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Advanced Method for Measuring Proteinase A in Beer and Application to Brewing *
Author(s) -
Kondo Hiroto,
Yomo Hideko,
Furukubo Susumu,
Fukui Nobuyuki,
Nakatani Kazuo,
Kawasaki Yasutsugu
Publication year - 1999
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.2050-0416.1999.tb00523.x
Subject(s) - brewing , yeast , fermentation , proteinase k , chemistry , peptide , enzyme , substrate (aquarium) , biochemistry , food science , chromatography , biology , ecology
Proteinase A, excreted from yeast cells into beer during fermentation in the brewing process, has been shown to degrade foam‐active proteins and to decrease foam stability. In order to improve the measurement of this enzyme in beer, a new fluorescent peptide, MOCAc‐Ala‐Pro‐Ala‐Lys‐Phe‐Phe‐Arg‐Leu‐Lys (Dnp)‐NH 2 , was synthesised and applied to the accurate and rapid estimation of proteinase A in commercial beer and fermenting wort. This novel substrate is several hundred times more sensitive to proteinase A than other previously reported synthetic substrates or native protein substrates. The concentration of proteinase A in beer is closely related to foam stability and proteinase A activity was found to increase gradually during fermentation. The concentration of proteinase A excreted from yeast cells is also closely related to the vitality of pitching yeast cells. This new method was successfully applied to the evaluation of yeast vitality and the development of optimum yeast handling procedures.