17 research outputs found
Discriminant Analysis of Volatile Fatty Acids Produced in Culture Medium: a Novel Approach to the Identification of Pseudomonas Species
Characterization of Flavobacterium Species by Analysis of Volatile Fatty Acid Production
The use of Oxygen 18 in appraising the impact of oxidation process during beer storage
To appraise the incidence of oxygen: in bottled beer, the stable nonradioactive oxygen isotope 18O(2) was injected into the headspace just before ageing and subsequently analysed by proton bombardment and isotopic mass spectroscopy of all the most interesting beer fractions. Although oxygen did cause considerable oxidation of sulphites, polyphenols, and isohumulones, it was not incorporated into the carbonyl fraction, indicating that the cardboard flavour in beer is not due to lipid oxidation but to wort preparation. Nonenal potential measurement was found to be a good indicator of beer flavour staling. The impact of beer stabilisation treatments (addition of polyvinyl pyrolidone powder, potassium metabisulphite, ascorbic acid) was also investigated