The method is suitable for the determination of water vapor volatile aroma compounds in beer.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanolic distillate is saturated with NaCl. Potassium hydrogen sulfite is added to separate carbonyl groups that might interfere with the analysis. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging.
Determination of xanthohumol and isoxanthohumol
All beers, beer-based beverages, wort, ethanol extracts, CO2 spent hops and xanthohumol products
Xanthohumol and isoxanthohumol are dissolved with acetonitrile from the sample and following separation, are determined using a Nucleodur C18 column and UV detection.
Determination of the aromatic alcohols guaiacol, tryptophol, 4-ethyl guaiacol, 4-vinyl guaiacol, eugenol, tyrosol, 4-ethylphenol, 2-phenylethanol in beer
The method is suitable for beer brewed to any original gravity or to any alcohol content.
The aromatic alcohols in beer are isolated using solid-phase extraction and are detected using gas chromatography-mass spectrometry.
The method describes how to determine the phosphate content of water photometrically with a cuvette test.
Phosphate ions form a yellow color in the presence of the molybdovanadate reagent. The color is determined using a photometer.
Water intended for use in beer brewing as well as in the production of other foods
Steam-volatile phenols form by bonding with diazotized p-nitroaniline azo dyes; the intensity of the resultant color is measured photometrically following extraction with n-butanol.
The intensity of the color, based on a saturation threshold of phenol of 100 %, is as follows:
phenol 100 % m-xylenol 52 %
o-cresol 147 % p-xylenol 92 %
m-cresol 120 % guaiacol 165 %
p-cresol 21 % pyrocatechol 29 %
o-xylenol 16 % α-naphthol 23 %
Determination of 4-vinylguaiacol and 4-vinylphenol in beer. The method can also be used for wort.
The method is suitable for beers of all original gravity ranges and alcohol contents. The method can also be used for wort.
4-Vinylguaiacol and 4-vinylphenol are separated by isocratic HPLC on a Spherisorb separation column and the concentration is determined by UV detection at 260 nm.