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 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 Prague, Prague, Czech Republic
Title: Biosynthesis of food constituents: Vitamins. 1. Fat-soluble vitamins - a review
Abstract: This review article gives a survey of the generally accepted biosynthetic pathways that lead to fat-soluble vitamins (vitamin A, vitamin D, vitamin E, vitamin K, the corresponding provitamins, and the closely related ubiquinones and plastoquinones) in animals, plants, and microorganisms. Extensively used are reaction schemes, sequences, and mechanisms with the enzymes involved, with detailed explanations using chemical principles and mechanisms.
Keywords: biosynthesis, vitamin A, vitamin D, vitamin E, vitamin K, retinal, 3, 4-didehydroretinol, retinoids, 7-dehydrocholesterol, cholecalciferol, ergosterol, ergocalciferol, tocopherols, tocotrienols, ubiquinones, plastoquinones, phylloquinone, menaquinones
Journal: Czech Journal of Food Sciences
Pages: 1-16
Volume: 25
Issue: 1
Year: 2007
DOI: 10.17221/736-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/736-CJFS.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200701-0001.txt
Handle: RePEc:caa:jnlcjf:v:25:y:2007:i:1:id:736-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Petr Botek
Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology 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 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 Prague, Prague, Czech Republic
Title: Determination of banned dyes in spices by liquid chromatography-mass spectrometry
Abstract: A simple and rapid multiresidue method for the determination of nine banned synthetic dyes in various spices has been developed. Reversed phase HPLC coupled with mass spectrometry (tandem in time-ion trap mass analyser) was employed for the examination of crude acetonitrile extract acidified with acetic acid. The detection limits of Para Red, Sudan Orange G, Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Red 7B and Rhodamine B were in the range of 0.02-0.1 mg/kg, the recoveries ranged from 75.7-92.3% with repeatability of 0.9-11.3%. Rather worse performance characteristics were obtained with Tropaeolin 000, obviously due to its more polar nature as compared to other dyes involved in this study. In spite of that, the developed method can be used for a reliable control of a wide range of dyes used for illegal colouring of various spices.
Keywords: Sudan dyes, Para Red, Rhodamine B, chilli, curry, liquid chromatography-mass spectrometry
Journal: Czech Journal of Food Sciences
Pages: 17-24
Volume: 25
Issue: 1
Year: 2007
DOI: 10.17221/737-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/737-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:25:y:2007:i:1:id:737-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Kateřina Míčková
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Author-Name: Jana Čopíková
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Author-Name: Andriy Synytsya
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Title: Determination of polydextrose as a fat replacer in butter
Abstract: Polydextrose is used in several countries as a low caloric sugar and fat substitute (bulking agent). It is prepared by condensation of glucose, D-glucitol, and citric acid (89:10:1). The resulting condensation product has no chemically defined structure but it represents a mixture of polymerisation products. The determination of polydextrose in butter is complicated owing to a large excess of fats and to the presence of other compounds, mainly proteins. FT-IR spectroscopy seems to be a satisfying method for the detection of polydextrose in samples derived from food products. The presence of polydextrose in butter was verified after the removal of fats by extraction with petroleum ether and deproteinisation with Sevag reagent, CHCl3/n-butanol (v/v = 4:1) mixture, or trichlorocetic acid. The solid fraction of butter and butter containing a known amount of polydextrose were prepared and analysed by FT-IR spectroscopy. IR marker bands of polydextrose centred at 1150, 1076 and 1040 cm-1 were found only in the case of the sample of butter with polydextrose.
Keywords: polydextrose, litesse, fat replacer, butter, FT-IR
Journal: Czech Journal of Food Sciences
Pages: 25-31
Volume: 25
Issue: 1
Year: 2007
DOI: 10.17221/738-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/738-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:25:y:2007:i:1:id:738-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Andriy Synytsya
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Author-Name: Lucie Fesslová
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Author-Name: Milan Marounek
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Author-Name: Jana Čopíková
Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Title: Sodium cholate sorption on N-octadecylpectinamide in comparison with cholestyramine
Abstract: N-Octadecylpectinamide is hydrophobically modified HM citrus pectin. Previously, it had been prepared by heterogeneous amino-de-alkoxylation of initial pectin with n-octadecylamine in dimethylsulphoxide and characterised as potential hydrophobic sorbent and cholesterol lowering agent. The sorption properties of N-octadecylpectinamide were analysed in comparison with cholestyramine, an effective bile acid sequestrant. Sorption experiments were carried out using sodium cholate as a model bile acid. Cholate concentration was estimated by enzymatic spectroscopic method. Sorption kinetics curves and sorption isotherms of both sorbents were constructed and analysed.
Keywords: N-octadecylpctinamide, cholestyramine, sodium cholate, sorption kinetics, sorption isotherm
Journal: Czech Journal of Food Sciences
Pages: 32-38
Volume: 25
Issue: 1
Year: 2007
DOI: 10.17221/739-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/739-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:25:y:2007:i:1:id:739-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Veronika Divinová
Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic
Author-Name: Marek Doležal
Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology 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 Prague, Prague, Czech Republic
Title: Free and bound 3-chloropropane-1,2-diol in coffee surrogates and malts
Abstract: The levels are reported of the free 3-chloropropane-1,2-diol (3-MCPD), its bound forms, the recognised precursors of 3-MCPD, and the factors influencing its formation in 5 selected coffee surrogates and 18 malts in the Czech Republic. The coffee surrogates had the free 3-MCPD level in the range of < 9.0 to 32 µg/kg while the highest amount was found in roasted barley. In malts, the free 3-MCPD levels were similarly low (< 9.0 to 45 µg/kg) being the highest in roasted malts (16-45 µg/kg). Nevertheless, the values found in either surrogates or malts, calculated after normalisation to 40% dry matter content, did not exceed the European Union limit of 20 µg/kg adopted for soy sauces and acid-HVP. The risk for consumers could arise from the bound 3-MCPD, its elevated levels having been found in both coffee surrogates and malts. In coffee surrogates, the bound 3-MCPD levels varied between 145-1184 µg/kg product; the highest level was found in roasted barley. The bound 3-MCPD levels exceeded the free 3-MCPD levels 32 to 81 times. In malts, the bound 3-MCPD levels ranged from 4.0-650 µg/kg, the highest amount having been found in roasted malts (463-650 µg/kg). The bound 3-MCPD levels exceeded the free 3-MCPD levels 0.4 to 36 times.
Keywords: chloropropanols, 3-chloropropane-1, 2-diol, 3-MCPD, bound 3-MCPD, 3-MCPD esters, contaminants, coffee surrogate, malt
Journal: Czech Journal of Food Sciences
Pages: 39-47
Volume: 25
Issue: 1
Year: 2007
DOI: 10.17221/735-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/735-CJFS.html
File-Format: text/html
X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200701-0005.txt
Handle: RePEc:caa:jnlcjf:v:25:y:2007:i:1:id:735-CJFS