JPH09103266A - Yeast material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a yeast material useful for foods, medicinal materials, etc., by suspending a yeast autolytic insoluble substance in ethanol, carrying the stirring treatment under alkaline conditions and removing the taste and deodorizing the yeast autolytic insoluble substance which is a by-product formed when producing the yeast extract. SOLUTION: This yeast material is a tasteless and deodorized white yeast autolytic insoluble substance. The yeast material is obtained by adding ethanol to a suspension containing a yeast autolytic insoluble substance which is a by-product formed when autolyzing a yeast such as a brewer's yeast and producing a yeast extract, stirring the resultant suspension at 4 deg.C for 30min, then centrifuging the suspension, collecting a yeast autolytic insoluble substance sediment, suspending the resultant sediment in water, adding ethanol in an amount equal to the water, regulating the pH to 11 with a 2 N solution of sodium hydroxide under stirring, carrying out the stirring treatment under alkaline conditions, subsequently suspending the sediment prepared by the centrifugation in water, adding the equal amount of ethanol to the suspension, regulating the pH to 6.5 with a 2N hydrochloric acid under stirring, successively washing the regulated suspension with ethanol and water after the centrifugation, centrifuging the suspension and freeze-drying the sediment. The yeast material is useful for foods, medicinal materials, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tasteless and odorless method for removing yeast indigestible insolubles produced as a by-product when a yeast extract is produced from yeast cells by an autodigestion method, and a tasteless and odorless white yeast self. Digestible insoluble matter.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 63-22177 discloses a method for improving the flavor of brewer's yeast by steam distillation and an organic solvent. In addition, JP-A-6-70751
The gazette discloses that the taste and off-flavor peculiar to yeast is reduced by treating yeast or a yeast-treated product with an acid and heat, but the taste, particularly the bitterness is not examined. It should be noted that these publications do not describe a yeast autolysate insoluble matter.

Japanese Unexamined Patent Publication (Kokai) No. 4-248968 relates to a method for decolorizing and deodorizing yeast extract extraction residue, that is, yeast self-digesting insoluble matter. This is characterized in that the yeast extract extraction residue is treated with alkali and acid, followed by high-concentration ozone treatment and ethanol treatment.

[0004]

Problems to be Solved by the Invention Yeast extract residue, which is a yeast self-digesting insoluble matter produced when a yeast extract is produced from yeast cells by an auto-digestion method, is unique to self-digestion as compared with live yeast and dry yeast. Since the odor is also added, the above-mentioned JP-A-63-22177 and JP-A-06-06
According to the method of -70751, it is difficult to make it tasteless and odorless. Further, in the method of the above-mentioned Japanese Patent Laid-Open No. 4-248986, deodorization has not been examined, and the use of ozone gas makes the operation complicated, and there is a problem that the cost and time are long.

Further, as a known method, it is known that the insoluble matter of yeast autolysis can be made tasteless and odorless by washing it with ethanol as a solvent 10 times or more. However, the use of a large amount of ethanol leads to a considerable cost reduction. Takes a
Moreover, the obtained powder is brown to light brown. On the other hand, the main component of the yeast insoluble matter is yeast cell wall, and the yeast cell wall contains abundant dietary fibers such as polysaccharides glucan and mannan, and thus can be used as a material for foods and pharmaceuticals. Therefore, when it is used as a material for foods and pharmaceuticals, it is necessary to remove the peculiar off-flavors so that it is easy to eat, and it is preferable to use a white powder so that it can be easily used.

[0006] Therefore, an object of the present invention is to produce a yeast extract from yeast cells by a self-digesting method by a yeast digestion method. The present invention is to provide a white yeast self-digesting insoluble matter that is tasteless and odorless.

[0007]

The inventors of the present invention have conducted studies to solve the above-mentioned problems, and as a result, the yeast self-digesting insoluble matter was suspended in ethanol and agitated under an alkaline condition to give a different taste. The causative substance of the offensive odor was eluted, and by removing it by centrifugation, the peculiar offensive odor of the yeast indigestible insoluble matter was removed, and further it was confirmed that the powder was white and the present invention was found out. .

[0008] That is, the first aspect of the present invention relates to a tasteless and odorless method for yeast indigestion insoluble matter characterized by suspending the yeast autolysis insoluble matter in ethanol and stirring the suspension under an alkali. The second aspect of the present invention relates to a tasteless and odorless white yeast self-digesting insoluble matter obtained by the above-mentioned production method.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a yeast self-digesting insoluble substance, which is intended to be tasteless and odorless, is a by-produced product from yeast cells when yeast extract is produced by a conventional autodigestion method. Although it is not particularly limited as long as it is produced as a product, examples of yeast cells used when producing a yeast extract include Saccharomyces.
s) genus, for example Saccharomyces cerevisiae (Sac
beer yeast, baker's yeast, genus Pichia, genus Hansenula, and the like, which are charomyces cerevisiae.

The yeast autolyzed insoluble matter produced as a by-product during the production of the yeast extract is usually produced as a suspension of water, which is centrifuged to obtain a yeast autolysed insoluble matter precipitate. At that time, it is more effective to wash the precipitate with water or ethanol as a pretreatment. 5 to 2 in the obtained sediment
0-fold amount of 20 to 100% ethanol, preferably 10-fold amount of 50% ethanol is added, and the pH is adjusted to 9 with an alkaline solution.
-12, preferably pH 11, and stirred at room temperature for 30 minutes to 2 hours. At this time, denatured nucleic acids, amino acids, etc., which contribute to the off-flavor and off-flavor, are eluted in the aqueous phase. Any alkaline solution can be used as long as it can adjust the pH, such as sodium hydroxide. Thereafter, the pH is made neutral with hydrochloric acid or the like, and the precipitate is obtained by centrifugation. Washing the sediment with water or ethanol is more effective.

Finally, it is dried by a usual method such as spray drying or freeze-drying to obtain the objective insoluble substance of yeast autolysis. The obtained yeast indigestible insoluble matter is tasteless and odorless and has a white color tone, and thus can be provided to foods, pharmaceuticals and the like.

[0012]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. Example 1 1 liter of ethanol was added to 2.5 liters of a suspension containing 14 w / v% of a yeast autolysate insoluble matter, which is a by-product when a yeast extract was produced by autolyzing brewer's yeast, and 4 Stirred at 30 ° C. for 30 minutes. After stirring 3000 rpm
After centrifugation for 10 minutes, a yeast self-digesting insoluble matter precipitate was obtained. The precipitate was suspended in 1.8 liters of water, 1.8 liters of ethanol was further added, and while well suspending, the pH was adjusted to 11 with a 2N sodium hydroxide solution.
Next, stirring and centrifugation were performed under the same conditions as above, the obtained precipitate was suspended again in 1.6 liters of water, the same amount of ethanol was added, and the mixture was stirred and centrifuged. Resuspend the precipitate in 1.5 liters of water, add the same amount of ethanol, and stir 2
Adjust the pH to 6.5 with hydrochloric acid at the specified concentration, and centrifuge it for 20%.
Suspension with ethanol and centrifugation were performed, and then suspension with water and centrifugation were repeated twice. The obtained precipitate was freeze-dried to obtain 205 g of white powder (product of the present invention).

Comparative Example 1 600 g of dry powder of yeast indigestion insoluble substance, which is a by-product when yeast extract was produced by autolyzing brewer's yeast
Was suspended in 1 liter of ethanol, stirred at room temperature of 25 ° C. for 30 minutes, centrifuged at 3000 rpm for 10 minutes to remove the supernatant, and an alcohol-washed yeast self-digesting insoluble matter precipitate was obtained. Suspend the precipitate in 1 liter of ethanol,
The same operation was repeated 6 times. Next, the precipitate was suspended in 2 liters of water, stirred under the same conditions as above, and washed by centrifugation twice. The obtained precipitate was suspended in 2 liters of ethanol, stirred and centrifuged, the precipitate was suspended in a mixed solution of 1 liter of ethanol and 0.5 liter of water, and stirred and centrifuged. Further, washing with 0.75 liters of water and twice with 0.75 liters of ethanol were performed. The obtained precipitate is washed twice with water, freeze-dried, and ethanol 11
270 g of a light brown powder was obtained as a product washed once (comparative product A). It should be noted that ethanol-unwashed (comparative product B), ethanol washed three times (comparative product C), and eight times washed (comparative product D) were also obtained as freeze-dried products.

Next, a comparison product A to 10 was prepared by 10 panelists.
With respect to D, a sensory test was performed to determine whether or not an offensive odor is felt.

[Table 1] From the above results, it was a comment that the comparative product A, which had been washed with ethanol 11 times, had an unusual odor characteristic of yeast in 2 out of 10 people, but it was very weak, and the other 8 people were tasteless and odorless. It was a comment.

Example 2 With respect to the product of the present invention obtained in Example 1 and the comparative product A obtained in Comparative Example 1, 14 panelists were subjected to a sensory test for taste and smell. The results obtained below show which sample is tasteless and odorless in the blind.

[Table 2]

Eight of the products of the present invention and 6 of the comparative products responded that they were more tasteless and odorless, and 8 of 14 responded that the difference was small. From this also, it was confirmed that the product of the present invention and the comparative product A were indistinguishable and were similarly tasteless and odorless. The comparative product A was a light brown powder, whereas the product of the present invention was a white powder.

[0017]

INDUSTRIAL APPLICABILITY According to the present invention, the yeast self-digesting insoluble matter produced as a by-product when a yeast extract is produced from yeast cells by the autodigestion method is suspended in ethanol and stirred under alkaline conditions. As a result, it is possible to provide a white yeast self-digesting insoluble matter which is suitable for use as a material for foods and pharmaceuticals and which is easy to eat and tasteless and odorless while allowing easy operation and cost reduction.

Claims (2)

[Claims] 1. A tasteless and odorless method for a yeast self-digesting insoluble matter, which comprises suspending the yeast self-digesting insoluble matter in ethanol and stirring the mixture under an alkaline condition. 2. A tasteless and odorless white yeast self-digesting insoluble matter obtained by the production method according to claim 1.