Czech Journal of Food Sciences, 2008 (vol. 26), Special Issue
Quality of Moravian and Czech wines and their future
J. Tříska, J. Balík
Czech J. Food Sci., 2008, 26(10):S1 | DOI: 10.17221/241/2008-CJFS 
Antimutagenic activity of raw materials and by-products by production of grape wines
JIŘÍ TOTUŠEK, DANUŠE LEFNEROVÁ, MARIE KYSELÁKOVÁ, JOSEF BALÍK, JAROMÍR VEVERKA, JAN TŘÍSKA, NADĚŽDA VRCHOTOVÁ
Czech J. Food Sci., 2008, 26(10):S55-S59 | DOI: 10.17221/247/2008-CJFS
The inhibition of mutagenicity was assessed by Ames test by bacterial strains Salmonella typhimurium TA98 and TA100 using two mutagens and methanolic extracts of healthy fresh berries of blue grapevine varieties - St. Laurent, Portugal, André and white varieties - Chardonnay, Welschriesling, Pinot Gris and berries infected with Botrytis cinerea fungus. As model mutagens, two compounds whose presence in food is real, 2-amino-3-methyl-3H-imidazo-(4.5-f-)-quinoline (IQ), arising from certain heat treatments of meat and acting as indirect mutagen after metabolic activation, and N-nitroso-N-methylurea (MNU) acting as a direct mutagen, were...
Antioxidant activity of wines and related matters studied by EPR spectroscopy
Pavel STOPKA, Jana KŘÍŽOVÁ, Naděžda VRCHOTOVÁ, Petra BÁBÍKOVÁ, Jan TŘÍSKA, Josef BALÍK, Marie KYSELÁKOVÁ
Czech J. Food Sci., 2008, 26(10):S49-S54 | DOI: 10.17221/248/2008-CJFS
Antioxidant activity and free radicals were studied in various parts of Vitis vinifera plant in vivo and in wines using EPR spectroscopy. Antioxidative properties of polyphenolic substances play an important role for the evaluation of quality of natural products. Determination of antioxidant activity of experimental samples by EPR method was based on measuring the changes of EPR spectrum of stable nitroxide radicals as a result of their interaction with antioxidants. In the leaves of Vitis vinifera vine varieties for the production of red wines there was observed a higher decrease in free Tempol radicals as compared to the leaves of varieties...
Multi-experimental characterisation of grape skin extracts
Lenka ŠŤAVÍKOVÁ, Martin POLOVKA, Barbora HOHNOVÁ, 3, Jana ZEMANOVÁ
Czech J. Food Sci., 2008, 26(10):S43-S48 | DOI: 10.17221/245/2008-CJFS
Grape skins contain a plenty of different flavonoids, most of them revealing significant antioxidant properties. In this contribution, a complex study is presented of grape skin ethanol extracts, prepared from grape skins of two vine grape varieties, Svatovavřinecké (St. Laurent) and Alibernet. Extracts were prepared from two different amounts of lyophilised grape skin powders using the pressurised fluid extraction (PFE). The antioxidant activity of the extracts was tested by EPR spectroscopy in Fenton system generating reactive radicals (*OH, O+>) assays. Total phenolic content (TPC) of the individual extracts and their tristimulus colour...
Determination of anthocyanins in red grape skin by pressurised fluid extraction and HPLC
Barbora HOHNOVÁ, Lenka ŠŤAVÍKOVÁ, Pavel KARÁSEK
Czech J. Food Sci., 2008, 26(10):S39-S42 | DOI: 10.17221/243/2008-CJFS
Grape anthocyanins not only play an important role in the colour quality of red wines but they also have many beneficial effects on human health, e.g., reduction of coronary heart disease incidence, or anticarcinogenic and antioxidant properties. Therefore, a rapid and efficient extraction technique prior to chromatographic analysis is of primary interest. Pressurised Fluid Extraction (PFE) presents a fast, effective, and environmentally friendly extraction method for the analysis of red grape pigments. In this study, PFE in static mode was utilised for the extraction of 3-monoglucoside anthocyanins from the grape skin of highly pigmented variety Alibernet....
Influence of tannin addition on the content and composition of polyphenolic compounds in wines
Marie CÍCHOVÁ, Jan PETŘÍČEK, Jaromír FIALA
Czech J. Food Sci., 2008, 26(10):S33-S38 | DOI: 10.17221/242/2008-CJFS
Polyphenols can greatly affect the sensorial characteristics and stability of wine. The concentration of polyphenols in wines is very low, the sample must be thus concentrated before the analytical measurement. The extraction on solid phase (SPE) is a suitable method for the isolation, purification, and concentration of polyphenols from complicated matrices. RP-HPLC with diode array detection was used for the separation and identification of polyphenols. A library of absorption spectra of standards was created and used for the identification of 14 polyphenols in wines. The contents of the individual polyphenols and their changes after the addition...
The changes of selected phenolic substances in wine technology
Josef BALÍK, Marie KYSELÁKOVÁ, Jan TŘÍSKA, Naděžda VRCHOTOVÁ, Jaromír VEVERKA, Pavel HÍC, Jiří TOTUŠEK, Danuše LEFNEROVÁ
Czech J. Food Sci., 2008, 26(10):S3-S12 | DOI: 10.17221/239/2008-CJFS
The effects of the pressing technology and clarification of white grape musts on concentrations of phenolic compounds and their antioxidative capacity were investigated. Four different varieties were processed by hydraulic or pneumatic pressing technologies. In the individual stages of pressing and after the application of different doses of the clarification agent, must samples were analysed for the content of polyphenols and the antioxidative capacity. The highest concentrations of caftaric acid were estimated in the musts made by hydraulic pressing from grapes of Welschriesling variety. On the other hand, musts made from grapes of Grüner Veltliner...
Relations between polyphenols content and antioxidant activity in vine grapes and leaves
Josef BALÍK, Marie KYSELÁKOVÁ, Naděžda VRCHOTOVÁ, Jan TŘÍSKA, Michal KUMŠTA, Jaromír VEVERKA, Pavel HÍC, Jiří TOTUŠEK, Danuše LEFNEROVÁ
Czech J. Food Sci., 2008, 26(10):S25-S32 | DOI: 10.17221/246/2008-CJFS
The occurrence and content of some polyphenols and the antioxidant activity of compounds present in grape berries, stems and leaves of Vitis vinifera L. were evaluated. Three white and three blue varieties of grapevine were investigated. The contents were determined of trans-resveratrol, trans-piceid, caftaric acid, tryptophan, catechin, epicatechin, total polyphenols, and flavanols, both in healthy material and in the samples of the plant material infested with microorganisms (Botryotinia fuckeliana Whetzel anamorph Botrytis cinerea Pers.; Uncinula necator (Schw.) Burr; Plasmopara viticola (Berk. & M.A....
Evaluation of colour content in grapes originating from south Moravia
Josef BALÍK, Michal KUMŠTA
Czech J. Food Sci., 2008, 26(10):S18-S24 | DOI: 10.17221/240/2008-CJFS
The content of total anthocyanins was determined in grapes of nine grapevine (Vitis vinifera L.) varieties belonging to the traditional blue vine varieties grown in south Moravia (Czech Republic) within the period of 2002-2007. Factors of vintage and health condition of grapes were observed. The material balance of the colour substances in grapes was related to the dry matter of skins of berries and that of fresh grapes used as raw material for vinification. The highest content of pigments was found in the variety Neronet (2.15-4.49 g/kg of fresh grapes), which belongs to the so-called Teinturier varieties. Besides the variety Neronet (containing...
Content of trans-resveratrol in leaves and berries of interspecific grapevine (Vitis sp.) varieties
Petra Bábíková, Naděžda Vrchotová, Jan Tříska, Marie Kyseláková
Czech J. Food Sci., 2008, 26(10):S13-S17 | DOI: 10.17221/238/2008-CJFS
The aim of this project was to study changes in the content of trans-resveratrol in berries and leaves of grapevine (Vitis sp.) infested by fungal diseases, especially by Botryotinia fuckeliana Whetzel, called as grey mildew, Plasmopara viticola (Berk. & M.A. Curtis) Berl & De Toni, called downy mildew and Uncinula necator (Schw.) Burr, called powdery mildew. In our experiments two white and two blue varieties were used. Contents of trans-resveratrol were determined in healthy and infested leaves and in healthy berries. Infested leaves of white varieties contained more trans-resveratrol than...
The influence of trans-resveratrol and quercetin on the activity of CYP1A2 in rat
Ondřej ZENDULKA, Lucia ZAHRADNÍKOVÁ, Jan JUŘICA, Jiří TOTUŠEK
Czech J. Food Sci., 2008, 26(10):S60-S64 | DOI: 10.17221/244/2008-CJFS
Polyphenolic compounds are widely distributed in plants and are a common part of human diet. Polyphenols are known to be potent bioactive molecules, predominantly with protective effects. Many of xenobiotics, including polyphenols, influence the activities of various enzymatic systems. Such interactions can modulate the activities of co-administered drugs. The identification of polyphenols' potential for the interactions based on metabolic changes is thus necessary. Cytochrome P450, which takes part in the metabolism of more than 90% of used drugs, is an important enzymatic system which can be influenced. We therefore determined the influence of quercetin...