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Biologically active substances of the Gotu kola plant
Šumberová, Michaela ; Nábělek, Jakub (referee) ; Zemanová, Jana (advisor)
The Bachelor thesis focuses on the preparation and characterization of the extract of Gotu kola (Centella asiatica). The theoretical part summarizes commonly analyzed groups of biologically active compounds of herbs and introduces potential applications of the extract in food industry. Moreover, an overview of possibly used extraction methods and analytical methods for the evaluation of biologically active compounds of the extract are presented. As for the experiment, the extract of the fresh Centella asiatica herb was prepared by maceration in ethanol and then analyzed by three chosen methods. The total phenolic content of the extract analyzed by the Folin-Ciocalteu test was 0.74 ± 0.08 mgGAE·g-1. As for the quantification of antioxidant activity, the TEAC test was performed and the antioxidant activity of the extract was 289 ± 81 µg·ml-1. The volatiles present in the extract were identified by gas-chromatography mass-spectrometry in combination with solid-phase micro-extraction. Sesquiterpenoid hydrocarbons were the most dominant group of the extract, in which -farnesene (33.28 %), -caryophyllene (25.01 %), and -humulene (20.91 %) were the major compounds.
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Study of the chemical profile of wine of Riesling variety
Šumberová, Michaela ; Trachtová, Štěpánka (referee) ; Vítová, Eva (advisor)
This diploma thesis focuses on the chemical profile and authentication of the geographical origin of varietal wine Rhine Riesling obtained from 4 Moravian wine regions. In the experiment, 20 wine samples were analysed with 5 instrumental analytical methods – aromatic compounds were determined by HS-SPME-GC-MS, phenolic compounds by HPLC-MS, total phenolic content by MAS, and elemental analysis by ICP-OES and ICP-MS. In total 36 aromatic compounds were detected, from which 7 were varietal terpenes and 2 of them C13 norisoprenoids. The total phenolic content for the Rhine Riesling wine was measured in the concentration range of 174,22–380,96 mg·l-1. Gallic acid (0,41–34,99 mg·l-1), catechin (0,05–7,44 mg·l-1), epicatechin (0,03–4,14 mg·l-1), caffeic acid (0,14–2,05 mg·l-1), and coumaric acid (0,30–4,04 mg·l-1) were the specific measured phenolics. In total 18 elements were measured in Rhine Riesling wine, macroelements K > P > Mg > Ca > Na with concentrations above 10 mg·l-1, microelements Al > Fe > Zn > Mn > Sr > Cu in the concentration range 0,1–10 mg·l-1, and trace elements Ni > Cr > V > Pb > Mo > Co > Cd in the concentration 0,0001–1 mg·l-1. Potassium was the most abundant element (386,37 mg·l-1). The results were used for the parametric and nonparametric univariate analysis of variance (ANOVA) and multivariate principal component analysis (PCA). Ni60 (p = 0,0029), ethyl benzoate (p = 0,0060), and diethyl succinate (p = 0,0247) were statistically the most significant parameters influenced by the wine region for the significance level = 0,05. Out of the 57 measured variables 7 parameters were identified as statistically significant and used for PCA graphic representation of the samples. PCA results show, that the varietal wine’s origin can be authenticated by chosen chemical compounds and chemometric methods.
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Biologically active substances of the Gotu kola plant
Šumberová, Michaela ; Nábělek, Jakub (referee) ; Zemanová, Jana (advisor)
The Bachelor thesis focuses on the preparation and characterization of the extract of Gotu kola (Centella asiatica). The theoretical part summarizes commonly analyzed groups of biologically active compounds of herbs and introduces potential applications of the extract in food industry. Moreover, an overview of possibly used extraction methods and analytical methods for the evaluation of biologically active compounds of the extract are presented. As for the experiment, the extract of the fresh Centella asiatica herb was prepared by maceration in ethanol and then analyzed by three chosen methods. The total phenolic content of the extract analyzed by the Folin-Ciocalteu test was 0.74 ± 0.08 mgGAE·g-1. As for the quantification of antioxidant activity, the TEAC test was performed and the antioxidant activity of the extract was 289 ± 81 µg·ml-1. The volatiles present in the extract were identified by gas-chromatography mass-spectrometry in combination with solid-phase micro-extraction. Sesquiterpenoid hydrocarbons were the most dominant group of the extract, in which -farnesene (33.28 %), -caryophyllene (25.01 %), and -humulene (20.91 %) were the major compounds.
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