DE1956146A1 - Active, dried baker's yeast and process for their production - Google Patents

Description

DR. ELISABETH JUNG. DR. VOLKER VOSSIUS ₁ DIPL-ING. GERHARD COLDEWEY

Patent attorney

19 ζβ1 AR

MÖNCHEN 23 - CLEMENSSTRASSE 30. TELEPHONE 345067. TELEGRAM ADDRESS: INVENT / MONCHEN. TELExI-29e7e

Nov 7, 1969

uZ E 816 (J / Mü / we)
DUI - 1125

KONIIiKLIJKE NEDERLANDSCHE GIST- EN SPIRITUSPABRIEK N.V. DeIft, Netherlands

"Active, Dried Baker's Yeast and Processes for Theirs Manufacture "

Priority: November 8, 1968, Great Britain, No. 52950/68

(Prov. Specif.)

The invention relates to active, dried baker's yeast and a process for their production.

Baker's yeast is generally available as compressed yeast with a dry matter content of about $ 26 to $ 32 or as active, dried yeast with a dry matter content of over $ 80, generally over 90 % .

Compressed yeast has the disadvantage of a relatively poor shelf life, so that in practice this type of yeast is only of importance in countries where the temperature is relatively low and / or fresh yeast is available essentially daily.

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Active, dried yeast does not have this disadvantage. Due to its high dry matter content, it is also at elevated levels Temperatures are remarkably stable over a longer period of time, making them useful for countries with relatively high temperatures, e.g. for tropical countries, is suitable *. Active, - has dried yeast. however, it has the disadvantage of a relatively low activity and also has to undergo a time-consuming rehydration process in water: so that it develops its activity before mixing it with the flour to make the dough «

However, the disadvantage of lower activity, which in order to obtain: the same baking results, must require larger amounts of yeast: makes and, as a result, the baker when using commercially available More active, dried yeast causes higher costs in tropical countries are accepted to take advantage of the to achieve better shelf life. As a result, there is essentially no interest in active, dried yeast because of the disadvantages mentioned above.

The lower activity of commercially available active, dried yeasts in comparison with compressed yeast can be seen from the following table.

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Yeast-
!sample shape salary
at
Dry
Dimensions Protein content
(^ Nx 6.25)
based on
the dry
Dimensions Phosphorus content
(# P ₂ O ₅ )
based on
the dry
Dimensions test Gas
procreation
(ml) i
D.
2)
i
!
3)
4)
5) Grains
Grains
Grains
small
Particle
powder 92.7
92.6
92.4
91.6
91.8 42.4
•
41.9
41.5
42.7
41.6 1.90
1.97
1, "92
1.36
3.36 ^A 1
B.
^A 1
B.
A_
Jl
A "
A. 500
295
493
269
444
417
369 6)
j pressed 29.0 52.5 3.20 B ⁵ 595

The gas generation values given in the table were obtained using the test methods described below. The active ones Dried yeasts are of various origins and are designated with the numbers 1) to 5).

From this table it can be seen that the gas generation values for the active, dried yeasts only with the gas generation of High protein compressed yeast (sample 6) is comparable when using considerably larger amounts of active, dried yeast i.e. 930 mg of active, dried yeast in comparison with 450 mg of compressed yeast, based on the dry matter. Will the investigations If the gas production is carried out with the same amounts of yeast, calculated on the dry matter, then the values for the gas production are for active, dried yeast considerably below the

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Values for compressed yeast.

Commercially available active, dried yeast generally has a low protein content of the order of 40 - 45 ° if ° N χ 6.25, nitrogen determined according to the * Kjeldahl method). Such yeasts are quite stable and can withstand the usual slow drying processes. Research has shown that yeasts with a high protein content are not suitable for the production of active, dry yeast, due to the fact that during the usual slow drying processes, large. E. Loss of activity occur and, moreover, the product obtained is very unstable. Rapid drying processes, for example spray drying, can be used with yeasts, but these processes also have the disadvantage that they lead to noticeable losses in activity in the yeast. In addition, very finely divided, powdery powders are obtained which are difficult to use when mixed with flour or rehydrated.

An active, dried baker's yeast has now been developed whose activity, based on equal amounts of dry matter, is much better than that of the best currently commercially available active, dried baker's yeast and which is even comparable to the activity of high-quality compressed yeast.

The active, dried baker's yeast according to the invention is characterized with a dry matter content of at least 85% by weight, a protein content ($ N χ 6.25, according to Kjeldahl

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true) from $ 45 to $ 60, based on the dry matter, and an activity value of 420 to 600, the method of determining the activity being that 480 mg of dried yeast is mixed in a mixer with 100 g of flour, 55 ml of a 2 g of NaCl-containing solution are added, the mass is ^{mixed for 6 minutes at 28 °} C. to form a dough, the dough is kept in a water bath at 28 ^° C. and the amount of gas evolved in the period from 10 to 175 minutes after the start of mixing is determined will. The amount of gas is given in ml at 28 C and 760 mm Hg. (This test procedure is hereinafter referred to as Test B.)

The yeast of the present invention has a much higher activity than that hitherto available active, dried yeasts and does not need to be rehydrated to develop their activity.

The yeast of the invention preferably has a dry matter content 90 - 96 weight ^, a protein content ($ N χ 6.25)

of 48-54 τ and an activity value of 440-580, especially 480-580, determined according to test B. The shelf life of the active, dried yeast is comparable to that of the active, dried yeast currently available on the market.

According to the invention, the yeast for the production of bread can be mixed directly with the flour and immediately distributed homogeneously in the dough. When mixing the yeasts of the invention with flour and Water for making the dough, it is very advantageous that the yeast particles largely dissolve and the yeast homogeneous is distributed in the dough.

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Most active, dried yeasts have this property not. To achieve the highest activities, the yeast of the invention preferably contains a swelling agent and / or a Wetting agents.

Suitable swelling agents, which are preferably used in amounts of 0.5 - 5 #, advantageously 1-2 ^, based on the dry matter, used are methyl cellulose and carboxymethyl cellulose.

Suitable wetting agents, which are preferably used in amounts of 0.5 - 5 ft, advantageously 1 - 2 ^, based on the dry matter, are esters of saturated fatty acids, such as fatty acid esters of sorbitol, e.g. sorbitol monolaureate, sorbitol monopalmitate, sorbitol monostearate or sorbitol monooleate, fatty acid esters of glycerol, for example glyceryl monostearate, glyceryl distearate or glyceryl monopalmitate, fatty acid esters of propylene glycol, for example propylene glycol monostearate, or mixtures of two or more of the above-mentioned compounds.

The invention further relates to a process for the production of active, dried baker's yeast, which is characterized in that fresh pressed yeast with a protein content ($ N χ 6.25) of 45-60 tfo, based on the dry matter, is comminuted into small particles and that these particles are dried within a period not exceeding 120 minutes to a dry matter content of at least 85 weight ^ means of a drying gas stream with the proviso that the particles during the drying treatment in a temperature range 20-50 ⁰ C.

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being held. In this way, active, dried yeast with an activity value of 420 - 600 when determined according to

the test procedure B. The drying of the yeast particles is preferably conducted at a temperature of 20 - carried out 35 ⁰ C - 40 ⁰ C, in particular from 30th

In general, drying times of 3 to 120 minutes are suitable. The drying time is preferably less than 50 minutes and in particular less than 20 minutes. To the particles To keep within the temperature range mentioned above, it is advantageous if the temperature of the drying gas stream is at The end of the drying treatment is lower than at the beginning of the same is. At the start of the drying treatment, the temperature of the drying gas stream can be up to 160 ° C.

To facilitate the drying process ssu and a light in the batter To obtain distributable final yeast product, the compressed yeast is divided into small particles, e.g. by extrusion of the yeast to Forming threads and by breaking these threads to form particles, the particles preferably having a cross-section in Have a range of 0.2 - 2 mm. From yeast particles of this size, a dried final yeast product of particles with a Cross-section in the range of 0.1-1 mm.

The process of the invention can be carried out batchwise, but it is particularly suitable for a continuous one Execution. The drying treatment can, for example, be carried out using the fluidized bed process.

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The invention is made with a yeast strain with good drying resistance, e.g. with the strain Ng 1777 described in British description 989.

The pressed yeast used as the starting material can be produced, for example, by a process in which yeast is produced by a hypotonic. Solution, such as a saline solution, is partially dehydrated and quickly washed as described in the British description 763 926 is described.

The active, dried yeast of the invention can be packaged in all conventional containers, for example cans and plastic bags in which the dried yeast is preferably kept under greatly reduced pressure or under a nitrogen atmosphere. Suitable plastic materials are e.g. polyester, polyamide, polyethylene, Laminates made of these materials or laminates with e.g. aluminum. Another suitable material is with a varnish coating provided, regenerated cellulose.

The examples illustrate the invention. Reference is made to the im

The following test procedures A, B, B and ~ 2> ■ are referred to.

Description of the test procedures used:

Test A (for common active, dried yeast)

930 mg of active, dried yeast are soaked ^{in 8 ml of water at 35 ° C. for 10 minutes.} The yeast suspension obtained is 100 g

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Flour and 47 ml of a solution containing 2 g of NaCl are mixed, the temperature of the flour and the salt solution being 28 ^° C. The mixture obtained is mixed for 6 minutes to form a dough which is placed in a 28 ^° C. water bath. The amount of gas developed in the period from 10 to 175 minutes after the start of mixing is determined in ml at 28 ^° C. and 760 mm Hg.

Test B ¹ .

Jl

This test is carried out in the same way as Test A except that 480 mg is active instead of 930 mg dried yeast can be used.

Test B ²

480 mg of dried active yeast are mixed directly with 100 g of flour in a mixer. The mass is -vermischt 6 minutes at 28 ⁰ C after the addition of 55 ml of a 2 g NaCl-containing solution. The rest of the procedure is as in test A.

Test B ⁵ (for compressed yeast)

An amount of pressed yeast corresponding to 450 mg dry matter is suspended in 55 ml of a solution containing 2 g of NaCl. After addition of 10og flour dough is prepared by mixing for 6 minutes at 28 ⁰ C. The rest of the procedure is as in test A.

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example 1

A centrifuged and washed yeast suspension with a dry matter content of 170 g / liter is mixed with such an amount of sorbitol monostearate suspension (wetting agent) in water that the mixture contains 1 g of sorbitol monostearate per 100 g of dry yeast, the suspension is filtered off. A pressed yeast is obtained with a dry matter content of about $ 30, a protein content (^ N χ 6.25) "of $ 52.5 >, based on the dry matter, and a wetting agent content of $ 1," based on the dry matter.

The pressed yeast is pressed through a perforated plate with openings 0.6 mm in diameter. The product obtained is dried to $ 92-95 dry matter by passing a stream of dry air through the yeast mass. The temperature of this air is changed during the drying process. During the first 6 minutes it is 60 ^{° C. and is lowered to 40 °} C. during the next 6 minutes so that the temperature of the yeast can be kept ^{below 40 ° C.} The total drying time is 12 minutes. The product thus obtained is fine-grained and consists of particles approximately 2 mm in length and approximately 0.4 mm in cross-section. The analysis of the product gives: dry matter content $ 93.4; Protein content ($ N χ 6.25) 54.0 ° />, based on dry matter; Phosphorus content as P ₂ ⁰ C, based on the dry matter, 3.20 ^C , O. This product can be added directly to the flour without prior soaking to make a dough and can be completely dispersed in the dough. Gas generation according to Tast B

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is 516 ml.

Example 2

For comparison purposes. Gas generation tests with (a) a yeast low protein and with (b) a high protein yeast. Both yeasts are (I) before drying, (II) after the usual 18 hour drum drying and (III) examined by the flash drying method of the invention. The results are given in the following table.

Dry
potential
ver
travel shape io trok-
ken mass protein
stop
($ 1x6.25)
based
on the
Dry
Dimensions phosphorus
salary
T ^ P ₂ O ₅ )
based
on the
Dry
Dimensions BeStim
mung s-
ver
travel M.
Gases
new
gun £ 3r- / yeast
γ pressed 30.0 41.5 1.76 B ⁵ 432 (a) (l) usual
Slow-
dry
tion (Corner 92.8 42.7 1.82 B ² D. (a) (Il) Fast
dry
tion (like
described
ben) small
Particle 93.0 41.6 1.78 B ² 398 Oa) (III) - pressed 29.0 52.5 3.20 B ⁵ 595 (bi). usual
Slow
dry
tion Grains 92.7 53.2 3.24 B ² 1)
! Cb) (II) Fast
dry
tion (like
described
ben) yours
Particle 93.4 52.6 3.20 B ² 516 (b) (m:

1) The gas generation was not measured because the grains are not Distribute homogeneously in the dough.

From the above results it can be seen that yeast (a) (III)

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has a lower activity than yeast (b) (III).

Likewise, undried yeast (a) (I) has a lower activity than dried yeast (b) (III), i.e. the undried compressed yeast low protein (a) (l) has a lower activity than the dried yeast (b) (III).

The yeasts (a) (II) and (b) (II) are dried according to the usual method. Therefore, the particles did _{not dissolve by n%} and had little activity.

Accordingly, it can be seen that in order to produce a dried For the high activity yeast of the invention, a high protein compressed yeast starting material can be used and the yeast needs to be dried quickly.

Example 3

A yeast suspension with the following properties is used: dry matter content 185 g / liter; Protein content ($ N χ 6.25) on a dry basis, $ 54.4; Phosphorus content as Ρο ^ κ »based on dry matter, $ 3.25>. The yeast is propagated under such conditions that maximum activity is achieved when fresh. The yeast is treated in the same way as in Example 1 using the same amount of wetting agent. The product obtained has the following properties: dry matter content 93.0 ^; Protein content ($ N χ 6.25) on a dry basis, $ 54.5; Phosphorus content as Pp ^ S 'based on dry matter, $ 3.26; Gas generation according to test B 560 ml.

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Example 4

Three yeast suspensions produced by the yeast propagation under conditions which give maximum activity in the fresh state are obtained in the same manner as in Example 1 get extracted using the same amount of wetting agent. Active, dried yeasts are obtained with the following properties:

fo dry
wet Protein content
(JON χ 6.25)
based on
the dry
Dimensions Phosphorus content
based on
the dry
Dimensions Determination
procedure Gas
procreation
(ml) 93.0
93.4
93.2 49.2
51.3
53.2 3.02
3.13
3.18 B ²
B ²
B ² 545
564
556

Example 5

The process of Example 1 is repeated with the modification that the drying is carried out in such a way that the temperature of the yeast is always 30 ^° C. during the drying. For this purpose, air is first blown from 100 ⁰ C by the yeast mass and then gradually lowering the air temperature during drying. The total drying time is 10 minutes. Analysis of the end product shows: dry matter content $ 92.4; Protein content ($ N χ 6.25) on a dry basis, $ 55.4; Phosphorus content as PgOc, based on the dry matter, $ 3.20> \ Gas generation naph test B ² 528 ml.

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Example 6

The procedure of Example 1 is repeated with the modification that first air of 16O C bubbled through the yeast mass and the air temperature is gradually lowered during the drying, whereupon taken that Üie temperature of the yeast is maintained below 40 ⁰ C. The total drying time is 8 minutes. The analysis of the final results: dry matter content 93.3 i> \ protein content (N $ χ 6.25), based on the dry matter, 52.4 ° i \ phosphorus content than PPPoE, based on the dry ·. mass, 3.15 f ⁰ ', gas generation according to test B 520 ml.

Example 7

The procedure of Example 4 is repeated with the modification that a mixture of glyceryl monostearate and as a wetting agent. Glyceryl distearate is used. The analysis of the end product shows: protein content ($ N χ 6.25), based on the dry matter, · 53.2 % phosphorus content as Pp ⁰ K »based on the dry matter, 3.16 % gas generation according to test B 521 ml.

Example 8

The procedure of Example 1 is repeated with the modification that instead of 1 weight ^ sorbitol monostearate 1.5 weight ^ Sorbitol monolaureate, both based on dry matter, is used will.

The following results are obtained using yeasts that have been grown in such a way that end products with different protein

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kept arising.

OK dry
Dimensions Protein content
(f ₀ N χ 6.25)
based on
the dry Phosphorus content
(# P ₂ ° 5 ⁾
based on
dier dry Gas generation
Test B ² Dimensions Dimensions 92.4 45.9 2.81 452 93.5 47.4 2.85 473 93.5 49.8 3.05 492, 93.5 51.3 3.12 '516 92.7 53.4 3.13 514 92.5 55.6 3.20 500 93.5 56.7 3.19 489 93.0
i 58.5 3.20 481

Example 9

The procedure of Example 1 v / iederholt with the modification that the sorbitol monostearate is replaced by 1 io methyl cellulose which is added to the compressed yeast before drying. The results obtained are shown in the table below.

OK dry
Dimensions Protein content
(/, N χ 6.25)
based on
the dry
Dimensions Phosphorus content
{$> P ₂ O ₅ )
based on
the dry
Dimensions Gas generation
Test B ² 93.6
93.0 51.6
52.6 3.06
3.09 493
500
t

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Example 10

To explain the baking properties of the yeast of the invention, comparative baking tests are carried out with a preferred embodiment of the product carried out.

The following yeasts are used for these investigations: A commercially available compressed yeast with a protein content ($ N x 6.25) of 46.1 ^c / o; a $ 30 dry matter content; and an activity of 408 (Test Ir) (Sample A).

A handelsübliche- compressed yeast with a protein content (N χ $ 6.25) of 52.5 ° i \ a dry matter content of 29.0%; and an activity of 595 (Test B ⁵ ) (Sample B).

The quick-dried, active yeast of the invention with a high protein content ($ N χ 6.25) of 52.6 <> \ a dry matter content of $ 93.4; and an activity of 516 (Test B) (Sample C).

For these investigations, 100 parts of flour, 53 parts of water, 2 parts of NaCl and yeast are mixed with one another. The active, dried yeast is mixed with the other ingredients without pre-soaking. 1.8 parts of compressed yeast are used. The amount of active, dried yeast (sample C) corresponds to the dry matter content of the pressed yeast. The mixtures obtained in this way are mixed for 15 minutes, taking care that the temperature of the dough is 26 ^° C.

First examination 30 minutes Second examination 25 minutes Intermediate examination 30 minutes Final examination 60 minutes

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The test temperature is 28-3O ⁰ G. The dough weight for each loaf is 890 g. After 30 minutes of baking at a temperature of 250 C, the volumes of the loaves are as follows:

Loaf made with sample A 2925 ml Loaf made with sample B 3540 ml Loaf made with sample C 3495 ml

From these values it can be seen that the baking properties of the active, dried high protein yeast product (Sample C) with those of the pressed yeast from which it was made, are comparable and far superior to those of fresh, low-protein yeast.

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Claims (26)

1956H6 claims 1. Active, dried baker's yeast, characterized by a dry matter content of at least 85 weight-56, a protein content (j'N x 6.25) of 45 - 60 ^c / °, based on the dry matter, and an activity value of 420 - 600, this value is determined according to a test method in which 480 mg of dried yeast are mixed with 100 g of flour in a mixer. Addition of 55 ml of a solution containing 2 g of KaCl are mixed, the mass is mixed 6 minutes at 28 C to a dough, the dough is kept in a water bath at 28 ⁰ C and the period of 10-175 minutes after the beginning of the Mixing generated gas amount in ml at 28 ⁰ C and 760 mm Hg is determined (test method B). 2. Active, dried baker's yeast according to claim 1, characterized in that that it contains one or more swelling agents and / or wetting agents. 3. Active, dried baker's yeast according to claim 2, characterized in that that it contains methyl cellulose or carboxymethyl cellulose as swelling agent. 4. Active, dried baker's yeast according to claim 2 or 3, characterized in that the amount of swelling agent is 0.5-5 fo, preferably 1-2 5 ^, based on the dry matter. 5. Active, dried baker's yeast according to claim 2, characterized in that that they use an ester, a saturated one, as a wetting agent or unsaturated fatty acid, a glycerol fatty acid 0 0 9838/1368 ester, a propylene glycol fatty acid ester, or a mixture of contains two or more of these compounds. 6. Active, dried baker's yeast according to claim 5, characterized in that that 'they use sorbitol monolaureate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monooleate, glyceryl monostearate, Contains glyceryl distearate, glyceryl monopalmitate or propylene glycol monostearate. 7. Active, dried baker's yeast according to claim 2, 5 or 6, characterized in that the amount of the wetting agent is 0.5 - 5 $, preferably 1 - 2 #, based on the dry matter . 8. Active, dried baker's yeast according to claim 1 to 7, characterized in that its protein content (^ N χ 6.25) is 48 - 54 % based on the dry matter. 9. Active, dried baker's yeast according to claim 1 to 8, characterized in that it has an activity value of 440-580, in particular from 480-580. 10. Active, dried baker's yeast according to claim 1 to 9, characterized in that it has a dry matter content of 90 95 Weight ^ has. 11. Process for the production of active, dried baker's yeast r ^ t an activity value of 420 - 600 according to ΑηβρΓμοΙι 1, 009838/1368 _ ₂₀ _ 1956H6 characterized in that fresh pressed yeast with a protein content ($ N χ 6.25) of 45-60? o, based on the dry matter, is comminuted into small particles and that these particles within a period of at most 120 minutes up to one Dry matter content of at least 85 wt ^ means of a drying gas stream to be dried, with the proviso that, during the drying treatment in a temperature range of 20 - 50 ⁰ C, preferably of 20 - are maintained 40 ⁰ C. 12. The method according to claim 11, characterized in that the drying time is less than 50 minutes, preferably less than 20 minutes. 13. The method according to claim 11 or 12, characterized in that that the temperature of the drying gas stream at the end of the drying treatment is lower than when it started. 14. The method according to claim 13, characterized in that the Temperature of the drying gas stream at the beginning of the drying treatment is not more than 160 ° C. 15. The method according to claim 11 to 14, characterized in that the pressed yeast in particles with a cross section of 0.2 - 2 mm is crushed. 16. The method according to claim 11 to 15, characterized in that that yeast filaments produced by extrusion are comminuted. 009838/1368 17. The method according to any one of claims 11 to 16, characterized in that that the protein content ($ N χ 6.25) of the starting material $ 48- $ 54 based on dry weight. 18. The method according to claim 1 * 1 to 17, characterized in that that the yeast has a dry matter content of 90-95% by weight is dried. 19. The method according to claim 11 to 18, characterized in that that the pressed yeast starting material is mixed with one or more swelling agents and / or wetting agents. 20. The method according to claim 19 »characterized in that as: Swelling agent methyl cellulose or carboxymethyl cellulose is used. 21. The method according to claim 19 or 20, characterized in that the amounts of swelling agents are 0.5-5 f °, based on the dry matter. 22. The method according to claim 19, characterized in that an ester of a saturated or unsaturated fatty acid, such as a sorbitol fatty acid ester, for example sorbitol monolaureate, sorbitol monopalmitate, sorbitol monostearate or sorbitol monooleate, a glycerol fatty acid ester, e.g. Glyceryl monostearate, glyceryl distearate or glyceryl monopalmitate, a propylene glycol fatty acid ester, for example propylene glycol monostearate, or a mixture of two or more of these compounds is used. 009838/1368 -22- 1956U6 23. 'The method according to claim 19 or 22, characterized in that the amount of wetting agent is 0.5-5 f °, preferably 1 2 fo, based on the dry matter. 24. The method according to claim 31 to 23, characterized in that that the yeast strain Ng 1777 is used as the starting material. 25. The method according to claim 11 to 24, characterized in that that the pressed yeast starting material by partial dehydration with a hypotonic solution and rapidly washing the solution from the yeast. 26. The method according to claim 11 to 25, characterized in that that the drying is carried out continuously. 009838/1368