distilled water, the iron intake from the drinking water was 0.01% or less, so it was determined that the influence on the iron intake could be ignored.
The mineral mixture of the experimental food described in Table 1 was the one containing no iron. For casein and α-corn starch used in the experimental diet, the iron content is determined in advance by the σ-phenanthroline colorimetric method, so that the total iron content in the experimental diet is 4.0 mg / 100 g (food). In addition, iron citrate was added for adjustment. In the experimental food of Comparative Example 1, 2% cellulose was used in place of the 2% acidic xylo-oligosaccharide of Example 1 as a control.
After the start of the breeding test, the animals were transferred to a metabolic cage during the 5th to 7th days (3 days), and all feces were collected. The collected feces were dried at 50 ° C., pulverized and stored frozen at −18 ° C. until used for analysis.

From the iron content contained in feces collected from rats, the iron absorption rates of Example 1 and Comparative Example 1 were determined by the following method. The results are shown in Table 2.
Iron absorption rate = (intake iron amount−feces excreted iron amount) / intake iron amount × 100 (%)
Ingested iron amount: After ashing the experimental food by the dry ashing method, dissolve it in hydrochloric acid, determine the iron content by the σ-phenanthroline colorimetric method, and multiply by the total food intake for 7 days. Iron intake calculated as average per day.
Excreted iron amount: 3 days of frozen feces were thawed, dry ashed, dissolved in hydrochloric acid, iron content was quantified by σ-phenanthroline colorimetric method, and excreted as an average per day Iron content.

  From Table 2, the iron absorption rate was significantly increased in the test group ingesting the experimental food of Example 1 compared to the test group ingesting the experimental food of Comparative Example 1 (P <0.05). .

  According to the present invention, it is possible to provide an iron absorption promoter having high safety and an excellent iron absorption promoting action. Such an iron absorption enhancer can be used as an iron absorption enhancer after improvement of anemia, etc., after blood donation, after surgery and after delivery. Moreover, the iron absorption promoter of the present invention can be easily added to foods and beverages and is excellent in food processing suitability. Furthermore, the iron absorption promoter of the present invention can be used as an iron agent having an excellent effect by adding an iron compound.

Claims (7)

  An iron absorption promoter characterized by containing an acidic xylo-oligosaccharide having at least one uronic acid residue as a side chain in one molecule as an active ingredient.   2. The iron absorption promoter according to claim 1, wherein the average degree of polymerization of the acidic xylo-oligosaccharide is 2.0 to 15.0.   The iron absorption promoter according to any one of claims 1 to 2, wherein uronic acid is glucuronic acid or 4-O-methyl-glucuronic acid.   The iron absorption promoter according to any one of claims 1 to 3, comprising an iron compound.   Iron compounds are ferrous chloride, ferrous sulfate, ferrous citrate, ammonium iron citrate, iron glucuronic acid, ferric glucuronic acid, sodium iron citrate succinate, iron lactate, chondroitin iron sulfate, fumarate ferric acid The iron absorption promoter according to claim 4, wherein the iron absorption promoter is one or more selected from the group consisting of monoiron and iron pyrophosphate.   The iron absorption promoter according to any one of claims 4 to 5, wherein the iron compound is chelate-bonded with acidic xylo-oligosaccharide.   A food or beverage comprising the iron absorption promoter according to any one of claims 1 to 6.