Kvasny Prumysl, 1980 (vol. 26), issue 6
Determining the content of nitrogenous compounds in barley and malt with the Mikro.Peer-reviewed article
J. ©ROGL, P. BENDOVÁ
Kvasny Prum. 1980; 26(6): 121-123 | DOI: 10.18832/kp1980019 
The authors outline the principles of the Mikro Rapid-N automatic apparatus manufactured by Heraeus, Hanau(West Germany) and designed for rapid determination of nitrogenous compounds in barley and malt. Comparison measurements confirm the accuracy and reproducibility of results. In these respects the apparatus is more reliable than the apparatuses used in laboratories applying either the Kjeldahl or Kunitake -Kobayshi conventional methods. The Mikro Rapid-N saves much time, since one analysis takes only 5 minutes. As far as its disadvantages are concerned, it is necessary to mention high requirements put to the purity of applied gases, especially of...
Effects of the concentration of dissolved gases (CO2 and O2) upon the stability of bottled beer.Peer-reviewed article
J. ©AVEL, M. PROKOPOVÁ
Kvasny Prum. 1980; 26(6): 124-126 | DOI: 10.18832/kp1980020
Samples of microbiologically contaminated beer containing different amounts of dissolved O2 and CO2 were bottled and divided for subsequent laboratory analyses into 4 series (A - D) with the following concentrations of the mentioned gases: A: 0,2-0,8 mg O2 1-1, 0,12-0,23 % CO2; B: 4,8-8,4 mg O2 1-1, 0,02-0,14 % CO2; C: 6,2-15,0 mg O2 1-1, 0,32-0,42 % CO2; D: 0,7-4,1 mg O2 1-1, 0,32-0,44 % CO2. All samples were stored at 22 °C. Propagation of microorganisms was ascertained by microscopic examination....
Neutralizing inhibiting effects of crotonaldehyde upon the growth of Candida utilis yeast.Peer-reviewed article
M. ©ESTÁKOVÁ, F. ©TROS
Kvasny Prum. 1980; 26(6): 126-130 | DOI: 10.18832/kp1980021
Screening tests which have been carried out with Candida utilis cultivated in agar show, that of 20 compared low-boiling compounds the highest toxical effects have crotonaldehyde, acrolein and allyl alcohol. Toxicity of crotonaldehyde was neutralized with ammonia. By applying gas chromatography methods to a series of samples consisting of ethanol + crotonaldehyde + ammonia it has been established that transformation of crotonaldehyde (which is present as a current impurity in various fractions of synthetic alcohol) into a trimer with ammonia takes place, if pH of the mixture exceeds 8. At normal room temperature the process takes only a...