JPH08332082A - Yeast containing zinc at high concentration - Google Patents

Abstract

PURPOSE: To obtain the subject yeast, capable of perorally and reasonably ingesting a large amount of zinc and useful for foods, feeds, baits, etc., by culturing a yeast in a suspended state in a solution containing a specific amount or more of zinc in a nonproliferating manner according to the spinner or shaking culture. CONSTITUTION: This yeast contains zinc at a high concentration. The yeast is obtained by using zinc sulfate, preparing an aqueous solution containing >=50ppm zinc, adding and suspending a yeast such as a baker' yeast therein, stirring and/or shaking the suspension at 30 deg.C for 72hr under aerobic conditions in a nonproliferating manner, then collecting the yeast fungal cell in the suspended state by centrifugation and washing the collected yeast fungal cell with ion exchange water. The resultant yeast contains >=600ppm, preferably >=10000ppm zinc based on the dry fungal cell and capable of perorally and reasonably ingesting a large amount of the zinc and useful for producing various foods such as bread, biscuits or miso. The cell wall of the resultant yeast is destroyed to take out the contents, which are used to afford foods and drinks such as a juice, an ice cream or a cracker, feeds, baits, etc. containing a large amount of the zinc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edible yeast containing a high concentration of minerals, especially zinc, and a method for producing the same.

[0002]

2. Description of the Related Art It has been known that zinc has a role as a coenzyme in about 200 kinds of enzymes in the living body. Therefore, it is well known that it is closely related to the formation and growth of new cells. In addition, as it has become clear that there are effects of improving taste disorders and improving or improving reproductive function, zinc is attracting attention as a mineral that plays a fundamental role in life. It is not always sufficient, and the intake balance is not appropriate.

In order to secure such zinc intake,
Or to maintain an appropriate intake balance,
The required amount of zinc must be taken from ordinary foods and drinks, but this is accompanied by considerable difficulty because the zinc content in ordinary foods and drinks is low.

[0004]

The present invention has been made with the object of developing a new system for reasonably ingesting a large amount of zinc orally.

[0005]

The present invention has been made in order to achieve the above-mentioned object, and is a conventional system for utilizing a food using a food material having a relatively high zinc content. By fundamentally changing the idea, we made a dietary microorganism to ingest and accumulate a large amount of zinc, and by utilizing this zinc-rich microorganism, we focused on a system that ingests zinc in the microorganism.

[0006] Then, although yeast was cultivated in a zinc salt-containing medium by paying attention to yeasts widely used for various edible uses, when the amount of zinc salt added was increased, the growth inhibition of yeast was observed as in the conventional technical common sense. However, it was not possible to obtain yeast containing a high concentration of zinc.

However, the inventors of the present invention dared to challenge such common general knowledge and set a new problem of creating a new yeast containing zinc in a high concentration of a level that could not be achieved conventionally. Therefore, as a result of examination from various directions, when yeast was aerobically agitated non-proliferating in a liquid containing a high concentration of zinc, instead of culturing the yeast in a nutrient medium, the yeast cells were unexpectedly unexpected. We obtained a new finding that a large amount of zinc is taken into the inside. Moreover, contrary to the conventional technical common sense, yeast is not killed even if the zinc concentration is increased, and the zinc content in the yeast cells also increases in accordance with the zinc concentration in the solution, resulting in 10,000 ppm per dry cell. It was confirmed that the above was reached. As described above, yeast containing zinc at a high concentration cannot be created at all.

The present invention has been completed as a result of further research based on such useful new knowledge, and the details thereof are as described below.

In order to carry out the present invention, it is necessary to suspend yeast in a high-concentration zinc-containing solution containing a large amount of a water-soluble salt of zinc, and agitate and / or shake it non-proliferatively. . In the present invention, a medium for culturing yeast is not used, but a nonproliferative treatment is performed. In other words, yeast is treated under conditions in which substances necessary for the growth of bacterial cells are substantially absent.

The zinc salt used in the present invention includes:
As long as it has appropriate water solubility and does not kill the yeast, and can be efficiently incorporated into the yeast cells,
One or more zinc compounds, both organic and inorganic, can be used. Non-limiting examples thereof include: zinc sulfate, zinc chloride, zinc citrate, zinc acetate, zinc tartrate, zinc lactate.

A good result can be obtained even if the amount of zinc salt added is 50 ppm, but a higher concentration than that, 2,000 ppm or more, particularly preferably 3,000 to 6,000 ppm is suitable. According to the conventional technical common sense, if yeast is treated with a high concentration of zinc, the yeast may be killed, or even if it is not killed, there is a serious fear of serious adverse effects. The present invention is a transcendental one, and, unexpectedly, it was the first time that yeast was not killed by such a high concentration of zinc, but rather it was first succeeded in incorporating it in a large amount. is there. Furthermore, it has been confirmed that treatment with zinc having a high concentration of 10,000 ppm or more is possible.

As a result, 600 to 10 per dry cell,
Finally, we succeeded in incorporating 000 ppm or more of zinc into the yeast cells. Such yeast containing a large amount of zinc has never existed in the past, and is a novel useful yeast that could not be created even if it was attempted to be created as described above. Even more surprisingly, according to the invention,
By using a 0 ppm zinc solution, it is even possible to incorporate a very large amount of zinc of 30,000 ppm or more per dry cell into yeast cells.

The treatment conditions for incorporating zinc into yeast cells are as follows:
The temperature is 0 ° C., preferably 20 to 35 ° C., 1 to 120 hours, preferably 40 to 100 hours, pH 4 to 7, preferably pH 4.5 to 6.5. It may be appropriately determined depending on the concentration, and may be out of the above range in some cases.

The stirring and / or shaking depends on the viscosity of the zinc solution and the yeast content, but it is 500 to 1,000 rpm.
If the stirring is moderate, or the amplitude is 12 cm, 100-
It is recommended to shake at 200 rpm. Good results can be obtained by performing aeration under aerobic conditions. Aeration is performed at about 0.5 to 5 vvm, but if necessary, the range may be deviated.

In the present invention, any yeast can be used as long as it is a yeast, including edible yeast. Non-limiting examples include yeasts belonging to each of the following genera: Saccharomyces, Torrlopsis (Tor).
ulopsis genus, Mycotorula genus, Torulaspora genus, Candida genus,
Rhodotorula genus, Pichia genus and others.

Specifically, Saccharomyces cerevisiae,
Uvarum, rouxii IFO 0439; Torulopsis utilis, same
candida IFO 0856; Mycotorula japonica, same lipolytic
a; Torulaspora delbrueckii, fermentati; Candida
sake, tropicalis, utilis ATCC 16321; Hansenula
anomala IFO 0140, suaveolens; Saccharomycopsis
fibligera IFO 1665, same lipolytica ATCC 20182; Rhodo
torula rubra IFO 0870; Pichia farinosa IFO 0607,
Other yeasts are exemplified.

Among these yeasts, especially as edible yeasts, Saccharomyces cerevisiae and uvaru are commonly used as yeasts for human food and drink, animal feed and fish feed.
Examples include baker's yeast, brewer's yeast, wine yeast, sake yeast, alcohol yeast, amazake yeast, miso soy sauce yeast, feed yeast, and feed yeast, which belong to m, rouxii, Saccharomycopsis fibligera and others.

Water is usually used as the liquid in which the yeast is suspended. The water may be distilled water or deionized water, but tap water is sufficient. The yeast cell concentration is, for example, 10 to 40%, preferably 15 to 25% as the compressed yeast, but is appropriately selected so as to efficiently take in zinc.

The yeast thus incorporating zinc is
After harvesting the cells by centrifugation, filtration, etc., the cells are washed to obtain the desired cells, and if necessary, freeze-dried or dried cells according to a conventional method and used for various purposes. Further, if desired, it is also possible to crush the cells or lyse the cells to take out the contents and use them.

Further, in the present invention, yeast containing a large amount of various minerals is agitated non-proliferatively in a solution containing 50 ppm or more of zinc in the same manner as in the case of the above-mentioned ordinary yeast. By or / and shaking, it is possible to create a novel yeast containing a large amount of multi-minerals, which further contains zinc in various minerals at a high concentration. The opposite method is also possible.

Examples of yeasts with a high content of multi-minerals include yeasts with a high content of zinc and iron, yeasts with a high content of magnesium and zinc, yeasts with a high content of magnesium, zinc and iron, and the like.

The yeast having a high zinc / iron content is obtained by preliminarily producing the zinc-rich yeast produced in advance under the above-mentioned conditions for producing a high-zinc content yeast according to the present invention as a starting yeast. It can be manufactured by a method of incorporating into.

The production conditions of yeast with a high iron content are as follows:
This is a method of suspending yeast in a solution containing 000 ppm or more and slowly stirring and / or shaking in a non-proliferative manner to the extent that yeast does not settle.

To carry out the present method, yeast is suspended in a high-concentration iron-containing solution containing a large amount of a water-soluble salt of iron, and the mixture is stirred and / or stirred so that the yeast does not settle slowly in a non-proliferative manner.
Or it is necessary to shake. In this method,
It does not use a medium for culturing yeast, but treats it non-proliferatively. In other words, yeast is treated under conditions in which substances necessary for the growth of bacterial cells are substantially absent.

As the iron salt used in the present method, as long as it has appropriate water solubility and does not kill the yeast, it can be efficiently taken up in the yeast cells.
One or more of all iron compounds, organic or inorganic, can be used. Non-limiting examples of which include: ferrous sulfate, ferrous chloride, ferrous citrate,
Ferrous fumarate, ferrous gluconate, ferrous acetate, ferrous tartrate, ferrous lactate.

The addition amount of the iron salt is higher than 1,500 ppm, preferably 2,000 ppm or more. If yeast is treated with iron at a concentration as high as 2,000 ppm, the yeast may be killed, or even if it is not killed, serious adverse effects may be suspected. Unexpectedly, rather than letting yeast die even at such a high concentration of iron, it can be taken up in large quantities in the cells. Moreover, 10,000 ppm
It has also been confirmed that it is possible to treat with a high concentration of iron.

As a result, 15,000 p per dry cell
For the first time, it was possible to incorporate pm or more of iron into yeast cells. Even more surprisingly, according to the present invention, it is even possible to incorporate a very large amount of iron of 30,000 ppm or more into yeast cells by using an iron solution of 10,000 ppm.

The treatment conditions for incorporating iron into yeast cells are as follows.
C., preferably 20 to 35.degree. C., 0.5 to 72 hours, preferably 1 to 36 hours, pH 4 to 7, preferably pH 4.5 to 6.5, but the type of yeast and iron salt used. It may be appropriately determined depending on the concentration, and may be out of the above range in some cases.

Stirring and / or shaking must be carried out at a slow speed such that the yeast and iron ions come into contact with each other,
500 rpm, depending on the viscosity of the iron solution and the yeast content
Or less, preferably 500 rpm or less, gentle stirring,
Or, when the amplitude is 12 cm, it is preferable to shake at 200 rpm or less, preferably about 150 rpm or less.

As described above, the zinc / iron-rich yeast can be produced. As a result, a novel multi-mineral edible yeast containing 10,000 ppm of zinc and 15,000 ppm or more of iron per dry cell can be obtained.

To produce magnesium / zinc yeast,
It can be produced by using a yeast having a high magnesium content produced in advance as a raw material yeast and subjecting the yeast to zinc incorporation under the above-described zinc-rich yeast production conditions of the present invention.

The high magnesium content yeast is produced by non-proliferative stirring and / or shaking of the yeast in suspension in a high magnesium content production condition, that is, in a solution containing a high concentration of magnesium. be able to.

In order to carry out the present method, it is necessary to suspend the yeast in a high concentration magnesium-containing solution containing a large amount of a water-soluble salt of magnesium, and aerobically agitate and / or shake it. . In this method, the magnesium concentration in the finally created yeast cells depends on the magnesium concentration in the solution in which the yeast is suspended, regardless of the composition of the medium for culturing the yeast. In other words, it is possible to allow magnesium to be incorporated into yeast even under the condition that a substance necessary for the growth of bacterial cells exists or under the condition that it does not substantially exist.

The magnesium salt used in the present method may be organic or inorganic, as long as it has appropriate water solubility, does not kill yeast, and is efficiently taken up by yeast cells. All magnesium compounds can be used alone or in combination. Non-limiting examples of which include: magnesium sulfate, magnesium chloride, magnesium citrate, magnesium acetate, primary magnesium tartrate, primary magnesium lactate.

The amount of magnesium salt added is preferably set so that the magnesium concentration in the liquid is 50 ppm or more. If yeast is treated with such a high concentration of magnesium, the yeast may be killed, or even if it is not killed, serious adverse effects such as reduced activity may be suspected. The method is significantly more transcendental, and, unexpectedly, yeast is not killed by such high concentration of magnesium, and extremely high concentration of magnesium can be accumulated in the bacterial cells. We obtained a useful new finding that the physiological activity of P.

As a result, 2,000 pp per dry cell
Finally, we succeeded in incorporating more than m of magnesium into the yeast cells. Even more surprisingly, according to this method, by using a solution containing 20,000 ppm of magnesium ions, it is possible to obtain 20,000 per dry cell.
It is even possible to incorporate a very large amount of magnesium of 0 ppm or more into yeast cells.

In order to make a large amount of magnesium contained in yeast cells according to this method, 5 to 30%, preferably 10 to 20% of yeast as wet cells are suspended in a magnesium solution and the temperature is set to 15 to 40 ° C. , Preferably 25-35
C., more preferably 28 to 33.degree. C., treatment time 1 to 120 hours, preferably 36 to 96 hours, pH 4 to 4.
7, preferably pH 4.5-6.0, aeration 0-5vv
m, preferably 1 to 3 vvm, stirring varies depending on the scale of equipment used, but is 50 to 1,000 ppm, and when shaking, 100 to 200 rp for equipment with an amplitude of 12 cm.
m, preferably 100 to 150 rpm, but can be appropriately selected depending on the type of yeast and magnesium salt used and the concentration thereof, and may deviate from the above range depending on the necessity.

As described above, the magnesium / zinc-rich yeast can be produced. As a result, magnesium per dry cell was 2,000 ppm and zinc was 10,
A novel multi-mineral edible yeast containing 000 ppm or more can be obtained.

By using the thus-produced high-magnesium-zinc-containing yeast as a raw material and further treating it under the above-described high-iron-rich yeast production conditions to add iron at a high concentration, magnesium-zinc- A high iron content yeast can be created. As a result, magnesium per dry cell is 2,000 ppm, zinc is 10,000 ppm,
A novel multi-mineral edible yeast containing 15,000 ppm or more of iron can be obtained.

Examples of the present invention will be described below.

[0041]

Example 1 Using zinc sulfate (ZnSO ₄ .7H ₂ O),
A solution was prepared so that zinc ions would be 50 to 10,000 ppm in the solution (Table 1 below), and 20 g of baker's yeast (Regular yeast manufactured by Oriental Yeast Co., Ltd.) in 100 ml of each concentration of zinc solution (2 x 10 ⁹ cells / ml) and suspend it in a 500 ml Sakaguchi flask at 72 ° C for 72 hours.
It was shaken for time (amplitude 12 cm, 110 rpm).

The cells after shaking were centrifuged (3,000 ×
g, 5 minutes) to collect the bacteria, and deionized water (Milli)
After washing twice with Q), the cells were wet-ashed and zinc was quantified by an atomic absorption spectrophotometer. In addition, the amount of residual zinc in the combined supernatant and washing solution after collecting the bacterial cells was
Colorimetric determination was carried out by the xylenol orange complex salt method. The obtained results are shown in Table 1 below.

[0043]

[Table 1]

[0044]

Example 2 Using zinc sulfate (ZnSO ₄ .7H ₂ O),
Zinc ions in solution at 5,000 ppm and 10,000
A solution was prepared so that the concentration became 0 ppm, and 300 g (2 × 10 ⁹ cells / ml) of baker's yeast (Regular yeast manufactured by Oriental Yeast Co., Ltd.) was suspended in 1.5 L of each zinc solution to prepare a 3 L jar fur. 1 at 30 ° C with a mentor
The mixture was stirred for 20 hours at aeration of 2.0 vvm and 650 rpm.

After stirring for a predetermined time, the cells were collected by centrifugation (3,000 xg, 5 minutes) and washed twice with ion-exchanged water (MilliQ), and then the cells were wet-ashed to remove atoms. Zinc was quantified by an absorption spectrophotometer. Also,
The amount of residual zinc in the combined solution of the supernatant after washing the cells and the washing solution was colorimetrically determined by the zinc-xylenol orange complex salt method. The obtained results are shown in FIG.

[0046]

EXAMPLE 3 Magnesium sulphate (MgSO ₄ · 7H ₂ O)
And magnesium ions in solution at 15,000 pp
A solution was prepared so that the amount of water would be m, 300 g (2 × 10 ⁹ cells / ml) of baker's yeast (Regular yeast manufactured by Oriental Yeast Co., Ltd.) was suspended in 1.5 L of this magnesium solution, and 3 L jar fermenter was suspended. With ventilation 2.0
The treatment was carried out under non-growth conditions at 30 ° C. for 72 hours with stirring at 650 rpm and vvm.

After aeration and stirring for a predetermined time, the cells were collected by centrifugation (3,000 xg, 5 minutes), washed twice with ion-exchanged water (MilliQ), and then wet-ashed. As a result of quantifying magnesium with an atomic absorption spectrophotometer, it was found that 7,830 ppm of magnesium was contained per dry cell.

The magnesium-rich yeast thus obtained was used as a raw material yeast and zinc sulfate (ZnSO ₄ .7H
₂ O), zinc ion in solution is 5,000 ppm
The solution was prepared so that 1.5 g of the zinc solution contained 300 g of magnesium-rich yeast (2 × 10 ⁹ cells / m 2).
1) was suspended and stirred in a 3 L jar fermenter with aeration of 2.0 vvm and 650 rpm, and treated at 30 ° C. for 72 hours under non-growth conditions.

After aeration and stirring for a predetermined time, the cells were collected by centrifugation (3,000 xg, 5 minutes) and washed twice with ion-exchanged water (MilliQ), and then the cells were wet ashed. Table 2 shows the results of quantifying magnesium and zinc with an atomic absorption spectrophotometer.

[0050]

[Table 2]

[0051]

Example 4 Using zinc sulfate (ZnSO ₄ .7H ₂ O),
So that the zinc ion is 5,000 ppm in the solution,
A solution was prepared, and 30 liters of baker's yeast (Regular yeast manufactured by Oriental Yeast Co., Ltd.) were added to 1.5 L of each zinc solution.
Suspend 0 g (2 × 10 ⁹ cells / ml) and in a 3 L jar fermenter at 30 ° C. for 72 hours, aeration 2.0 vv
The mixture was stirred at 650 rpm.

After stirring for a predetermined time, the bacterial cells were collected by centrifugation (3,000 xg, 5 minutes), washed twice with ion-exchanged water (MilliQ), wet-ashed and then atomized. Zinc was quantified by an absorption spectrophotometer. Using this yeast with a high zinc content as the raw material yeast, ferrous sulfate (FeSO
₄ ), divalent iron ions in the solution are 5,000pp
The solution of the raw material yeast 3 containing a high concentration of zinc prepared in advance in 1.5 L of this iron solution 3
00 g (2 × 10 ⁹ cells / ml) was suspended and gently stirred in a 3 L jar fermenter at 30 ° C. for 24 hours at 200 rpm at which yeast did not precipitate.

After stirring for a predetermined time, the cells were collected by centrifugation (3,000 xg, 5 minutes), washed twice with ion-exchanged water (MilliQ), wet-ashed to remove the atoms. Iron and zinc were quantified by an absorption spectrophotometer.
Table 3 shows the obtained results.

[0054]

[Table 3]

[0055]

Example 5 Ferrous sulfate (FeSO ₄ ) was used as the raw material yeast for the magnesium / zinc-rich yeast obtained under the conditions described in Example 3, and divalent iron ions were added to the solution.
A solution was prepared so as to have a concentration of 000 ppm, and 300 g of raw material yeast (2 × 10 ⁹ cells / m 2) containing a high concentration of magnesium and zinc prepared in advance in 1.5 L of this iron solution.
l) and suspend in a 3 L jar fermenter for 30
The mixture was gently stirred at 200 rpm for 24 hours at 200 ° C. at which yeast did not settle.

After stirring for a predetermined time, the cells were collected by centrifugation (3,000 xg, 5 minutes), washed twice with ion-exchanged water (MilliQ), wet-ashed, and then atomized. Magnesium, zinc and iron were quantified by an absorption spectrophotometer. The results obtained are shown in Table 4.

[0057]

[Table 4]

[0058]

EFFECTS OF THE INVENTION According to the present invention
It was possible for the first time to make yeast contain a large amount of zinc of 000 ppm or more. A yeast containing such a large amount of zinc cannot be obtained in the past and is a completely novel yeast.

The yeast with high zinc content created by the present invention can be widely used for various purposes, and various foods such as bread, biscuits, and miso containing a large amount of zinc can be obtained. In addition, the cell wall of yeast can be destroyed, the contents can be taken out, and it can be used for the production of various foods and drinks such as juice, ice cream, crackers, and the production of feed and feed containing a large amount of zinc. can do.

In the present invention, the conventional system of culturing yeast is not adopted, but a completely new system of stirring yeast in a high-concentration aqueous solution of zinc salt is adopted. Therefore, not only the cost is reduced by not requiring a culture medium, but since the aqueous solution of zinc salt is simply used, the washing of the yeast cells after the collection is extremely easy, and the separation of the cells can be performed. Purification can also be carried out very easily.

Furthermore, according to the present invention, various kinds of minerals in addition to zinc can be contained in yeast in a large amount. Therefore, in addition to zinc, minerals such as iron and / or magnesium can be highly concentrated. It is also possible to create new yeast containing yeast (yeast with high content of multi-minerals), which can be used for various purposes.

[Brief description of drawings]

FIG. 1 shows the relationship between the zinc concentration in a liquid and the treatment time, which affects the zinc concentration in dried yeast cells.

Claims (9)

[Claims] 1. An edible yeast containing a high concentration of zinc. 2. An edible yeast containing 600 ppm or more, preferably 10,000 ppm or more, of zinc per dry cell. 3. The edible yeast according to claim 1 or 2, wherein the yeast is agitated and / or shaken in a suspension state non-proliferatively in a solution containing 50 ppm or more of zinc. how to. 4. The method according to claim 3, which comprises stirring and / or shaking under aerobic conditions. 5. A yeast containing a high concentration of minerals is used as the yeast, wherein the yeast is used.
The method described in. 6. The method according to claim 5, wherein the mineral is magnesium and / or iron. 7. Zinc and iron characterized in that the yeast according to claim 1 or 2 is slowly stirred and / or shaken in a suspension state in a solution containing 2,000 ppm or more of iron. A method for producing a large amount of edible yeast. 8. The use of the yeast obtained by collecting and washing the yeast after stirring and / or shaking the yeast in suspension in a medium or solution containing 50 ppm or more of magnesium. 3. The method for producing an edible yeast containing a large amount of magnesium and zinc, which is produced by the method according to 3 or 4. 9. A large amount of magnesium, zinc and iron, characterized in that the yeast containing a large amount of magnesium and zinc produced by the method of claim 8 is produced by the method of claim 7. A method for producing an edible yeast contained in.