This diploma thesis deals with the questions of determination of aroma active compounds present in yoghurts. These compounds are crucial for flavour of these fermented dairy products. Four types of yoghurts were analyzed, creamy (10 % of fat), medium-fat and medium-fat Bio (3 % of fat) and light (0,1 % of fat), produced by Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Five groups of different aroma active compounds such as ketones, aldehydes, organic acids and their esters and alcohols in different amounts were determined. These compounds are mostly metabolic products of Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, dairy yoghurt cultures usually used for yoghurt production. Less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensorially evaluated using ranking test and scale test for determination of acceptability and flavour. The assessors were students and staffs of faculty of chemistry BUT.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:216547 |
| Date | January 2009 |
| Creators | Malina, Jiří |
| Contributors | Babák, Libor, Vítová, Eva |
| Publisher | Vysoké učení technické v Brně. Fakulta chemická |
| 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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