Pothou E.,National and Kapodistrian University of Athens |
Melliou E.,University of Athen |
Skaltsounis A.-L.,University of Athen |
Liouni M.,National and Kapodistrian University of Athens |
Magiatis P.,University of Athen
Journal of the American Society of Brewing Chemists | Year: 2013
The volatile constituents of 22 samples of commercial beers (lager, ale, and lambic) were isolated using adsorption resin XAD-4 and analyzed by gas chromatography, using mass-spectrometric detection. The presence of 63 volatile components was examined in each sample. Major common compounds identified in all of the studied samples were 2-methylpropanol (0.77-12.9%), 3-methylbutanol (32.0-55.5%), phenylethanol (18.7- 58.8%), and tyrosol (0.69-5.82%), expressed as TIC percent. Most other components were found in various concentrations but their presence was not uniformly distributed in all the studied beers. One of the minor volatile compounds, 2-(3H)-benzoxazolone, was found only in beers made with wheat malt. Additionally, for the first time, tryptophol acetate was identified as beer constituent. Finally, principal component analysis of the volatile compounds was able to discriminate the group of beers containing wheat. © 2013 American Society of Brewing Chemists, Inc.
Mallios A.,University of Athen
Complex Analysis and Operator Theory | Year: 2012
The term "A-invariance" refers to the invariance of our results, with respect to the "arithmetic" employed, viz. to an appropriate algebra sheaf A. This, combined with the categorical notion of "adjunction", particularized here with the homological, in nature Hom-⊗ adjunction, affords the classical perspective of Utiyama, pertaining to the characteristic type of field interactions. Yet, all this, without any "space-time" support, in the classical sense of the term (: smooth manifolds), but, just based on the "functorial" character of ADG (acronym of "Abstract Differential Geometry") and the aforementioned two fundamental principles (:"A-invariance" and "adjunction"). © 2011 Springer Basel AG.