DE3225970A1 - Process for the production of compressed yeast and dried yeast having improved activity or raising power in the acid environment and also the use of the yeast produced in the process for the production of bakery products - Google Patents

Abstract

Compressed yeast and dried yeast are produced by cultivation and treatment of yeast in a conventional manner, approximately 0.05-5 mg of thiamine hydrochloride (vitamin B1) per litre of cultivation substrate being added in the last stage of growth or in an earlier stage of growth. Compressed yeast or dried yeast produced in this manner is highly suitable for use in the production of bakery products, in particular sliced bread.

Description

Description.

The present invention relates to a method for producing Compressed yeast and dry yeast with improved activity or driving force in an acidic environment by cultivating and processing in the usual way as well as using the at Process produced yeast for the production of baked goods, in particular sliced bread.

Compressed yeast and dry yeast produced by the usual methods generally has a qute in unsweetened and sugared neutral doughs Activity or driving force, its fermentation activity in sour doughs in the presence of short-chain ones organic acids such as acetic acid, propionic acid and lactic acid is unsatisfactory. Below certain pH values, these acids inhibit the fermentation activity of the usual ones Yeast to a considerable extent.

When preparing many types of bread, however, you can use them at the same time The presence or use of the acids and yeast mentioned cannot be dispensed with. Propionic acid and salts thereof, which have fungicidal effects in the acidic pH range, are thus a frequently used mold protection agent in the bread industry. These Acid and the salts thereof are also part of many baking agents for bread is calculated for roasting. The production of a storable, calculated for roasting, Sliced bread on an industrial scale was only possible through the application of mold protection agents possible. Also for the preparation of unleavened bread Addition of calcium acetate or acetic acid to the dough to prevent so-called stringing recommended. Also in the production of a mixed bread containing rye flour, such as It is especially common in Germany that organic acids are added to the dough, or these are formed during the fermentation process.

The organic acids, especially acetic and lactic acids, improve the baking ability of rye flour considerably. Acetic acid and lactic acid are used in the production of these rye flour breads either through the bacterial flora, e.g. in the application of a mixture of yeast and sourdough, formed or the dough in In connection with the use of ready-made sourdough added directly.

The above problem is evident from DE-OS No. 2.810.601, and in this laid-open specification are also reported on tests that the effect of calcium = propionate, calcium acetate and 80% lactic acid added to the dough, the contains commercially available pre-yeasts. By adding 0.5% calcium propionate, 0.58 calcium acetate or 1% 80% lactic acid is a percentage reduction in activity of about 40, about 8% and about 20%, respectively.

The amounts added are in relation to the amount of wheat flour used (280 g), and the fermentation activity was calculated as the amount of CO 2 evolved Measured for 2 hours at 300C, the amount of CO 2 evolved with the corresponding Amount of C02 is compared, which during fermentation run for a dough without the addition of carboxylic acids or a salt thereof.

Corresponding attempts that the action of short-chain carboxylic acids point to the driving force of yeast (dough with 3% yeast), go from the book Die Yefen, Volume 2, "Backhefe und Bäckerei" 19 .., of the publishing house Hans Carl, Nuremberg, 1962, pages 722-723. From the above results it can be seen that lactic acid additives by up to 0.4% in relation to the flour weight, increase the driving force, but that the driving force is reduced by adding more than 0.68. But it is note that lactic acid has a stimulating effect on yeast when the Acid density is kept below low limits.

While lactic acid thus promotes the driving force when the addition below If certain limit values are maintained, the addition of 0.25% acetic acid occurs in the Relation to the flour weight, already a considerable inhibition of fermentation in the dough a.

Concerning propionic acid already happens with an addition of 0.1% a considerable reduction in fermentation activity, and must therefore be added of propionic acid or salts thereof in part with a view to preserving the produced Expect bread with prolonged fermentation times or the use of increased amounts of yeast.

In the tests described in DE-OS No. 2.810.601 with an additive of calcium propionate and calcium acetate, the pH was 6.6, while it rose in the test with lactic acid was 4.7. The inhibiting effect of the dough additives described on the The driving force of the dough can be further increased by reducing the pH value, and it should be noted that the pH can be around 4.0 in the sour dough.

If you use a dough composition that is used in practice applied approximately, and a commercial baking agent with approximately 10% propionate used, i.e. a baking agent for making toast, the reduction in the short-chain carboxylic acids of the driving force becomes even more significant.

A particularly strong reduction in fermentation activity occurs when used of dry yeast a. The use of dry yeast instead of fresh yeast, i.e. compressed yeast, was therefore earlier in this field of bakery production because of the lack of Fermentation activity of dry yeast in doughs with a high degree of acidity or in doughs with added Carboxylic acids not possible.

DE-OS No. 2.810.601 contains experiments in which the fermentation activity of commercial fresh yeast and instant dry yeast in a batter with a mold protection agent compares to the production of toast bread.

From the above results it can be seen that the fermentation activity drops by about 40% if you use dry yeast instead of compressed yeast in a dough, Besides the yeast, 1000 g of wheat flour, 590 g of water, 20 g of table salt, 40 g of fat and Contains 75 g baking agent with calcium propionate. The amount of yeast corresponded to 21 g yeast dry matter, and fermentation was carried out at 300C for 50 minutes.

DE-OS No. 2.810.601 relates to a process for the production of compressed yeast and dry yeast with improved leavening power in an acidic environment, where yeast is used breeds and processes in the usual way, but where it is in the last stage of propagation 0.1 - 10 g of aliphatic short-chain carboxylic acids are added per culture broth. According to the laid-open specification, a freshness prepared in this way has Compressed yeast has a high fermentation activity even in doughs with a high degree of acidity, and the Yeast can be converted into a durable dry yeast, which, like pressed yeast, is a has improved fermentation activity in doughs with a high degree of acidity.

It now turned out, surprisingly, that compressed yeast and dry yeast were included a corresponding or further improved Activity or driving force can be produced in an acidic medium in a process in which the yeast is more commonly used Wise bred and processed, but which is characterized in that one in the last stage of propagation or in an earlier stage of propagation pro Liter of cultivation substrate contains approximately 0.5-5 mg thiamine chlorohydrate (vitamin B1).

This partly creates a yeast with fermentation activity in doughs reached with a high degree of acidity, which is superior to the fermentation activity of pressed yeast, those with the addition of short-chain aliphatic carboxylic acids in the last propagation stage was achieved, and partly an increased yeast yield achieved in yeast production.

According to an embodiment of the method according to the invention fresh compressed yeast in particle form is used to produce an active dry yeast grinded, and the yeast particles formed are dried by drying air at 40-600C in up to 120 minutes to achieve a dry matter content in the yeast of at least 85% dried. The yeast is preferably after in a fluidized bed Addition of an emulsion of fat, emulsifier and water, dried. This will enables dry yeast to be produced while maintaining the increased fermentation activity, which characterizes the pressed yeast produced.

Further improved results in the manufacture of dry yeast is achieved when the yeast, after adding an emulsion of soybean oil, monoglyceride citrate, Calcium stearoyllactoyl = lactate and water is granulated and dried.

The invention is explained in more detail below with the aid of examples.

Example 1: Production of compressed yeast.

5,500 liters of tap water and 166 kg of gest (with a dry matter content of 27% corresponding to 44.82 kg of dry matter), which is the standard in Denmark Yeast is filled into a fermenter with a usable volume of 8,500 liters. Thereafter, 18.5 kg of diammonium hydrogen phosphate, 3.5 kg of magnesium sulfate, 0.25 g d-l desthiobiothin and 30 kg of sterile beet molasses added, which with water in 400 Balling has been thinned.

After aeration with 800 med Nm3 / h of sterile air, in the course of 16 hours 1,350 kg of sterile beet molasses were added, also in 400 Balling has been diluted, as well as 126 kg of 25% ammonia water. The ammonia water is in Relation to the flow of diluted beet molasses from the 4th to the 15th hour of fermentation added. The amount of molasses and ammonia is growing in exponentially increasing amounts fed by flow regulators controlled by a cam cup.

The molasses flow is controlled so that the ethanol content in the Fermentation liquid does not exceed 0.2%. The pH will be from the 4th fermentation stage controlled by the supply of sulfuric acid, the supply being controlled by a pH regulator is controlled. The pH is kept at 4.5-5.0. The foam development at fermentation is regulated by adding a defoaming agent.

At the end of the molasses feed, the amount of yeast has increased by around 1,400 kg been. The yeast is made by standing in the fermenter for 30 minutes with aeration at 300 Nm3 / h of sterile air matured. After that, the yeast from the fermented wort through Centrifugation separated. The yeast cream is mixed with cold water in an amount accordingly 4 times the volume of the yeast cream, washed, after which it is centrifuged and up to stored in a yeast cream tank, cooled to about 2 ° C, while stirring.

Yeast produced on a pilot plant like the one above, possesses the same fermentation properties as yeast, which is produced on a large scale is. After filtering off the yeast content of the yeast cream on a filter drum the Filtered pressed yeast can be used in a dough with a view to fermentation experiments. the PreXhefe contains around 27% yeast like the starting yeast.

Example 2: Production of pressed yeast treated with propionic acid.

Fermentation is carried out in the same way as in Example 1, but with the change that during fermentation (in the 10th fermentation hour) 2 x 4 liters Propionic acid can be added.

Example 3: Preparation of thiamine hydrochloride treated PreD yeast.

Fermentation is carried out in the same way as in Example 1, but with the change that at the beginning of the fermentation together with the nutrient salts and 12 g of thiamine hydrochloride are added to the Desthiobio = thin.

When mixed, 10 g of the samples 1, 2 and 3 yeast made with 280 g of wheat flour, 2.8 g of table salt, 2.8 g of sucrose and 160 ml of tap water to make a dough. The rising liquid was preheated (to about 350C) in such a way that the finished dough after one Stirring time of 5 minutes had a temperature of 300C. The dough was then in poured a bread pan, which is placed in an SJA device (Svenska Jäst AB) at 300C after which the carbon dioxide evolution in the dough was measured after 20 and 60 minutes became.

The opening attempts were then repeated with the change that the dough 0.2, 0.4 and 0.6% calcium propionate, based on the weight of the flour, was added.

The following results listed in Table 1 were achieved in the rising tests: TABLE 1 Comparison of the fermentation activity of compressed yeast, which is produced by adding propionic acid or thiamine hydrochloride during the cultivation and processing of the yeast, in a dough with 0%, 0.2% , 0.4% and 0.6% calcium propionate. Yeast dough without dough with 0.28 dough with 0.4% dough with 0.6% Her- addition Ca propionate Ca propionate Ca propionate adjusts ml C02 to ml 002 to ml C02 to ml 002 Ex. 20 min. 60 min. 20 min. 60 min. 20 plin, 60 min. 20 min. 20 min. 60 min 1 280 1,075 170 810 125 590 100 I 475 2 270 1,000 180 875 140 690 110 555 3 250 1,030 200 940 170 780 160 710 From the results shown in the table it can be seen that the calcium propionate additives to the dough with the untreated yeast cause an activity reduction of about 25%, about 45% and about 56%. When a propionic acid treated yeast is used, the activity drop can be limited to about 12%, about 31% and about 45%, and by using the thiamine hydrochloride treated yeast the activity reduction is further limited to about 9%, about 25% and about 31%, respectively , measured as the reduction in CO 2 evolution after a rise time of 60 minutes.

Example 4: Production of active dry yeast.

Yeast cream made according to Example 1 with a dry matter content of 180 g / l has been produced, was with a suspension of sorbitan monostearate or a corresponding wetting agent mixed in water in such an amount, that per ton of pressed yeast 3.3 kg sorbitan monostearate (or a corresponding wetting agent) were added. The suspension was to achieve compressed yeast with a dry substance salary of about 30% and a wetting agent content of about 1% filtered, in proportion related to the dry matter content.

The pressed yeast was extruded through a perforated plate, whose Openings were approximately 0.6 mm in diameter. This achieved Product turned to a dry matter content of approximately 92-95% by hot Dried air stream passed through the swirled yeast product. The air temperature varied during drying, where it was about 600C over the course of the first 30 minutes after which it decreased to about 400C over the next 30 minutes keeping the yeast temperature below 400C. The entire dry season was 60 minutes. The product thus obtained had a fine, granular structure and contained particles-with a length of about 2 mm and with a cross-section of 0.4 mm. An analysis of the product showed a dry matter content of 95.0%, a nitrogen content of 7.13% in relation to the dry matter content, and a phosphorus content of 3.12%, based on P205 in relation to the dry matter content. The product could easily be added to the flour for making a dough Add soaking immediately.

Example 5: Production of Propionic Acid Treated Active Dry Yeast.

Yeast cream was prepared as mentioned in Example 2 and then, as described in Example 4, dried.

Example 6: Preparation of thiamine hydrochloride treated active Dry yeast.

Yeast cream was prepared as stated in Example 3 and then, as described in Example 4, dried.

5 q of the dry yeast produced were mixed with 8 g of table salt, 2 g of sucrose, 280 g of wheat flour and 170 ml of water are mixed to make a dough that can with an attempt to open it was used. By rising in an SJA device for 1 hour at 300C a CO 2 evolution, as shown in Table 2 below, achieved.

TABLE 2 Comparison of the fermentation activity of active dry yeast obtained by adding propionic acid or thiamine hydrochloride during the cultivation and processing of the yeast in an a-dough (5 g dry yeast, 8 g sodium chloride, 2 g sucrose, 280 g wheat flour, 170 ml water) is made. Dry dough a-dough without a-dough not a dough with a dough with yeast her- addition of addition of addition of addition of put propionate 0.2% Ca-Pro = 0.4% Ca-Pro = 0.6% Ca-Pro = according to pionat pionat pionat example 60 min. 60 min. 60 min. 60 min. 4 740 520 400 300 5 670 560 450 360 6 750 700 600 520 From the results shown in Table 2, it can be seen that the calcium propionate additives to the dough cause activity reductions of about 30%, about 46% and about 59%, respectively. When using propionic acid treated yeast, the activity drop can be limited to about 16%, about 33% and about 46%, respectively, and by using thiamine hydrochloride the activity drop is about 7%, about 20% and about 31%, respectively, measured as the reduction the development of CO2 with a rise time of 60 minutes at 300C.

Claims (5)

Process for the production of compressed yeast and dry yeast with improved Activity or driving force in the acidic environment and the use of the in the process Yeast produced for the production of baked goods Patent claims 1. Method for Production of compressed yeast and dry yeast with improved activity or driving force in an acidic medium by growing and processing in the usual way, characterized in that that one is in the last stage of propagation or in an earlier stage of propagation Add about 0.55 mg of thiamine chlorohydrate (vitamin B1) per liter of growing medium. 2. The method according to claim 1 for the production of an active dry yeast, characterized in that fresh pressed yeast is ground in particle form, and that the yeast particles formed by drying air at 40-600C in up to 120 Minutes to achieve a dry matter content in the yeast of at least 85 wt. 3. The method according to claim 1 or 2, characterized in that the Yeast after adding an emulsion of fat, emulsifier and water in a fluidized bed is dried. 4. The method according to claim 1, 2 or 3, characterized in that the yeast after adding an emulsion of soybean oil, monoglyceride citrate, calcium stearoyl lactoyl lactate and water is granulated and dried. 5. The use of compressed yeast or dry yeast in the process according to any one of the preceding claims 1 to 4 for manufacture of baked goods, in particular sliced bread.