Data Bases • Custom Term Papers • Free Term Papers • Free Research Papers • Free Essays • Free Book Reports • Plagiarism? Links • Top 100 Term Paper Sites • Top 25 Essay Sites • Top 50 Essay Sites • Search 97,000 Papers @ DirectEssays.com • Search 101,000 Papers @ ExampleEssays.com • Search 90,000 Papers @ MegaEssays.com Free Essays • Term Paper Sites • Chuck III's Free Essays • Free College Essays • TermPaperSites.com • My Term Papers • Get Free Essays • Essay World • Planet Papers	Search Lots of Essays Back to Subjects - Engineering enzymes in brewing industry enzymes in brewing industry Topic: Fermentation uses of enzymes in Brewing Enzymes are catalysts or proteins that are produced by a living cell, but in process are independent of the cell itself. There are two types of enzymes i.e Enzymes are long chains of amino acids held together by peptide bonds. They exist in all living cells, usually controlling the metabolic process whereby nutrients are converted into energy. Enzymes are also catalyst, this mean that enzymes can speed up chemical processes that would normally move very slowly. Enzymes unfortunately don’t last forever they have limited stability or lifespan when they have completed their function in the chemical reaction. Science shows that enzymes work on raw material. Fruit, cereal, milk, beer or wood are some typical products for enzymatic conversion. Enzymes are specific, they usually break down or synthesize one particular compound, and in some cases enzymes limit their actions to specific bonds in the compound with in which they react. An example gluconases is one of the many enzymes used in beer brewing. This enzyme is used in industrial applications of brewing beer and is a very efficient catalyst. It breaks down the wheat and converts the carbohydrates into sugars that speed up the reaction in the aspect of the beer’s fermentation. Enzymes need certain types of conditions to operate, these conditions are usually mild in the areas of temperature and acidity. Many enzymes function around 30º- 70ºC and their acidity are usually around neutral (ph 7). Enzymes are very important to industrial processes, enzymes they are energy saving and also protect the lifespan of equipment used in processes and also having to buy special equipment resistant to heat, pressure or corrosion. Industrial enzymes can be produced in an ecological way, one of the main ways enzymes can be produced industrially is to culture enzymes in vats. Man has been exploiting enzymes in nature unknowingly for centuries. Also for thousands of years the beer brewing processes of many countries has relied heavily on barley malt. In this period of time barley was malted without brewers understanding what happen to the barley during the malting process. The idea back then was good beer couldn’t be made without malted barley. The unknown fact of that time was that the most important difference between raw barley and malted barley was the enzymes present in the malted barley Enzymes in malt can be produced industrially, in some cases the industrially created enzymes are an improvement of the malt’s enzymes. Better in the sense that they are better conditioned or adapted to the conditions found in brewing. The quality of malt and also its enzymes content can vary. Industrial enzymes can allow the brewer’s batch to make up for malt’s deficiency or it can replace a quantity of the malt with cheaper raw material such a raw barley to cut down on costs. Beer production is a sequence of chemical engineering “ unit operations” the processes of brewing beer are as follows milling, boiling, fermentation and filtration/extraction. There are three steps in beer brewing: (1) preparation of the wort or liquid extract of the malt, (2) the conversion of this liquid extract which is called fermentation, (3) refining of fermented beer into salable/drinking beer. The process of brewing beer, is show in the plant design below which shows the sequence of action as the barley makes its way though the different stages to become a finished product which is great tasting beer. The design of plant below shows the process and the description of the enzymes in that process: Malted Barley, malting (enzyme: cytase, amylase, catalase) Hot water (preteolysis,amylases) Bottles, Cans, Kegs Hops Water Air Yeast Cold Wort Malting is the process that affects the softening of cell walls in the barley by using the enzymes “cytase” and hydrolysis of the protein in the grain. The enzyme cytase is very important in this process because there are other enzymes that cannot operate until cytase has done its job. Cytase although it is an enzyme, it can broken into groups can broken into separate enzymes namely: hydrolyzemannan, galatan, xylan, and araban. The nature of these enzymes is not known. Malting is not possible without oxygen, and oxygen during the mating process increases alcohol formation. Inadequate respiration is detrimental to enzyme formation. During the germination process in malting there is an increase of dehydrase an enzymes important to the respiration of barley. Oxidases are found in malt which are perioxidase, phenolases and catalase. The color of beer is due to the action of phenolases, this darkens the malt extract and is also due to non-enzymatic contact with air. Then is also amylase, an enzyme that binds to insoluble proteins and inactive particles. Amylase is used extensively in the mashing process. The mashing process is where the crushed barley is transferred to the mashing tanks, to prepare the barley for fermentation. Amylases are temperature sensitive enzymes, there are two types of amylases enzymes ; alpha amylase, and beta amylase. Beta amylases work along side its alphs counterpart, they break down carbohydrates in their most simple form which is glucose. The optimal temperature for the formation of maltose is result of the thermal activity of amylases is greatly decreases by boiling and the protective action of maltose on the enzymes. Alpha amylase produces polysaccharide sugars that survive at higher temperatures than beta amylase. It is common for beta amylase to break down before the alpha amylase since it has a higher heat tolerance thus making the life expectancy of the beta amylase shorter. This results in an malt extract that is richer in poly saccharides and dextrins. Proteolysis is another enzyme found in the mashing process. This enzyme is readily extracted using water. This enzyme is important to the process since it creates enough breakdown of protein to give the beer its flavor and also character. Proteolytic enzymes are a successful way of chillproofing beer, a process that allows the enzyme to digest the proteins in the finished product, when the temperature is changed from stable to extreme cold. The composition of the proteolysis is needed to provide the yeast with nutrients needed during fermentation At this point in the process the extracted is aerated to provide oxygen for fermentation of the product. Special yeast enzymes are added depending on the process of fermentation chosen. With fermentation being an exothermic process, when the yeast enzyme is S.Carlsbergenisis the temperature of the fermentation is between 8-9ºC it takes about 7-8 days for the fermentation of the malt extract to reach about 85% completion. S.Carlsbergenisis causes the beer batch to flocculate and settle at the bottom at the end of the fermentation process. The other enzyme the can be added the batch is S.Cerevisiae. This enzyme when added to the batch can accelerate the fermentation process, this enzyme operates at a higher temperature usually between 16-20ºC and the fermentation process takes place in about three days. In the cases of this enzyme when it is added to the batch it causes the batch particles to settle this time at the top of the batch. Fermentation in the beer brewing process can be problematic. It is possible for the fermented batch to get stuck, this happens when the yeast that is added to produce enzymes for the conversion of sugars other than glucose into glucose, the conditions of the enzymes(yeast) cannot consume or ferment the sugars that they would normally consume rapidly. This problem arises when too much corm sugar is added to increase the beer batch’s alcoholic content, to produced a high alcohol beer. When this happens the yeast strains become stressed and when weakened the yeast loses its ability to produce enzymes needed to convert the sugars. This can be corrected by addingenzymes to the fermenting beer. The enzymes should allow the enzymes beta amylases to breakdown to enable the conversion of sugars to glucose, which can still be produces by the yeast. This will start up the otherwise “stuck fermentation”. The enzymes containing beta amylases are needed to fix the situation only because glucose used by the yeast in this case, and only beta amylase can produce glucose. The carbon produced during fermentation can be later used to carbonate the beer in the final phase before bottling. The beer when it leaves the fermentation phase, it is called young or green beer. The beer contains suspended solids and the final quality of the beer has to be still developed. This phase is usually called secondary fermentation. This is where the beer is stored in special vats for weeks until fully pasteurized and then bottled or racked into kegs. The enzymes used in beer production have their various properties and are like workers who know their function in their various processes. In the cases of the enzymes phenolases and Amylase, these two enzymes are very important to the initial start of the processing of the malt barley. They provide the color and also the production of oxygen to keep the batch , oxygen is detrimental to the formations of enzymes that increase germination of the barley in the areas of malting and mashing of barley. The enzyme proteolysis provide the batch with enough soluble protein to breakdown the malting process give the beer many drinkers love its taste, body, and its flavor this here is the defining factor of any beer, the enzyme make the brand of beer distinct from all others. In the aspect of fermentation the beer batch inhibits the formation of alcohol due to the addition of yeast with allows the suspension of particles to take the beer to the final point of production. The process of beer production is long and drawn out, many consumers of beer many at times have no idea about the wonderful engineers called enzymes and the role that they play in a drink the world seems to love. Fermentation & Enzyme Technology. Vols 1, 2, Wang, Cooney Chemistry and Technology of Enzymes, Tauber Enzyme growth in relation to the brewing environment is very essential to the lifespan and productivity of enzymes. In the fermentation environment the calculation and the determination the enzymes ability to grow and synthesize in the barley extract is the main point where enzyme kinetics matters most. There are two factors that ensure the success of the batch in the fermentation process. First, there must be a good selection of yeast strains and also their mutation of strains. Second, the effects of the environment parameters for cell growth and product formation. Since Enzyme Kinetics is relatively induced by temperature. The mathematical determination of the growth of enzymes is: Dx /Dt = μx – άx In order to plot this information down on a chart/graph showing the growth rate of enzymes of the maximum growth rate at different temperatures using the Arrhenius equation to plot. The figure below shows the Arrhenius plot vs. absolute temperature for Enterobacter aerogenes & Candida utilis:- (Growth rate) μ = Ae (-Ea/RT) (Death Rate) ά = Ǻe (-Ea’/RT) Typical activation energies for enzyme growth are around 18-20 kcal/mol and the death of enzymes is usually around 60-70 kcal/mol. In enzyme kinetics the death rate energy is more temperature sensitive than the growth energy. Bibliography: References Fermentation & Enzyme Technology. Vols 1, 2, Wang, Cooney Chemistry and Technology of Enzymes, Tauber Word Count: 1905
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