JPS6040826B2 - Method for manufacturing improved yeast products - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improved method of making yeast products.

More specifically, the present invention relates to a method for producing a white yeast product without yeast odor. Yeast is a substance rich in nutrients including protein, and can be stably obtained in large quantities.
It has been proposed to be used as food and feed, and some have already commercialized it.

Yeast has a unique odor called yeast odor and a yellowish color, so its uses are often restricted.

As a means to solve these problems, for example, a bleaching method using hydrogen peroxide (Japanese Patent Publication No. 47-41546), an extraction method using alcohol, and a washing method (Japanese Patent Application Laid-Open No. 47-3
731), a method of cleaning with lower fatty acids (Japanese Patent Application Laid-open No. 5
0-13800) and other methods for decolorizing yeast are known.

However, the bleaching method using hydrogen peroxide is not preferable because it leaves a unique odor caused by hydrogen peroxide. Furthermore, in the treatment method using hot ethanol or fatty acids, degreasing is performed at the same time as decolorization, so the resulting product is dry and has poor texture, making it undesirable as a food material. On the other hand, as a method of deodorizing yeast, there is a method of frying yeast in edible fat (Special Public Interest
No. 7-42519) is known, but it has the drawback of significant coloring. The object of the present invention is to solve the above-mentioned drawbacks, simultaneously decolorize and deodorize yeast, and produce a yeast product with good texture.

The present invention provides an improved method for producing yeast products characterized by contacting yeast with a polyhydric alcohol.

The yeast used in the present invention is not particularly limited, but it is preferably one that can be stably supplied in large quantities and at low cost.

Considering the uses of yeast products, it is desirable to use so-called edible yeast, which is either edible or used in the production of various foods and whose safety is well known.
An example of edible yeast is Candida utilis.
Saccharomyces cerevisiae), Saccharomyces cerevisiae
, Saccharomyces fragilis (Saccharomyces fragilis)
ms), Saccharomyces rubrusbergensis (Sac
Ch. Carlsbergensis), etc., and specifically alcohol yeast, beer yeast, baker's yeast, etc. are preferred. Either fresh yeast or dry yeast can be used, and if necessary, the yeast can be subjected to pretreatment such as a nucleic acid removal step and a crushing step before use. In particular, crushing treatment is convenient for easily and effectively decolorizing yeast. As the polyhydric alcohol, glycerin, propylene glycol, ethylene glycol, etc. can be suitably used.

The amount of polyhydric alcohol used is usually 30% or more based on the weight of dry yeast. If it is less than 30%, the decolorizing and deodorizing effects will not be sufficient.

Note that water can also be present together with the polyhydric alcohol, and in this case, water can be added at a ratio of 1 to 40% by volume relative to the polyhydric alcohol.

Since polyhydric alcohol has a high viscosity, when a relatively large amount of yeast is brought into contact with the polyhydric alcohol, it becomes solid and difficult to homogenize. In this respect, hydrous polyhydric alcohol has good workability. Contact between the yeast and the polyhydric alcohol can be carried out by mixing the yeast and the polyhydric alcohol and then heating it, or by pouring the yeast into a large amount of preheated polyhydric alcohol or by continuously passing the yeast through the mixture. .

This contact between yeast and polyhydric alcohol is preferably carried out at a temperature of 20 to 160 oo. The reason is 160oo
This is because, if the temperature exceeds 20%, the yeast odor can be removed, but browning of the yeast is unavoidable, and if the temperature is lower than 20°C, the decolorizing power is weak and furthermore, a long treatment time is required. Although the contact time must be considered in relation to other factors, it is generally 1 to 24 minutes, preferably 2 to 30 minutes. Polyhydric alcohols have a sweet taste and cannot be digested, so it is necessary to remove them as much as possible after contact with yeast. As a means for removing polyhydric alcohol, any known method can be applied, and a method of cleaning using alcohol is particularly effective. The yeast after washing can be used as is, but it may be dried if necessary.

For the drying process, any method such as vacuum drying, hot air drying, freeze drying, etc. can be applied, but a method that does not cause discoloration such as browning should be adopted. According to the present invention, it is possible to remove the characteristic yeast odor from yeast and also to decolorize it.

Moreover, a yeast product with a good texture can be obtained. Therefore, the scope of use of the yeast product obtained by the present invention in the food industry has been expanded, and the yeast product is also extremely excellent in quality. Next, the present invention will be explained in detail by way of examples.

Example 1 Five drops of glycerin or propylene glycol were added to 40 g of a 25% solids slurry of the yeast Candida utilis obtained by culturing ethanol as a carbon source, and the slurry was incubated at a predetermined temperature for 20 minutes.

After the fly treatment, the mixture was cooled to a temperature of 2,500 ml, 200 ml of ethanol was added, and the solids and alcohol were separated by filtration. After further washing with 300 mL of ethanol, the yeast powder was vacuum dried to obtain yeast powder. The color of the yeast powder thus obtained was measured using a color difference meter.

Color difference △E is standard white plate (L=90.5, aL=-0.7
, bL=-1.2). The results are shown in Table-1. Furthermore, all of the yeast powders had no yeast odor and were pale yellow to almost white in color. -1 Comparative Example 1 The yeast Candida utilis slurry obtained by the same method as in Example 1 was spray-dried, and the dried yeast and yeast were washed with 500% Z of ethanol at a predetermined temperature, and then vacuum-dried. The color of the obtained powdered yeast was measured.

The results are shown in Table-2. Table 2 Comparative Example 2 A culture solution of the yeast Candida utilis obtained by culturing in the same manner as in Example 1 was subjected to centrifugal D separation to obtain a yeast slurry with a solid content of 27%.

This slurry was poured into corn oil heated to 165 qo, held for 2 minutes, taken out, and centrifuged (14,000 qo).
xg) to remove oil from the yeast. Next, the yeast was powdered in a mortar to obtain powdered yeast. The color of the powder of this yeast was measured.

The results were: L was 54.9, aL was 7.6, and bL was 15.
8, ΔE was 40.3. As is clear from the results, this yeast was significantly discolored to a brownish color.

Example 2 Yeast Candida obtained by culturing in the same manner as in Example 1
A 1% by weight aqueous suspension of P. utilis was crushed using a high-pressure homogenizer (manufactured by Sanwa Kikai, homogeneous pressure 800k9/ground) and spray-dried at an inlet temperature of 210°C and an outlet temperature of 105°C.

Two pieces of this yeast powder (moisture content 7%) were added to five pieces of glycerin, and the mixture was incubated at the specified temperature for 20 minutes.

Thereafter, the mixture was cooled to a temperature of 25 °C, and 300 °C of ethanol was added thereto. Another 300 secretions of ethanol
Yeast powder was obtained by washing with a vacuum cleaner and vacuum drying. The obtained yeast powder was smooth, had no yeast odor, and had a whiter color than the previous ethanol-washed yeast product. Table 3 shows the color measurement results of this powder product. Table-3 Example 3 20g of spray-dried yeast obtained by the same method as Example 2
and glycerin or propylene glycol and 50 g of water were mixed and incubated at 100 qO for 20 minutes.

After cooling to 25°C, 200ml of ethanol was added and filtered. After further washing with 300 volumes of ethanol, the yeast powder was vacuum dried to obtain yeast powder. The obtained yeast powder was smooth, had no yeast odor, and had a good color. Table 4 shows the color measurement results of this powder product. Table-4

Claims (1)

[Claims] 1. An improved method for producing a yeast product, which comprises contacting yeast with a polyhydric alcohol. 2. The manufacturing method according to claim 1, wherein the polyhydric alcohol is any one of glycerin, propylene glycol, and ethylene glycol. 3. The manufacturing method according to claim 1, wherein the contact is carried out at a temperature of 20 to 160°C.