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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analytical and sensory evaluation of hop varieties

Sanchez, Nora B. 30 March 1990 (has links)
The German hop Hallertauer, hallertauer is highly valued because of its "noble aroma", but it has a very low yield when cultivated in the U.S. Two new crosses of Hallertauer, U.S.D.A. 21455 and 21459, have high yields and promising aroma characteristics. In order to predict sensory properties of beers as a function of the varieties of hop used in brewing, a more complete sensory and chemical characterization of hop oils is necessary. The aims of this study were to compare the aroma profiles of the new crosses against the German variety by determining their most important odor active compounds, and correlating the sensory attributes evaluated by a descriptive sensory panel (DSP) with the odor intensities detected during the gas chromatograph (GC) effluent detected during the gas chromatograph (GC) effluent sniffing. Oxygenated fractions were spiked into spring water and evaluated by the DSP. The same samples were injected into the GC and the effluents were evaluated quantitatively and qualitatively by four subjects using a special data collection device. Samples were then analyzed by mass spectrometry (MS). There were no significant differences among the three varieties based upon the DSP results and the "aromagrams" obtained during the sniffing of the GC effluents. Important odor active peaks were associated with humulene oxidation products. A number of statistical correlations existed between the sensory attributes and the odor active peaks. In summary, the new varieties are potential contributors to "noble aroma". Trials with beers brewed with these hops are underway in order to establish their contribution to beer flavor. / Graduation date: 1990

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