JP2016049020A - Copper-containing yeast extract and manufacturing method of the same, and food product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a copper-containing yeast extract in which copper can be extracted from yeast containing copper at a high extraction rate, and which is more suitable for food product application, a copper-containing yeast extract obtained by the manufacturing method, and a food product containing the copper-containing yeast extract.SOLUTION: A manufacturing method of a copper-containing yeast extract includes an extraction process in which yeast containing copper is suspended into solution containing an extraction accelerator or the extraction accelerator is added and mixed into the solution in which yeast containing copper is suspended, and a solid component and a liquid component of obtained suspension is separated, and the extraction accelerator contains at least one of peptide and protein (excluding the case where the accelerator consists of amino acid only).SELECTED DRAWING: None

Description

  The present invention relates to a copper-containing yeast extract, a method for producing the same, and food.

According to the recent data published by the Ministry of Health, Labor and Welfare, copper is estimated to be about 0.7 mg (about 0.6 mg for adult women) as an estimated average daily requirement for adult men. , May cause anemia and heart disease (see Non-Patent Document 1). Therefore, it is necessary to develop safe food materials such as liquid foods and beverages that can efficiently ingest or absorb copper into the living body and can improve anemia due to copper deficiency, heart disease, and the like.
On the other hand, yeast has long been used as a food material by humans. For example, brewer's yeast has been used as a source of dietary fiber, vitamins and minerals. In particular, it is considered that a yeast (copper-containing yeast) in which copper has been taken into cells or an extract thereof can be used as a safe food material reinforced with copper.
However, in the conventional copper-containing yeast, the unique odor such as yeast odor and the unique taste such as yeast taste have not been sufficiently reduced, so that they are not sufficiently satisfactory for food use.

  In order to solve the above problem, it is conceivable to obtain a copper-containing yeast extract extracted from the copper-containing yeast. So far, (1) hot water extraction method, (2) self-digestion method, (3) enzymatic degradation method, etc. have been used for extraction from mineral-containing yeasts such as copper (see Non-Patent Document 2). However, the methods (1) to (3) have a problem that the recovery rate of minerals (hereinafter sometimes referred to as “extraction rate”) is low. Among minerals, the extraction rate of copper is particularly low, and there is a strong demand for the development of technology that can increase the extraction rate.

  As a method for increasing the extraction rate of copper, a method using at least one of carboxylic acid and carboxylate has been proposed (for example, see Patent Document 1). According to the proposal, although copper can be extracted at a high extraction rate, from the viewpoint of use for food use, there is a copper extraction rate equivalent to the proposal, and there is an extraction method using a material more suitable for food use. The current situation is what is required.

“Japanese food intake standards 2010 edition” Ministry of Health, Labor and Welfare “Japanese food intake standards” study report, Daiichi Publishing Co., Ltd., p. 231-p. 233, Appendix XLIX (2010) Hiroshi Sugimoto "Transition of Yeast Extract Production Method (I) -From the Trend of Domestic Patent Applications-" New Food Industry 1994, Vol. 36, no. 10, p. 41-48

International Publication No. 2013/146465

  An object of the present invention is to meet such demands, overcome the current situation, solve the above-described problems, and achieve the following objects. That is, the present invention can extract copper from a yeast containing copper at a high extraction rate and is suitable for food use, a method for producing a copper-containing yeast extract, and a copper-containing yeast extract obtained by the production method And a food containing the copper-containing yeast extract.

Means for solving the problems are as follows. That is,
<1> Suspension obtained by suspending yeast containing copper in a solution containing an extraction accelerator or adding and mixing an extraction accelerator to a solution in which yeast containing copper is suspended. An extraction step of separating the solid component and the liquid component of
The method for producing a copper-containing yeast extract, wherein the extraction accelerator contains at least one of a peptide and a protein (except for a case consisting of only an amino acid).
<2> The method for producing a copper-containing yeast extract according to <1>, wherein the extraction accelerator is a yeast extract.
<3> The method for producing a copper-containing yeast extract according to any one of <1> to <2>, wherein an extraction rate of copper represented by the following formula is 50% or more.
Copper extraction rate (%) = {total copper (mass) in extract / total copper (mass) contained in yeast used for extraction} × 100
<4> The above-mentioned <1> including a hydrothermal treatment step of suspending yeast in hot water at 60 ° C. to 120 ° C. and separating a solid component and a liquid component of the obtained suspension before the extraction step. To <3>, the method for producing a copper-containing yeast extract.
<5> A copper-containing yeast extract produced by the method for producing a copper-containing yeast extract according to any one of <1> to <4>.
<6> The copper-containing yeast extract according to <5>, wherein the yeast is an edible yeast.
<7> The copper-containing yeast extract according to <6>, wherein the edible yeast is at least one selected from baker's yeast, beer yeast, wine yeast, sake yeast, and miso soy yeast.
<8> The copper-containing yeast extract according to <7>, wherein the edible yeast is Saccharomyces cerevisiae .
<9> The copper-containing yeast extract according to any one of <5> to <8>, which is used by being added to food.
<10> A food comprising the copper-containing yeast extract according to any one of <5> to <9>.

  According to the present invention, the conventional problems can be solved, copper can be extracted from a yeast containing copper at a high extraction rate, and the method for producing a copper-containing yeast extract more suitable for food use, The copper containing yeast extract obtained by a manufacturing method and the foodstuff containing this copper containing yeast extract can be provided.

(Method for producing copper-containing yeast extract)
The manufacturing method of the copper containing yeast extract of this invention contains an extraction process, and also includes other processes, such as a hot-water treatment process and a drying process, as needed.

<Extraction process>
In the extraction step, the copper-containing yeast is suspended in a solution containing the extraction accelerator, or the extraction accelerator is added to and mixed with the solution in which the copper-containing yeast is suspended. This is a step of separating the solid component and the liquid component of the suspension. Through the extraction step, a liquid component containing copper (hereinafter sometimes referred to as “extract”) can be obtained.

<< Yeast >>
There is no restriction | limiting in particular as long as the said yeast contains copper in a microbial cell, According to the objective, it can select suitably. As the copper content in the yeast, it is preferable that the copper-containing yeast extract is used as a copper-reinforced food material or the like, but the limit of copper uptake in the yeast and the copper-containing yeast extract are efficiently produced. From a viewpoint, 0.01 mass%-10 mass% per dry cell mass are preferable, and 0.5 mass%-2 mass% are more preferable.

Here, the copper content refers to the copper content in the yeast cells. For example, even if the cells are washed with water or the like, the copper content is preferably kept high even after washing. Even if such yeast is washed, the copper is not removed and remains inside the microbial cells, so it is copper derived from the microbial cells and is highly safe, reducing the odor and taste peculiar to yeast. When hot water treatment (washing) is performed, the flavor and the like of the added food are not impaired, and copper is contained at a high concentration, so that it is suitable as a food material.
In addition, the copper content in the said yeast can be measured by a well-known method, for example, can be measured by an atomic absorption method.

  The yeast containing copper may be prepared by adding copper to the culture medium and culturing the yeast so that copper is taken into the yeast cells, or a commercially available product may be used. As a commercial item, 1.1% of mineral yeast copper, yeast mineral copper (above, Oriental Yeast Co., Ltd. product) etc. are mentioned, for example.

  The yeast containing copper may be further crushed. Even when the yeast is a crushed material, the higher the copper content, the better. The copper content per dry cell mass in the precipitate fraction obtained by washing the crushed material with water or the like is dried in the microbial cells before crushing. 70 mass% or more of copper content per microbial cell mass is preferable, 80 mass% or more is more preferable, and 90 mass% or more is especially preferable.

  The crushing method is not particularly limited and may be appropriately selected depending on the purpose. For example, physical crushing treatment or chemical crushing treatment may be used. For example, a method using a dyno mill in which a cylinder having 50 mm% of 0.5 mm diameter beads is filled may be preferably used.

  Moreover, there is no restriction | limiting in particular as an aspect of the yeast containing the said copper, According to the objective, it can select suitably, For example, the aspect of a wet cell body, the aspect of a powder, etc. are mentioned.

  The yeast may further contain other mineral components in addition to copper, and the mineral components are not particularly limited and can be appropriately selected according to the purpose. For example, iron, magnesium, manganese And zinc. These mineral components may be contained singly or in combination of two or more in yeast, and the concentration contained is different according to the purpose and is generally defined. In general, a high concentration is preferred.

The yeast is particularly preferably an edible yeast when the copper-containing yeast extract is used as a food material or the like.
There is no restriction | limiting in particular as said edible yeast, It can select from well-known things, For example, baker's yeast, beer yeast, wine yeast, sake yeast, miso soy sauce yeast, etc. are mentioned. Among these, baker's yeast is particularly preferable.

The strain of the edible yeast is not particularly limited and may be appropriately selected depending on the purpose, for example, Saccharomyces (Saccharomyces) genus Torulopsis (Torulopsis) genus Mikotorura (Mycotorula) genus Torulaspora (Torulaspora) genus, Candida (Candida) genus Rhodotorula (Rhodotorula) genus Pichia (Pichia) sp, and the like.

Specific examples of strains of the edible yeast, Saccharomyces cerevisiae, Saccharomyces carlsbergensis, Saccharomyces uvarum, Saccharomyces rouxii, Torulopsis utilis, Torulopsis candida, Mycotorula japonica, Mycotorula lipolytica, Torulaspora delbrueckii, Torulaspora fermentati, Candida sake, Candida tropicalis, Candida utilis, Hansenula anomala , Hansenula suaveolens , Sacchar omycopsis fibrigera , Saccharomyces lipolytica , Rhodotorula rubra , Pichia farinosa and the like.
Among these, Saccharomyces cerevisiae and Saccharomyces carlsbergensis are preferable, and Saccharomyces cerevisiae is particularly preferable.

<< Solution containing extraction accelerator >>
The solution containing the extraction accelerator contains at least an extraction accelerator, and further contains other components as necessary.
The solution containing the extraction accelerator may be prepared by adding the extraction accelerator to a solvent, or by adding and mixing the extraction accelerator in a solution in which yeast containing copper is suspended. May be.

-Extraction accelerator-
The extraction accelerator contains at least one of a peptide and a protein. Accordingly, when the extraction accelerator is composed of only amino acids, it is excluded from the embodiment of the present invention.
The extraction accelerator may consist of at least one of peptides and proteins, or may contain other components.

  The peptide refers to a polypeptide having a length of less than 50 amino acids and a molecular weight of 1,000 to less than 6,000 and an oligopeptide having a length of 2 to 10 amino acids and a molecular weight of less than 1,000.

  The protein refers to a polypeptide having a length of 50 amino acids or more and a molecular weight of 6,000 or more.

There is no restriction | limiting in particular as content of at least one of the peptide and protein in the said extraction promoter, Although it can select suitably according to the objective, 10 mass%-90 mass% are preferable.
The peptide and protein quantification method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include Kjeldahl method, Raleigh method, Bradford method and the like.

  The extraction promoter preferably contains mainly a peptide, more preferably contains an oligopeptide, and further contains at least one of a polypeptide and a protein. The extraction accelerator may contain a mixture of amino acids.

Other components in the extraction promoter are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. Examples thereof include nucleic acids contained in yeast extract.
There is no restriction | limiting in particular as content of the other component in the said extraction promoter, According to the objective, it can select suitably.

As the extraction accelerator, yeast extract is preferable.
The yeast extract is not particularly limited as long as it contains at least one of a peptide and a protein, and can be appropriately selected according to the purpose.

There is no restriction | limiting in particular as a total nucleic acid amount of the said yeast extract, Although it can select suitably according to the objective, 3.0 mass%-10.0 mass% are preferable, 5.0 mass%-7.0 % By mass is more preferable, and more than 6.0% by mass and less than 7.0% by mass is particularly preferable. Within the preferred range, it is advantageous in that the copper extraction rate is more excellent.
The total nucleic acid amount of the yeast extract can be analyzed by a simple method using an A ₂₆₀ / A ₂₈₀ ratio by preparing an aqueous solution containing 10% by mass of the yeast extract, measuring the absorbance at a wavelength of 260 nm and 280 nm.

The molecular weight distribution of the yeast extract is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a molecular weight of less than 6,000 is 80% to 99%, a molecular weight of 6,000 or more is 0.1 % To 5%.
The molecular weight distribution can be measured by a high performance liquid chromatograph and calculated from the peak area percentage, for example, as described in the item of Examples described later.

  A commercially available product can be used as the yeast extract. The said yeast extract may be used individually by 1 type, and may use 2 or more types together.

  As a commercial item of the said yeast extract, C-101 (sales origin Oriental yeast industry company), BSP-B (sales origin Oriental yeast industry company), etc. are mentioned, for example. Among these, C-101 is preferable in that the copper extraction rate is more excellent.

  There is no restriction | limiting in particular as content of the said extraction accelerator in the solution containing the said extraction accelerator, Although it can select suitably according to the objective, 0.1 mass%-20 mass% are preferable, and 1 mass% is preferable. 10 mass% is more preferable. Within the preferred range, it is advantageous in that the copper extraction rate is more excellent.

-Solvent-
The solvent used in the solution containing the extraction accelerator is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually water and is a mixed solution of water and an organic solvent such as alcohol. Also good.

-Other ingredients-
The other components in the solution containing the extraction accelerator are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected depending on the purpose. Examples thereof include sodium hydroxide.
There is no restriction | limiting in particular as content of the said other component in the solution containing the said extraction promoter, According to the objective, it can select suitably.

<< Suspension >>
There is no particular limitation on the method of adding and mixing the extraction accelerator to the solution containing the extraction accelerator, or suspending the copper-containing yeast in the solution containing the copper-containing yeast, A known stirring method or shaking method can be used.
In the extraction step, the suspension may be further shaken. The shaking conditions are not particularly limited and can be appropriately selected depending on the purpose.

  There is no restriction | limiting in particular as content of the yeast containing the said copper in the said suspension, Although it can select suitably according to the objective, 1 mass%-15 mass% are preferable, and 3 mass%-10 mass. % Is more preferable. Within the preferred range, it is advantageous in that the copper extraction rate is more excellent.

  There is no restriction | limiting in particular as an quantity of the said extraction promoter with respect to the mass of the said copper containing yeast in the said suspension, Although it can select suitably according to the objective, 1 mass%-200 mass% are preferable, 10 The mass% to 150 mass% is more preferable. Within the preferred range, it is advantageous in that the copper extraction rate is more excellent.

  There is no restriction | limiting in particular as pH of the said suspension, Although it can select suitably according to the objective, 7.0-11.0 is preferable. A known method can be appropriately selected as a method for adjusting the pH of the suspension.

  There is no restriction | limiting in particular as temperature of the said suspension, Although it can select suitably according to the objective, 20 to 80 degreeC is preferable.

  There is no restriction | limiting in particular as extraction time in the said extraction process, Although it can select suitably according to the objective, 10 minutes-30 hours are preferable, 30 minutes-15 hours are more preferable, 1 hour-5 hours are especially preferable.

<< Separation of solid component and liquid component >>
The method for separating the solid component and the liquid component of the suspension is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include separation by filtration and separation by centrifugation.
There is no restriction | limiting in particular as said filtration method, A well-known filtration apparatus can be selected suitably, for example, a filter press, a line filter, etc. can be used. These may be used in combination.
There is no restriction | limiting in particular as the method of the said centrifugation, A well-known centrifuge can be selected suitably and can be performed. Further, the centrifugation conditions are not particularly limited and can be appropriately selected according to the amount of the suspension. For example, when the amount of the suspension is 5 mL, it is 3,000 rpm for 5 minutes. It can be mentioned as a condition.

There is no restriction | limiting in particular as a copper extraction rate in the said extraction process (henceforth a "copper elution rate"), Although it can select suitably according to the objective, 50% or more is preferable and 55% or more Is more preferable, and 60% or more is particularly preferable.
The said copper extraction rate can be calculated | required by a following formula.
Copper extraction rate (%) = {total copper (mass) in extract / total copper (mass) contained in yeast used for extraction} × 100

<Other processes>
The other steps are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. Examples thereof include a hydrothermal treatment step, a drying step, a concentration step, and a dilution step. It is done. Among these, it is preferable to include a hot water treatment step.

<< Hot water treatment process >>
The hot water treatment step is a step of suspending a yeast containing copper in hot water at 60 ° C. to 120 ° C. and separating a solid component and a liquid component of the obtained suspension before the extraction step. It is. By performing the hot water treatment step before the extraction step, the smell and taste peculiar to yeast (yeast odor, yeast taste) can be reduced, and the obtained copper-containing yeast extract can be used for foods, etc. It is preferable in that it does not impair the flavor of foods and the like when added.
The temperature of the hot water is not particularly limited and can be appropriately selected according to the purpose. However, 80 ° C to 120 ° C is preferable in that the higher the temperature, the higher the effect of reducing yeast odor and yeast taste. More preferably, the temperature is 95 ° C to 120 ° C.
There is no restriction | limiting in particular as the method of suspending the said yeast and the method of isolate | separating the solid component and liquid component of the obtained suspension, The method similar to the extraction process mentioned above is mentioned.

In the hot water treatment step, in order to reduce the smell and taste peculiar to yeast, it is preferable to add a yeast odor and a yeast taste extraction accelerator that promotes extraction (removal) of the yeast odor and yeast taste to the hot water. The yeast odor and yeast taste extraction promoter are not particularly limited as long as they do not adversely affect the copper extraction rate in the extraction step, and can be appropriately selected according to the purpose.
There is no restriction | limiting in particular as addition amount of the said yeast odor and a yeast taste extraction promoter, Although it can select suitably according to the objective, 5 mass%-50 mass% are preferable per dry yeast cell mass, 20 More preferably, 50% by mass.

<< Drying process, concentration process, dilution process >>
The drying step is a step of drying the copper-containing yeast extract.
There is no restriction | limiting in particular as said drying method, According to the objective, it can select suitably, For example, it can carry out using spray dryer L-8 (made by Okawara Chemical Industries Co., Ltd.). Thereby, the yeast extraction solid substance (powder) containing copper can be obtained. In addition, when setting it as the said solid substance, you may contain excipient | fillers, such as dextrin, suitably.
The concentration step is a step of concentrating the copper-containing yeast extract, and the dilution step is a step of diluting the copper-containing yeast extract.
There is no restriction | limiting in particular as the method of the said concentration and dilution, A well-known method can be selected suitably and can be used.

(Copper-containing yeast extract)
The copper containing yeast extract of this invention is manufactured by the manufacturing method of the copper containing yeast extract of this invention.
Since the said copper containing yeast extract is manufactured by the manufacturing method of the said copper containing yeast extract, it contains the copper derived from a natural product in high concentration. Moreover, the said copper containing yeast extract is excellent also in the solubility to water.

  There is no restriction | limiting in particular as a form of the said copper containing yeast extract, According to the objective, it can select suitably, Even if it is the liquid (extracted liquids, filtrate, supernatant, etc.) obtained by the said extraction process. It may be a solid such as powder, particles, or a sheet, or may be a semi-solid such as a gel or a slurry.

  There is no restriction | limiting in particular as a form at the time of use of the said copper containing yeast extract, According to a use, it can select suitably, The state of the dried powder (For example, what dried the extract by spray drying etc.) ), May be used in the form of a solution dissolved in a solvent, or may be used in a semi-solid state (for example, a gel or cream). In addition, there is no restriction | limiting in particular as a preparation method of the copper containing extract for setting it to the said usage form, It can carry out according to a well-known method using a well-known apparatus etc.

(Food)
The food of the present invention contains the copper-containing yeast extract of the present invention, and further contains other components as necessary.
Here, the food is one that is less likely to harm human health and is taken by oral or gastrointestinal administration in normal social life. It is not limited to such categories as, for example, it means a wide range of foods that are taken orally, such as general foods, health foods, health functional foods, quasi drugs, and pharmaceuticals.
The type of food is not particularly limited and may be appropriately selected depending on the intended purpose.For example, liquid food, bread, biscuits, crackers and other confectionery, processed fishery products, processed meat products, noodles, miso, etc. Seasonings, processed vegetable products, beverages such as juice, ice confections such as ice cream, health foods and the like are preferable, and liquid foods and beverages are particularly preferable.

  There is no restriction | limiting in particular as the addition amount of the said copper containing yeast extract to the said foodstuff, According to a use, the objective, etc., it can select suitably.

There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, the auxiliary | assistant raw material or additive etc. which are normally used in manufacturing a foodstuff are mentioned.
The auxiliary raw material or additive is not particularly limited and may be appropriately selected depending on the intended purpose. For example, glucose, fructose, sucrose, maltose, sorbitol, stevioside, rubusoside, corn syrup, lactose, citric acid , Tartaric acid, malic acid, succinic acid, lactic acid, L-ascorbic acid, dl-α-tocopherol, sodium erythorbate, glycerin, propylene glycol, glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, Arabia Examples include gum, carrageenan, casein, gelatin, pectin, agar, vitamin Bs, nicotinic acid amide, calcium pantothenate, amino acids, calcium salts, pigments, fragrances, preservatives and the like.
There is no restriction | limiting in particular as content of the said other component, According to the objective, it can select suitably.

  Examples of the present invention and comparative examples will be described below, but the present invention is not limited to these examples.

(Examples 1 and 2, Comparative Example 1: Extraction of copper with various extraction accelerators)
<Extraction accelerator>
The following was prepared as an extraction accelerator.
(1) Example 1: Yeast extract-1
Product name: C-101 (distributor: Oriental Yeast Co., Ltd.)
Molecular weight distribution:
Molecular weight 6,000 or more ・ ・ ・ 5%
Molecular weight 3,000 or more and less than 6,000 2%
Molecular weight 1,000 or more and less than 3,000 4%
Molecular weight 500 or more and less than 1,000 ・ ・ ・ 5%
Molecular weight less than 500 ... 84%
Total nucleic acid content: 6.5% by mass
(2) Example 2: Yeast extract-2
Product name: BSP-B (Seller: Oriental Yeast Co., Ltd.)
Molecular weight distribution:
Molecular weight 6,000 or more ・ ・ ・ Trace amount Molecular weight 3,000 or more and less than 6,000 ・ ・ ・ 1%
Molecular weight 1,000 or more and less than 3,000 ... 12%
Molecular weight 500 or more and less than 1,000 ... 9%
Molecular weight less than 500 ... 78%
Total nucleic acid content: 6.0% by mass
(3) Comparative Example 1: Sodium glutamate “Gluace S-1” (manufactured by MC Food Specialties Co., Ltd.)

-Molecular weight distribution-
Measurement was performed under the following high performance liquid chromatograph operating conditions, and the molecular weight distribution was calculated as a percentage of peak area.
-Calibration curve-
The following molecular weight standards were dissolved in a mixed solution of water, acetonitrile, and trifluoroacetic acid (water: acetonitrile: trifluoroacetic acid = 55: 45: 0.1), and a relational expression of molecular weight and elution time was determined.
(Molecular weight standard)
1. Cytochrome C (Molecular weight 12,500)
2. Aprotinin ・ ・ ・ Molecular weight 6,512
3. Bacitracin ・ ・ ・ Molecular weight 1,450
4). Angiotensin II (Molecular weight 1,046)
5). Gly-Gly-Tyr-Arg (peptide) ... molecular weight 451
6). Gly-Gly-Gly (peptide) ... molecular weight 189

-Preparation of test solution-
About 0.02 g of a sample (extraction accelerator) is collected, and 10 mL of a mixed solution of water, acetonitrile, and trifluoroacetic acid (water: acetonitrile: trifluoroacetic acid = 55: 45: 0.1) is added. After leaving overnight at room temperature, it was filtered through a membrane filter having a pore size of 0.45 μm, and the resulting liquid was used as a test solution.

--High-performance liquid chromatograph operating conditions--
Model: Shodex GPC-101 (manufactured by Showa Denko KK)
Detector: UV spectrophotometer UV-41 (manufactured by Showa Denko KK)
Column: TSKgel GP2500PW _XL , φ7.8 mm × 300 mm (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Mobile phase: Mixture of water, acetonitrile, and trifluoroacetic acid (water: acetonitrile: trifluoroacetic acid = 55: 45: 0.1)
Flow rate: 0.5 mL / min Measurement wavelength: 220 nm
Injection volume: 20 μL

-Total nucleic acid content-
The total nucleic acid amount of the yeast extract was analyzed by a simple method using an A ₂₆₀ / A ₂₈₀ ratio by preparing an aqueous solution containing 10% by mass of the yeast extract, measuring the absorbance at a wavelength of 260 nm and 280 nm.

<Extraction>
A copper-containing yeast powder (mineral yeast Cu1, copper content: 11,422 mass ppm, manufactured by Oriental Yeast Co., Ltd.) having a dry substance amount of 250 mg contains 3% by mass of an extraction accelerator and 100 mmol / L NaOH. 5 mL of an aqueous solution was added and stirred to suspend the copper-containing yeast to obtain a suspension (pH 9 to 11).
The suspension was heated at 70 ° C. for 1 hour with stirring by a stirrer, and then centrifuged at 3,000 rpm for 5 minutes.
The obtained supernatant was filtered with a filter for an ICP emission spectroscopic analyzer and collected in a test tube to obtain a yeast extract (hereinafter sometimes referred to as “extract”), and its mass was measured.
The copper extraction rate was determined by measuring the copper content in the yeast extract by ICP emission spectroscopy using an ICP emission spectrometer (Optima 2100 DV, manufactured by PerkinElmer), and measuring the copper content eluted in the extract. The ratio was calculated from the following formula. The results are shown in Table 1.
Copper extraction rate (%) = {total copper (mass) in extract / total copper (mass) contained in yeast used for extraction} × 100

  From the results in Table 1, it was shown that copper can be extracted at a high extraction rate by using an extraction accelerator containing at least one of peptides and proteins. Moreover, it turned out that the extraction rate of copper becomes higher when the yeast extract-1 is used among the extraction accelerators.

According to the method for producing a copper-containing yeast extract of the present invention, copper can be extracted at a high extraction rate, and a copper-containing yeast extract containing a high concentration of natural-derived copper is efficiently produced. Can do.
The copper-containing yeast extract of the present invention can be suitably used as oral tube feeding compositions such as liquid foods and beverages, food materials, vegetable green preservation and restoration agents, and the like. Moreover, by using the copper-containing yeast extract of the present invention as the oral tube feeding composition and the food material, anemia due to copper deficiency, heart disease and the like can be prevented or improved.

Claims (5)

The yeast containing copper is suspended in a solution containing the extraction accelerator, or the extraction accelerator is added to and mixed with the solution in which the yeast containing copper is suspended, and the resulting suspension is a solid component. And an extraction step for separating the liquid component from
The method for producing a copper-containing yeast extract, wherein the extraction accelerator contains at least one of a peptide and a protein (excluding a case consisting of only an amino acid).   The method for producing a copper-containing yeast extract according to claim 1, wherein the extraction accelerator is a yeast extract. The method for producing a copper-containing yeast extract according to any one of claims 1 to 2, wherein an extraction rate of copper represented by the following formula is 50% or more.
Copper extraction rate (%) = {total copper (mass) in extract / total copper (mass) contained in yeast used for extraction} × 100   A copper-containing yeast extract produced by the method for producing a copper-containing yeast extract according to any one of claims 1 to 3.   A food comprising the copper-containing yeast extract according to claim 4.