Stem constitutes approximately from 3 to 5 percent of total weight of a grape. The chemical structure of stem is mainly related to a variety, habitat conditions and ripeness. Stem consists from 35 to 90 percent of water, it also consists of sugar, tartaric acid and malic acid, tannins and vegetable dyes. In the production proccess of making wine, stem is perceived only as a residual part and there is a fact often omitted that stem is not only an integral part of grapes but it is also an indicator to the presence of a disease on the Vitis vinifera. Although stems have a drainage effect, they are improper for the production of wine itself, because the green stems in the stum cause the objectionable taste of grass. The first part of the thesis contains the general informations about stem: its composition, detailed description of the most contained substances and possibilities of the use of stem as well. My thesis also contains of detailed descripted spectrometric and chromatografic analysis and results as a part of the conducted research on substances contained in stem. In the last part of the thesis there are proccesed facts using the search method. They are mainly derived from foreign literature and are divided to several chapters: comparison of the derived results with international studies, new technologies that evaluate the substances contained in stem and also the effects of stem on human health.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:424838 |
| Date | January 2017 |
| Creators | Šlorová, Kamila |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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