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: Amino acids: 2. The alanine-valine-leucine, serine-cysteine-glycine, and aromatic and heterocyclic amino acids groups - a review
Abstract: This review article gives a survey of principal pathways that lead to the biosynthesis of the proteinogenic amino acids of the alanine-valine-leucine group starting with pyruvic acid from the glycolytic pathway and serine-cysteine-glycine group starting with 3-phospho-d-glyceric acid from the glycolytic pathway. A survey is further given to the aromatic and heterocyclic amino acids (phenylalanine, tyrosine, tryptophan, histidine) starting with 3-phosphoenolpyruvic acid from the glycolytic pathway and d-erythrose 4-phosphate, an intermediate in the pentose phosphate cycle and Calvin cycle.
Keywords: biosynthesis, amino acids, alanine, valine, leucine, serine, glycine, cysteine, phenylalanine, tyrosine, tryptophan, histidine
Journal: Czech Journal of Food Sciences
Pages: 45-58
Volume: 24
Issue: 2
Year: 2006
DOI: 10.17221/3299-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3299-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:2:id:3299-CJFS

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: Amino acids. 3. Modified proteinogenic amino acids - a review
Abstract: This review article gives a survey of principal pathways that lead to the biosynthesis of the modified principal proteinogenic amino acids, i.e. cystine, 4-hydroxyproline, 5-hydroxylysine, 3-methylhistidine, and O-phosphoserine. Except the proteinogenic amino acids, peptides and proteins often contain several unusual amino acids arising by specific modifications (e.g. oxidation or esterification) of amino acid residues present in the already synthesised polypeptide chain. The post-translational products include, e.g., the oxidation of the thiol groups of two cysteine residues to form a disulfide bridge (cystine), thus allowing cross-linking of polypeptide chains; the hydroxylation of proline to 4-hydroxyproline and of lysine to 5-hydroxylysine; N-methylation of histidine to 3-methylhistidine; and the phosphorylation of serine to O-phosphoserine. There also exist several other modified proteinogenic amino acids that are of minor significance to foods.
Keywords: biosynthesis, amino acids, cystine, hydroxyproline, hydroxylysine, methylhistidine, phosphoserine
Journal: Czech Journal of Food Sciences
Pages: 59-61
Volume: 24
Issue: 2
Year: 2006
DOI: 10.17221/3300-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3300-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:2:id:3300-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Renée Street
Author-Workplace-Name: Department of Soil Science and Geology and
Author-Name: Jiřina Száková
Author-Workplace-Name: Department of Agrochemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Agriculture in Prague, Prague, Czech Republic
Author-Name: Ondřej Drábek
Author-Workplace-Name: Department of Soil Science and Geology and
Author-Name: Lenka Mládková
Author-Workplace-Name: Department of Soil Science and Geology and
Title: The status of micronutrients (Cu, Fe, Mn, Zn) in tea and tea infusions in selected samples imported to the Czech Republic
Abstract: A total of 30 tea samples of different origins, thirteen green tea samples, thirteen black tea samples, two semi-fermented tea samples and one white tea, imported to the Czech Republic, were collected and analysed for the total content of copper, iron, manganese, and zinc in tea leaves and tea infusions. The total contents of metals in tea leaves differ according to the type of tea (green or black) and are probably influenced by many other factors, e.g. soil properties. The total contents of Mn were much higher compared to the total contents of Cu, Fe, and Zn, and varied between 511-2220 mg/kg. To compare easily hot water soluble concentrations of Cu, Fe, Mn and Zn, 5 min, 60 min, and 24 h infusions were prepared. The extractability of the elements was in the order Cu > Zn > Mn > Fe. The proportions of the element contents in the infusion related to the respective total contents in leaves were 30 ± 16% Cu, 26 ± 10% Zn, 18 ± 10% Mn, and 1.5 ± 0.8% Fe, respectively. The results confirmed that tea infusion can be an important dietary source of Mn.
Keywords: tea, tea infusion, copper, iron, manganese, zinc, nutrient status
Journal: Czech Journal of Food Sciences
Pages: 62-71
Volume: 24
Issue: 2
Year: 2006
DOI: 10.17221/3301-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3301-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:2:id:3301-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Petr Šmerák
Author-Workplace-Name: Department of General Biology and Genetics and 4Department of General Hygiene, Center of Biomedical Science, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
Author-Name: Zdeňka Polívková
Author-Workplace-Name: Department of General Biology and Genetics and 4Department of General Hygiene, Center of Biomedical Science, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
Author-Name: Helena Šestáková
Author-Workplace-Name: National Institute of Public Health, Prague, Czech Republic
Author-Name: Rudolf Štětina
Author-Workplace-Name: Faculty of Military Health Sciences, Department of Toxicology, Hradec Kralové, Czech Republic
Author-Name: Ivo Bárta
Author-Workplace-Name: Department of General Biology and Genetics and 4Department of General Hygiene, Center of Biomedical Science, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
Author-Name: Martina Langová
Author-Workplace-Name: Department of General Biology and Genetics and 4Department of General Hygiene, Center of Biomedical Science, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
Author-Name: Bohumil Turek
Author-Workplace-Name: National Institute of Public Health, Prague, Czech Republic
Author-Name: Jiřina Bártová
Title: Antimutagenic effect of curcumin and its effect on the immune response in mice
Abstract: A wide array of antioxidative and anti-inflammatory substances derived from edible plants have been reported to possess chemopreventive and chemoprotective activities. Among the most extensively investigated and well-defined dietary chemopreventives is curcumin. Using the Ames test and in vivo micronucleus test, chemiluminescence test, blastic transformation test, and comet assay, we examined the antimutagenic effects of the chemically identified chemoprotective substance curcumin (diferuloylmethane) in the pure form on mutagenicity induced by three reference mutagens: aflatoxin B1 (AFB1), 2-amino-3-metylimidazo[4,5-f]quinoline (IQ), and N-nitroso-N-metylurea (MNU), and the effect of curcumin on the immunosuppression caused by these mutagens. Curcumin in the pure form showed a clear antimutagenic and immunomodulatory activities on mutagenicity and immunosuppression induced by reference mutagens.
Keywords: curcumin, antimutagenic effects, response of immune, Ames test, micronucleus test, comet assay, chemiluminescence, blastic transformation tests
Journal: Czech Journal of Food Sciences
Pages: 72-83
Volume: 24
Issue: 2
Year: 2006
DOI: 10.17221/3302-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3302-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:2:id:3302-CJFS

Template-Type: ReDIF-Article 1.0
Author-Name: Milena Dömötörová
Author-Workplace-Name: Department of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
Author-Name: Andrea Hercegová
Author-Workplace-Name: Department of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
Author-Name: Eva Matisová
Author-Workplace-Name: Department of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak Republic
Title: Monitoring of pesticide residues in apples from Slovakia for baby food production
Abstract: There is a basic lack of information about the presence of pesticide residues in apples obtained from farms in Slovakia collaborating with baby food producer. Residues of several pesticides (widely used for the protection on apple trees) have been determined in apples (a common raw material for the baby food production and baby food) from Slovakia (agricultural area in the South of Slovakia). The analysis of the pesticides was performed by gas chromatography on CP-Sil 5 CB (15 m long, 0.15 mm I.D., film thickness 0.15 μm) with normal bore retention gap (1 m long, 0.32 mm I.D.) using the subsequent determination with MS detector in SIM mode, after the acetonitrile extraction of the pesticide residues from apples, the clean-up and preconcentration steps of samples with SPE-NH2. For the study pesticides belonging to various groups were selected, such as organophosporus pesticides, oximinoacetates, anilinopyrimidines, triazoles, and triazines pyrethroids. The GC-MS analysis of pesticide residues in all samples searched showed that most of the detected and quantified residues were below 10 μg/kg which corresponds to the maximum residual limit for pesticide residues in baby food.
Keywords: pesticides, apples, baby food, sample preparation, fast CG
Journal: Czech Journal of Food Sciences
Pages: 84-92
Volume: 24
Issue: 2
Year: 2006
DOI: 10.17221/3303-CJFS
File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3303-CJFS.html
File-Format: text/html
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Handle: RePEc:caa:jnlcjf:v:24:y:2006:i:2:id:3303-CJFS