Template-Type: ReDIF-Article 1.0 Author-Name: J. Tříska Author-Name: J. Balík Title: Quality of Moravian and Czech wines and their future Journal: Czech Journal of Food Sciences Pages: S1 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/241/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/241/2008-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:241-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Petra Bábíková Author-Workplace-Name: Department of Viticulture and Enology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Naděžda Vrchotová Author-Workplace-Name: Laboratory of Environmental Analytical Chemistry, Institute of Systems Biology and Ecology of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Jan Tříska Author-Workplace-Name: Laboratory of Environmental Analytical Chemistry, Institute of Systems Biology and Ecology of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Marie Kyseláková Author-Workplace-Name: Department of Viticulture and Enology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Title: Content of trans-resveratrol in leaves and berries of interspecific grapevine (Vitis sp.) varieties Abstract: 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 those of blue varieties. The content of trans-resveratrol in berries was lower than that in leaves. Keywords: trans-resveratrol, HPLC, wine Journal: Czech Journal of Food Sciences Pages: S13-S17 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/238/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/238/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0002.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:238-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Josef BALÍK Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products and Author-Name: Michal KUMŠTA Author-Workplace-Name: Department of Viticulture and Viniculture, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Title: Evaluation of colour content in grapes originating from south Moravia Abstract: 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 30.6-73.4 mg/g of dry skin), high contents of total anthocyanins in dry skins were found in the varieties Dornfelder (24.7-59.0 mg/g of dry skin) and Cabernet Moravia (20.1-59.3 mg/g of dry skin). In the long run, the lowest concentrations of pigments were determined in grapes of the varieties Blauer Portugieser (0.51-1.02 g/kg of fresh grapes) and Pinot noir (0.27-0.60 g/kg of fresh grapes). The highest colour capacity was found in grapes harvested in the 2003 and 2006. Contents of anthocyanins were significantly lower (P = 0.001) in damaged grapes. Grapes containing more than 40% of rotten berries revealed in skins and whole grapes only 41% and 55%, respectively, of the colour capacity of the healthy raw material. Keywords: total anthocyanins, extraction, grape, grape berries, skin of grape berries, grape varieties, rotten grapes Journal: Czech Journal of Food Sciences Pages: S18-S24 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/240/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/240/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0003.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:240-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Josef BALÍK Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products and Author-Name: Marie KYSELÁKOVÁ Author-Workplace-Name: Department of Viticulture and Oenology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Naděžda VRCHOTOVÁ Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Jan TŘÍSKA Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Michal KUMŠTA Author-Workplace-Name: Department of Viticulture and Oenology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Jaromír VEVERKA Author-Workplace-Name: Department of Viticulture and Oenology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Pavel HÍC Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products and Author-Name: Jiří TOTUŠEK Author-Workplace-Name: Institute of Preventive Medicine, Medical Faculty, Masaryk University, Brno, Czech Republic$2 Author-Name: Danuše LEFNEROVÁ Author-Workplace-Name: Institute of Preventive Medicine, Medical Faculty, Masaryk University, Brno, Czech Republic$2 Title: Relations between polyphenols content and antioxidant activity in vine grapes and leaves Abstract: 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. Curtis) Berl & De Toni). The antioxidant activity of the extracts obtained was determined by different methods: FRAP (Ferric Reducing Antioxidant Power), DPPH (2,2-diphenyl-1-picrylhydrazyl radical) and TAC-PCL (Total Antioxidant Capacity of Photochemiluminescence). The content of trans-resveratrol varied between 0.3-2.3 mg/kg and 0.7-12.1 mg/kg in non-infested and infested grape berries, respectively. The content of trans-piceid between 0.6-2.9 mg/kg and 1.5-6.3 mg/kg in non-infested and infested grape berries, respectively. The content of trans-resveratrol varied between 2.5-10.3 mg/kg and 3.7-20.9 mg/kg in healthy and in infected leaves, respectively. The content trans-piceid varied between 11.3-58.4 mg/kg and 18.5-60.9 mg/kg in the healthy and in the infected leaves, respectively. The highest content of trans-resveratrol was found in stems (16.3-276.3 mg/kg). In young lateral shoots, the highest levels of trans-piceid (12.6-99.7 mg/kg) and caftaric acid (474-2257 mg/kg) were determined. The infested grape berries showed a higher antioxidant activity, which was most closely correlated with the content of total polyphenols (correlation coefficient = 0.8336-0.9952). Keywords: vine grapes, vine leaves, stems, downy mildew, powdery mildew, grey mould, piceid, resveratrol, caftaric acid, catechin, epicatechin, photochemiluminescence, DPPH, FRAP Journal: Czech Journal of Food Sciences Pages: S25-S32 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/246/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/246/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0004.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:246-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Josef BALÍK Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products Author-Name: Marie KYSELÁKOVÁ Author-Workplace-Name: Department of Viticulture and Oenology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Jan TŘÍSKA Author-Name: Naděžda VRCHOTOVÁ Author-Name: Jaromír VEVERKA Author-Workplace-Name: Department of Viticulture and Oenology, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Pavel HÍC Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products Author-Name: Jiří TOTUŠEK Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: Danuše LEFNEROVÁ Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Title: The changes of selected phenolic substances in wine technology Abstract: 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 showed the highest contents of trans-piceid in both variants of pressing. The values of antioxidative capacity of the must samples analysed were not significantly different. The influence of clarification on the changes of phenolic substances in young red wines of Saint Laurent variety was also studied. Six various clarifiers were tested as applied in two different doses. Polyvinylpolypyrrolidone caused the highest losses of trans-resveratrol in the course of red wine clarification. The concentrations of catechin, epicatechin, and total anthocyanins as well as the colour parameters of red wines were influenced at most by the application of egg white. Keywords: polyphenols, piceid, resveratrol, caftaric acid, colour, antioxidative capacity, grape must, pressing, red wine, clarifying agents Journal: Czech Journal of Food Sciences Pages: S3-S12 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/239/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/239/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0005.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:239-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Marie CÍCHOVÁ Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jan PETŘÍČEK Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jaromír FIALA Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Influence of tannin addition on the content and composition of polyphenolic compounds in wines Abstract: 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 of four tannin preparations were determined in eight white and two rosé wine samples. The influence of the flavour profile of the applied tannin preparations on sensorial characteristics of wines was established Keywords: wine, polyphenols, determination, HPLC-DAD, SPE, tanin Journal: Czech Journal of Food Sciences Pages: S33-S38 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/242/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/242/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0006.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:242-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Barbora HOHNOVÁ Author-Workplace-Name: Faculty of Chemistry, Brno University of Technology, Brno, Czech Republic, Author-Workplace-Name: Institute of Analytical Chemistry of the Academy of Sciences of the Czech Republic, Brno, Czech Republic Author-Name: Lenka ŠŤAVÍKOVÁ Author-Workplace-Name: Faculty of Chemistry, Brno University of Technology, Brno, Czech Republic, Author-Name: Pavel KARÁSEK Author-Workplace-Name: Institute of Analytical Chemistry of the Academy of Sciences of the Czech Republic, Brno, Czech Republic Title: Determination of anthocyanins in red grape skin by pressurised fluid extraction and HPLC Abstract: 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. The effects of the type of the extraction solvent and the extraction temperature were studied. The identification of the above given compounds were performed by high-performance liquid chromatography with diode array detection (HPLC-DAD) based on Synergi C-12 column separation. The wavelength was set at 520 nm. All compounds were determined and identified during 50 minutes. Keywords: flavonoids, grapes, PFE, HPLC analysis Journal: Czech Journal of Food Sciences Pages: S39-S42 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/243/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/243/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0007.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:243-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Lenka ŠŤAVÍKOVÁ Author-Workplace-Name: Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology, Brno, Czech Republic, Author-Name: Martin POLOVKA Author-Workplace-Name: Department of Chemistry and Food Analysis, Food Research Institute, Bratislava, Slovak Republic, Author-Name: Barbora HOHNOVÁ Author-Workplace-Name: Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology, Brno, Czech Republic, Author-Name: Jana ZEMANOVÁ Author-Workplace-Name: Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology, Brno, Czech Republic, Title: Multi-experimental characterisation of grape skin extracts Abstract: 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 values (CIE Lab) were evaluated, using an UV-VIS spectrophotometer. All the data obtained were subsequently correlated and discriminated, using the multivariate statistics, involving the canonical discriminant analysis, principal component analysis, and canonical correlation analysis. Results obtained indicated that PFE is a suitable extraction technique, only slightly influencing antioxidant ability as well as composition of the so-prepared extracts. The influence of extraction conditions on the entire monitored characteristics was insignificant. Keywords: grape skin, ethanol extracts, PFE, EPR, DPPH, ABTS Journal: Czech Journal of Food Sciences Pages: S43-S48 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/245/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/245/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0008.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:245-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Pavel STOPKA Author-Workplace-Name: Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic, Husinec-Řež, Czech Republic Author-Name: Jana KŘÍŽOVÁ Author-Workplace-Name: Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic, Husinec-Řež, Czech Republic Author-Name: Naděžda VRCHOTOVÁ Author-Workplace-Name: Department of Viticulture and Oenology Author-Name: Petra BÁBÍKOVÁ Author-Name: Jan TŘÍSKA Author-Workplace-Name: Department of Viticulture and Oenology Author-Name: Josef BALÍK Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: Marie KYSELÁKOVÁ Title: Antioxidant activity of wines and related matters studied by EPR spectroscopy Abstract: 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 used for the production of white wines. For all monitored wines there was established a clear decrease in free Tempol radicals to the average value of 75.5 ± 15.6% as compared to the original EPR spectrum. A higher antioxidant activity was observed in yeast sediments from the production of red wines than in those from white ones. Keywords: antioxidant activity, EPR, wine, vine grape, vine leaf, yeast sediment Journal: Czech Journal of Food Sciences Pages: S49-S54 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/248/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/248/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0009.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:248-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: JIŘÍ TOTUŠEK Author-Workplace-Name: Department of Viticulture and Oenology@2 Author-Name: DANUŠE LEFNEROVÁ Author-Workplace-Name: Department of Viticulture and Oenology@2 Author-Name: MARIE KYSELÁKOVÁ Author-Name: JOSEF BALÍK Author-Workplace-Name: Department of Post-harvest Technology of Horticultural Products, Faculty of Horticulture, Mendel University of Agriculture and Forestry in Brno, Lednice, Czech Republic Author-Name: JAROMÍR VEVERKA Author-Name: JAN TŘÍSKA Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Author-Name: NADĚŽDA VRCHOTOVÁ Author-Workplace-Name: Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic Title: Antimutagenic activity of raw materials and by-products by production of grape wines Abstract: 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 applied. An increased risk of MNU is due to its possible endogenous formation. Fermentation sediment after vinification of the varieties Chardonnay, Welschriesling and André was tested by similar experimental system. All extracts showed strong positive inhibition of mutagenicity, berries infested with Botrytis cinerea also in diluted extracts. Positive inhibition was demonstrated also by fermentation sludge. Keywords: wine, grape berries, polyphenolic compounds, antimutagenicity Journal: Czech Journal of Food Sciences Pages: S55-S59 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/247/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/247/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0010.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:247-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ondřej ZENDULKA Author-Workplace-Name: Department of Pharmacology and Author-Name: Lucia ZAHRADNÍKOVÁ Author-Workplace-Name: Department of Pharmacology and Author-Name: Jan JUŘICA Author-Workplace-Name: Department of Pharmacology and Author-Name: Jiří TOTUŠEK Author-Workplace-Name: Department of Preventive Medicine, Faculty of Medicine, Masaryk University, Brno, Czech Republic Title: The influence of trans-resveratrol and quercetin on the activity of CYP1A2 in rat Abstract: 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 and trans-resveratrol on the activity of cytochrome P450 1A2 in rats. A perfused rat liver model and phenacetin as a marker of 1A2 activity were used. Moreover, we studied the dependence of trans-resveratrol's activity on sex in both sexes. Trans-resveratrol did not influence the 1A2 activity, but it enhanced sexual differences in the metabolic activity. Our results also confirmed different metabolic activities between sexes. Female rats metabolised faster through 1A2. Based on our results, we suggest that quercetin is an inhibitor of cytochrome P450 1A2 isoenzyme. Keywords: trans-resveratrol, quercetin, CYP 1A2, rat Journal: Czech Journal of Food Sciences Pages: S60-S64 Volume: 26 Issue: SpecialIssue Year: 2008 DOI: 10.17221/244/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/244/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200810-0011.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:SpecialIssue:id:244-2008-CJFS