This diploma thesis deals with reductive sulphur off-odors in wines and possibilities of their removal. The theoretical part describes substances causing these defects, their threshold values, most common causes of defects and possibility of their prevention or removal. The practical part is focused on the determination of hydrogen sulphide (H2S) in wine with reductive sulphur off-odor and the possibility of reducing its content using particles of gold, silver and copper. A wine with reductive off-odor made of the Zweigeltrebe variety from 2018 was used for the experiment. 10 l micro-samples were created and various doses of silver, gold and copper-based products were applied to the wine. The control samples were left untreated. The UV / VIS HPLC instrumentation was used for determination of the hydrogen sulphide concentration using so far unpublished method for converting H2S to methylene blue with direct injection of the derivatized wine sample. The H2S concentration in the samples varied from 13,1 to 68,7 µg/l. Basic analytical parameters were also measured and compared in this work, but they did not changed significantly with added products doses. The GC-MS method was used to measure the levels of particular volatile compounds. Treated wines were also sensory evaluated. The best sensory properties exhibited wines treated with copper products.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:426570 |
| Date | January 2019 |
| Creators | Maleňáková, Daniela |
| 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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