Malt enzyme

B.C.—beer brewing by malting procedure (malt enzymes)... 

Grits -malt enzymes m [MALTS AND MALTING] (Vol 15) -soybean and other oilseeds [SOYBEANS AND OTHER OILSEEDS] (Vol 22)... 

Table III Analysis of Malt Enzymes of Herta Barley...

Hopkins and coworkers have compared the action of malt a-amylase with that of bacterial amylase (from B. suhtilis). The bacterial enzyme closely resembled the malt enzyme in respect to the kinetics of the reaction and produced much the same products. 

Other enzymes are required to obtain good quality beer with good shelf-life. The major use of non-malt enzymes is an enzyme that is added to fermented beer to chillproof the beer. Beer is fermented and aged under chilled conditions. Almost all packed beer is filtered while cold to achieve clarity. In spite of the filtration steps beer becomes cloudy after it is packed, distributed and chilled again for serving. The cloudiness that develops is caused by formation of haze particles called chill haze which are the result of the interaction between peptides and polyphenol compounds. 

Coloured malt is produced by roasting of kiln-dried malt without prior saccharification at a temperature of 190-220°C. It is used to increase the colour of dark beers. The ground malt is dispersed in water, a process which also causes a hydrolysis of starch and other malt components through the malt enzymes. By means of filtration, these flavours are gained in a fermentable, clear solution which is then cooked for the flavourisation with hop. 

For the mash, the ground malt is combined with brewing water and partially degraded by the malt enzymes and solubilised. Approx. 8 hectolitres are needed for 100 kg of malt. Important for the composition of the wort, and thus for type and quality of the beer, are pH-value and temperature. The alpha-amylases of the malts show optimum efficiency at a temperature of 72-76°C and a pH-value of 5.3-5.8. The beta-amylases have their optimum between 60-65°C and a pH-value of 4.6, and the proteinases between 55-65°C and a pH-value of 4.6. Since wort has a neutral pH-value of approx. 6.0, there are no optimum conditions without the correction of pH-value. 

A convenient source of esterase for in vitro laboratory use is malt enzyme (diastase, J. P.) the application of which was described by Noguchi (N-672, N-673). Noguchi reported the successful hydrolysis of acetates at the IBa-, 17/3-, 20a-, 20/3-, and 21-positions (N-672). He also extended this method to 21-esters of other straight-chain aliphatic carboxylic acids (formate, butyrate, and caprylate), dibasic aliphatic hemiesters (hemisuccinate and hemitartrate) and JV-substituted amino acid esters (diraethylaminoacetate and diethylaminoacetate) (N-673). 17/3-Formate was hydrolyzed, t 17/3-propionate was not. 

The coarsely ground malt is dispersed in water. During this time, the malt enzymes hydrolyze starch and other ingredients. A clear fermentable solution, the so-called wort, is obtained by filtration. When boiled with added hops, the wort takes on the typical beer flavors. 

In the mashing step, the malt meal is made into a paste with brewing water (heatable mixing vessel) and partially degraded and solubilized with malt enzymes. 

Mashing Key process used by the brewing industry in which malt/enzymes are blended with the brewing adjuncts in the presence of water so as to optimize starch hydrolysis into dextrins, and fermentable carbohydrates and proteins into simpler soluble compounds. The process is usually performed at a controlled temperature profile to optimize starch conversion. 

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