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Oxalate and Oxalate Oxidase in Malt
Author(s) -
Kanauchi Makoto,
Milet Jérôme,
Bamforth Charles W.
Publication year - 2009
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.2009.tb00374.x
Subject(s) - mashing , aleurone , oxalate , oxalic acid , chemistry , germination , oxidase test , oxygen , biochemistry , enzyme , food science , botany , biology , inorganic chemistry , organic chemistry
Barley kernels contain a single oxalate oxidase located in the embryo and aleurone. It is already present in substantial quantities in unmalted grain and increases in activity during germination. It displays a very broad pH optimum: the optimum was at pH 4.0, but the enzyme still displayed more than 50% of its activity at pH 7. Oxalate oxidase is highly resistant to heat. However, its low affinity for oxygen suggests that it probably does not play a major role in the consumption of oxygen in mashing. The decrease in oxalic acid levels late in germination may be a result of oxalate oxidase action. Oxalic acid was not detected in raw barley.