Template-Type: ReDIF-Article 1.0 Author-Name: Jan Velíšek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jiří Davídek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Karel Cejpek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Biosynthesis of food constituents: Natural pigments. Part 2 - a review Abstract: This review article is a part of the survey of the generally accepted biosynthetic pathways that lead to the most important natural pigments in organisms closely related to foods and feeds. The biosynthetic pathways leading to xanthones, flavonoids, carotenoids, and some minor pigments are described including the enzymes involved and reaction schemes with detailed mechanisms. Keywords: biosynthesis, xanthones, flavonoids, isoflavonoids, neoflavonoids, flavonols, (epi)catechins, flavandiols, leucoanthocyanidins, flavanones, dihydroflavones, flavanonoles, dihydroflavonols, flavones, anthocyanidins, anthocyanins, chalcones, dihydrochalcones, quinochalcones, aurones, isochromenes, curcuminoids, carotenoids, carotenes, xanthophylls, apocarotenoids, iridoids Journal: Czech Journal of Food Sciences Pages: 73-98 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/2463-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2463-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0001.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:2463-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Pavel KADLEC Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology and Author-Name: Jana DOSTÁLOVÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jana BERNÁŠKOVÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Michaela SKULINOVÁ Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology and Title: Degradation of α-galactosides during the germination of grain legume seeds Abstract: Germination is one of the most effective ways of preparing grain legumes for consumption. Because it involves the total or partial elimination of some anti-nutritional compounds, it is also one of the simplest methods of enhancing the palatability of grain legumes, thereby increasing their consumption as a valuable source of nutrition. The main objective of this paper is to describe the changes that take place in α-galactosides during germination. During germination, galactose molecules gradually become detached from α-galactosides due to the effect of the enzyme α-D-galactosidase activated during the process. To simulate the degradation of α-galactosides during legume seed germination, we applied nine equations to the evaluation of the experimental data obtained with the germination of three types of grain legume seeds; mung bean, chickpea, and lentil. Keywords: α -galactosides, germination, grain legume seeds Journal: Czech Journal of Food Sciences Pages: 99-108 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/3/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0002.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:3-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ebru Firatligil-Durmuş Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Evžen Šárka Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Zdeněk Bubník Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Image vision technology for the characterisation of shape and geometrical properties of two varieties of lentil grown in Turkey Abstract: Geometrical features of lentil seeds (Lens culinaris Medik) were analysed using the image analysis LUCIA system Ver. 3.52. The values of the weight of 1000 kernels, kernel density, specific volume, specific surface area, and surface area of 1000 kernels of red and green lentils were determined as 66.61 and 138.56 g, 1504.5 and 1376.4 kg/m3, 0.6647 and 0.7265 cm3/g, 0.594 and 0.579 m2/kg, 395.4 and 801.9 cm2,, respectively. The lentil volume was simulated by an oblate spheroid and two sphere segments and the volumes obtained with both models were compared with that obtained by pycnometric method. Percentage differences of the two sphere segment approximation for red and green lentils were 4.4% and 4.2%, respectively. The height (thickness) of lentils was constant and practically the same with both varieties (2.6 mm) and therefore it was possible to simplify the geometrical models. Thus, 2D image analysis is suitable for a quick evaluation of the specific volume and surface area of grains on the basis of the projected area (equivalent diameter) without the measurement of the height. Image processing provides a simple, rapid, and non-invasive methodology to estimate lentil geometric features and engineering parameters. Keywords: image analysis, lentil, legumes, size parameters, geometrical model Journal: Czech Journal of Food Sciences Pages: 109-116 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/1/2008-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/1/2008-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0003.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:1-2008-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ondřej Novotný Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Karel Cejpek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jan Velíšek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Formation of carboxylic acids during degradation of monosaccharides Abstract: The formation of low molecular carboxylic and hydroxycarboxylic acids as well as sugar and deoxysugar acids from monosaccharides (D-glucose, D-fructose, D-arabinose, DL-glyceraldehyde, and 1,3-dihydroxyacetone) was studied in three different model systems: aqueous and alkaline solutions of potassium peroxodisulfate (K2S2O8), and sodium hydroxide solution. In total, 3 low molecular carboxylic acids (formic, acetic and propionic), 24 hydroxycarboxylic acids, and 12 corresponding lactones were identified and quantified by GC/MS. Formic, acetic, and propionic acids were isolated by extraction with diethyl ether and directly analysed by GC/MS; hydroxycarboxylic acids and their lactones were monitored as their trimethylsilylated derivatives using the same method. Formic, acetic, L-lactic, glycollic, DL-2,4-dihydroxybutanoic acids and aldonic acids derived from the parent sugars were the most abundant compounds in all model systems. Within the models investigated, the yield of carboxylic acids and hydroxycarboxylic acids (together with their lactones) ranged between 9.3-22.2% (n/n) and between 3.6-116.9% (n/n), respectively. The amount of acids was significantly lower in aqueous solutions of K2S2O8 than in the alkaline solutions. The data obtained indicate that lower carboxylic acids are formed by both subsequent reactions (oxidation and/or intramolecular Cannizzaro reaction) of the sugar fragmentation products and direct decomposition of some intermediates such as uloses or hydroperoxides derived from the parent sugars. The acids possessing the original sugar skeleton are formed as a result of sugar oxidation or benzilic acid type rearrangement of deoxyuloses. Lower acids may also be formed by a recombination of free radicals. Keywords: carboxylic acids, hydroxycarboxylic acids, lactones, oxidation, Cannizzaro reaction, benzilic acid type rearrangement, peroxodisulfate Journal: Czech Journal of Food Sciences Pages: 113-131 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/2465-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2465-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0004.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:2465-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Lucie BUŘIČOVÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Zuzana RÉBLOVÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Czech medicinal plants as possible sources of antioxidants Abstract: The antioxidant activity of 17 Czech medicinal plants was studied and compared with the antioxidant activity of green tea. The antioxidant activities of water and ethanol extracts of the plants tested were determined by a spectrophotometric method using the stable free radical DPPH (2,2-diphenyl-1-picrylhydrazyl), and further the contents of the compounds with reducing properties in water extracts were determined by flow injection analysis with amperometric detection (using a detection potential +0.7 V). Considerable antioxidant activities were found in the extracts of plants from the Rosaceae family (rosehips and leaves of raspberry, blackberry, and strawberry), the Lamiaceae family (oregano, sweet balm, thyme, dead-nettle, and mint), and flowers of linden and elder. Keywords: antioxidant activity, plant extracts, free radicals DPPH Journal: Czech Journal of Food Sciences Pages: 132-138 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/2468-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2468-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0005.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:2468-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Zdeňka PANOVSKÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Alena ŠEDIVÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Markéta JEDELSKÁ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jan POKORNÝ Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Effect of ethanol on interactions of bitter and sweet tastes in aqueous solutions Abstract: Experimental samples simulated the composition of vermouths. In all experiments, 0.01% quinine was used as a standard bitter substance. Sucrose increased the acceptability in the concentration range of up to 14%, remaining constant at higher concentrations, both in aqueous and 16% ethanolic solutions. A decrease of bitterness was observed in water but not in 16% ethanol. Ethanol did not affect the sweetness appreciably at the concentrations of up to 16%, but 32% ethanolic solutions appeared less sweet. Ethanol enhanced the bitterness only at high concentrations; interactions were similar in the samples containing 10% and 16% sucrose. Aspartame and Neotame sweetness increased the acceptability and decreased the bitterness similarly to sucrose, both in aqueous and in 16% ethanolic solutions. Keywords: sweetness, bitterness, ethanol, sucrose, Aspartame, Neotame, sensory analysis Journal: Czech Journal of Food Sciences Pages: 139-145 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/2466-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2466-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0006.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:2466-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Tomáš Kovalczuk Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jan Poustka Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: Jana Hajšlová Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: HPLC-MS/MS method for analysis of isoproturon in difficult matrix: poppy seeds Abstract: While several validated methods have been developed for analysis of phenylurea herbicides in staple food plants, analytical procedures suitable for their quantification in minor crops such as poppy seeds are not available. For the registration of isoproturon use in this crop, the documentation of dynamics of its residues following treatment was requested. To accomplish this task, HPLC-MS/MS method was developed. Extraction of residues was realised by methanol-water mixture, Supelclean LC-18 SPE cartridges were used for purification of crude extracts. For HPLC separation of isoproturon SPE fraction Lichrospher C18 column (25 cm × 4 mm, 5 μm) was employed. For detection and quantification of target analyte, mass spectrometer with ion trap analyser operated in positive atmospheric pressure chemical ionisation (APCI) and MS/MS mode was used. Following performance parameters of method were obtained: detection limit 0.01 mg/kg, recovery 84%, and repeatability 7%. Keywords: HPLC-MS/MS, isoproturon, method development, SPE, poppy seeds Journal: Czech Journal of Food Sciences Pages: 146-152 Volume: 26 Issue: 2 Year: 2008 DOI: 10.17221/2469-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/2469-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200802-0007.txt Handle: RePEc:caa:jnlcjf:v:26:y:2008:i:2:id:2469-CJFS