UNIFERM. Baker s yeast.... natural baking!

Transcription

1 UNIFERM Baker s yeast... natural baking!

2 UNIFERM UNIFERM s roots date back to the year 1737 with the foundation of the yeast company R. Moormann. In 1975, UNIFERM, one of the largest producers of baker s yeast in Europe, emerged from the amalgamation of several yeast companies. Today, due to continuous growth and expansion of the product range, UNIFERM has become one of the top suppliers of bakery ingredients. The product range includes baker s yeast, butter shortening, improvers, premixes for bread and rolls as well as ingredients for pastry products. Our mission has not changed over the years: We supply our customers with fresh and high quality products. In pursuing this goal, UNIFERM has set up a quality management system. The company was the first German producer of baker s yeast to be certified according to DIN EN ISO The IFS higher level certificate also confirms our efforts in the fields of quality, safety, service and customer orientation. Satiety alone is no longer sufficient today - taste must become an experience. It is baker s yeast which makes bread, rolls and pastries tender and rich in vitamins. It also gives freshly baked goods their tempting smell and full flavor. Baker s yeast as a natural leavening agent is up-to-date and corresponds to today s consumer preferences.

3 Table of contents Seite 1. Yeast production Important facts at a glance Raw materials Fermentation Processing 6 2. Product format 9 3. Application of UNIFERM baker s yeast Quality - shelf life - leavening power Influence of salt on baker s yeast 13

4 1. Yeast production 1.1 Important facts at a glance Fermentation is the key process in the production of baker s yeast. Yeast cells are living microorganisms. This means all necessary nutrients have to be provided in optimal quantities. Different types of baker's yeast will originate depending on the type of nutrients available in the fermentation process. Ensuring their individual availability on a constant level requires many years of fermentation know-how. A computer supported control system regulates the sensitive data for best results. Simplified depiction of yeast production Raw materials Fermentation Yeast broth Liquid yeast Dewatering Tank truck Container Block/Compressed yeast Granulated yeast 3

5 1.2 Raw materials Molasses is the main raw material used in yeast fermentation processes. Molasses is a by-product from sugar production and consists mainly of sugar. During fermentation it is mainly used to feed the yeast cells with carbohydrates. The cells also need nitrogen for protein synthesis as well as minerals and vitamins. Both latter substances are already contained in high amounts in the raw material molasses so that only minor amounts have to be added separately. Sugar beets The use of modern, computer supported process controls allows for the optimal adjustment of the amount of nutrients for the yeast cells demand. This prevents needless environmental impacts. With a high amount of commitment and consciousness of the environment, UNI- FERM has succeeded in closing a raw materials cycle by optimal utilization of the molasses. In this way, the by-product from sugar manufacture turns into a raw material for new products such as baker s yeast, animal feed, fertilizers and biogas. Computer supported process control 4

6 UNIFERM production of baker s yeast Sugar Molasses Sugar beets Biogas Vinasse salt (fertilizer) Vinasse (animal feed) Baker s yeast 1.3 Fermentation During fermentation, oxygen is continuously added to the yeast broth, which is the entire content of the fermenter, to ensure the proper multiplication of the yeast cells and to optimize the process. Foam develops during this process and extracts from vegetable oils are used to impede the foam development. In accordance with our environmental awareness, we use only those oil fractions which have a foam-retarding effect. In this way the application amount is reduced to about 1/10 of the original quantity. The quality and with that the properties of the baker s yeast are not only dependent on the quality of the raw materials but also on the processing parameters during the multiplication (fermentation). Besides comprehensive raw materials tests, the temperature management and the supply of 5

7 nutrients available during the fermentation are decisive for the leavening power and the shelf life of the baker s yeast. UNIFERM uses the latest technologies for the monitoring and maintenance of all decisive processing parameters to ensure the highest product quality. After the multiplication of the yeast cells - biologically called budding - is concluded, the yeast is separated from the non-fermentable molasses components by centrifugation. The cream yeast produced this way is stored in large tanks for further processing. 1.4 Processing The cream yeast is processed into three different forms: liquid yeast, block or compressed yeast and granulated or crumbled yeast. Liquid yeast The cream yeast is directly used as liquid yeast. It is pumped from chilled storage tanks into dispatch containers or tank trucks which have already been cleaned and sterilized. Block or compressed yeast In order to obtain cake yeast, the liquid must be removed from the cream yeast. This also includes liquid inside the yeast cells. For that, water is extracted from the cells by applying an osmosic process. The cream yeast is mixed with common salt, which leads to the extracellular salt concentration increasing to a value that is higher than the one inside the cell. Dispatch container 6

8 Due to the natural tendency to equalize the concentration difference, the yeast cells release some liquid into the surrounding matrix. This process is called osmosis. Following this, rotary vacuum filters are used to remove the salty excess water from the salty cream yeast. When the salty water is removed, fresh water is added to flush out the salt residues between the yeast cells and discharge them with the water stream. Scrapers are then used to peel the dewatered and desalted yeast from the filter drums. The yeast is transported to the packaging machine (extruder) where it is pressed into strands which are cut into blocks and wrapped in special paper. Twenty blocks, each with 500 g of yeast or four blocks each with 2.5 kg of yeast are then wrapped in a special packaging material with defined water vapor permeability and placed in a special cardboard box. Rotary vacuum filter This special type of packaging allows for the discharge of condensed water and respiratory moisture into the environment. At the same time, it prevents the introduction of oxygen from the air which would activate the yeast and cause premature ageing. Packaging plant for compressed yeast 7

9 Granulated yeast Granulated or crumbled yeast is produced by pressing the dewatered and desalted yeast through perforated sheets located at the exit of the extruder. The granulated yeast is then immediately filled into 25 kg bags. The bags are closed by seams in order to keep the oxygen out. Packaging plant for granulated yeast 8

10 2. Product forms Block or compressed yeast In terms of quantity, block yeast is still the number one yeast format used in European bakeries, even though granulated and liquid yeast are also available on the market. It is universally applicable in bakeries of any size. Granulated or crumbled yeast Many producers of baked goods prefer granulated yeast because of larger batch sizes. It is packed in 25 kg poly bags. This type of yeast is the first step on the way to producing liquid yeast in the bakery as the granulated yeast can be dissolved in water before use. After that it can be dosed via weight or volume and added to the other ingredients. The use of granulated yeast is recommended, in particular, for bakeries with a weekly yeast consumption of more than 300 kg. Once opened, the contents of the bag should be immediately dissolved and used within one day. Liquid yeast For larger bakeries where the filling of the mixers is computer-controlled and fully automatic, the use of liquid yeast is more feasible. This type of yeast is supplied in special containers each holding 840 kg or in tank trucks. It is pumped from the container or storage tank to the mixers. The processing of liquid yeast requires initial investments in chilled intermediate storage tanks, feed lines including pumps and cleaning systems. The main benefits are simple handling, precise dosing and waste reduction. The investment needed is economically reasonable for bakeries with high yeast consumption. 9

11 3. Application of UNIFERM baker s yeast All product forms provided by UNIFERM - compressed, granulated and liquid yeast - are suitable for universal applications. This applies to all types of flour and premixes for traditional dough processing as well as for all different methods of proofing control. The change from the use of block yeast to granulated or liquid yeast is very simple. Based on the use of UNIFERM s compressed baker s yeast, we recommend the following method: UNIFERM granulated yeast Dissolve the contents of one bag (25 kg) with 30 l water in a yeast fermenter 25 kg granulated yeast is dissolved in 30 l water Replace 500 g of UNIFERM s compressed yeast with 1 liter dissolved granulated yeast Add dissolved granulated yeast to the other ingredients 10

12 4. Quality shelf life - leavening power Providing a uniform leavening power from batch to batch is one of the distinctive features of all UNIFERM baker s yeast forms. A proprietary standardization process makes sure that the addition of the same amount of yeast always results in a constant volume of the baked item. Standardized high leavening power for uniform baked goods all year long Another advantage is the shelf life of UNIFERM s baker's yeasts. Their high purity, secured by the strict implementation of hygiene measures during the fermentation stages and the packaging process, ensures a lower loss in leavening power until the end of shelf life. UNIFERM s baker s yeasts with their high purity maintain their leavening power 11

13 Last but not least, the taste of baked goods is also a decisive criterion. Here the selection of the yeast strain plays an important role. The strains used by UNIFERM produce large amounts of characteristic yeast flavours during the yeast fermentation and later during the proofing of the dough. These flavours are contained in the finished baked goods. High amounts of characteristic yeast flavours for more aroma and taste 12

14 5. Influence of salt on baker s yeast A direct contact between salt and yeast or the introduction of yeast in a saline solution causes the yeast cells to release cell liquid into the surrounding matrix. This effect (osmosis) is based on the different salt concentrations inside and outside of the cells. Yeast cells are surrounded by a semi-permeable cell membrane which allows water molecules to pass but not salt molecules (ions). Due to the different salt concentrations on both sides of the membrane, the yeast cells release cell liquid into the environment in order to achieve equilibrium. They shrink and may stop being active. The Petri dishes shown illustrate the liquefaction of baker s yeast under the influence of salt. Baker s yeast without salt Baker s yeast with salt If the contact between yeast cells and salt is very short or if the salt concentration is rather low, the yeast cells are not damaged. If water is available afterwards, the cells are capable of readjusting their water balance accordingly. With prolonged contact or too high salt concentration, the cells may be damaged and lose their activity. 13

15 The micrographs show yeast cells in different salt concentrations. Did you know that in certain cases the destruction of the cell membrane is deliberately promoted? One example is the salt-yeast process where yeast, salt and water are kept in a suspension for several hours. A portion of the yeast cells dies because of the influence of the salt. During this process glutathione, a yeast-inherent component is released. Glutathione has an effect comparable with the one of the amino acid cysteine. Up to a certain extent, it improves the dough properties and wheat dough becomes more pliable. Today, the salt-yeast process is rarely applied anymore because modern improvers are available for precise control of the dough properties. Yeast cells suspended in water Contrary to common belief, the destruction of the yeast cells through contact with salt does not affect the leavening power in the dough. The dead yeast cells are not able to multiply any more but the enzymatic systems of the yeast which split sugar molecules into CO2 and alcohol are still unharmed. Yeast cells suspended in saline solution 14

16 The illustration shows the leavening power of baker s yeast with different contact times between yeast and salt. Different contact times between salt and baker s yeast Volume in % (no contact = 100 %) no contact 30 min 60 min 24 h 15

17 If you would like to learn more about us or our product or if you would like to provide suggestions, compliments or criticism, please contact our service department. Phone +49 (0) 23 89/ Fermentation facility, Monheim 16

18 January 2010 UNIFERM GmbH & Co. KG Werne, Germany All rights reserved. Reproduction or copying of individual paragraphs of the text, tables, pictures or drawings is not permitted without written approval from UNIFERM.

19 UNIFERM GmbH & Co. KG PO BOX Werne Germany Brede Werne Germany Telefon +49 (0) / Telefax +49 (0) / Baking service hotline: +49 (0) /