JP2019201596A - Method for producing yeast or extract thereof with reduced coloring of bacterial cells - Google Patents

Abstract

To provide yeast or extract thereof in which coloring of cells is remarkably reduced without going through a special process for removing undesired colors attached to yeast or extract thereof, in the production of yeast or extract thereof using sugar as a carbon source.SOLUTION: The present invention provides a method for producing a culture medium for yeast culture, comprising a step of separately heat-sterilizing a carbon source and a medium component other than the carbon source.SELECTED DRAWING: Figure 1

Description

  This field relates to a method for producing yeast or an extract thereof. In particular, the present invention relates to a yeast having a markedly reduced color without passing through a special step of removing an undesired color adhering to the yeast or its extract in the production of a yeast using sugar as a carbon source or an extract thereof. The present invention relates to a method for producing an extract.

  Yeast extract is widely used as a seasoning made of natural materials, and its features are highly safe and has a unique umami, kokumi and other complex qualities that are not found in chemically synthesized seasonings. That is. Furthermore, taking advantage of the fact that yeast extract contains abundant useful amino acids, nucleic acids and the like, in recent years it has attracted attention as a cosmetic material and a health food material. However, yeast extract usually has a yellow or brown color characteristic of yeast, and this is a factor that limits the application range or amount of yeast extract.

  In yeast extract production, yeast culture is usually carried out using sugars such as molasses and glucose as the main carbon source. Since these raw materials are usually sterilized in a state where they are mixed with medium raw materials containing nitrogen such as amino compounds in production on an industrial scale, a brown substance is generated by an aminocarbonyl reaction or the like, and the medium is browned. When yeast is cultured using such a medium, the brown substance cannot be completely removed even after the washing process, which contributes to browning of the final product yeast extract.

  As prior art which examined the browning or coloring in the manufacturing process of a yeast extract, after heating and making an aminocarbonyl reaction advance actively, the method of removing a coloring substance with an ion exchange resin (patent document 1 and patent document 2) ), A method using a liquid film falling-type vacuum concentration method in the concentration step (Patent Document 3), etc., but these methods have a drawback that the steps become complicated. In particular, when extracting an extract from yeast that has been cultivated industrially in large quantities, it is not realistic to subject all cultures and their extracts to the above-mentioned process for the purpose of decolorization.

International Publication No. 98/46089 Pamphlet Japanese Patent No. 3935510 JP 2004-254545 A

  The present invention provides a yeast or extract thereof in which the coloration of bacterial cells is remarkably reduced without going through a special step for removing undesired coloration in the production of a yeast using sugar as a carbon source or an extract thereof. With the goal.

  As a result of intensive studies to solve the above problems, the present inventors have used sugar as a carbon source, a substance containing an amino compound as a nitrogen source, or an inorganic ammonium salt, and the carbon source and the nitrogen source are individually separated. As a result of culturing yeast using a medium prepared by heat sterilization, it was found that yeast or its extract with significantly reduced cell coloration could be produced, and the present invention was completed.

That is, this application includes the following inventions.
[1] A method for producing a yeast culture medium, comprising a step of separately heat-sterilizing a carbon source and a nitrogen-containing compound.
[2] The production method according to [1], wherein the carbon source is a carbohydrate.
[3] The production method according to [2], wherein the carbohydrate is a reducing sugar.
[4] The production method according to [3], wherein the reducing sugar is glucose.
[5] The production method according to any one of [1] to [4], wherein the nitrogen-containing compound is an amino compound and / or an inorganic ammonium salt.
[6] A method for producing cultured yeast or an extract thereof, comprising a step of culturing yeast in a medium produced according to the method according to any one of [1] to [5].
[7] Three of the following (a) to (d) as RGB relative values and brightness relative values for white (W) of the Nippon Color Research Coloring System (PCCS) in the powder state when the produced yeast extract is in a powder state: The method for producing a yeast or extract thereof according to [6], which satisfies the above.
(A) 0.90 ≦ R value ≦ 1
(B) 0.90 ≦ G value ≦ 1
(C) 0.85 ≦ B value ≦ 1
(D) 0.90 ≦ brightness (L value) ≦ 1
[8] The production method according to [6] or [7], wherein the yeast is Saccharomyces or Candida.
[9] The production method according to any one of [6] to [8], wherein the yeast is Saccharomyces cerevisiae or Candida utilis.
[10] The production method according to any one of [6] to [9], wherein the yeast is Saccharomyces cerevisiae.
[11] The production method according to any one of [6] to [10], wherein the yeast is sake yeast.
[12] The production method according to any one of [6] to [11], wherein the yeast is sake yeast No. 7.
[13] A method for producing a food or drink, comprising a step of adding the yeast produced by the production method according to any one of [6] to [12] or an extract thereof.
[14] A method for suppressing coloration in yeast or an extract thereof, comprising a step of culturing yeast in a medium produced according to the production method according to any one of [1] to [5].
[15] A coloring inhibitor in yeast or an extract thereof, comprising a carbon source and a nitrogen-containing compound that are separately heat-sterilized. [16] A medium containing the coloring inhibitor according to [15].

  According to the present invention, it is possible to produce a yeast or an extract thereof in which the coloration of the bacterial cells is remarkably reduced without going through a special step of removing undesired coloring in the yeast or the extract thereof. Further, the present invention provides a yeast extract in which undesirable coloration is significantly reduced.

FIG. 1 shows photographs of yeast extract powders of the present invention and comparative examples.

  Hereinafter, embodiments of the present invention will be described in detail.

  In 1st embodiment, this invention provides the manufacturing method of the culture medium for yeast culture | cultivation including the process of heat-sterilizing a carbon source and a nitrogen-containing compound separately. Typical causes of the coloration of the culture medium, and yeast and its extract, are to use substances that are colored (such as molasses, yeast extract, etc.), reducing sugars and amino compounds (amino acids, peptides and proteins). Examples thereof include a Maillard reaction (aminocarbonyl reaction) that produces a brown substance (melanoidin) and a caramelization reaction that produces a brown substance when sugar is heated. Therefore, as used herein, a “carbon source” is a carbohydrate that is used in normal yeast culture and has a nearly colorless color, and in the presence of a nitrogen-containing compound such as an amino compound. , Meaning something that causes coloration in the medium. In a preferred embodiment, one or more kinds selected from the group consisting of starch, glucose, fructose, galactose, sucrose, molasses, sulfite pulp waste liquor and the like are used as such carbohydrates. In the method of the present invention, a reducing sugar such as glucose can be suitably used as a carbon source.

  As used herein, “nitrogen-containing compound” means a component containing nitrogen, which is commonly used as a yeast culture medium, and preferably causes coloration such as browning in the culture medium in combination with the above carbon source. Means a component containing nitrogen. More specifically, “a component containing nitrogen that brings about coloration such as browning in a medium or the like in combination with a carbon source” means an amino compound and / or an inorganic ammonium salt. Examples of amino compounds include organic compounds containing an amino group, such as amino acids, urea, and methylamine. Examples of inorganic ammonium salts include ammonium sulfate, ammonium phosphate, and ammonium chloride. In addition, examples of the nitrogen-containing component include ammonia corn steep liquor (CSL), casein, yeast extract or peptone.

  Further, a phosphate component, a potassium component, and a magnesium component may be used for the production of the culture medium. These include normal lime, phosphate, potassium chloride, potassium hydroxide, magnesium sulfate, magnesium hydrochloride and the like. The raw material can be used. In addition, inorganic salts such as zinc, copper, manganese, and iron ions may be used. Further, vitamins, nucleic acid-related substances and the like may be added to the medium as necessary. The vitamins may be, for example, one or more selected from the group consisting of biotin, pantothenic acid, nicotinic acid, inositol, thiamine, pyridoxine and 4-aminobenzoic acid. Even when performing multiple cultures such as pre-culture and pre-culture before the main culture, the medium composition is the same as described above, but for the carbon source used before the main culture, for example, glucose, sucrose, The use of carbohydrates such as starch, molasses or organic acids such as acetic acid is contemplated.

  Heat sterilization should just be the conditions used by normal autoclave sterilization, for example, is performed at 121 degreeC for 40 minutes. As long as the final product is not adversely affected, the heating temperature may be over 121 ° C., and the heating time may be over 40 minutes. In addition, depending on the sterilization target, such as bacteria that die at low temperatures, the heating temperature can be less than 121 ° C, for example, about 60 to 80 ° C. From the viewpoint of suppressing coloring, it is preferable to heat at 121 ° C. for 40 minutes under milder conditions. For example, from the viewpoint of suppressing browning of a non-reducing sugar such as sucrose in the presence of an ammonium salt or the like, the heating temperature is preferably as low as possible.

  The method for suppressing the coloration of the medium or the like does not exclude the removal of the colored substance by a conventionally used ion exchange resin or the like, and these may be used in combination with the method for producing a medium according to the present invention.

  In 2nd embodiment, this invention provides the manufacturing method of cultured yeast or its extract including the process of culture | cultivating yeast with the said culture medium. The yeast may be any unicellular fungus suitable for producing a yeast with reduced coloring or an extract thereof. Specifically, the genus Saccharomyces, the genus Shizosaccharomyces, Pichia spp., Candida spp., Kluyveromyces spp., Williopsis spp., Debaryomyces spp., Galactomyces spp. Genus, Rhodotorula, Yarrowia, Zygosaccharomyces Such as bacteria and the like.

  Among these, since it is suitable for producing yeast with reduced coloring or an extract thereof and is edible, Candida tropicalis, Candida lipolytica, Candida Utyris (Candida utilis), Candida salmon (Candida sake), Saccharomyces cerevisiae (Saccharomyces cerevisiae) and the like are preferable, and Saccharomyces cerevisiae and Candida utilis that are widely used are more preferable. More preferably, it is Saccharomyces cerevisiae or Candida utilis.

  The culture conditions for culturing the yeast, such as temperature and pH, may be any conditions as long as they do not cause a culture failure for the yeast to be used, but optimum conditions for the yeast to be used are preferred. Further, the culture period is not particularly limited. In the case of fed-batch culture, the culture period is usually about several days, and if it is long, it is about several weeks. The culture format may be batch culture, fed-batch culture, or continuous culture, but industrially fed-batch culture or continuous culture is employed.

During the culture, carbon dioxide and organic acids are produced from the yeast, and the pH decreases with time. In order to suppress growth inhibition due to acidification of pH, an alkaline substance may be added to the medium. The alkaline substance to be added to the medium is not particularly limited, but NH ₄ OH (ammonia water), ammonia gas, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide and other inorganic alkalis, carbonic acid Alkaline bases such as sodium and potassium carbonate, urea and the like are preferred.

  Yeast can be produced as described above. As a method for producing a yeast extract from cultured yeast, any method may be used as long as it is a conventional method. For example, an autolysis method, an enzymatic decomposition method, an acid decomposition method, an alkali extraction method, hot water, Extraction methods are adopted. From the viewpoint of producing a yeast extract exhibiting a preferable color, alkali extraction or enzyme extraction is preferred.

  Furthermore, by making the yeast extract of the present invention into a powder form, an extract powder with significantly reduced coloring can be produced. As a method for preparing the dry yeast extract powder, any method can be used as long as it is a usual method, but industrially, freeze-drying method, spray-drying method, drum-drying method and the like are adopted. The

The produced yeast extract is in a powder state, preferably three or more of the following (a) to (d) as RGB relative values and brightness relative values to the white color (W) of the Japan Color Research Coloring System (PCCS). Can satisfy all:
(A) 0.90 ≦ R value ≦ 1
(B) 0.90 ≦ G value ≦ 1
(C) 0.85 ≦ B value ≦ 1
(D) 0.90 ≦ brightness (L value) ≦ 1

  RGB is a kind of color expression method, and is a kind of additive mixing that reproduces a wide range of colors by mixing three primary colors of red (Red), green (Green), and blue (Blue). The reduction in coloring only needs to be confirmed by comparison with a yeast extract obtained by a conventional production method, and is not limited to the method of determining the RGB relative values. For example, the color reduction may be determined by visual observation by a person skilled in the art or by absorbance.

  In 3rd embodiment, this invention provides the manufacturing method of the food-drinks composition including the process of adding the yeast manufactured by the said method, or its extract.

  The yeast or yeast extract produced by the present invention, or a processed product thereof, for example, yeast extract powder may be used as a seasoning composition. The seasoning composition may be composed only of the yeast extract of the present invention and contains other components such as a stabilizer and a preservative in addition to the yeast extract of the present invention. May be. The seasoning composition can be appropriately used for various foods and drinks as in the case of other general seasoning compositions.

  Furthermore, this invention relates to the food-drinks containing the yeast or yeast extract obtained by said method. The yeast or yeast extract of the present invention, or a processed product thereof, for example, the yeast extract powder is suitable for foods and drinks for which use of the yeast extract has been avoided for some time because of concerns about coloring.

  These foods and drinks may be any foods and drinks to which yeast itself, yeast extract and seasoning composition containing yeast extract can be added, for example, alcoholic beverages, soft drinks, fermented foods, kneaded products, seasonings, Examples include soups, breads, and confectionery.

  In order to produce the food or drink of the present invention, a preparation obtained from the yeast or a fraction of yeast may be added in the process of producing the food or drink.

  In 4th embodiment, this invention provides the coloring suppression method in yeast or its extract including the process of culture | cultivating yeast with the culture medium manufactured according to the said method. The kind of yeast and the culture conditions are as described above.

  In a fifth embodiment, the present invention provides a color inhibitor in yeast or an extract thereof, comprising a carbon source that has been separately heat-sterilized and a medium component other than the carbon source. The medium components other than the carbon source and the carbon source are as described above.

  In a sixth embodiment, the present invention provides a medium containing the above color inhibitor.

  Hereinafter, the present invention will be described in more detail with specific examples, but the present invention is not limited to these specific examples.

(Examination of the presence or absence of precipitation in the medium)
The presence or absence of precipitate formation in the medium sterilization process was examined. 50 ml of the medium having the following composition was prepared in 100 ml Erlenmeyer flasks, sterilized by autoclave (121 ° C., 20 minutes), and the presence or absence of precipitation was confirmed.

  As apparent from Table 1, medium No. 1-1 (hereinafter referred to as main medium) and medium No. When 1-2 was sterilized individually (hereinafter referred to as trace mineral liquid), precipitation did not occur. 1-1 and medium No. Medium No. 1-2 comprising the composition of 1-2. In 1-3, precipitation occurred after sterilization. Thereafter, the main medium and trace minerals were not sterilized at the same time.

(Examination of medium coloring)
The color of the medium in the medium sterilization process was examined. 50 ml of the medium having the following composition was prepared in 100 ml Erlenmeyer flasks and sterilized by autoclave (121 ° C., 40 minutes), and the presence or absence of coloring of the medium was confirmed.

Note) “+” for the ingredients in the table means addition, “−” means no addition. More specifically, 2-1 and 3-1 in Table 2 indicate that no brown substance is produced when glucose or sucrose is sterilized alone. 2-2 and 3-2 in Table 2 indicate that a brown substance is not produced even if the main medium components other than sugar and ammonium sulfate are sterilized at the same time. When 2-3 and 3-3 in Table 2 are sterilized with sugar and ammonium sulfate, caramelization is promoted to produce a brown substance, the degree of which is sucrose, which is a non-reducing sugar (caramelization) Compared with, the use of glucose (Maillard reaction + caramelization) is more prominent. 2-4 and 3-4 in Table 2 indicate that a brown substance was produced by the coloration of the yeast extract itself and the reaction between the amino compound and the sugar contained in the yeast extract. 2-5 and 3-5 in Table 2 are 2-3, 2-4, 3-3, or -3, 2-4, 3-3 or the like due to caramelization, Maillard reaction and coloring of yeast extract itself when sugar, yeast extract and ammonium sulfate are co-sterilized. Compared with 3-4, more brown material was produced.

  As is apparent from Table 2, when the sugar and ammonium sulfate or yeast extract were simultaneously sterilized, the medium was browned. In the culture medium to which the yeast extract (Eastock S-Pd (Asahi Group Foods)) was added, the brown color derived from the yeast extract was exhibited before sterilization. In addition, although a result is not shown, the yeast extract solution (final concentration of 9 g / L) which melt | dissolved the yeast extract independently is exhibiting the color corresponded to + light brown in the said table | surface.

  In the culture medium used in Table 2, Kyoto yeast No. 7 (hereinafter referred to as K-7 strain) distributed by the Japan Brewing Association was cultured, and coloring of the cells was confirmed. Each medium of Table 2 contained a trace mineral solution (composition of Table 1) and 85 μl of vitamin solution (0.00085 g / L biotin, 0.017 g / L calcium pantothenate, 0.017 g / L nicotinic acid, 0.43 g / L inositol, 0.017 g / L thiamine hydrochloride, 0.017 g / L pyridoxine hydrochloride, 0.0034 g / L 4-aminobenzoic acid) was added. Here, the K-7 strain was inoculated and cultured at 30 ° C. for 24 hours. 1.0 ml of the culture solution was transferred to a 1.5 ml capacity microtube and centrifuged (8000 rpm, 20 ° C., 5 minutes). The supernatant was collected in a new 1.5 ml capacity microtube, and the cells were suspended in distilled water using a vortex mixer to make 1.0 ml. Centrifugation, supernatant collection and cell suspension were repeated twice under the same conditions, and coloring of the cells and supernatant was confirmed.

  As is apparent from Table 3, the cells cultured in the colored medium were not able to remove the colored substance from the cells even after sufficient washing treatment by vortexing.

Example 1
By the method shown in the following (1) to (8), the K-7 strain was cultured using glucose as a carbon source and extracted to obtain a yeast extract.

(1) Pre-culture 5 ml YM medium (1% Glucose, 0.3% Yeast Extract, 0.3% Malt extract) was prepared in a glass test tube and autoclaved (121 ° C., 20 minutes). 50 μl of the glycerol stock of K-7 strain was inoculated into the above test tube medium, and cultured with shaking at 30 ° C. for 19 hours.

(2) Preculture 15 ml YM medium (1% Glucose, 0.3% Yeast Extract, 0.3% Malt extract) was prepared in a 50 ml Erlenmeyer flask and autoclaved (121 ° C., 20 minutes). 150 μl of the previous culture solution of K-7 strain was inoculated into the above flask medium, and cultured with shaking at 30 ° C. for 21 hours.

(3) Main culture Fed-batch culture was performed under the following conditions.
Apparatus: MDL-3L (manufactured by Maruhishi Bioengineer Co., Ltd.)
Carbon source: glucose culture temperature: 30 ° C
Ventilation: 1.5L / min
Stirring: 900rpm
pH control: Lower limit control pH 5.8 with 12.5% aqueous ammonia, no upper limit control Initial medium: 4 g / L ammonium sulfate, 8 g / L potassium dihydrogen phosphate, 2 g / L magnesium sulfate heptahydrate, 0.4 g / L calcium chloride dihydrate, 0.068 g / L zinc sulfate heptahydrate, 0.12 g / L anhydrous citric acid, 0.18 g / L ferrous sulfate heptahydrate, 0.003 g / L sulfuric acid Copper pentahydrate, 0.17 g / L sodium chloride, 0.00085 g / L biotin, 0.017 g / L calcium pantothenate, 0.017 g / L nicotinic acid, 0.43 g / L inositol, 0.017 g / L Thiamine hydrochloride, 0.017 g / L pyridoxine hydrochloride, 0.0034 g / L 4-aminobenzoic acid, 2 g / L KM-72 (antifoaming agent)
Feed medium: 153 g glucose was dissolved in distilled water to make 830 ml. This was poured into a 1 L medium bottle and autoclaved (121 ° C., 20 minutes). After confirming that the glucose solution was sufficiently cooled, each component except KM-72 of the initial medium was aseptically added so as to have the same concentration as the initial medium (final liquid volume 1 L).
Cultivation period: It ended 46 hours after the start of main culture.

  The initial culture medium and the supply medium prepared in this manner are the medium No. in Table 2. Similar to 2-2, no browning of the medium after sterilization was observed.

(4) Bacteria collection The main culture was transferred to a 500 ml plastic centrifuge bottle and centrifuged (5000 rpm, 20 ° C., 10 minutes). The supernatant was discarded, and the cells were suspended in distilled water so that the cell concentration was about 10%.

(5) Measurement of dry cell weight A predetermined amount of yeast suspension was taken in a stainless centrifuge tube that had been weighed in advance, and centrifuged (10000 rpm, 25 ° C., 5 minutes). The supernatant was discarded and dried overnight at 105 ° C. The weight after drying was measured, and the weight of the solid content (dry cell weight, unit g / L) was calculated.
<Calculation formula> Dry cell weight = Weight after yeast drying-Weight of stainless centrifuge tube

(6) Preparation of extract solution by alkali extraction method A part of the yeast suspension was transferred to a 250 ml capacity resin container, and 0.1 g of sodium hydroxide was added per 1 g of dry cell weight. This was treated at 90 ° C. for 1.5 hours, neutralized with 5N hydrochloric acid to pH 7.0 to pH 7.5, and centrifuged (10000 rpm, 20 ° C., 10 min) to obtain a supernatant (extract solution). .

(7) Preparation of Extract Solution by Enzyme Extraction Method A part of the yeast suspension was transferred to a 250 ml resin container, and 0.01 g of proteax (Amano Enzyme Co., Ltd.) was added per 1 g of dry cell weight. This was treated at 50 ° C. for 5 hours while gently permeating it, then treated at 80 ° C. for 20 minutes to stop the enzyme reaction, and centrifuged (10000 rpm, 20 ° C., 10 minutes) to obtain a supernatant (extract solution). Acquired.

(8) Spray-drying of extract solution The extract solution obtained by alkali extraction and enzyme extraction was spray-dried with a spray-drying device (BUCHI Spray Dryer B-290) to obtain alkali-extracted extract powder and enzyme-extracted extract powder.

(Example 2)
In the same manner as in the method used in Example 1, the K-7 strain was pre-cultured and pre-cultured, and main culture was performed under the following conditions.
Apparatus: MDL-3L (manufactured by Maruhishi Bioengineer Co., Ltd.)
Culture method: Continuous culture carbon source: Glucose culture temperature: 30 ° C
Ventilation: 1.5L / min
Stirring: 900rpm
pH control: Lower limit control pH 5.8 with 12.5% aqueous ammonia, no upper limit control Initial medium: 4 g / L ammonium sulfate, 8 g / L potassium dihydrogen phosphate, 2 g / L magnesium sulfate heptahydrate, 0.4 g / L calcium chloride dihydrate, 0.068 g / L zinc sulfate heptahydrate, 0.12 g / L anhydrous citric acid, 0.18 g / L ferrous sulfate heptahydrate, 0.003 g / L sulfuric acid Copper pentahydrate, 0.17 g / L sodium chloride, 0.00085 g / L biotin, 0.017 g / L calcium pantothenate, 0.017 g / L nicotinic acid, 0.43 g / L inositol, 0.017 g / L Thiamine hydrochloride, 0.017 g / L pyridoxine hydrochloride, 0.0034 g / L 4-aminobenzoic acid, 2 g / L KM-72 (antifoaming agent)
Feed medium: 3.4 kg glucose, 160 g potassium dihydrogen phosphate, 40 g magnesium sulfate heptahydrate, 8 g calcium chloride dihydrate, 20 g KM-72 was dissolved in distilled water to 19.7 kg and autoclaved (121 ° C., 40 min). After confirming that it was sufficiently cooled, the remaining components were aseptically added so as to have the same concentration as the initial medium shown in Table 1 (final liquid volume 20 kg).

  In the initial medium and the supply medium of Example 2, as in Example 1, no browning of the medium after sterilization was observed. This is considered to be caused by heat sterilization of glucose in the absence of a nitrogen-containing compound.

  In the same manner as in Example 1, bacterial collection, extract extraction treatment, and spray drying of the extract solution were performed to obtain an enzyme extract extract powder.

(Comparative Example 1)
In the same manner as in Example 1, the K-7 strain was precultured and precultured, and main culture was performed under the following conditions.
Apparatus: MDL-3L (manufactured by Maruhishi Bioengineer Co., Ltd.)
Culture method: Continuous culture carbon source: Glucose culture temperature: 30 ° C
Ventilation: 1.5L / min
Stirring: 900rpm
pH control: Lower limit control pH 5.8 with 12.5% aqueous ammonia, no upper limit control Initial medium: 4 g / L ammonium sulfate, 8 g / L potassium dihydrogen phosphate, 2 g / L magnesium sulfate heptahydrate, 0.4 g / L calcium chloride dihydrate, 0.068 g / L zinc sulfate heptahydrate, 0.12 g / L anhydrous citric acid, 0.18 g / L ferrous sulfate heptahydrate, 0.003 g / L sulfuric acid Copper pentahydrate, 0.17 g / L sodium chloride, 0.00085 g / L biotin, 0.017 g / L calcium pantothenate, 0.017 g / L nicotinic acid, 0.43 g / L inositol, 0.017 g / L Thiamine hydrochloride, 0.017 g / L pyridoxine hydrochloride, 0.0034 g / L 4-aminobenzoic acid, 2 g / L KM-72 (antifoaming agent: manufactured by Shin-Etsu Chemical Co., Ltd.)
Feed medium: 3.4 kg glucose, 80 g ammonium sulfate, 160 g potassium dihydrogen phosphate, 40 g magnesium sulfate heptahydrate, 8 g calcium chloride dihydrate, 20 g KM-72 dissolved in distilled water to 19.9 kg, Autoclaved (121 ° C., 40 min). After confirming that it was sufficiently cooled, the remaining components were aseptically added to the same concentration as the initial culture medium of Example 1 (final liquid volume 20 kg).

  In a common yeast eutrophic medium (for example, YEPD medium), yeast extract is added to the medium as a nitrogen source and a vitamin source. The supply medium of Comparative Example 1 in which the yeast extract that causes coloring was replaced with vitamins was the medium No. 1 in Table 2. Similar to 2-3, the medium turned brown after medium sterilization.

  In the same manner as in Example 1, bacterial collection, extract extraction treatment, and spray drying of the extract solution were performed to obtain an enzyme extract extract powder.

(Comparative Example 2)
In the same manner as in Example 1, the K-7 strain was precultured and precultured, and main culture was performed under the following conditions.
Apparatus: MDL-3L (manufactured by Maruhishi Bioengineer Co., Ltd.)
Culture method: Continuous culture carbon source: Glucose culture temperature: 30 ° C
Ventilation: 1.5L / min
Stirring: 900rpm
pH control: Lower limit control pH 5.8 with 12.5% aqueous ammonia, no upper limit control Initial medium: 4 g / L ammonium sulfate, 8 g / L potassium dihydrogen phosphate, 2 g / L magnesium sulfate heptahydrate, 0.4 g / L calcium chloride dihydrate, 0.068 g / L zinc sulfate heptahydrate, 0.12 g / L anhydrous citric acid, 0.18 g / L ferrous sulfate heptahydrate, 0.003 g / L sulfuric acid Copper pentahydrate, 0.17 g / L sodium chloride, 9 g / L yeast extract, 10 g / L CA-L2 (antifoaming agent)
Feed medium: 3.4 kg glucose, 180 g yeast extract, 80 g ammonium sulfate, 160 g potassium dihydrogen phosphate, 40 g magnesium sulfate heptahydrate, 8 g calcium chloride dihydrate, 100 g CA-L2 dissolved in distilled water and 19 0.9 kg and autoclaved (121 ° C., 40 min). After confirming that it was sufficiently cooled, the remaining components were aseptically added to the same concentration as the initial culture medium of Example 1 (final liquid volume 20 kg).
Other conditions were the same as in Example 1.

  The supply medium of Comparative Example 2 containing the yeast extract was the medium No. of Table 2. Similar to 2-5, the medium browned after sterilization of the medium, and the degree of browning was greater than that of Comparative Example 1.

  In the same manner as in Example 1, bacterial collection, extract extraction treatment, and spray drying of the extract solution were performed to obtain an alkaline extract powder.

(Comparative Example 3-5)
Yeast extract powder prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2, and commercially available yeast extract (Comparative Example 3: Eastoc S-Pd (Asahi Group Foods, Inc.) (listed above) ); Comparative Example 4: Hyper Mist HG (Asahi Group Foods) (commercial product B); Comparative Example 5: Vertex IG20 (Fuji Food Industry) (commercial product C)) was compared in color. As shown in FIG. 1, the coloring of the product of the present invention was clearly reduced as compared with the comparative example.

  The color tone of the yeast extract powders of Example 1, Example 2, and Comparative Examples 1 to 5 was compared. The color tone of the yeast extract powder is obtained by scanning the yeast extract powder with a scanner, averaging the measured RGB values of three arbitrary points in the scanned yeast extract powder image, and scanning the same in the same way. Comparison was made with respect to the RGB measurement average values of arbitrary three points in the white (W) image of the laboratory, Lot No. 01407). In addition, using the new color card 199a, the color closest to the actual yeast extract powder was visually selected.

  As shown in Table 4, the alkaline extract of the present invention has higher RGB relative values and brightness values and lower brightness values than the yeast 1 and 2 extract powders of the comparative examples ( That is, the characteristic of being close to white) was observed. This seems to be due to the difference in the degree of coloring of the cells used for the extraction of the extract. In addition, the enzyme extract of the present invention was characterized by high RGB relative values and brightness values (ie, less coloring) compared to the yeast extract powders of Comparative Examples 1 and 2. Furthermore, the product of the present invention has a color tone equivalent to that of Gy-9.0 or off N-1 of the new color card 199a, and the coloring is extremely reduced compared to the comparative example.

  Although the manufacturing method of the yeast extract of Comparative Examples 3-5 (commercial products AC) which showed the color tone equivalent to the enzyme extract of the comparative example 2 is unknown, all yeast extracts use a microbial cell with much coloring. It is presumed that the product was manufactured using a medium with a high coloration (that is, a medium different from the medium manufactured according to the present invention).

  Using the yeast extract solution obtained by dissolving the yeast extract powders of Example 1, Example 2, and Comparative Examples 1 to 5 in distilled water to 1 wt%, the color tone of the yeast extract solution was compared. As for the color tone of the yeast extract solution, the absorption at a wavelength of 440 nm was measured, and the lower the measured value, the less the coloring was determined.

  As shown in Table 5, when the yeast extract of the present invention was made into a solution, coloring was reduced compared to the comparative example.

  From the results shown in Tables 3 to 5, the problem of coloring the yeast extract is that a colored substance that cannot be removed by washing is brought into the cell body and brought into the cell body. It became clear that can be manufactured. Although not intended to be bound by theory, it is considered that the mechanism of action of the present invention is not limited to the type of yeast. Therefore, yeasts of the genus Saccharomyces other than the yeast yeast 7 or other yeasts such as Even when using Candida yeast, a similar color reduction effect is expected.

  The yeast extract of the present invention in which undesirable coloring is significantly reduced can be applied to various food fields. Furthermore, it can be expected to be applied to the food field where the amount of use has been limited due to concerns about coloring and the use has been avoided.

Claims (16)

  The manufacturing method of the culture medium for yeast including the process of heat-sterilizing a carbon source and a nitrogen-containing compound separately.   The production method according to claim 1, wherein the carbon source is a carbohydrate.   The production method according to claim 2, wherein the carbohydrate is a reducing sugar.   The production method according to claim 3, wherein the reducing sugar is glucose.   The production method according to any one of claims 1 to 4, wherein the nitrogen-containing compound is an amino compound and / or an inorganic ammonium salt.   The manufacturing method of cultured yeast or its extract including the process of culture | cultivating yeast with the culture medium manufactured according to the method of any one of Claims 1-5. The produced yeast extract satisfies three or more of the following (a) to (d) as RGB relative values and brightness relative values to white (W) of the Japan Color Research Coloring System (PCCS) in a powder state. The manufacturing method of the yeast of Claim 6, or its extract.
(A) 0.90 ≦ R value ≦ 1
(B) 0.90 ≦ G value ≦ 1
(C) 0.85 ≦ B value ≦ 1
(D) 0.90 ≦ brightness (L value) ≦ 1   The production method according to claim 6 or 7, wherein the yeast is Saccharomyces or Candida.   The production method according to any one of claims 6 to 8, wherein the yeast is Saccharomyces cerevisiae or Candida utilis.   The production method according to any one of claims 6 to 9, wherein the yeast is Saccharomyces cerevisiae.   The manufacturing method of any one of Claims 6-10 whose yeast is sake yeast.   The production method according to any one of claims 6 to 11, wherein the yeast is sake yeast No. 7.   The manufacturing method of food-drinks including the process of adding the yeast manufactured by the manufacturing method of any one of Claims 6-12, or its extract.   The coloring suppression method in yeast or its extract including the process of culture | cultivating yeast with the culture medium manufactured according to the manufacturing method of any one of Claims 1-5.   The coloring inhibitor in yeast or its extract containing the carbon source and nitrogen-containing compound which were separately heat-sterilized.   A culture medium containing the coloring inhibitor according to claim 15.