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The possibility of using of elderberry fruit pomace
Ondrušová, Pavlína ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
This diploma thesis concerns the determination of anthocyanin pigments in the elderberry pomace (Sambucus nigra L). The theoretical part describes in general the plant specification, its chemical composition, botanical characteristics and the possibility of utilization of elderberry in food processing industry and in pharmacy. However, the main concern of this thesis are the anthocyanins. This part is closely focused on chemical structure and factors that have significant influence over their stability. There are briefly summarized the positive effects of these colourants and their use in the food industry. In the experimental part, the elderberry juice and the extracts from the rhizomes were prepared. Two different solvents, a 1: 1 water / ethanol mixture and a mixture of water and methanol in the same ratio were used as extractors. To identify and quantify the dyes in the prepared samples, a chromatographic separation system (HPLC) with a Kinetex EVO C18 column and isocratic elution of the combined mobile phases of water of acetonitrile and formic acid was developed. The analysis only took 12 minutes. Two major dyes cyanidin-3-glucoside and cyanidin-3-sambubioside were identified and quantified by HPLC. The largest amount of anthocyanins was obtained by extracting mixture methanol / water (594.6 ± 0.42 mg.100 g-1). The content of anthocyanin dyes in dry extracts and juice was also determined by the often-used pH-differential method. Both results were compared. The HPLC method provided very accurate results against the less demanding pH-differential assay method, which proved to be suitable for the indicative measurement of anthocyanin content in real samples.
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