Enzymes: Difference between revisions

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An enzyme is a protein that facilitates a chemical reaction. Enzymes play an important role in every fermented beverage.

For beer production, grain is malted in order to increase the amount of enzymes. Enzymes active during the mash include α- and β-amylase, proteases, peptidases, β- (1,3)(1,4)-glucanases and lipases.^[1] The most important action of these enzymes is that during the mash they break down the starches in the grain into fermentable sugars. Brewers may sometimes add extra enzymes such as glucoamylase in order to further break down the complex sugars (dextrins). Hops also have enzymes that can break down dextrins.

During the mash, enzymes break down components in the malt (i.e. proteins and starch). This activity depends on various factors, but most importantly on the temperature. Each enzyme has its own optimal temperature. At higher temperatures, the enzymes denature, which is the unfolding of the enzymes' three-dimensional structure, making them inactive. Enzyme activity is also affected by pH. Enzyme activity is also affected by pH, and activity decreases at pH values higher or lower than each enzyme's respective optimal value, although the effect of pH is not as large as the effect of temperature. Enzyme activity lasts longer in thicker mashes than in thinner mashes.^[2]

Proteolytic enzymes in the mash and their optimal temperatures:^[2]

Endopeptidases (45-50°C)
Carboxypeptidase (50°C)
Aminopeptidase (45°C)
Dipeptidases (45°C)

Lipoxygenases (LOX) oxidize fatty acids to hydroxy fatty acids, which are precursors to staling compounds. These enzymes are formed during malting and activated during milling and mashing. LOX activity is enhanced with a low dough-in temperature and pH closer to 6.0.^[2] Much of the LOX is destroyed during kilning, moreso in darker malts. Things that reduce LOX activity:

Selecting a more kilned malt
LOX does not require oxygen, however it is inhibited by preventing oxygen (air) from contacting the milled grain
High dough-in temperature, high mash temperature, and short mash duration
A more coarse crush
Milling temperature?
Low pH value

In wine production, a group of enzymes known as pectinase is commonly added to improve clarity and extraction.

Microbes use a large variety of enzymes in order to grow, survive, and conduct fermentation. (See Fermentation.)

Some enzymes can have a negative impact (such as polyphenol oxidase in fruit) and we can take steps to inhibit their undesirable effects.

The action of enzymes is influenced by pH, temperature, and other factors. High temperatures will permanently disable enzymes because the protein structure becomes irreversibly distorted, preventing them from functioning.

References

↑ Szwajgier, D. "Dry and Wet Milling of Malt. A Preliminary Study Comparing Fermentable Sugar, Total Protein, Total Phenolics and the Ferulic Acid Content in Non-Hopped Worts." J. Inst. Brew. vol. 117, no. 4, 2011, pp. 569–577.
↑ ^a ^b ^c Kunze, Wolfgang. "3.2 Mashing." Technology Brewing & Malting. Edited by Olaf Hendel, 6th English Edition ed., VBL Berlin, 2019. p. 230.

[1] Szwajgier, D. "Dry and Wet Milling of Malt. A Preliminary Study Comparing Fermentable Sugar, Total Protein, Total Phenolics and the Ferulic Acid Content in Non-Hopped Worts." J. Inst. Brew. vol. 117, no. 4, 2011, pp. 569–577.

[kunzemashing-2] Kunze, Wolfgang. "3.2 Mashing." Technology Brewing & Malting. Edited by Olaf Hendel, 6th English Edition ed., VBL Berlin, 2019. p. 230.

[1]

[2]

@@ Line 5: / Line 5: @@
 For [[beer production]], grain is [[malting|malted]] in order to increase the amount of enzymes. Enzymes active during the mash include α- and β-amylase, proteases, peptidases, β-
 (1,3)(1,4)-glucanases and lipases.<ref>Szwajgier, D. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2011.tb00505.x "Dry and Wet Milling of Malt. A Preliminary Study Comparing Fermentable Sugar, Total Protein, Total Phenolics and the Ferulic Acid Content in Non-Hopped Worts."] ''J. Inst. Brew.'' vol. 117, no. 4, 2011, pp. 569–577.</ref> The most important action of these enzymes is that during the [[mashing|mash]] they break down the [[starch]]es in the grain into [[sugars|fermentable sugars]]. Brewers may sometimes add extra enzymes such as [[glucoamylase]] in order to further break down the complex sugars ([[sugars|dextrins]]). [[Hops]] also have enzymes that can break down dextrins.
+During the mash, enzymes break down components in the malt (i.e. proteins and starch). This activity depends on various factors, but most importantly on the temperature. Each enzyme has its own optimal temperature. At higher temperatures, the enzymes denature, which is the unfolding of the enzymes' three-dimensional structure, making them inactive. Enzyme activity is also affected by pH. Enzyme activity is also affected by pH, and activity decreases at pH values higher or lower than each enzyme's respective optimal value, although the effect of pH is not as large as the effect of temperature. Enzyme activity lasts longer in thicker mashes than in thinner mashes.<ref name=kunzemashing/>
 Proteolytic enzymes in the mash and their optimal temperatures:<ref name=kunzemashing>Kunze, Wolfgang. "3.2 Mashing." ''Technology Brewing & Malting.'' Edited by Olaf Hendel, 6th English Edition ed., VBL Berlin, 2019. p. 230.</ref>