Ferulic acid: Difference between revisions

Ferulic acid is one of the main [[phenolic compounds|phenolic]] acids in [[barley]], [[wheat]], and [[rye]] grains (365 to 605 µg/g in barley).<ref name=egi/> It is an effective [[antioxidants|antioxidant]], it  retards the degradation of iso-α-acids, and it is a potent UV light absorber.<ref name=habkos>Habschied K, Košir IJ, Krstanović V, Kumrić G, Mastanjević K. [https://www.mdpi.com/2306-5710/7/2/38 Beer polyphenols—bitterness, astringency, and off-flavors.] ''Beverages.'' 2021;7(2):38.</ref><ref name=bsp/><ref name=Siqueira/> Ferulic acid exists mainly ester-bound to [[arabinoxylans]]; only a minor part of ferulic acid is present in malts in free forms.<ref name=Siqueira>Siqueira PB, Bolini H, Macedo GA. [https://www.researchgate.net/publication/49599952_O_PROCESSO_DE_FABRICACAO_DA_CERVEJA_E_SEUS_EFEITOS_NA_PRESENCA_DE_POLIFENOIS O processo de fabricação da cerveja e seus efeitos na presença de polifenóis. (The beer manufacturing process and its effects on the presence of polyphenols.)] ''Alimentos e nutrição.'' 2008;19(4):491–498.</ref> Some additional ferulic acid can be released from the arabinoxylans by [[enzymes]] during [[mashing]].<ref name=Szwajgier>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><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><ref name=egi>Egi A, Speers RA, Schwarz PB. [https://www.mbaa.com/publications/tq/tqPastIssues/2004/Abstracts/0803-01.htm Arabinoxylans and their behavior during malting and brewing.] ''Tech Q Master Brew Assoc Am.'' 2004;41(3):248–267.</ref><ref name=vanvan/><ref name=wangas/><ref name=zhao/><ref name=sibpla/> Release is driven by cinnamoyl esterase, an enzyme that is most effective during an extended rest at 40–45°C and pH 5.2–6.6.<ref name=cargui/><ref name=wangas/><ref name=vanvan/><ref name=schwarz/> Enzymatic release declines with increasing temperature up to about 65°C where there is none; at this point the amount of phenolic acid extracted is solely dependent on the free form created during malting.<ref name=vanvan/><ref name=cargui/><ref name=schwarz>Schwarz KJ, Boitz LI, Methner FJ. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-2012-1011-02 Release of phenolic acids and amino acids during mashing dependent on temperature, pH, time, and raw materials.] ''J Am Soc Brew Chem.'' 2012;70(4):290–295.</ref>