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Ovocno-zeleninové šťávy konzervované vysokým tlakem
Houška, M. ; Strohalm, J. ; Totušek, J. ; Lefnerová, D. ; Tříska, Jan ; Vrchotová, Naděžda ; Gabrovská, D. ; Průchová, J. ; Gřesová, P. ; Loučková, K. ; Fiedlerová, V. ; Paulíčková, I. ; Winterová, R.
Byly vyvinuty ovocno/zeleninové šťávy pasterované vysokým tlakem a byly testovány na jejich antimutagenní aktivitu.
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Quantitative and qualitative changes of phenolic compounds in alder leaf litter
Elhottová, Dana ; Vrchotová, Naděžda ; Tříska, Jan ; Krištůfek, Václav
Quantitative as well as qualitative changes of phenolic compounds were investigated in different decomposition stages (I-IV) of native alder leaf litter. The Folin-Ciocalteau method was applied for the determination of total phenolic compounds and the reserved phase HPLC for the determination of the phenolic acids. Both values decreased in dependence on stage of litter decomposition. The reduction of the total phenolic compounds and the phenolic acids was 20% and 50%, respectively, in the most decomposed litter (stage IV) in comparison with fresh litter (stage I, 100%). The ratio of free (simple extracted) and bound phenolic compounds (extracted after acid hydrolysis) in the group of total phenolic compounds and phenolic acids was determined. The characteristic feature of the fresh litter (stage I) was higher amount of the free phenolic acids as well as higher ratio of the free phenolic compounds to the bound ones. The following stage II was characterised by two times higher portion of free to bound total phenolic compounds in contrary to phenolic acids where the bound acids dominat ed over the free ones. Higher level of bound to free compounds in both observed phenolic groups was typical for the most decomposed litter samples (stage III and IV).In addition, the stage III and IV were characterised by new compounds, which were formed in the litter during its decomposition and were not detectable in the previous stages (I,II).
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