CA2114265A1 - Instant dry yeast - Google Patents
Instant dry yeastInfo
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- CA2114265A1 CA2114265A1 CA002114265A CA2114265A CA2114265A1 CA 2114265 A1 CA2114265 A1 CA 2114265A1 CA 002114265 A CA002114265 A CA 002114265A CA 2114265 A CA2114265 A CA 2114265A CA 2114265 A1 CA2114265 A1 CA 2114265A1
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- yeast
- rehydration
- controlling agent
- ester
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Abstract
Abstract Instant dry yeast Instant dry yeast is improved by the addition of a rehydration controlling agent.
Description
2~1~26~
Gist-Brocades N.V.
Ini3tant dry yeast The present invention relates to an instant dry yeast composition, the production thereof and its use in bakery products and beverages.
The manufacture of yeast starts with a small sample of 5 a pure culture. This sample is used to inoculate the first of a series of fermentations in fermentors of successively increasing size. The first few are mildly aerated batch fermentations. Only the last two (or sometimes three) stages are performed using full aeration and incremental feeding of ~-10 molasses. These fed-batch fermentations are carried out in fermentors having a volume of 100 m3 or more. Fermentation time is typically in the range of 12-20 hours, in which some 10,000-30,000 kg of compre~sed yeast is produced.
I Further processing includes separating the yeast from j 15 the broth by centrifugation and washing which results in I yeast cream (17-23% (w/w) dry matter content).
The yeast cream may be processed into compressed yeast (27-33% (w/w) dry matter content) which is either sold as such or extruded and dried to produce active dry yeast (ADY) 20 or instant dry yeast (IDY) with moisture contents of 6-8%
¦ (w/w) and 2-8% (w/w), respectively.
¦ In the case of ADY, drying usually takes place in belt ! or rotolouvre (drum) dryers. For IDY production fluidized-¦ bed drying is commonly used. Drying of the yeast to a level 25 of about 20% water content involves only the evaporation of ~, free water. Further reducing of the moisture content involves the removal of a portion of the bound water from the yeast which may cause damage to the yeast cell membran~.
In US patent 3,843,800 and US 4,248,420 wetting agents such 30 as esters of saturated fatty acids of glycerol and/or fatty :1 .
- 2 - 2~
acid esters of propylene glycol are added to preserve the desired high direct leavening activity of the yeast during the drying step.
Dry yeast loses part of its leavening activity during 5 the drying process as well as during the rehydration procedure. Dry yeasts are still commonly used in the bakery trade because of their extended stability and because refrigeration is unnecessary. Dry yeasts are used in wine making to obtain a fast and reproducible fermentation 10 thereby minimizing the risk of failure of the natural fermentation. Moreover, the yeast is immediately available throughout the year.
Instant dry yeast (IDY) is the latest type of baker's yeast, introduced in the early 1970's (see for example US patent 3,843,800) a few years later followed by instant dry wine yeast (IWY), which can be seen as a special form of instant dry yeast. To obtain a high quality IDY, compressed yeast of relatively high protein content (42-60% (w/w)) must be dried in a quick-drying process. The leavening activity 20 of IDY under conditions of application is about 75-85% that of compressed yeast; the shelf life in a vacuum-sealed package is comparable to that of ADY.
IDY is presented typically in the form of very small rods that are highly porous and easy to rehydrate. On the 25 one hand, this allows immediate use, without prior rehydration. On the other hand, the high porosity gives easy access to water and oxygen (from air), which results in a rather rapid loss of activity upon exposure to atmospheric conditions. For satisfactory results, IDY should be used 30 within 3-5 days of opening the package. ~oreover, the high porosity of IDY makes it sansitive to extreme rehydration conditions.
IDY usually has a moisture content of 2-8% (w/w) and a protein content between 42 and 60% (w/w) on a dry matter 35 basis.
~ 3 ~ 211~
As with ADY, some manufacturers add antioxidants (e.y~
BHA) to their product for improved stability. Ascorbic acid may be added to IDY products to improve stability.
A problem encountered with ADY and IDY is the leakage s of yeast solids from the cells upon rehydration. This results in a loss of gassing power or a loss of capacity to produce ethanol. The various methods of adding yeast and mixing dough differ from country to country. Although for the more porous IDY the dry yeast shoud be mixed with flour before water is added, it often happens that the dry yeast is suspended in water together with other soluble additions before flour is added. Additives such as sugar, ~ -calciumpropionate and salt affect yeast performance, as does the water temperature. In countries with warm climates or 15 where bakers use high speed mixers with extra heat input, the water is cooled, for example by adding ice, to obtain proper dough temperatures after mixing. Under these conditions instant dry yeast comes in direct contact with the chilled water, thus redu~ing the yeast performance 20 substantially. In US-A-4,764,472 this problem is partly solved by the incorporation of 0.1 to 2% by weight of locust bean gum, gum ghatti and mixtures thereof, which prevents a loss of activity when water of about 20C is added. However, in practice, water of 15C or less, even sometimes a 25 water/ice mixture, is used and at such temperatures activity after rehydration is extremely low.
We have now surprisingly found that when 1.1 to 5%
(w/w, dry weight) of a rehydration controlling agent is incorporated in the dry yeast, the yeast is much better 30 protected against the loss of activity due to rehydration of the dry yeast at low temperatures. The present invention therefore provides a dry yeast composition having a moisture content of less than 8% (w/w), preferably 3 to 6% (w/w) and which comprises 1.1 to 5% (w/w) of a rehydration controlling 35 agent. The rehydration controlling agent has preferably a moisture content of less than 10%. When added these agents ;.
.
.. .... . . ., . .. . -. ... .. - ~ . . -~ 4 ~ 21~2~ ' are often suspended in water to improve the distribution in the yeast.
The rehydration controlling agent is responsible for a controlled rehydration (wetting) of IDY particles and the 5 individual yeast cells. This rehydration contxolling agent functions as an extra barrier for water penetration into the cells.
Preferably 1.5 to 3~ by weight and more preferably 2 to 3% by weight of a rehydration controlling agent is used.
10 Preferably the rehydration agent comprises at least 50~
(w/w) of an emulsifier, for example 55%, 60~, 65%, 70% or 75% (w/w).
Typical examples of rehydration contrslling agents are:
- esters of fatty acids such as fatty acid esters of sorbitan, e.g. sorbitan monolaurate, monopalmitate, monostearate or mono-oleate;
- acid esters of mono and/or diglyceride such as citric acid ester or diacetyltartaric acid ester;
- fatty acid esters of glycerol or polyglycerol, e.g.
glyceryl monostearate, glyceryl distearate or glyceryl monopalmitate, - fatty acid esters of propylene glycol e.g. propylene glycol monostearate;
- arabic gum;
- xanthan gum;
- yeast extract;
~ CMC (sodium carboxy methyl cellulose) - or mixtures of two or more of the above mentioned 30 compounds.
We have found that the addition of the rehydration controlling agents according to the invention substantially protects the dry yeast against a loss of activity when water of 15C, even 10C or less is added to the yeast.
The rehydration controlling agent is added before the final drying step when the yeast is still wet. The yeast is thus protected during this drying step, there~y preserving ~ 5 ~ 21 ~2~i~
the desired high leavening activity of the yeast. When the yeast is mixed in the flour, gassing power under standard conditions is unaffected.
Surprisingly, when the yeast was rehydrated in water, 5 the performance of the instant yeast improves substantially~
The greatest improvement is attained at the lowest temperature.
The present invention further provides a method for preparing a dry yeast composition which comprises drying 10 yeast in the presence of 1.1 to 5% (w/w) of a rehydration controlling agent. The present invention additionally provides a method of preparing bread which comprises incorporating into a dough a composition as claimed in any one of claims 1 to 7 and baking the dough.
It will be appreciated that the dough will contain besides the yeast, ingredients generally used in dough preparation.
Surprisingly it has been found that in a dough prepared with the yeast of the present invention the rate of 20 the gas production is increased and the bread volume of the baked product increased substantially.
The amount of rehydration controlling agent present in the yeast may be varied according to different application methods.
All publications and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application was specifically and individually indicated to be incorparated.
30 Performance of the yeasts prepared according to the present invention.
a. This test was carried out under optimal instant 3S yeast conditions.
300 mg of instant dry yeast was mixed with 62.5 g o~
flour. After addition of 34.4 ml of a solution containing 1.25 g of NaCl, the mass is mixed for 6 minutes at 28 a C into ;
- 6 2~14~
a dough and placed in a water bath at 28C. The voluma of gas produced within the period from 10 to 175 minutes after the start of mixing was determined in ml at 28C and 760 mm Hg.
bl. Identical to (a) except the yeast was wetted as a monolayer of particles on a water surface by means of a small funnel in an erlenmeyer-flask at 35C, thus allowing every particle to come directly into contact with water. The test was therefore carried out under maximum rehydration 10 conditions.
b2. Identical to (bl) with water temperature of 20C.
b3. Identical to (bl) with water temperature of 10 ~C.
Example 1 Experiment 1:
The tests (Examples 1 to 5) were carried out using fresh baker's yeast, a normal cultivation of strain 210 Ng, 20 CBS 406.87. This product has a moisture content of approximately 68% and a protein content of approximately 50%
on dry weight. This block yeast was compresssed to reduce extracellular moisture content to 66%. ~ `
This yeast was crumbled and mixed with 0.25% of the 25 rehydration controlling agent Span-60TM (sorbitan monostearate) (on basis of total dry weight) using the following procedure:
The Span-60TM was melted at 65~C and suspended in water at 60C using a high sheer laboratory mixer. This 30 emulsion was added to compressed baker's yeast up to a content of 0.25~ on total dry weight.
The combination was then extruded three times through a screen with holes of 0.8 mm to form rod-shaped j particles, containing the rehydration controlling agent 35 properly distributed.
,,;,` , " , ` . : . ; ~ ~ ~ , _ 7 _ 2 ~ ~2~
The product from this exercise was pressed ~inally through a screen with holes of 0.8 mm to form again rod-shaped particles.
The drying of this product was performed in a s laboratory scale fluid bed-dryerl consisting of a conical glass tube built on an air 5Upply system, fenced by an appropriate screen to create a calm fluidisation pattern.
The air supply system consisted of a two way control valve/
leading air partly through an electrical heaking section. By 10 means of this control valve a constant outlet air temperature of 39C was maintained during the drying. The airflow was set at a superficial speed of 1.6 m/s at the bottom of the conus.
The airflow was stopped as soon as the inlet-air 15 temperature had reached a temperature of 45C.
The product was collected and packed in sachets under vacuum for analysing.
ExT~eriment 2 As described in test 1, but with the Span-60 constituting 0.50% of the total dry matter.
Experiment 3 As described in test 1, but with the Span-60TM
25 constituting 0.75% of the total dry matter.
Experiment 4 As described in test 1, but with the Span-60TU
constituting 1.0% of the total dry matter.
Experiment 5 As described in test 1, but with the Span-60TM
constituting 1.50% of the total dry matter.
35 Experiment 6 As described in test 1, but with the Span-~OTM
constituting 2.0% of the total dry matter.
8 - 2~ 1~2 Experiment 7 As described in test 1, but with the Span-60 constituting 3.0% of the total dry matter.
Results in gassing power of ~xam]ple 1:
, ~ _ , .
AdditionResult Resu:Lt Result Result test a test bl test b2 test b3 (ml) (ml) (ml) (ml) ¦Span-60T~ 0.25% 283 173 83 29 ¦Span-60TM 0.5%290 207 130 69 ¦
10 ¦Span-60TU 0.75% 290 223 159 85 ¦Span-60T~ 1.0%300 227 170 88 i I
¦Span-60TU 1.5%304 246 197 122 ¦
¦Span-60TU 2.0%303 249 189 123 ¦
¦Span-60T~ 3.0%298 248 201 129 ~xample 2 The experiment was carried out in a manner identical to Example 1, but with a commercially available citric acid ~ -20 ester o~ glycerine monostearate (CGM) as rehydration controlling agent.
Results in gassing pow~r of Example 2:
Addition Result Result Result ¦ Result ll test a test bl test b2 ¦ test b3 ¦¦
(ml) (ml)(ml) ¦ (ml) l , 25 ¦ CGM 0.25%288 174 96 ¦ 37 CGM 0.5% 290 193 128 ¦ 54 CGM 0.75% 297 215 146 ¦ 71 CGM 1.0% 300 225 165 ¦ 93 ~ CGM 1.5% 303 241 181 1 98 i l 11 30 I CGM 2.0% 307 233 189 ¦ 109 l CGM 3.0% 310 249 199 ¦ 121 9 21~2~
~xample 3 Identical to experiment 1 of Example 1 except for the concentration of rehydration controlling agent being Span-5 60TU at a final concentration of 1.0% and an extra additionof yeast extract powder to a final concentration of 2.0%.
Example ~
Identical to experiment 1 of Example 1 except for the concentration of rehydration controlling agent being Span-60~M at a final concentration of 1.0% and xanthane gum solution to a final concentration of 1.4%. ~ -15 Example 5 Identical to experiment 1 of Example 1 except for the concentration of rehydration controlling agent being Span-60TU at a final concentration of 1.0% and sodium carboxy :~ :
20 methyl cellulose to a final concentration of 1.0%.
Results in gassing power of Example 3 to 5. ~ ~-Addition Result Result Result Result test a test bl test b2 test b3 l (ml) (ml) (ml) (ml) .
l Span-60TM 1.0% + low 298 244 229 133 25 1 salt yeast extract I .
2.0% (d.m.) ::
Span-60TM 1.0% + 308 282 246 157 xanthane gum 1.4%
(d.m.) .
30 l Span-60TM 1.0% + sodium 299 261 213 151 carboxy methyl cellulose 1.0% (d.m.) -lo- 211~
E~ample 6 Identical to experiment 4 of Example 1 except for the strain applied being 227 Ng, CBS 155.91 (deposited on March 5~ 1991)-Example 7 Identical to Example 6, except for the choice andconcentration of rehydration controlling agent being CGM at a final concentration of 2.5%.
Example 8 Identical to Example 6, except for the choice of rehydration controlling agent being a combination of 1.0%
Span-60TU and 1.0% sodium carboxy methyl cellulose dissolved as a 5% solution in water before mixing with the Span-60 emulsion.
Results Example 6, 7, and 8 _ __ Addition Result Result test a test b3 (ml) (ml) span-60TM 1.0% 325 87 CGM 2.5% 324159 ¦
Span-60TM 1.0% + sodium 319 146 carboxy methyl cellulose 1.0% (d.m.) E~ample 9 Identical to experiment 4 of Example 1, except for the strain applied being 237 Ng, CBS 158.86 (deposited on March 25, 1986) a sugar resistant type of strain.
~o Contrary to Examples 1 to 8 the gas performance tests with the samples of Example 9, 10 and 11 were carried out applying an extra addition of 10% sugar on flour weight.
2 ~ 2 ~
Examplo 10 Identical to Example 9, except for the choice and concentration of rehydration controlling agent being CGM at a final concentration of 2.5%. .
~xampl~
Identical to Example 9, except for the choice of rehydration controlling agent being a combination of Span-60T~ and sodium carboxy methyl cellulose as in 10 Example 8.
Results Example 9, 10 and 11 Addition Result Result test a test b3 (ml) (ml) l Span-60TM 1.0% 270 59 ~:
CGM 2.5~ Z68 89 Span-60TM 1.0% + sodium271 92 carboxy methyl cellulose ¦ :
¦1.0% (d.m.) E~ample 12 In one type of baking trial producing French batard type of bread (method I) 3000 g wheat flour having a temperature of 20C, 1.75% salt, 1% Unipan Plus~ ~bread 25 improver, Gist-brocades), and 0.45~ instant dry yeast of 227 Ng strain (CBS 155.91), containing varying contents of rehydration controlling agent being CGM, are mixed by hand in the bowl of a Phebus mixer. Afterwards 56% water having a temperature of 32C is added and kneading starts (2 minutes . 30 at speed 1 and 18 minutes at speed 2). The dough temperature ~ is 27C. The dough is given a first proof of 15 minutes in a i proofing cabinet at 30C and 85% RH. Afterwards the dough is I divided into 12 pieces of 350 gO These pieces are moulded J and given an i.ntermediate proof of 15 minutes at 30C and 35 85~ R5. A~ter this stage the pieces sre again moulded, - 12 - 21~2'~
shaped, and givan a final proof of 110 minutes at 30C and 85% RH. Afterwards the fully proofed doughs are brought into the oven and baked at 240C for 25 minutes.
In a second type of baking trial producing French 5 batard type of bread (method II)y 3000 g wheat flour having a temperature of 42C, 1.75% sal1:, 1% Unipan Plus~ (bread improver, Gist-brocades) are introduced in the bowl of the Phebus mixer. 0.45% Instant dry yeast of 227 Ng strain, containing varying contents of rehydration controlling agent 10 being CGM, is spread over the surface of this mixture.
Afterwards 56% water having a temperature of 4C is poured out over the surface and mixing starts with 2 minutes at speed 1 and 28 minutes at speed 2 to reach the dough temperature of 27%. Dough handling, fermentation and baking 15 procedure is the same as described above, only the final proof time is varying. Final proof time is determined by putting 45 g of dough (after first and second proof) in a standardized measuring cylinder and let it rise to a fixed height of 10 cm.
In both methods, after cooling down to room temperature, loaf volumes are obtained by the rapeseed displacement method. Results are shown in the Table hereinbelow. Loaf volumes are an average of volume measurements of 4 loaves of bread.
From this Table it is clear that in method I, using flour of 20~C and water of 32C, an increase in loaf volume is seen after introducing instant yeast containing a higher rehydration controlling agent.
This result corresponds to the gassing results shown 30 in Example 2.
Breadmaking according to method II leads to shorter final proof times and somewhat higher loaf volumes in those cases where instant yeast is used having a higher ¦ rehydration controlling agent.
.
2 g ~ :
Loaf volumes of Example 12 , . .
Method I Method II
addition Loaf volume Final proof Loaf volume l (ml) time (min.) (ml) C&M 1.0% 1460 160 1336 :
CGM 1.5% 1472 150 1393 ~::
CGM 2.0% 1514 _ 135 1419 ~GM 3.0% 1563 135 1377 :~ :
As a consequence of the shorter final proof times the overall bread quality is improved: a better break and shred of the crust and a fin~r texture of the crumb.
Gist-Brocades N.V.
Ini3tant dry yeast The present invention relates to an instant dry yeast composition, the production thereof and its use in bakery products and beverages.
The manufacture of yeast starts with a small sample of 5 a pure culture. This sample is used to inoculate the first of a series of fermentations in fermentors of successively increasing size. The first few are mildly aerated batch fermentations. Only the last two (or sometimes three) stages are performed using full aeration and incremental feeding of ~-10 molasses. These fed-batch fermentations are carried out in fermentors having a volume of 100 m3 or more. Fermentation time is typically in the range of 12-20 hours, in which some 10,000-30,000 kg of compre~sed yeast is produced.
I Further processing includes separating the yeast from j 15 the broth by centrifugation and washing which results in I yeast cream (17-23% (w/w) dry matter content).
The yeast cream may be processed into compressed yeast (27-33% (w/w) dry matter content) which is either sold as such or extruded and dried to produce active dry yeast (ADY) 20 or instant dry yeast (IDY) with moisture contents of 6-8%
¦ (w/w) and 2-8% (w/w), respectively.
¦ In the case of ADY, drying usually takes place in belt ! or rotolouvre (drum) dryers. For IDY production fluidized-¦ bed drying is commonly used. Drying of the yeast to a level 25 of about 20% water content involves only the evaporation of ~, free water. Further reducing of the moisture content involves the removal of a portion of the bound water from the yeast which may cause damage to the yeast cell membran~.
In US patent 3,843,800 and US 4,248,420 wetting agents such 30 as esters of saturated fatty acids of glycerol and/or fatty :1 .
- 2 - 2~
acid esters of propylene glycol are added to preserve the desired high direct leavening activity of the yeast during the drying step.
Dry yeast loses part of its leavening activity during 5 the drying process as well as during the rehydration procedure. Dry yeasts are still commonly used in the bakery trade because of their extended stability and because refrigeration is unnecessary. Dry yeasts are used in wine making to obtain a fast and reproducible fermentation 10 thereby minimizing the risk of failure of the natural fermentation. Moreover, the yeast is immediately available throughout the year.
Instant dry yeast (IDY) is the latest type of baker's yeast, introduced in the early 1970's (see for example US patent 3,843,800) a few years later followed by instant dry wine yeast (IWY), which can be seen as a special form of instant dry yeast. To obtain a high quality IDY, compressed yeast of relatively high protein content (42-60% (w/w)) must be dried in a quick-drying process. The leavening activity 20 of IDY under conditions of application is about 75-85% that of compressed yeast; the shelf life in a vacuum-sealed package is comparable to that of ADY.
IDY is presented typically in the form of very small rods that are highly porous and easy to rehydrate. On the 25 one hand, this allows immediate use, without prior rehydration. On the other hand, the high porosity gives easy access to water and oxygen (from air), which results in a rather rapid loss of activity upon exposure to atmospheric conditions. For satisfactory results, IDY should be used 30 within 3-5 days of opening the package. ~oreover, the high porosity of IDY makes it sansitive to extreme rehydration conditions.
IDY usually has a moisture content of 2-8% (w/w) and a protein content between 42 and 60% (w/w) on a dry matter 35 basis.
~ 3 ~ 211~
As with ADY, some manufacturers add antioxidants (e.y~
BHA) to their product for improved stability. Ascorbic acid may be added to IDY products to improve stability.
A problem encountered with ADY and IDY is the leakage s of yeast solids from the cells upon rehydration. This results in a loss of gassing power or a loss of capacity to produce ethanol. The various methods of adding yeast and mixing dough differ from country to country. Although for the more porous IDY the dry yeast shoud be mixed with flour before water is added, it often happens that the dry yeast is suspended in water together with other soluble additions before flour is added. Additives such as sugar, ~ -calciumpropionate and salt affect yeast performance, as does the water temperature. In countries with warm climates or 15 where bakers use high speed mixers with extra heat input, the water is cooled, for example by adding ice, to obtain proper dough temperatures after mixing. Under these conditions instant dry yeast comes in direct contact with the chilled water, thus redu~ing the yeast performance 20 substantially. In US-A-4,764,472 this problem is partly solved by the incorporation of 0.1 to 2% by weight of locust bean gum, gum ghatti and mixtures thereof, which prevents a loss of activity when water of about 20C is added. However, in practice, water of 15C or less, even sometimes a 25 water/ice mixture, is used and at such temperatures activity after rehydration is extremely low.
We have now surprisingly found that when 1.1 to 5%
(w/w, dry weight) of a rehydration controlling agent is incorporated in the dry yeast, the yeast is much better 30 protected against the loss of activity due to rehydration of the dry yeast at low temperatures. The present invention therefore provides a dry yeast composition having a moisture content of less than 8% (w/w), preferably 3 to 6% (w/w) and which comprises 1.1 to 5% (w/w) of a rehydration controlling 35 agent. The rehydration controlling agent has preferably a moisture content of less than 10%. When added these agents ;.
.
.. .... . . ., . .. . -. ... .. - ~ . . -~ 4 ~ 21~2~ ' are often suspended in water to improve the distribution in the yeast.
The rehydration controlling agent is responsible for a controlled rehydration (wetting) of IDY particles and the 5 individual yeast cells. This rehydration contxolling agent functions as an extra barrier for water penetration into the cells.
Preferably 1.5 to 3~ by weight and more preferably 2 to 3% by weight of a rehydration controlling agent is used.
10 Preferably the rehydration agent comprises at least 50~
(w/w) of an emulsifier, for example 55%, 60~, 65%, 70% or 75% (w/w).
Typical examples of rehydration contrslling agents are:
- esters of fatty acids such as fatty acid esters of sorbitan, e.g. sorbitan monolaurate, monopalmitate, monostearate or mono-oleate;
- acid esters of mono and/or diglyceride such as citric acid ester or diacetyltartaric acid ester;
- fatty acid esters of glycerol or polyglycerol, e.g.
glyceryl monostearate, glyceryl distearate or glyceryl monopalmitate, - fatty acid esters of propylene glycol e.g. propylene glycol monostearate;
- arabic gum;
- xanthan gum;
- yeast extract;
~ CMC (sodium carboxy methyl cellulose) - or mixtures of two or more of the above mentioned 30 compounds.
We have found that the addition of the rehydration controlling agents according to the invention substantially protects the dry yeast against a loss of activity when water of 15C, even 10C or less is added to the yeast.
The rehydration controlling agent is added before the final drying step when the yeast is still wet. The yeast is thus protected during this drying step, there~y preserving ~ 5 ~ 21 ~2~i~
the desired high leavening activity of the yeast. When the yeast is mixed in the flour, gassing power under standard conditions is unaffected.
Surprisingly, when the yeast was rehydrated in water, 5 the performance of the instant yeast improves substantially~
The greatest improvement is attained at the lowest temperature.
The present invention further provides a method for preparing a dry yeast composition which comprises drying 10 yeast in the presence of 1.1 to 5% (w/w) of a rehydration controlling agent. The present invention additionally provides a method of preparing bread which comprises incorporating into a dough a composition as claimed in any one of claims 1 to 7 and baking the dough.
It will be appreciated that the dough will contain besides the yeast, ingredients generally used in dough preparation.
Surprisingly it has been found that in a dough prepared with the yeast of the present invention the rate of 20 the gas production is increased and the bread volume of the baked product increased substantially.
The amount of rehydration controlling agent present in the yeast may be varied according to different application methods.
All publications and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application was specifically and individually indicated to be incorparated.
30 Performance of the yeasts prepared according to the present invention.
a. This test was carried out under optimal instant 3S yeast conditions.
300 mg of instant dry yeast was mixed with 62.5 g o~
flour. After addition of 34.4 ml of a solution containing 1.25 g of NaCl, the mass is mixed for 6 minutes at 28 a C into ;
- 6 2~14~
a dough and placed in a water bath at 28C. The voluma of gas produced within the period from 10 to 175 minutes after the start of mixing was determined in ml at 28C and 760 mm Hg.
bl. Identical to (a) except the yeast was wetted as a monolayer of particles on a water surface by means of a small funnel in an erlenmeyer-flask at 35C, thus allowing every particle to come directly into contact with water. The test was therefore carried out under maximum rehydration 10 conditions.
b2. Identical to (bl) with water temperature of 20C.
b3. Identical to (bl) with water temperature of 10 ~C.
Example 1 Experiment 1:
The tests (Examples 1 to 5) were carried out using fresh baker's yeast, a normal cultivation of strain 210 Ng, 20 CBS 406.87. This product has a moisture content of approximately 68% and a protein content of approximately 50%
on dry weight. This block yeast was compresssed to reduce extracellular moisture content to 66%. ~ `
This yeast was crumbled and mixed with 0.25% of the 25 rehydration controlling agent Span-60TM (sorbitan monostearate) (on basis of total dry weight) using the following procedure:
The Span-60TM was melted at 65~C and suspended in water at 60C using a high sheer laboratory mixer. This 30 emulsion was added to compressed baker's yeast up to a content of 0.25~ on total dry weight.
The combination was then extruded three times through a screen with holes of 0.8 mm to form rod-shaped j particles, containing the rehydration controlling agent 35 properly distributed.
,,;,` , " , ` . : . ; ~ ~ ~ , _ 7 _ 2 ~ ~2~
The product from this exercise was pressed ~inally through a screen with holes of 0.8 mm to form again rod-shaped particles.
The drying of this product was performed in a s laboratory scale fluid bed-dryerl consisting of a conical glass tube built on an air 5Upply system, fenced by an appropriate screen to create a calm fluidisation pattern.
The air supply system consisted of a two way control valve/
leading air partly through an electrical heaking section. By 10 means of this control valve a constant outlet air temperature of 39C was maintained during the drying. The airflow was set at a superficial speed of 1.6 m/s at the bottom of the conus.
The airflow was stopped as soon as the inlet-air 15 temperature had reached a temperature of 45C.
The product was collected and packed in sachets under vacuum for analysing.
ExT~eriment 2 As described in test 1, but with the Span-60 constituting 0.50% of the total dry matter.
Experiment 3 As described in test 1, but with the Span-60TM
25 constituting 0.75% of the total dry matter.
Experiment 4 As described in test 1, but with the Span-60TU
constituting 1.0% of the total dry matter.
Experiment 5 As described in test 1, but with the Span-60TM
constituting 1.50% of the total dry matter.
35 Experiment 6 As described in test 1, but with the Span-~OTM
constituting 2.0% of the total dry matter.
8 - 2~ 1~2 Experiment 7 As described in test 1, but with the Span-60 constituting 3.0% of the total dry matter.
Results in gassing power of ~xam]ple 1:
, ~ _ , .
AdditionResult Resu:Lt Result Result test a test bl test b2 test b3 (ml) (ml) (ml) (ml) ¦Span-60T~ 0.25% 283 173 83 29 ¦Span-60TM 0.5%290 207 130 69 ¦
10 ¦Span-60TU 0.75% 290 223 159 85 ¦Span-60T~ 1.0%300 227 170 88 i I
¦Span-60TU 1.5%304 246 197 122 ¦
¦Span-60TU 2.0%303 249 189 123 ¦
¦Span-60T~ 3.0%298 248 201 129 ~xample 2 The experiment was carried out in a manner identical to Example 1, but with a commercially available citric acid ~ -20 ester o~ glycerine monostearate (CGM) as rehydration controlling agent.
Results in gassing pow~r of Example 2:
Addition Result Result Result ¦ Result ll test a test bl test b2 ¦ test b3 ¦¦
(ml) (ml)(ml) ¦ (ml) l , 25 ¦ CGM 0.25%288 174 96 ¦ 37 CGM 0.5% 290 193 128 ¦ 54 CGM 0.75% 297 215 146 ¦ 71 CGM 1.0% 300 225 165 ¦ 93 ~ CGM 1.5% 303 241 181 1 98 i l 11 30 I CGM 2.0% 307 233 189 ¦ 109 l CGM 3.0% 310 249 199 ¦ 121 9 21~2~
~xample 3 Identical to experiment 1 of Example 1 except for the concentration of rehydration controlling agent being Span-5 60TU at a final concentration of 1.0% and an extra additionof yeast extract powder to a final concentration of 2.0%.
Example ~
Identical to experiment 1 of Example 1 except for the concentration of rehydration controlling agent being Span-60~M at a final concentration of 1.0% and xanthane gum solution to a final concentration of 1.4%. ~ -15 Example 5 Identical to experiment 1 of Example 1 except for the concentration of rehydration controlling agent being Span-60TU at a final concentration of 1.0% and sodium carboxy :~ :
20 methyl cellulose to a final concentration of 1.0%.
Results in gassing power of Example 3 to 5. ~ ~-Addition Result Result Result Result test a test bl test b2 test b3 l (ml) (ml) (ml) (ml) .
l Span-60TM 1.0% + low 298 244 229 133 25 1 salt yeast extract I .
2.0% (d.m.) ::
Span-60TM 1.0% + 308 282 246 157 xanthane gum 1.4%
(d.m.) .
30 l Span-60TM 1.0% + sodium 299 261 213 151 carboxy methyl cellulose 1.0% (d.m.) -lo- 211~
E~ample 6 Identical to experiment 4 of Example 1 except for the strain applied being 227 Ng, CBS 155.91 (deposited on March 5~ 1991)-Example 7 Identical to Example 6, except for the choice andconcentration of rehydration controlling agent being CGM at a final concentration of 2.5%.
Example 8 Identical to Example 6, except for the choice of rehydration controlling agent being a combination of 1.0%
Span-60TU and 1.0% sodium carboxy methyl cellulose dissolved as a 5% solution in water before mixing with the Span-60 emulsion.
Results Example 6, 7, and 8 _ __ Addition Result Result test a test b3 (ml) (ml) span-60TM 1.0% 325 87 CGM 2.5% 324159 ¦
Span-60TM 1.0% + sodium 319 146 carboxy methyl cellulose 1.0% (d.m.) E~ample 9 Identical to experiment 4 of Example 1, except for the strain applied being 237 Ng, CBS 158.86 (deposited on March 25, 1986) a sugar resistant type of strain.
~o Contrary to Examples 1 to 8 the gas performance tests with the samples of Example 9, 10 and 11 were carried out applying an extra addition of 10% sugar on flour weight.
2 ~ 2 ~
Examplo 10 Identical to Example 9, except for the choice and concentration of rehydration controlling agent being CGM at a final concentration of 2.5%. .
~xampl~
Identical to Example 9, except for the choice of rehydration controlling agent being a combination of Span-60T~ and sodium carboxy methyl cellulose as in 10 Example 8.
Results Example 9, 10 and 11 Addition Result Result test a test b3 (ml) (ml) l Span-60TM 1.0% 270 59 ~:
CGM 2.5~ Z68 89 Span-60TM 1.0% + sodium271 92 carboxy methyl cellulose ¦ :
¦1.0% (d.m.) E~ample 12 In one type of baking trial producing French batard type of bread (method I) 3000 g wheat flour having a temperature of 20C, 1.75% salt, 1% Unipan Plus~ ~bread 25 improver, Gist-brocades), and 0.45~ instant dry yeast of 227 Ng strain (CBS 155.91), containing varying contents of rehydration controlling agent being CGM, are mixed by hand in the bowl of a Phebus mixer. Afterwards 56% water having a temperature of 32C is added and kneading starts (2 minutes . 30 at speed 1 and 18 minutes at speed 2). The dough temperature ~ is 27C. The dough is given a first proof of 15 minutes in a i proofing cabinet at 30C and 85% RH. Afterwards the dough is I divided into 12 pieces of 350 gO These pieces are moulded J and given an i.ntermediate proof of 15 minutes at 30C and 35 85~ R5. A~ter this stage the pieces sre again moulded, - 12 - 21~2'~
shaped, and givan a final proof of 110 minutes at 30C and 85% RH. Afterwards the fully proofed doughs are brought into the oven and baked at 240C for 25 minutes.
In a second type of baking trial producing French 5 batard type of bread (method II)y 3000 g wheat flour having a temperature of 42C, 1.75% sal1:, 1% Unipan Plus~ (bread improver, Gist-brocades) are introduced in the bowl of the Phebus mixer. 0.45% Instant dry yeast of 227 Ng strain, containing varying contents of rehydration controlling agent 10 being CGM, is spread over the surface of this mixture.
Afterwards 56% water having a temperature of 4C is poured out over the surface and mixing starts with 2 minutes at speed 1 and 28 minutes at speed 2 to reach the dough temperature of 27%. Dough handling, fermentation and baking 15 procedure is the same as described above, only the final proof time is varying. Final proof time is determined by putting 45 g of dough (after first and second proof) in a standardized measuring cylinder and let it rise to a fixed height of 10 cm.
In both methods, after cooling down to room temperature, loaf volumes are obtained by the rapeseed displacement method. Results are shown in the Table hereinbelow. Loaf volumes are an average of volume measurements of 4 loaves of bread.
From this Table it is clear that in method I, using flour of 20~C and water of 32C, an increase in loaf volume is seen after introducing instant yeast containing a higher rehydration controlling agent.
This result corresponds to the gassing results shown 30 in Example 2.
Breadmaking according to method II leads to shorter final proof times and somewhat higher loaf volumes in those cases where instant yeast is used having a higher ¦ rehydration controlling agent.
.
2 g ~ :
Loaf volumes of Example 12 , . .
Method I Method II
addition Loaf volume Final proof Loaf volume l (ml) time (min.) (ml) C&M 1.0% 1460 160 1336 :
CGM 1.5% 1472 150 1393 ~::
CGM 2.0% 1514 _ 135 1419 ~GM 3.0% 1563 135 1377 :~ :
As a consequence of the shorter final proof times the overall bread quality is improved: a better break and shred of the crust and a fin~r texture of the crumb.
Claims (13)
1. A dry yeast composition having a moisture content of less than 8% (w/w) which comprises 1.1 to 5% (w/w) of a rehydration controlling agent.
2. A composition according to claim 1 wherein the rehydration controlling agent comprises at least one of - an ester of a fatty acid - an acid ester of a mono and/or a diglyceride - arabic gum;
- xanthan gum;
- yeast extract or - sodium carboxy methyl cellulose (CMC);
- xanthan gum;
- yeast extract or - sodium carboxy methyl cellulose (CMC);
3. A composition according to claim 1 or 2 wherein the ester of fatty acid is a sorbitan ester, a glycerol ester, a polyglycerol ester of a propylene glycol ester.
4. A composition according to claim 3 wherein the ester of a fatty acid is sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate or sorbitan mono-oleate, glyceryl monostearate, glyceryl distearate, glyceryl monopalmitate or propylene glycol monostearate.
5. A composition according to claim 2 wherein the acid ester of the mono and/or diglyceride is a citric acid ester or a diacetyltartaric acid ester.
6. A composition according to any one of the preceding claims which comprises from 1.5 to 3% (w/w), preferably 2 to 3% (w/w) of the rehydration controlling agent.
7. A composition according to any one of the preceding claims wherein the rehydration controlling agent comprises at least 50% w/w emulsifier.
8. A method for preparing a dry yeast composition which comprises drying yeast in the presence of 1.1 to 5%
(w/w) of a rehydration controlling agent.
(w/w) of a rehydration controlling agent.
9. A method according to claim 8 wherein the rehydration controlling agent is as defined in any one of claims 2 to 7.
10. A method of preventing loss of yeast activity during rehydration which comprises incorporating a rehydration controlling agent into the yeast during the drying thereof.
11. A method of preparing bread which comprises incorporating into a dough a composition as claimed in any one of claims 1 to 7 or 11 and baking the dough.
12. Use of a rehydration controlling agent as defined in any one of claims 2 to 7 for protecting the yeast during hydration to produce yeast with a moisture content of less than 8% (w/w).
13. Use of a composition according to any one of claim 2 to 7 for the preparation of a dough whereby water of 0 to 15°C is used.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP93200221.5 | 1993-01-27 | ||
| EP93200221 | 1993-01-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2114265A1 true CA2114265A1 (en) | 1994-07-28 |
Family
ID=8213593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002114265A Abandoned CA2114265A1 (en) | 1993-01-27 | 1994-01-26 | Instant dry yeast |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPH0739370A (en) |
| AU (1) | AU668000B2 (en) |
| CA (1) | CA2114265A1 (en) |
| FI (1) | FI940334A (en) |
| IL (1) | IL108273A (en) |
| NZ (1) | NZ250759A (en) |
| ZA (1) | ZA94574B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11421256B2 (en) | 2009-10-08 | 2022-08-23 | Dsm Ip Assets B.V. | Process for enzymatic hydrolysis of lignocellulosic material and fermentation of sugars |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11155559A (en) | 1997-11-26 | 1999-06-15 | Oriental Yeast Co Ltd | Instant dried yeast for frozen dough for bread |
| WO2008023442A1 (en) * | 2006-08-21 | 2008-02-28 | Kabusiki Kaisha Sanyoprecision | Long-term and normal temperature storage method for bacteria in spore form or microorganisms, biological tissues or cells or cell-derived substances, and reviving/culture method for bacteria or microorganisms, biological tissues or cells or cell-derived substances stored at normal temperature by drying or sealing |
| EP2028265A1 (en) * | 2007-08-21 | 2009-02-25 | Beldem | Compositions for the release and protection of instant active dry yeasts |
| NO2557151T3 (en) * | 2010-04-07 | 2018-03-03 |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU6577080A (en) * | 1979-11-19 | 1981-06-03 | Gist-Brocades N.V. | Process for the preparation of active dried microorganisms |
| AU7965791A (en) * | 1990-05-30 | 1991-12-31 | Ici Australia Operations Proprietary Limited | Rehydratable yeast composition |
-
1994
- 1994-01-05 IL IL108273A patent/IL108273A/en not_active IP Right Cessation
- 1994-01-24 FI FI940334A patent/FI940334A/en unknown
- 1994-01-25 AU AU53938/94A patent/AU668000B2/en not_active Ceased
- 1994-01-26 CA CA002114265A patent/CA2114265A1/en not_active Abandoned
- 1994-01-26 NZ NZ25075994A patent/NZ250759A/en unknown
- 1994-01-27 ZA ZA94574A patent/ZA94574B/en unknown
- 1994-01-27 JP JP6007689A patent/JPH0739370A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11421256B2 (en) | 2009-10-08 | 2022-08-23 | Dsm Ip Assets B.V. | Process for enzymatic hydrolysis of lignocellulosic material and fermentation of sugars |
Also Published As
| Publication number | Publication date |
|---|---|
| NZ250759A (en) | 1995-12-21 |
| ZA94574B (en) | 1994-09-13 |
| IL108273A0 (en) | 1994-04-12 |
| AU668000B2 (en) | 1996-04-18 |
| AU5393894A (en) | 1994-08-04 |
| FI940334A0 (en) | 1994-01-24 |
| FI940334A (en) | 1994-07-28 |
| JPH0739370A (en) | 1995-02-10 |
| IL108273A (en) | 1998-04-05 |
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| FZDE | Discontinued |
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