Maria Uusimaa Application Manager Vaisala Helsinki, Finland

Mastering the process and carbon dioxide measurements for fermentation

A speci c group of , largely medium.  e fermentation process itself unknown to the general public but typically takes place in a tank called a used in various industrial processes, are or fermentor, but the whole manufactured by a Finnish company. production process can be composed Roal Corporation produces these of multiple process steps that re ne the proteins for the needs of food, raw materials to the end product.  ese paper, baking, and textile industries.  e process steps include raw material treat- biological process utilized to produce the ments such as blending and sterilization is called fermentation. as well as end product processing such Roal produces enzymes in submerged as ltration, concentration, drying, and fermentation units.  e company is nally packaging. jointly owned by ABF Ingredients, a In the heart of the fermentation division of Associated British Foods, process - the bioreactor - the control of and Altia Corporation, a publicly held acidity and temperature of the growth beverage company that focuses on medium is important.  e constant and spirits and operates in the Nordic supply of nutrients as well as gases such and Baltic countries.  e plant is located as CO and O is also monitored. Oxygen in Rajamäki, Finland and it produces is the most important gaseous substrate enzyme products mainly for use in the in aerobic fermentation, while carbon textile industry, for example in cloth dioxide is the most important gaseous desizing, denim nishing or bio nishing. by-product of the process. In the adjacent pilot plant, new research projects for novel enzyme processes Enzyme manufacturing are carried out.  e person in charge of  e production of yeast and alcohols is Roal’s pilot plant is R&D Manager Dan a large part of the fermentation industry. Haglund. Besides this, it also produces , enzymes, and amino acids. Fermentation basics A growing eld of fermentation is  e souring of milk to yogurt, the rising enzyme manufacturing. Most of the of dough with yeast, or the conver- enzymes produced globally are used in sion of sugar to alcohol in making detergents. In the future, more enzymes or brewing are common everyday will be needed for example in the examples of fermentation. baking industry, which uses enzymes Fermentation is a chemical change in bread manufacturing. Enzymes are brought about by the action of micro- also produced for food and animal feed organisms. In industrial fermentation, as well as the pulp and paper industry. the term is used broadly to refer to the Enzyme manufacturers have to maintain growth of micro-organisms on a growth constant research activities, so that new

10 | Vaisala News 172 / 2006 A schematic of a .PUPS fermentor tank: CO "DJECBTF and O concentrations 1SFTTVSFJOEJDBUPS are measured from SFTFSWPJS the exhaust line of $FMMTPSOVUSJUJPO the fermentor. BEEJUJPO

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5FNQFSBUVSF SFDPSEFS BOEDPOUSPM R&D Manager Dan Haglund from ROAL states that Vaisala carbon diox- &YIBVTU ide transmitters require minimal MJOF maintenance, and minimize the down-

$0BOE0 time of the fermentation process. NFBTVSFNFOU enables removing undesired elements such as foam or excess humidity from "JSTVQQMZ the exhaust gas.  e carbon dioxide DPOUSPM concentration of the enzyme production applications for enzyme use are devel- production capacity, and better quality process is typically from 0 to 5% of CO, oped and the production of older enzyme of the end product. Using enzymes gener- in exceptional cases concentrations as generations is enhanced. ally requires minor investments. high as 10% of CO have been measured. In a fermentation process where mould What are enzymes? The pilot plant at Roal is elevated, the carbon dioxide concen- Enzymes are proteins composed of At the pilot plant at Roal, careful moni- tration is typically around 1 or 2% of CO. amino acids.  ey are produced by all toring of the fermentation process is  e oxygen concentration of the exhaust living organisms - in the fermentation essential.  e pH-value, temperature, gas also depends on the metabolism. industry by moulds or , but they dissolved oxygen, and carbon dioxide Often the metabolism consumes O as are not living organisms.  e enzyme are usually measured from the fermentor much as it produces CO.  e relation of production process requires a strictly broth.  e oxygen and carbon dioxide the volume of CO released to the volume controlled environment within the biore- levels are measured from the exhaust of O consumed is called the respiratory actor. In the fermentation process the gas.  e gas temperature is typically 25°- quotient (RQ). enzymes are produced in the microbial 30°C and the relative humidity is around At the Roal plant, the humidity of cells and then secreted into the fermen- 100%.  e exhaust gas may also contain the fresh air blown into the bioreactor is tation broth. Prior to the production , since the substance is used to measured with Vaisala humidity instru- fermentor, the serving as the control the pH levels of the fermentor ments. Carbon dioxide and oxygen are is built up in several broth. Also the humidity of the fresh air monitored with the Vaisala CARBOCAP® inoculum fermentors. blown into the fermentor is measured. Carbon Dioxide Transmitter GMT221  e demanding surroundings require and the Vaisala SPECTRACAP® Oxygen What are enzymes used for? reliable measurement instruments. Transmitter OMT355, respectively. Enzymes work in various industrial  e CO concentration of the enzyme  e Vaisala carbon dioxide trans- production processes breaking more production process is monitored in order mitter has been installed in the pilot complex compounds into simpler to get a picture of the state of the process. plant to measure the exhaust gas line ones. In baking, enzymes are used for  e level of CO is an indication of the with the aid of a eld-check adapter from example to increase baking volume, act metabolic activity of the mould or bacteria, a secondary line. A water trap and a foam as stabilizers, and extend the shelf-life and the information is used to control the removing trap are used since the exhaust of the product. Enzymes are used in the feed of new nutrient pulses to the process. gas is very humid and occasionally foam extraction of fruit juices in the beverage “ e correct level depends on the microbial rises into the exhaust tube.  e extremely industry and in wine making. In the and the fermentation process itself, robust Vaisala oxygen transmitter is animal feed industry, enzymes are used and it is a matter of experience to know installed directly into the exhaust tube. for improved animal feed conversion. In when a new nutrient pulse should be fed “ e Vaisala instruments have proved to the textile industry, enzymes are used for into the process”, says Dan Haglund, the be very reliable in the pilot plant.  ey bio nishing, cloth desizing, and denim R&D Manager of the pilot plant at Roal. It require minimal maintenance and mini- nishing.  e pulp and paper industry is essential to ensure that fresh air supply mize the downtime of the fermentation uses enzymes for bleaching, deinking, to the bioreactor is su cient to keep the process”, says Dan Haglund. and improved paper production. fermentation process on-going.  e use of enzymes in industries results Exhaust gas measurements are gener- in reduced chemical costs, increased ally taken from a secondary line, which

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