Editing Enzymes
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An enzyme is a [[protein]] that catalyzes a chemical reaction, greatly speeding it up while not being consumed by the reaction. This allows enzymes to be active even in very low concentrations. Enzymes play an important role in the creation of all fermented beverages, and more generally, they are needed for all life processes.<ref name=kunzemashing/> As with all proteins, enzymes have particular temperature and pH ranges in which they function, and more narrow ranges in which the activity is considered optimal. | An enzyme is a [[protein]] that catalyzes a chemical reaction, greatly speeding it up while not being consumed by the reaction. This allows enzymes to be active even in very low concentrations. Enzymes play an important role in the creation of all fermented beverages, and more generally, they are needed for all life processes.<ref name=kunzemashing/> As with all proteins, enzymes have particular temperature and pH ranges in which they function, and more narrow ranges in which the activity is considered optimal. The effect of temperature is greater than the effect of pH. Knowing the optimal ranges can be helpful, but it must be realized that the enzymes will be active to some extent outside those ranges.<ref name=bsp/> Enzymes denature (the three-dimensional structure unfolds) at higher temperatures, rendering them inactive.<ref name=kunzemashing/> Enzymes tend to have a very specific substrate upon which they act, and therefore are often named after the substrate, adding "-ase" to the end.<ref name=fix>Fix G. [[Library|''Principles of Brewing Science.'']] 2nd ed. Brewers Publications; 1999.</ref> | ||
'''Coenzymes''': The action of many enzymes is tied to the presence of an additional non-protein component that binds with its structure. For example, bivalent metal ions (e.g. iron, magnesium, calcium) are often involved as coenzymes. | '''Coenzymes''': The action of many enzymes is tied to the presence of an additional non-protein component that binds with its structure. For example, bivalent metal ions (e.g. iron, magnesium, calcium) are often involved as coenzymes. | ||
'''Isoenzymes''': Enzymes that have different structures but catalyze the same reaction are called isoenzymes. Each isoenzyme may have different characteristics such as optimal temperature and pH ranges. Generally, most enzymes in living organisms have several isoenzymes. | '''Isoenzymes''': Enzymes that have different structures but catalyze the same reaction are called isoenzymes. Each isoenzyme may have different characteristics such as optimal temperature and pH ranges. Generally, most enzymes in living organisms have several isoenzymes. | ||
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** '''Cytase''' degrades cell wall structures.<ref name=fix/> | ** '''Cytase''' degrades cell wall structures.<ref name=fix/> | ||
=== Mashing === | ===Mashing=== | ||
During [[mashing]], a very large number of enzymes act simultaneously on the components of the grist under conditions that are far from optimal for many of them in terms of substrate concentration and accessibility, pH, and enzyme stability. Enzymes are progressively inactivated at different rates depending on the temperature, the pH, the presence of substrate and other substances (such as tannins and cofactors such as calcium ions) in solution.<ref name=bsp/> Starch, proteins, nucleic acids, lipids and other substances are degraded, usually by hydrolytic (cleaving) reactions, but other reactions, such as oxidations, also occur.<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.'' 2011;117(4):569–577.</ref> | During [[mashing]], a very large number of enzymes act simultaneously on the components of the grist under conditions that are far from optimal for many of them in terms of substrate concentration and accessibility, pH, and enzyme stability. Enzymes are progressively inactivated at different rates depending on the temperature, the pH, the presence of substrate and other substances (such as tannins and cofactors such as calcium ions) in solution.<ref name=bsp/> Starch, proteins, nucleic acids, lipids and other substances are degraded, usually by hydrolytic (cleaving) reactions, but other reactions, such as oxidations, also occur.<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.'' 2011;117(4):569–577.</ref> | ||
*Starch and sugar degradation (see [[Saccharification]], [[Starch]], [[Sugars]]) | |||
* Starch and sugar degradation (see [[Starch]] | |||
** '''α-amylase''' (optimal 72–75°C, pH 5.6–5.8) degrades starch and dextrins into smaller sugars by cleaving α-1,4-bonds.<ref name=esslinger>Krottenthaler M, Back W, Zarnkow M. Wort production. In: Esslinger HM, ed. [[Library|''Handbook of Brewing: Processes, Technology, Markets.'']] Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2009.</ref><ref name=adb/><ref name=kunzemashing/><ref name=bsp/> Rapid inactivation occurs at 78–80°C and above.<ref name=visser>Visser MJ. [https://core.ac.uk/download/pdf/37326474.pdf Evaluation of malted barley with different degrees of fermentability using the Rapid Visco Analyser (RVA).] University of Stellenbosch. 2011.</ref><ref name=adb/> | ** '''α-amylase''' (optimal 72–75°C, pH 5.6–5.8) degrades starch and dextrins into smaller sugars by cleaving α-1,4-bonds.<ref name=esslinger>Krottenthaler M, Back W, Zarnkow M. Wort production. In: Esslinger HM, ed. [[Library|''Handbook of Brewing: Processes, Technology, Markets.'']] Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2009.</ref><ref name=adb/><ref name=kunzemashing/><ref name=bsp/> Rapid inactivation occurs at 78–80°C and above.<ref name=visser>Visser MJ. [https://core.ac.uk/download/pdf/37326474.pdf Evaluation of malted barley with different degrees of fermentability using the Rapid Visco Analyser (RVA).] University of Stellenbosch. 2011.</ref><ref name=adb/> | ||
** '''β-amylase''' (optimal 60–65°C, pH 5.4–5.6) releases maltose from the ends of sugar chains by cleaving α-1,4-bonds.<ref name=esslinger/><ref name=adb>Narziss L, Back W, Gastl M, Zarnkow M. [[Library|''Abriss der Bierbrauerei.'']] 8th ed. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2017.</ref><ref name=kunzemashing/> Rapid inactivation occurs at temperatures of 65-70°C and above.<ref name=visser/><ref name=adb/><ref name=evans>Evans DE, Fox GP. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-2017-4707-01 Comparison of diastatic power enzyme release and persistence during modified Institute of Brewing 65°C and Congress programmed mashes]. ''J Am Soc Brew Chem.'' 2017;75(4):302–311.</ref> | ** '''β-amylase''' (optimal 60–65°C, pH 5.4–5.6) releases maltose from the ends of sugar chains by cleaving α-1,4-bonds.<ref name=esslinger/><ref name=adb>Narziss L, Back W, Gastl M, Zarnkow M. [[Library|''Abriss der Bierbrauerei.'']] 8th ed. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2017.</ref><ref name=kunzemashing/> Rapid inactivation occurs at temperatures of 65-70°C and above.<ref name=visser/><ref name=adb/><ref name=evans>Evans DE, Fox GP. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-2017-4707-01 Comparison of diastatic power enzyme release and persistence during modified Institute of Brewing 65°C and Congress programmed mashes]. ''J Am Soc Brew Chem.'' 2017;75(4):302–311.</ref> | ||
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** '''Glucoamylase''' (optimal 35–40°C) cleaves a single glucose unit from the end of any sugar chain (both α-1,4 and α-1,6 bonds).<ref name=Vriesekoop>Vriesekoop F, Rathband A, MacKinlay J, Bryce JH. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2010.tb00425.x The evolution of dextrins during the mashing and fermentation of all-malt whisky production.] ''J Inst Brew.'' 2010;116(3):230–238.</ref><ref name=guerra/> Its activity is virtually non-existent during mashing because of its very low optimal temperature. | ** '''Glucoamylase''' (optimal 35–40°C) cleaves a single glucose unit from the end of any sugar chain (both α-1,4 and α-1,6 bonds).<ref name=Vriesekoop>Vriesekoop F, Rathband A, MacKinlay J, Bryce JH. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2010.tb00425.x The evolution of dextrins during the mashing and fermentation of all-malt whisky production.] ''J Inst Brew.'' 2010;116(3):230–238.</ref><ref name=guerra/> Its activity is virtually non-existent during mashing because of its very low optimal temperature. | ||
** '''Invertase''' (optimal 50°C, pH 5.5) splits sucrose into glucose and fructose. Active up to 62–67°C.<ref name=adb/> | ** '''Invertase''' (optimal 50°C, pH 5.5) splits sucrose into glucose and fructose. Active up to 62–67°C.<ref name=adb/> | ||
*Protein degradation (see [[Protein]]) | |||
* Protein degradation | ** '''Endopeptidases''', which include '''metalloproteases''', '''cysteine proteases''', '''aspartic proteases''', and '''serine proteases''' (optimal 45–50°C, pH 3.9–5.5) over 40 different endopeptidase enzymes degrade proteins into peptides and free amino acids.<ref name=esslinger/><ref name=kunzemashing>Kunze W. Wort production. In: Hendel O, ed. [[Library|''Technology Brewing & Malting.'']] 6th ed. VBL Berlin; 2019. p. 230.</ref> | ||
** '''Endopeptidases''', which include '''metalloproteases''', '''cysteine proteases''', '''aspartic proteases''', and '''serine proteases''' (optimal 45–50°C, pH 3.9–5.5) over 40 different endopeptidase enzymes degrade proteins into peptides and free amino acids.<ref name=esslinger/><ref name=kunzemashing>Kunze W. Wort production. In: Hendel O, ed. [[Library|''Technology Brewing & Malting.'']] 6th ed. | |||
** '''Carboxypeptidases''' (optimal 50°C, pH 4.8–5.6) degrade proteins & peptides into free amino acids.<ref name=esslinger/><ref name=kunzemashing/> | ** '''Carboxypeptidases''' (optimal 50°C, pH 4.8–5.6) degrade proteins & peptides into free amino acids.<ref name=esslinger/><ref name=kunzemashing/> | ||
** '''Aminopeptidases''' (optimal 45°C, pH 7.0–7.2) degrade proteins & peptides into free amino acids.<ref name=esslinger/><ref name=kunzemashing/> Inactive during mashing. | ** '''Aminopeptidases''' (optimal 45°C, pH 7.0–7.2) degrade proteins & peptides into free amino acids.<ref name=esslinger/><ref name=kunzemashing/> Inactive during mashing. | ||
** '''Dipeptidase''' (optimal 45°C, pH 8.8) degrades dipeptides into free amino acids.<ref name=esslinger/><ref name=kunzemashing/> Inactive during mashing. | ** '''Dipeptidase''' (optimal 45°C, pH 8.8) degrades dipeptides into free amino acids.<ref name=esslinger/><ref name=kunzemashing/> Inactive during mashing. | ||
*Beta-glucan liberation and degradation (see [[Beta-glucans]]) | |||
* Beta-glucan liberation and degradation (see [[Beta-glucans | |||
** '''β-glucan solubilase''' (optimal 62–65°C, pH 6.8) releases high-molecular-weight matrix-bound β-glucans, increasing the amount in the wort.<ref name=esslinger/><ref name=sacher2/> | ** '''β-glucan solubilase''' (optimal 62–65°C, pH 6.8) releases high-molecular-weight matrix-bound β-glucans, increasing the amount in the wort.<ref name=esslinger/><ref name=sacher2/> | ||
** '''Endo-(1,3;1,4)-β-glucanase''' (optimal 48°C, pH 4.7) degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan.<ref name=esslinger/><ref name=jin>Jin YL, Speers RA, Paulson AT, Stewart RJ. [https://www.researchgate.net/profile/Robert-Speers/publication/296811873_Barley_b-glucans_and_their_degradation_during_malting_and_brewing/links/595a4f16458515a5406fc54e/Barley-b-glucans-and-their-degradation-during-malting-and-brewing.pdf Barley β-glucans and their degradation during malting and brewing.] ''Tech Q Master Brew Assoc Am.'' 2004;41(3):231–240.</ref> | ** '''Endo-(1,3;1,4)-β-glucanase''' (optimal 48°C, pH 4.7) degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan.<ref name=esslinger/><ref name=jin>Jin YL, Speers RA, Paulson AT, Stewart RJ. [https://www.researchgate.net/profile/Robert-Speers/publication/296811873_Barley_b-glucans_and_their_degradation_during_malting_and_brewing/links/595a4f16458515a5406fc54e/Barley-b-glucans-and-their-degradation-during-malting-and-brewing.pdf Barley β-glucans and their degradation during malting and brewing.] ''Tech Q Master Brew Assoc Am.'' 2004;41(3):231–240.</ref> | ||
** '''Endo-(1,3)-β-glucanase''' degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan, and may also help solubilize β-glucan.<ref name=muller>Muller R. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-53-0136 Factors influencing the stability of barley malt β-glucanase during mashing.] ''J Am Soc Brew Chem.'' 1995;53(3):136–140.</ref><ref name=kanbam>Kanauchi M, Bamforth CW. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2008.tb00332.x The relevance of different enzymes for the hydrolysis of β-glucans in malting and mashing.] ''J Inst Brew.'' 2008;114(3);224–229.</ref> | ** '''Endo-(1,3)-β-glucanase''' degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan, and may also help solubilize β-glucan.<ref name=muller>Muller R. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-53-0136 Factors influencing the stability of barley malt β-glucanase during mashing.] ''J Am Soc Brew Chem.'' 1995;53(3):136–140.</ref><ref name=kanbam>Kanauchi M, Bamforth CW. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2008.tb00332.x The relevance of different enzymes for the hydrolysis of β-glucans in malting and mashing.] ''J Inst Brew.'' 2008;114(3);224–229.</ref> | ||
** '''Endo-(1,4)-β-glucanase''' AKA '''cellulase''' degrades soluble high-molecular-weight β-glucan | ** '''Endo-(1,4)-β-glucanase''' AKA '''cellulase''' degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan.<ref name=muller/><ref name=kanbam/> | ||
** '''Exo-β-glucanase''' (optimal <40°C pH 4.5) degrades glucose from the ends of β-glucan.<ref name=esslinger/><ref name=kanbam/> | ** '''Exo-β-glucanase''' (optimal <40°C pH 4.5) degrades glucose from the ends of β-glucan.<ref name=esslinger/><ref name=kanbam/> | ||
*Phosphate liberation (see [[Phosphates]]) | |||
* Phosphate liberation (see [[Phosphates]]) | ** '''Phosphatases''' (optimal 50–53°C, pH 5.0) releases organic-bound phosphate, increasing inorganic phosphate in the wort.<ref name=esslinger/><ref name=sacher2>Sacher B, Becker T, Narziss L. [http://www.lowoxygenbrewing.com/wp-content/uploads/2017/04/pddvxvf.pdf Some reflections on mashing – Part 2.] ''Brauwelt International.'' 2016;6:392-397.</ref> Inactive at 62°C.<ref name=sacher2/> | ||
** '''Phosphatases''' (optimal 50–53°C, pH 5.0) releases organic-bound phosphate, increasing inorganic phosphate in the wort.<ref name=esslinger/><ref name=sacher2>Sacher B, Becker T, Narziss L. [http://www. | *Lipid degradation and oxidation (see [[Lipids]]) | ||
* Lipid degradation and oxidation (see [[Lipids]]) | |||
** '''Lipase''' (optimal 55–65°C, pH 6.8–7.0) degrades lipids & lipid hydroperoxides into glycerine plus free fatty acids, and/or hydroperoxides.<ref name=esslinger/><ref name=golston>Golston AM. The impact of barley lipids on the brewing process and final beer quality: A mini-review. ''Tech Q Master Brew Assoc Am.'' 2021;58(1):43–51.</ref><ref name=schwarzp>Schwarz P, Stanley P, Solberg S. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-60-0107 Activity of lipase during mashing.] ''J Am Soc Brew Chem.'' 2002;60(3):107–109.</ref><ref name=mashing>Evans E. [[Library|''Mashing.'']] American Society of Brewing Chemists and Master Brewers Association of the Americas; 2021.</ref> | ** '''Lipase''' (optimal 55–65°C, pH 6.8–7.0) degrades lipids & lipid hydroperoxides into glycerine plus free fatty acids, and/or hydroperoxides.<ref name=esslinger/><ref name=golston>Golston AM. The impact of barley lipids on the brewing process and final beer quality: A mini-review. ''Tech Q Master Brew Assoc Am.'' 2021;58(1):43–51.</ref><ref name=schwarzp>Schwarz P, Stanley P, Solberg S. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-60-0107 Activity of lipase during mashing.] ''J Am Soc Brew Chem.'' 2002;60(3):107–109.</ref><ref name=mashing>Evans E. [[Library|''Mashing.'']] American Society of Brewing Chemists and Master Brewers Association of the Americas; 2021.</ref> | ||
** '''Lipoxygenases''' (optimal 45–55°C, pH 6.3–7.0) oxidizes fatty acids into fatty acids hydroperoxides.<ref name=esslinger/><ref name=golston/><ref name=mashing | ** '''Lipoxygenases''' (optimal 45–55°C, pH 6.3–7.0) oxidizes fatty acids into fatty acids hydroperoxides.<ref name=esslinger/><ref name=golston/><ref name=mashing/> | ||
** '''Hydroperoxide lyase''' transforms lipid hydroperoxides through a series of steps into staling compounds such as trans-2-nonenal.<ref name=mashing/> | ** '''Hydroperoxide lyase''' transforms lipid hydroperoxides through a series of steps into staling compounds such as trans-2-nonenal.<ref name=mashing/> | ||
*Phenolic compound oxidation (see [[Phenolic compounds]], [[Oxidation]]) | |||
* Phenolic compound | ** '''Polyphenol oxidase''' (optimal 60–65°C, pH 6.5–7.0) oxidizes polyphenols.<ref name=esslinger/> | ||
** '''Polyphenol oxidase''' (optimal 60–65°C, pH 6.5–7.0) oxidizes polyphenols | *Non-specific oxidation (see [[Oxidation]]) | ||
** '''Peroxidase''' (optimal >60°C, pH 6.2) generates free radicals from various organic and inorganic substrates.<ref name=esslinger>Krottenthaler M, Back W, Zarnkow M. Wort production. In: Esslinger HM, ed. [[Library|''Handbook of Brewing: Processes, Technology, Markets.'']] Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2009.</ref> Requires [[iron]] coenzyme.<ref name=bsp/> | |||
** '''Peroxidase''' (optimal >60°C, pH 6.2) generates free radicals from various organic and inorganic substrates.<ref name=esslinger>Krottenthaler M, Back W, Zarnkow M. Wort production. In: Esslinger HM, ed. [[Library|''Handbook of Brewing: Processes, Technology, Markets.'']] Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2009.</ref> Requires [[iron]] coenzyme.<ref name=bsp/> | |||
* Other | * Other | ||
** '''Endo-xylanase''', '''exo-xylanase''', and '''arabinosidases''' (optimal 45°C) degrade [[pentosans]].<ref name=adb/> | ** '''Endo-xylanase''', '''exo-xylanase''', and '''arabinosidases''' (optimal 45°C) degrade [[pentosans]].<ref name=adb/> | ||
** '''Pentosan solubilase''' releases bound pentosans.<ref name=adb/> | ** '''Pentosan solubilase''' releases bound pentosans.<ref name=adb/> | ||
** '''Feruloyl esterase''' (optimal 35-47°C, pH >5.7) dissolves the ester bond between ferulic acid and arabinose (see [[Pentosans]] and [[Phenolic compounds]]).<ref name=adb/> | |||
** '''Phosphorylase''' cleaves the terminal alpha-(1, 4) links in non-reducing chain ends with inorganic phosphate to release glucose-1-phosphate. Apparently its possible role in mashing has never been investigated.<ref name=bsp/> | ** '''Phosphorylase''' cleaves the terminal alpha-(1, 4) links in non-reducing chain ends with inorganic phosphate to release glucose-1-phosphate. Apparently its possible role in mashing has never been investigated.<ref name=bsp/> | ||
** '''Catalase''' catalyses the conversion of peroxides to water and ground state (unreactive) oxygen, however it is rapidly destroyed during mashing at 149°F (65°C) and therefore it is largely irrelevant in the brewhouse.<ref name=etokakpan/ | ** '''Catalase''' catalyses the conversion of peroxides to water and ground state (unreactive) oxygen, however it is rapidly destroyed during mashing at 149°F (65°C) and therefore it is largely irrelevant in the brewhouse.<ref name=etokakpan/> | ||
** '''Superoxide dismutase''' catalyses the formation of peroxides from superoxides which in the absence of catalase leads to the formation of the hydroxyl radical.<ref name=etokakpan>EtokAkpan OU. [https://link.springer.com/article/10.1023/B:WIBI.0000043169.65135.b4 Preliminary study of fat oxidation in sorghum and maize brewing.] ''World J Microbiol Biotechnol.'' 2004;20:569–573.</ref | ** '''Superoxide dismutase''' catalyses the formation of peroxides from superoxides which in the absence of catalase leads to the formation of the hydroxyl radical.<ref name=etokakpan>EtokAkpan | ||
OU. [https://link.springer.com/article/10.1023/B:WIBI.0000043169.65135.b4 Preliminary study of fat oxidation in sorghum and maize brewing.] ''World J Microbiol Biotechnol.'' 2004;20:569–573.</ref> | |||
===Fermentation=== | ===Fermentation=== | ||
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* Yeast enzymes | * Yeast enzymes | ||
** '''Invertase''' breaks sucrose into its constituents glucose and fructose. | ** '''Invertase''' breaks sucrose into its constituents glucose and fructose. | ||
===Wine=== | |||
''Coming eventually'' | |||
==Added enzymes== | ==Added enzymes== | ||
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* '''Lysovin''' (lysozyme) | * '''Lysovin''' (lysozyme) | ||
* Alpha galactosidase [https://www.homebrewing.org/Alpha-Galactosidase-Enzyme-3-Pack_p_8270.html from AIH] | * Alpha galactosidase [https://www.homebrewing.org/Alpha-Galactosidase-Enzyme-3-Pack_p_8270.html from AIH] | ||
<!-- Enzymes that may be difficult to acquire and/or just aren't used by home brewers ... | <!-- Enzymes that may be difficult to acquire and/or just aren't used by home brewers ... | ||
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---- | ---- | ||
Potential sources | Potential sources | ||
*http:// | *http://lowoxygenbrewing.com/forum/viewtopic.php?f=11&t=1821 | ||
*[http://www. | *[http://www.lowoxygenbrewing.com/wp-content/uploads/2017/04/BrewingScience_0910_James_2014.pdf Amino Acid Permeases and their Influence on Flavour Compounds in Beer] | ||
*https://scholar.google.com/scholar?hl=en&as_sdt=1%2C36&q=sun+A+quantitative+assessment+of+the+importance+of+barley+seed+alpha-amylase%2C+beta-amylase%2C+debranching+enzyme+and+alpha-glucosidase+in+starch+degradation.&btnG=#d=gs_qabs&u=%23p%3DRr5Dbt7Zj7MJ | *https://scholar.google.com/scholar?hl=en&as_sdt=1%2C36&q=sun+A+quantitative+assessment+of+the+importance+of+barley+seed+alpha-amylase%2C+beta-amylase%2C+debranching+enzyme+and+alpha-glucosidase+in+starch+degradation.&btnG=#d=gs_qabs&u=%23p%3DRr5Dbt7Zj7MJ | ||
*https://www.researchgate.net/profile/Ahmed_Gomaa35/publication/323252887_Application_of_Enzymes_in_Brewing/links/5b5f33ae458515c4b2531f59/Application-of-Enzymes-in-Brewing.pdf | *https://www.researchgate.net/profile/Ahmed_Gomaa35/publication/323252887_Application_of_Enzymes_in_Brewing/links/5b5f33ae458515c4b2531f59/Application-of-Enzymes-in-Brewing.pdf | ||
*https://hibernianbrewingschool.ie/wp-content/uploads/2015/09/The-role-of-enzymes-IOB.pdf | |||
*http://www.knudsenbeverageconsulting.com/wp-content/uploads/2011/mbaa/mbaarmdpresentationenzymesinbrewing51102.pdf | *http://www.knudsenbeverageconsulting.com/wp-content/uploads/2011/mbaa/mbaarmdpresentationenzymesinbrewing51102.pdf | ||
*http://themodernbrewhouse.com/forum/viewtopic.php?f=11&t=2168 | *http://themodernbrewhouse.com/forum/viewtopic.php?f=11&t=2168 |