JP2537361B2 - Fermentative production method using yeast - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fermentation production method using yeast such as beer, sake, wine and bread.

(Conventional Technology) Conventional fermentation methods using yeast include beer brewing,
Other brewing of alcoholic beverages, bread making, etc. In order to improve the fermentability of the wort raw material in beer brewing, recently, a very small amount of 0.5 to 5 ppm of zinc, zinc and manganese, and various metal ions such as iron and manganese are added and dissolved directly into the fermentation wort. However, test reports have been made to measure yeast growth and improve fermentability. 〔K.Steine
r and U. Lnzlin′ger; Brauerei Rundschau 89 , 3〜7
(1978)].

(Problems to be Solved by the Invention) However, as disclosed in the above-mentioned document, it is possible to slightly improve the fermentability by directly adding an extremely small amount of metal to the stock solution of beer brewing, but on the other hand, The added metal tends to remain in the fermentation liquor.

In connection with this, the inventor has conducted repeated studies and tests and found that the fermentability was increased in proportion to the increase in the amount of metal added and the increase in the metal content in yeast. However, it has been found that when the desired substantial amount is added to the fermentation stock solution, the amount of residual metal in the fermentation solution also increases and the quality of the product beer deteriorates, which cannot be put to practical use. Therefore, it would be desirable to improve fermentation productivity and provide high-quality fermentation products without such adverse effects.

On the other hand, yeasts used for various fermentative productions can be stored without being reduced in activity until they are used, and in the case of yeasts once used for fermentative production, yeasts with reduced activity can be used. It is desirable to be able to perform good fermentation production of the target product by using it after improving the activity. In view of the above points, the inventors have conducted various test studies, and as a result, among various metals, zinc,
Metals such as magnesium, after being taken up by yeast,
It was found that they were not discharged outside the cells. Based on this knowledge, a fermentation production method using yeast, which can produce beer and other fermented products of good quality which are unchanged from the conventional ones while satisfying the above-mentioned requirements, can be produced while improving the fermentation productivity. What was provided, a desired amount of yeast was immersed in a treatment liquid containing a trace amount of at least one of zinc and magnesium for a required time, and the metal was incorporated into the yeast to prepare a metal-containing treated yeast, which was fractionated. The method is characterized in that yeast is added to a fermentable raw material to perform fermentation treatment.

(Example) Next, the Example of this invention is described.

INDUSTRIAL APPLICABILITY The present invention is for culturing yeast used for fermentation production, for example, a culture solution used for pre-culture or water that has been stored until the yeast is used for fermentation production after culture or once used for fermentation production. Afterwards, the yeast with reduced activity is selected as a treatment liquid such as an activation liquid such as preserved water or an aqueous solution in which a small amount of nutrients is dissolved in water to increase its activity for reuse, and this treatment liquid is added. In the container, a metal capable of accumulating in cells, most preferably zinc, and at least one metal such as magnesium, which is preferable next, is selected and added in a trace amount. For example, when the metal is zinc, water-soluble zinc such as zinc salts such as zinc metal, zinc sulfate, zinc chloride, and zinc acetate is used, and the amount of zinc added is about 0.01% zinc equivalent. It is sufficient to use an aqueous solution, and in the case of yeast for beer brewing, up to 5000 ppm (0.5%) is preferable.

Generally, when a small amount of metal is added and dissolved, yeast is added in an appropriate amount, usually about 10%, and when the treatment liquid is a culture liquid,
Culturing is carried out by a conventional method, and in the case of preservation water, it is preserved at a low temperature, and in the case of an activating liquid, it is activated at a low temperature or an appropriate temperature.

Thus, the added metal in the treatment liquid is taken up by yeast. After the required time has elapsed, the treatment liquid is removed to obtain yeast containing a required amount of metal, that is, metal-containing treated yeast. Whether or not the treated yeast contains a metal,
Its content was confirmed by an atomic absorption method. As a result of various test studies, by the above treatment, the treated yeast was brewer's yeast,
In the case of brewing yeast such as wine yeast and sake yeast, it is preferable to treat so that the yeast cells contain 100 ppm or more of metal, and in the case of baker's yeast, 220 p in yeast cells.
It is preferable to treat so as to contain a metal of pm or more.

It is generally accepted that the yeast in the treatment liquid takes up about 80% of the amount of metal added to the treatment liquid 24 hours after the immersion.

As described above, according to the present invention, the yeast used for fermentation production is preliminarily described above, and a metal-containing treated yeast is prepared by containing a metal capable of intracellular accumulation, and then used as a raw material for the fermentation product. When adding and performing fermentation production by a conventional method,
As detailed below, it has been found that the yeast in its good active state results in an improved fermentation rate. Also, in the fermentation product, there is no metal secretion from yeast, and therefore,
It has been found to result in the production of conventional fermentation products that are metal free. On the other hand, it was confirmed that, on the other hand, it has effects such as prevention of yeast activity decrease during storage before fermentation production and activation of yeast having once decreased activity.

 Next, more specific examples of the present invention will be described.

Example 1 One platinum loop of bottom brewer's yeast was added to 10 ml of a treated solution containing wort containing 15 ppm of zinc sulfate for food addition in terms of zinc, and the mixture was shake-cultured at 30 ° C. for 24 hours. From this, the zinc-containing treated yeast was collected by centrifugation, to which was added treatment liquid 1 consisting of 15 ppm zinc-containing wort prepared in the same manner as above and shake-cultured at 30 ° C for 48 hours. Keeping in mind, to the obtained bacterial cells of the zinc-containing treated yeast, the treatment solution 2 consisting of 15 ppm-containing wort prepared in the same manner as above was added and shake-cultured at 15 ° C for 48 hours to obtain 25 g of the zinc-containing treated yeast. It was The zinc content was measured by the atomic absorption method, and it was confirmed that the zinc content was 107 ppm in the dry matter cells. As described above,
It is preferable to perform the treatment containing the required amount of zinc by dividing the yeast culture treatment liquid into several times. The zinc-treated yeast of this method was added to a wort stock solution for beer brewing, and a beer was produced through a fermentation process according to a conventional method. The wort fermentability was 78.2%. No zinc was contained in the sample beer. For comparison, a beer was produced through a fermentation process according to a conventional method in the same manner as above, using untreated yeast that was cultivated and divided in three stages in the same manner as above without adding zinc to the wort. The wort fermentability was 77.3%.
As is clear from the above, according to this method, when the zinc-containing treated yeast prepared in advance was used for brewing beer, its fermentability was remarkably improved.

Example 2 To 200 ml of a treatment solution prepared by adding and dissolving 100 ppm of zinc-sulfate for food addition in terms of zinc was added 50 g of pressed yeast of brewer's yeast (Satsucaromyces curlsbergensis IAM4778), and the mixture was stored at 0 ° C. for 4 weeks.

For comparison, a stock solution was prepared by adding 50 g of the yeast to 200 ml of zinc-free water, and stored in the same manner.

Next, from each of the liquids stored for 4 weeks, yeasts were separately collected, and 0.5% of each of the pressed yeasts was added to the wort contained in each container and fermented at 15 ° C for 6 days. Let The extract reduction rate at this time was measured as fermentability.

Further, for comparison, the pressed yeast before the preservation treatment was used and immediately subjected to the same wort fermentation treatment as described above.

The zinc content in the yeast before and after the storage treatment was measured by the atomic absorption method, and the relationship between the zinc content and the yeast storage stability and wort fermentability was examined. The results are shown in Table 1 below.

As is clear from Table 1 above, in the case of the treated solution in which the yeast is stored only with water, the activity is lowered and the fermentability is also lowered, whereas the preservation with the treated solution of the present method prevents the activity from being lowered. Therefore, it can be seen that the fermentability is slightly improved compared to before storage.

Next, a certain amount of each type of yeast was added to a treatment solution in which a certain concentration of zinc was dissolved, and the relationship between the standing time and the amount of zinc taken up by the yeast was investigated. The example is shown below.

Example 3 A treatment liquid obtained by dissolving 400 g of squeezed yeast of beer yeast, sake yeast (Association No. 6) and commercially available baker's yeast (SANKYO yeast) in an amount of 400 g of zinc sulfate for food addition in water.
Put in each test container containing 200 ml,
It was stored at 0 ° C., and the zinc content in the yeast cells was measured every hour. The results are shown in Table 2 below. It is common to all yeasts that the uptake rate is maximum up to 24 hours and most of zinc is taken up, and thereafter the uptake rate becomes slow. I found out.

Next, a treatment solution of zinc aqueous solution for each concentration was prepared, yeast was added to this, and the change in each zinc content when left for a certain period of time and the relationship between this content and wort fermentability were tested. .

Example 4 A certain amount of the above-mentioned pressed yeast of brewer's yeast was added to a treatment solution consisting of various aqueous solutions prepared by changing the concentration of zinc sulfate for food addition as shown in Table 3 below, and the mixture was left for 24 hours. Then, yeast was fractionated from each treated solution and the zinc content of each was measured. Using yeast with different zinc contents thus obtained, each of the wort containers created separately,
It was added in a fixed amount and fermented under constant conditions. The results are shown in Table 3 below. For comparison, the zinc content in the untreated brewer's yeast was 28.9 ppm.
When fermented under the same conditions with this untreated beer yeast,
Its fermentability was 77.0%.

It was confirmed that the zinc content in the brewer's yeast cells was about 100 ppm to 600 ppm, which was particularly effective for improving the wort fermentability.

It is also found that the higher the zinc concentration, the higher the zinc content yeast can be obtained for a certain period of time.

Next, the untreated brewer's yeast and the zinc-containing treated yeast were used to examine the yeast growth effect and the zinc content in the fermentation liquor when beer was produced. The test example is shown below.

Example 5 The above-mentioned brewer's yeast was allowed to stand for 24 hours in a treatment liquid prepared by dissolving 500 ppm of zinc sulfate for food addition in 200 ml of water, and the zinc-containing yeast of the present invention which had been subjected to a zinc-containing treatment was fractionated and pressed. ,
A sample prepared by adding 15 g thereof to 3 worts and a sample prepared by adding 15 g of the same type of untreated untreated press yeast to 3 worts were respectively subjected to main fermentation at 12 ° C for 10 days, and further at 3 ° C at 2 ° C. The fermentation liquid, that is, beer was obtained by aging for a time. The fermentability was 78% in the former case and 77% in the latter case using untreated yeast. Furthermore, when the yeast growth property and the presence or absence of zinc in the fermentation broth during this period were measured, the results shown in Table 4 below were obtained.

As is clear from Table 4 above, the growth of the zinc-containing treated yeast during fermentation is significantly improved as compared with the untreated yeast.

It is also found that yeast is not secreted zinc in the fermentatively produced beer, and the conventional good beer with good flavor, which does not contain zinc like the fermentatively produced beer produced by the untreated yeast, is obtained.

Example 6 Treatment liquids of various zincs, which were dissolved and contained in water in an amount of 100 ppm in terms of zinc, were prepared, and 200 g of each treatment liquid was added with 15 g of the above-mentioned pressed brewer's yeast, and the mixture was allowed to stand for 24 hours. Was removed, water was newly added, and the mixture was left for 1 month. For comparison, 15 g of the pressed brewer's yeast was added to 200 ml of a treatment liquid consisting of cold water to which zinc was not added, and this was left for one month.

Thus, the dead cell rate after storage was measured. After being left for one month, various kinds of zinc-containing treated yeasts and untreated yeasts were used and fermented under the same conditions with the same wort. The wort fermentability of each was measured. The results are shown in Table 5 below.

As is clear from Table 5 above, the preservability and wort fermentability of various zinc-containing treated yeasts were significantly improved as compared with the preservability and wort fermentability of untreated yeast.

Incidentally, the wort fermentability of the yeast before storage was 77.0%, so when it was simply stored in cold water for 24 hours, as described above, 21.3% of dead cells were generated, and the wheat Although the juice fermentability is reduced by 8.1%, the dead cells are reduced to 4 to 5% by this method treatment, and the fermentability can be improved as compared with simply storing in cold water. I understand.

Next, examples of baker's yeast will be described together with comparative examples.

Example 7 15 g of commercially available SANKYO yeast was added to 200 ml of a treatment liquid consisting of a 500 ppm food-grade zinc sulfate aqueous solution at 0 ° C., left for 24 hours, and then the liquid was separated and converted to zinc and treated with 530 ppm. I got yeast. For comparison, zinc-free 200m
15 g of the yeast was added to l of stored water and left for 24 hours,
Then, the untreated yeast obtained by separating the liquid was obtained. Using each of these yeasts, a comparative test was conducted on the amount of carbon dioxide gas generated and the durability. That is, 4 g of glucose is added to 20 ml of distilled water, and 10 ml of an aqueous solution containing 0.25 g of potassium phosphate and 0.25 g of ammonium phosphate is added thereto. 1.5 g of this fermented liquor, which was squeezed with the zinc-containing treated yeast, was well mixed with 20 ml of distilled water, and was 1.5 g, similarly squeezed of the untreated yeast.
Was mixed with 20 ml of distilled water well, and each test solution was added to the container. About 5 ml of sulfuric acid (concentrated sulfuric acid: water = 1: 1) was attached to the carbon dioxide absorption tube, and the temperature was adjusted to 30 ° C. Fermentation was carried out for 5 hours in the incubator, and the amount of carbon dioxide gas generated was defined as the difference in weight before and after fermentation. Regarding the durability test, about 15 g of each of the above-mentioned compressed yeast was tightly packed in a sheath with an inner diameter of about 4 cm, put on a lid and placed in a thermostat at 30 ° C, and observed for softening every 24 hours to soften. The durability was determined by the time when it was started. The results are shown in Table 6 below.

As is clear from this table, the zinc-containing treated yeast has increased sugar fermentability and improved durability as compared with the untreated yeast.

Next, an example will be described in which yeast that has been once used for fermentation production and has a reduced activity is subjected to a zinc-containing treatment to improve its activity.

Example 8 Beer yeast (fermentability 69.6%) and sake yeast (association No. 6) (fermentability 68.8), which had once been used for fermentation production and had decreased activity
%), Wine yeast (fermentability: 68.0%), and the various types of zinc shown in Table 7 below were added to each of the treated liquids prepared by adding 100 ppm of zinc conversion to 200 ml of water.
Add g of each and leave each for 24 hours at low temperature,
Each zinc-containing treated yeast was prepared. From each of these liquids, the various treated yeasts were collected and pressed to obtain pressed yeasts, and a container containing a certain amount of wort prepared separately,
0.5% of each pressed yeast was added and fermented at 15 ° C for 6 days. The extract reduction rate was defined as fermentability. The results are shown in Table 7 below.

As mentioned above, it can be seen that the reduced activity of each of the various yeasts is improved to the order of 70% or more, regardless of the zinc form.

It should be noted that the activity effect is somewhat lower than that of zinc, but even when the yeast is treated to contain magnesium, a decrease in activity during storage can be prevented, an activation is obtained, and wort fermentability is improved. .

For example, in Example 8 above, when magnesium sulfate was used instead of zinc, the fermentability of brewer's yeast was 72.7.
%, Sake yeast fermentability is 73.3%, wine yeast fermentability is
It can be improved to 70.5%. When zinc in Example 1 was replaced with magnesium sulfate, the dead cell rate was 4.
The wort fermentability after 2% fermentation at 15 ° C for 6 days was improved to 75.9%. When a brewer's yeast containing 400 ppm was added to both zinc sulfate and magnesium sulfate, the dead cell rate was 4.5%, and the fermentability of wort fermented using this was 74.8%. It was improving.

For sake brewing yeast such as brewer's yeast,
It contains up to about 70ppm zinc, but even if it is simply put in water and stored at low temperature, the decrease in activity is inevitable. Therefore, as in the present invention, if water in which zinc is dissolved is prepared and immersed in this water so that zinc is taken into yeast during standing, the dead cell rate during storage decreases. On the other hand, a zinc-containing treated yeast having good activity can be obtained. For brewing alcoholic beverages, it is preferable to use yeast containing zinc up to about 100 to 500 ppm. In baker's yeast, the untreated yeast contains a significantly larger amount of zinc than in yeast used in alcoholic beverages. However, in storage and the like, storage in an aqueous solution containing zinc can prevent the activity from decreasing.

(Effect of the invention) As described above, according to the present invention, yeast used for fermentation production is added to a treatment liquid to which at least one of zinc and magnesium is added, and the culture is
Since storage was performed, yeasts with improved fermentability were obtained compared to those cultured in a culture solution containing no metal or stored in storage water containing no metal, and the activity was maintained well. In addition to obtaining improved or improved yeast, the yeast to be used for fermentation production is prepared in advance as a yeast containing metal capable of accumulating metal in the cell. A relatively high metal-containing treated yeast can be freely obtained in the treatment liquid, and when this is used for fermentation production, there is no metal secretion in the fermentation raw material, and a good quality fermentation product can be produced, and It has the effect of improving fermentation productivity.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C12N 1/16 8828-4B C12N 1/16 F

Claims (5)

(57) [Claims] 1. A desired amount of yeast is immersed in a treatment liquid containing a trace amount of at least one of zinc and magnesium for a required time, and the metal is incorporated into the yeast to prepare a metal-containing treated yeast, which is then fractionated. A fermentation production method using yeast, which comprises adding yeast to a fermentable raw material to perform fermentation treatment. 2. The fermentation production method according to claim 1, wherein a water-soluble zinc salt is used as zinc and a water-soluble magnesium salt is used as magnesium. 3. The yeast to be treated containing the metal is brewer's yeast,
The fermentation production method according to claim 1, wherein when the yeast is used for brewing wine yeast or sake yeast, the content of the metal in the treated yeast containing metal is 100 ppm or more. 4. When the yeast to be treated containing the metal is baker's yeast, the content of the metal in the treated yeast containing the metal is 220 p.
The fermentation production method according to claim 1, wherein the fermentation production is set to pm or more. 5. The fermentation production method according to claim 1, wherein the treatment liquid is water containing or not containing nutrients used before fermentation production for culturing, storing and activating yeast.