Kvasný průmysl (Oct 2002)
Direct Analyses of Beer Macromolecular Complexes by Means of a New Differential Nephelometric Titration Method.
Abstract
A new method of analyses of beer and intermediates macromolecular complexes - Differential Nephelometric Titration (DNT) was developed. The method was analytically evaluated in various protein and PVP model solutions and their mixtures by titration with ammonium sulphate saturated solution. Observed characteristic structural maxima, minima and shoulders on the DNT curves were correlated with molecular weight bands of complexes in solution. Using the DNT method, the principal molecular weight bands of beer macromolecular complexes at approx. 100, 40 and 15 kDa were identified in agreement with literature data obtained by various chromatographic methods and correlated with saturation of ammonium sulphate in solution. The DNT method will be particularly effective for direct studies of interactions of macromolecular complexes in native brewing and malting samples at various technological stages without pre-treatment used necessary for chromatographic methods.A new method of analyses of beer and intermediates macromolecular complexes - Differential Nephelometric Titration (DNT) was developed. The method was analytically evaluated in various protein and PVP model solutions and their mixtures by titration with ammonium sulphate saturated solution. Observed characteristic structural maxima, minima and shoulders on the DNT curves were correlated with molecular weight bands of complexes in solution. Using the DNT method, the principal molecular weight bands of beer macromolecular complexes at approx. 100, 40 and 15 kDa were identified in agreement with literature data obtained by various chromatographic methods and correlated with saturation of ammonium sulphate in solution. The DNT method will be particularly effective for direct studies of interactions of macromolecular complexes in native brewing and malting samples at various technological stages without pre-treatment used necessary for chromatographic methods.
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