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Enzymes: Difference between revisions
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** '''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.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/> | ||
*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> | ** '''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/> | ** '''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/> | |||
*Phenolic compound oxidation (see [[Phenolic compounds]], [[Oxidation]]) | *Phenolic compound oxidation (see [[Phenolic compounds]], [[Oxidation]]) | ||
** '''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.<ref name=esslinger/> | ||