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- | ** '''Endo-1,3-β-glucanase''' (optimal <60°C, pH 4.6) degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan, cellobiose, & laminaribiose.<ref name=esslinger/> | ||
** '''Endo- | ** '''Endo-1,4-β-glucanase''' (optimal 40–45°C pH 4.5–4.8) degrades soluble high-molecular-weight β-glucan into low-molecular-weight β-glucan, cellobiose, & laminaribiose.<ref name=esslinger/> | ||
** '''Exo-β-glucanase''' (optimal <40°C pH 4.5) degrades cellobiose & laminaribiose into glucose.<ref name=esslinger/> | |||
** '''Exo-β-glucanase''' (optimal <40°C pH 4.5) degrades glucose | *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/> | |||
* Phosphate liberation (see [[Phosphates]]) | *Lipid degradation and oxidation (see [[Lipids]]) | ||
** '''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. | ** '''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/> | ||
** '''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/> | |||
* 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 | |||
** '''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/> | ||
===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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'''Storage''' - Enzyme preparations are not stable, so they should be stored cool and used fresh since the activity decreases over time.<ref name=bsp/><ref name=hob10/> Refer to the manufacturer for specific recommendations. | '''Storage''' - Enzyme preparations are not stable, so they should be stored cool and used fresh since the activity decreases over time.<ref name=bsp/><ref name=hob10/> Refer to the manufacturer for specific recommendations. | ||
'''Impurities''' - Enzyme products are created by living organisms. | '''Impurities''' - Enzyme products are created by living organisms. Therefore these products are not "pure", and will usually contain other substances such as residual materials from the nutrient medium in which the microbes were cultured, other enzymes besides the one(s) specified, diluents, extenders or carriers, and preservatives. Be aware that these impurities can potentially lead to haze formation, deterioration of beer foam, and loss of yeast flocculation. Modern enzyme products usually do NOT contain viable microbes.<ref name=bsp/><ref name=hob10>Ryder DS. Processing aids in brewing. In: Stewart GG, Russell I, Anstruther A, eds. [[Library|''Handbook of Brewing.'']] 3rd ed. CRC Press; 2017.</ref> | ||
'''Product comparison''' - Products from different suppliers should be considered distinct, and it can be difficult to make comparisons between them due to lack of standardization. Also, the action of enzyme products can be greatly influenced by the usage conditions (e.g. temperature and pH), and therefore the results may vary between different brews. Consequently, the effectiveness of the addition of an enzyme preparation must be determined by brewers under their particular processing conditions.<ref name=bsp>Briggs DE, Boulton CA, Brookes PA, Stevens R. [[Library|''Brewing Science and Practice.'']] Woodhead Publishing Limited and CRC Press LLC; 2004.</ref> | '''Product comparison''' - Products from different suppliers should be considered distinct, and it can be difficult to make comparisons between them due to lack of standardization. Also, the action of enzyme products can be greatly influenced by the usage conditions (e.g. temperature and pH), and therefore the results may vary between different brews. Consequently, the effectiveness of the addition of an enzyme preparation must be determined by brewers under their particular processing conditions.<ref name=bsp>Briggs DE, Boulton CA, Brookes PA, Stevens R. [[Library|''Brewing Science and Practice.'']] Woodhead Publishing Limited and CRC Press LLC; 2004.</ref> | ||
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[[File:Amylase-comparison-chart.jpg|600px]] | [[File:Amylase-comparison-chart.jpg|600px]] | ||
* '''Clarity Ferm''' AKA '''Clearzyme''' | * '''Clarity Ferm''' AKA '''Clearzyme''' | ||
* '''Glucabuster''' | * '''Glucabuster''' | ||
* '''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 ... | ||
Tested Shearzyme 500L (xylanase, Novozymes), Glucanase (Megazyme), Ultraflo Max (glucanase + xylanase, Novozymes) Neutrase 0.8L (proteinase, Novozymes): All exogenous enzymes gave, to different extents, increased activities of starch-degrading enzymes compared with the control to which no enzymes were added. Neutrase 0.8L proteinase was the most effective enzyme and the maximal activities of α-amylase, β-amylase and limit dextrinase during mashing were improved by 12, 57 and 173%, respectively, compared with the control.<ref>Hu S, Dong J, Fan W, et al. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/jib.172 The influence of proteolytic and cytolytic enzymes on starch degradation during mashing.] ''J Inst Brew.'' 2014;120(4):379–384.</ref> The β-glucanase, Shearzyme 500L, Ultraflo Max and Neutrase 0.8L enhanced the soluble starch content by 20, 14, 23 and 43% respectively, at the end of the | Tested Shearzyme 500L (xylanase, Novozymes), Glucanase (Megazyme), Ultraflo Max (glucanase + xylanase, Novozymes) Neutrase 0.8L (proteinase, Novozymes): All exogenous enzymes gave, to different extents, increased activities of starch-degrading enzymes compared with the control to which no enzymes were added. Neutrase 0.8L proteinase was the most effective enzyme and the maximal activities of α-amylase, β-amylase and limit dextrinase during mashing were improved by 12, 57 and 173%, respectively, compared with the control.<ref>Hu S, Dong J, Fan W, et al. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/jib.172 The influence of proteolytic and cytolytic enzymes on starch degradation during mashing.] ''J Inst Brew.'' 2014;120(4):379–384.</ref> The β-glucanase, Shearzyme 500L, Ultraflo Max and Neutrase 0.8L enhanced the soluble starch content by 20, 14, 23 and 43% respectively, at the end of the | ||
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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 |