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Biosynthesis of food constituents: Amino acids: 2. The alanine-valine-leucine, serine-cysteine-glycine, and aromatic and heterocyclic amino acids groups - a reviewJan Velíšek, Karel CejpekCzech J. Food Sci., 2006, 24(2):45-58 | DOI: 10.17221/3299-CJFS 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. |
Antimutagenic effect of epigallocatechin gallate and its effect on the immune response in micePetr Šmerák, Helena Šestáková, Zdeňka Polívková, Rudolf Štětina, Martina Langová, Ivo Bárta, Bohumil Turek, Jiřina BártováCzech J. Food Sci., 2006, 24(4):180-192 | DOI: 10.17221/3315-CJFS Green tea is the second-most consumed beverage in the world (water is the first one) and has been used medicinally for centuries in Indiaand China. The active substances in the green tea are polyphenols (catechins) and flavonols which possess a potent antioxidant activity. Epigallocatechin gallate (EGCG) is one of the four major green tea catechins. Using the Ames test, micronucleus test, comet assay, chemiluminescence test, and blastic transformation test, we examined the antimutagenic effects of chemoprotective substance epigallocatechin gallate (EGCG) in the pure form on the mutagenicity induced by three reference mutagens: aflatoxin B1 (AFB1), 2-amino-3-methylimidazo [4,5-f] qui-noline (IQ), and N-nitroso-N-methylurea (MNU), and the effect of EGCG on the immunosuppression caused by these mutagens. Using the Ames test the dose dependent antimutagenic activity of EGCG was proved against indirect mutagens AFB1 and IQ, but not against the direct mutagen MNU. In the micronucleus test, EGCG had antimutagenic effect upon all three mutagens. EGCG decreased the level of DNA breaks induced by AFB1 in bone marrow cells and colon epithelium, and the level of DNA breaks induced by MNU in colon cells to the level found in control. The reparatory effect of EGCG on immunosupression induced by all three carcinogenic compounds was proved using chemiluminescence and blastic trasformation tests. |
Genetic and Physical Mapping of Genic Microsatellites in Barley (Hordeum vulgare L.)R K Varshney, U Hähnel, T Thiel, N Stein, L Altschmied, P Langridge, A GranerCzech J. Genet. Plant Breed., 2005, 41(4):153-159 | DOI: 10.17221/3661-CJGPB Due to the availability of sequence data from large-scale EST (expressed sequence tag) projects, it has become feasible to develop microsatellite or simple sequence repeat (SSR) markers from genes. A set of 111 090 barley ESTs (corresponding to 55.9 Mb of sequence) was employed for the identification of microsatellites with the help of a PERL5 script called MISA. As a result, a total of 9 564 microsatellites were identified in 8 766 ESTs (SSR-ESTs). Cluster analysis revealed the presence of 2 823 non-redundant SSR-ESTs in this set. From these 754 primer pairs were designed and analysed in a set of seven genotypes including the parents of three mapping populations. Finally, 185 microsatellite (EST-SSRs) loci were placed onto the barley genetic map. These markers show a uniform distribution on all the linkage groups ranging from 21 markers (on 7H) to 35 markers (3H). The polymorphism information content (PIC) for the developed markers ranged from 0.24 to 0.78 with an average of 0.48. For the assignment of these markers to BAC clones, a PCR-based strategy was established to screen the "Morex"-BAC library. By using this strategy BAC addresses were obtained for a total of 127 mapped EST-SSRs, which may provide at least two markers located on a single BAC. This observation is indicative of an uneven distribution of genes and may lead to the identification of gene-rich regions in the barley genome. |
Effects of dietary vitamin E and vitamin C supplementation on the level of α-tocopherol and L-ascorbic acid in muscle and on the antioxidative status and meat quality of pigsR. Lahučký, I. Bahelka, K. Novotná, K. VašíčkováCzech J. Anim. Sci., 2005, 50(4):175-184 | DOI: 10.17221/4012-CJAS In total thirty pigs (Slovak Meaty) defined by DNA based test as not susceptible to malignant hyperthermia (non-mutant on RYR1) were used in the experiment. Treatment consisted in supplementation of vitamin E (500 mg α-tocopherol/kg diet as α-tocopherol acetate) (group E) and the same doses of vitamin E plus vitamin C (200 mg L-ascorbic acid/kg diet) (group E + C) to finishing pigs for the last 30 days before slaughter. The higher dietary vitamin E level resulted in higher levels of α-tocopherol in fresh (24 h), chill-stored (5 days, 4°C), chill-stored and cooked (80°C) and frozen meat (3 months, -25°C), (P < 0.05). Higher dietary vitamin C resulted in higher levels L-ascorbic acid in fresh and chill-stored meat (P < 0.05) but no significant differences vs. control pigs were observed in cooked and frozen meats. Supplementation with vitamins E and C (group E + C) had positive effects on pH (45 min) (P = 0.06) and on drip loss (P < 0.05) values as compared to control group. The rate of oxidation (malondialdehyde-MDA production) by stimulation with Fe2+/ascorbate (incubation of muscle LD for 0 and 30 min) was higher in control group as compared to both experimental groups (P < 0.05). Positive effects of vitamin E on oxidative stability measured as thiobarbituric acid reactive substances (TBARS, MDA) were observed mainly in chill-stored meat (P < 0.05). Using TBARS method, no additional effect of vitamin C on oxidative stability of fresh, chill-stored, cooked and frozen meat was found. In conclusion, supplementation of the combination of vitamin E (500 mg α-tocopherol/kg diet) and vitamin C (200 mg L-ascorbic acid/kg diet) for 30 days before slaughter improved meat quality values (drip loss, pH), however, it seems to depend on the genetic background of animals (occurrence of mutation on RYR1). Oxidative stability of meat lipids measured as TBARS value can be improved by vitamin E supplementation to feed. |
Determination of the contents of A- and B-starches in barley using Low Angle Laser Light ScatteringIvan Bohačenko, Josef Chmelík, Vratislav PsotaCzech J. Food Sci., 2006, 24(1):11-18 | DOI: 10.17221/3288-CJFS A method was proposed for the determination of the contents of A- and B-starches in barley and for the use in plant breeding stations and brewing/malting laboratories. A combination was used of classical methods (incl. crushing of barley kernels by a roll crusher, steeping in 0.02M HCl, repeated rubbing and filtering through the sieve of 0.08 mm), and novel pieces of know-how (treatment with β-glucanase and cellulase, alkalisation at pH = 10.0 and centrifugation of crude starch suspension through the layer of CsCl). In this way, barley starch of high purity was obtained at a very low loss, using Low Angle Laser Light Scattering for the determination of the size distribution of starch granules. The boundary of the particle size between the peaks of A-starch and B-starch (7 µm) was evaluated from the distribution curves, while the contents of A- and B-starches were calculated from the cumulative curves. As a whole, the method was internally validated and for its repeatability and uncertainty of measurement the stimates of standard deviation s = 1.56 and confidence interval L1,2 = x± 1.9% were established, respectively. Taking into account the generally well known difficulties associated with the extraction of substances from biological materials, in this case the separation of starch from barley kernels, we believe that the proposed method will bring satisfactory results in practice. |
Effect of plastic packages on benzo[a]pyrene concentration in sunflower oilPeter Šimko, Božena Skláršová, Peter Šimon, Elena BelajováCzech J. Food Sci., 2006, 24(3):143-148 | DOI: 10.17221/3310-CJFS Commercially available sunflower oil and the same oil distilled additionally in a molecular evaporator (to remove naturally occurring compounds) was spiked with benzo[a]pyrene (BaP) at the levels of 37.1 and 38.6 μg/kg, respectively. Then, it was filled into polyethylene terephtalate (PET) and low density polyethylene (LDPE) receptacles of cylindrical shape, and BaP concentration was followed within 49 h. At the end of the experiments, BaP concentration in the non-distilled oil packed into PET decreased to 25.9 μg/kg, and BaP concentration in the distilled oil decreased to 34.6 μg/kg. The rate and the extent of BaP removal were evaluated comparing the diffusion and equilibrium coefficients. The results showed that PET is able to reduce BaP concentration in sunflower oil due to BaP sorption on the PET surface, but the rate and the extent of BaP removal are also affected by other compounds present in the oil. As found, LDPE is an inappropriate material for the BaP removal from sunflower and rapeseed oils, because BaP concentration in the oils remained at a constant level during the whole experiment. |
Occurrence of Alternaria toxins in fibre flax, linseed, and peas grown in organic and conventional farms: Monitoring pilot studyJana Králová, Jana Hajšlová, Jan Poustka, Miroslav Hochman, Marie Bjelková, Lenka OdstrčilováCzech J. Food Sci., 2006, 24(6):288-296 | DOI: 10.17221/3327-CJFS Fungi representing Alternaria spp. are ubiquitous pathogens that may under certain conditions cause spoilage of various food crops. Several Alternaria species are known producers of toxic secondary metabolites in some fruits and vegetables, nevertheless, only limited knowledge is available on the occurrence of these mycotoxins in legumes and/or oilseeds used for human nutrition. In the first part of the presented study, the analytical method employing reversed phase high-performance liquid chromatography (HPLC) coupled with fluorescence detection (FLD) was implemented to enable the examination of these food commodities for the presence of altenuene (AE), alternariol (AOH), and alternariol monomethyl ether (AME); the limits of detection were 1, 3 and 2 µg/kg for AE, AOH, and AME, respectively. Altogether 122 flax and 84 pea seed samples grown under organic and/or conventional farming conditions were analysed in the years 2002-2003. AME was detected in 20 flax seed samples; AE and AOH were present in only 2 and 4 samples, respectively. More frequent incidence of Alternaria toxins was recognised in fibre flax seeds as compared to linseed samples. Compared to the crops from the conventional farming, the concentrations of these mycotoxins found in positive organic samples were higher. No Alternaria mycotoxins were detected in the pea samples, probably due to the presence of antifungal compounds in the respective crop. |
Vegetation of the Nature Reserve Voskop (Protected Landscape Area Český kras) and possible trends of its developmentOriginal PaperJ. Möllerová, J. VieweghJ. For. Sci., 2005, 51(20):24-26 | DOI: 10.17221/11845-JFS Nine plots on transect situated through the ridge of Nature Reserve (NR) Voskop (Protected Landscape Area Český kras) demonstrate local vegetation variability. Ordinations with some transformation phytosociological relevés showed possible development trends. |
Changes in the macrocomponents and microstructure of white bean seeds upon mild hydrothermal treatmentMaria Soral-Śmietana, Urszula KrupaCzech J. Food Sci., 2005, 23(2):74-83 | DOI: 10.17221/3375-CJFS The mild hydrothermal treatment (water bath at 40°C/24 h) of three Polish bean varieties (Phaseolus vulgaris and Phaseolus coccineus) with different sizes of seeds: the small-seed variety Raba, the medium-seed variety Aura, the large-seed variety Eureka, had a significant effect on the microstructure of the cross-sections of bean cotyledons. The first 3 hours were decisive with almost all physical and chemical parameters investigated in the study. After this time, the highest water binding or water holding capacities were observed. The tendency to a distinct decrease in the resistant starch fraction was observed especially in the large and medium bean seeds (Phaseolus sp.), based on the comparison before and after the processing. It seems that the too high dietary fibre content determined in the study resulted from exceptional sorption properties while the especially high increase in the insoluble fraction of dietary fibre (IDF) was observed during this mild hydrothermal treatment. This suggests the possibility of the occurrence of hydrophilic domains in dietary fibre. Although it cannot be explained explicitly, distinct differences were found in both fractions of dietary fibre in the varieties examined. The results obtained indicate that the conditions of the mild hydrothermal treatment can affect the nutritional and non-nutritional components of bean seeds which play an important role in the human gastrointestinal tract as both food products and diet components. |
A study of the factors affecting the foaming properties of egg white - a reviewKateryna Lomakina, Kamila MíkováCzech J. Food Sci., 2006, 24(3):110-118 | DOI: 10.17221/3305-CJFS Many foods are prepared using egg white, most of them being based on the foaming properties of egg white which are due to albumen proteins ability to encapsulate and retain air. Therefore, many scientists aim to find new methods to improve the volume and the stability of egg white foam. This paper is a review of various factors affecting the foaming ability of egg white. |
Factors affecting growth traits of beef cattle breeds raised inSlovakiaE. Krupa, M. Oravcová, P. Polák, J. Huba, Z. KrupováCzech J. Anim. Sci., 2005, 50(1):14-21 | DOI: 10.17221/3990-CJAS Growth traits of purebred calves of six beef breeds (Aberdeen Angus - AA, Blonde d'Aquitaine - BA, Charolais - CH,Hereford - HE, Limousine - LI and Beef Simmental - BS) born from 1998 to 2002 were analysed. Traits under study were birth weight (BW), weight at 120 days (W120), weight at 210 days - weaning weight (WW), weight at 365 days - yearling weight (YW) and average daily gains from birth to 120 days (ADG1), from birth to 210 days (ADG2), from birth to 365 days (ADG3), from 120 to 210 days (ADG4). General linear model with class effects of breed, dam's age at calving, sex, herd-year-season (HYS) and covariation of age at weighing was used for analyses. All effects significantly affected both weight and gain traits except for dam's age that was significant for BW, W120, YW and ADG3, and age at weighing that was significant for W120, WW, YW, ADG2, ADG3, ADG4. Estimated least squares means of growth traits were compared using Scheffe's multiple-range tests. Highest BW (40.57 kg) and W120 (172.43 kg) were found for BA calves. BS calves had highest WW (260.30 kg), YW (424.07 kg), ADG1 (1 154 g), ADG2 (1 053 g), ADG3 (1 054 g) and ADG4 (1 098 g). Highest BW, YW, ADG3 and ADG4 were found for males-singles. Males-twins had highest W120, WW, ADG1 and ADG2. Calves descending from 5-7 years old dams had highest BW, W120, WW, ADG1, ADG2 and ADG4. The proportion of variability of growth traits explained by HYS effect (42.96-71.69%) was high, whereas proportions of variability explained by SEX effect (2.03-5.77%), age of dam (1.02-2.24%) and breed (1.05-2.21%) were low. Residuals accounted for 23.71 up to 53.79% of total variance. |
Changes in cold hardiness of silver fir and larch bare-rooted seedlings during autumn and springM. SarvašJ. For. Sci., 2004, 50(5):237-242 | DOI: 10.17221/4620-JFS The objective of this study was to obtain information about changes in cold hardiness of larch and silver fir seedlings during autumn and spring by help of measurements of electrolyte leakage from shoots (SEL) and root system (REL). The values of electrolyte leakage from the untreated (control) root system of silver fir decreased during autumn (from 28% on September 25 to 24% on November 27). Minimum values were reached on March 26. A decrease in electrolyte leakage was found for silver fir shoots (SEL) (the maximum was detected on October 2 - 12% and minimum on November 27 - 7%). Contrary to REL, SEL increased in March. The rate of electrolyte leakage from treated (after artificial frost) roots and shoots decreased during autumn (REL and SEL minimum on November 27). The change in the rate of electrolyte leakage from untreated larch roots was similar to that from silver fir roots during autumn. The values continually decreased from 26% (on September 25) to 12% (on November 27). The course of electrolyte leakage from the treated root system was similar for both species. The differences between electrolyte leakage from larch shoots (treated und untreated ones) were statistically significant, but without any clear tendency during autumn. |
Biosynthesis of food constituents: Amino acids. 3. Modified proteinogenic amino acids - a reviewJan Velíšek, Karel CejpekCzech J. Food Sci., 2006, 24(2):59-61 | DOI: 10.17221/3300-CJFS 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. |
Biosynthesis of food constituents: Lipids. 1. Fatty acids and derivated compounds - a reviewJan Velíšek, Karel CejpekCzech J. Food Sci., 2006, 24(5):193-216 | DOI: 10.17221/3317-CJFS This review article gives a survey of the principal biosynthetic pathways that lead to the most important common fatty acids and their derivatives occurring in foods and feeds. Fatty acids are further subdivided to saturated fatty acids and unsaturated fatty acids. This review is focused on the less common fatty acids including geometrical and positional isomers of unsaturated fatty acids, acetylenic fatty acids, branched-chain fatty acids, alicyclic fatty acids, epoxy fatty acids, hydroxy fatty acids, and oxo fatty acids. A survey is further given on the biosynthesis of the aliphatic very-long-chain components (alkanes, primary and secondary alcohols, aldehydes, ketones, and esters) of plant cuticular wax derived from saturated fatty acids. Subdivision of the topics is predominantly via biosynthesis. There is extensive use of reaction schemes, sequences, and mechanisms with enzymes involved and detailed explanations using chemical principles and mechanisms. |
Effect of cadmium on flavonoid content in young barley (Hordeum sativum L.) plantsJ. Lachman, J. Dudjak, D. Miholová, D. Kolihová, V. PivecPlant Soil Environ., 2005, 51(11):513-516 | DOI: 10.17221/3625-PSE The effect of an abiotic stress caused by cadmium on the total flavonoid content in roots, shoots and leaf blades of spring barley variety Kompakt grown in a climate-control room for 28 days was investigated. Total flavonoid content (F) was determined spectrophotometrically with sodium nitrite, Cd content by atomic absorption spectrometry. Treatment of barley plants with Cd (1.10-6 mol/l) in nutrition solution caused the decrease of F in the all parts of the plant. The relatively highest decrease was found in the roots (from 20.0 to 3.05 g/kg dry matter), lesser decrease in the shoots (from 24.2 to 9.33 g/kg dry matter) and the leaf blades (from 58.3 to 27.3 g/kg dry matter). Statistically significant decrease (at least p < 0.05) of F and increase of Cd contents in all the investigated parts of the plant was found. Statistically significant differences of F and Cd contents among barley roots, shoots, and leaf blades were found. |
Non-contact thermometry in the milking stopping control systemI. Karas, R. GálikCzech J. Anim. Sci., 2005, 50(5):196-200 | DOI: 10.17221/4148-CJAS The paper deals with the detection of "idle milking" times for individual quarters of the udder in a group of dairy cows (randomly selected) in a parallel 2 × 12 milking parlour. A non-contact laser thermometer Raynger ST-6 was used to measure temperatures of the inner surfaces of liners instantly after milking. In a group of 12 dairy cows, the minimum liner temperature after milking was 15.3°C, the maximum temperature was 28.9°C. It follows from the regression correlation that an increase in the cooling time by 1 second decreases the temperature of the liner inner surface by 0.0324°C. On average, fore left quarters were milked idle 2.55 min, fore right 2.21 min, rear left 0.24 min, rear right 0.56 min. Differences in the temperatures of liner inner surfaces determined between fore and rear udder quarters were statistically significant; the negative statistically significant correlation coefficient was recorded between the total milking time and the temperature of liners in fore quarters (r = -0.7802++, resp. r = -0.6058+). |
Biosynthesis of food constituents: Peptides - a reviewJan Velíšek, Roman Kubec, Karel CejpekCzech J. Food Sci., 2006, 24(4):149-155 | DOI: 10.17221/3311-CJFS This review article gives a brief survey of principal pathways that lead to the biosynthesis of most important peptides occurring in foods. Glutathione, selected plant γ-glutamyl peptides, and animal histidine dipeptides are included in this review. |
Antimutagenic effect of genisteinZdeňka Polívková, Martina Langová, Petr Šmerák, Jiřina Bártová, Ivo BártaCzech J. Food Sci., 2006, 24(3):119-126 | DOI: 10.17221/3306-CJFS A great variety of health benefits including the protection against breast and prostate cancers has been attributed to the soya consumption, because of the presence of soy beans isoflavones, genistein, and others. We investigated the antigenotoxic effect of genistein on the genotoxicity of three mutagens and carcinogens - aflatoxine B1 (AFB1), 2-amino-3-methylimidazo [4,5-f]quinoline (IQ), and N-nitroso-N-methylurea (MNU), using the Ames bacterial mutagenicity test and the micronucleus test. In the Ames test on Salmonella typhimurium, a significant antimutagenic effect was determined against the indirect mutagen AFB1 in two strains, TA98 and TA100. However, the effect on the IQ indirect mutagenicity was more pronounced in the test with TA98 than with TA100. The mutagenicity of the direct mutagen MNU was suppressed by genistein only at its highest concentration used (300 µg/plate). The protective effect of genistein against all three mutagens was proved in the micronucleus test as the treatment of mice with the combinations of genistein and mutagens resulted in a significant reduction of the number of micronuclei in comparison with the number of micronuclei induced by the individual mutagens alone. |
Freezing point of heat-treated drinking milk in the Czech RepublicPavlína Navrátilová, Bohumíra Janštová, Petra Glossová, Lenka VorlováCzech J. Food Sci., 2006, 24(4):156-163 | DOI: 10.17221/3313-CJFS In theCzechRepublic, the freezing point of milk is presently used as a quality indicator of cows' raw milk as well as of heat-treated drinking milk, and its limit value is ≤ -0.520°C. Of the total of 295 drinking milk samples examined over a period of one year, 145 were samples of pasteurised milk and 150 were samples of UHT milk. In compliance with the Czech State Standard57 05 38, the freezing point was determined by a thermistor cryoscope. The measured mean value of the freezing point of the heat-treated drinking milk was -0.515°C ± 0.0078. A total of 207 (70.2%) samples of the heat-treated drinking milk, i.e. 93 (64.1%) samples of pasteurised and 114 (76%) samples of UHT milk, were found above the maximum limit value. The unsatisfactory results of the monitoring of the freezing point of drinking milk emphasise the need for a reassessment of the current system of the milk quality evaluation with respect to this quality index. |
Solid-phase microextraction for analysis of mould cheese aromaEva Vítová, Blanka Loupancová, Jana Zemanová, Hana Štoudková, Pavel Březina, Libor BabákCzech J. Food Sci., 2006, 24(6):268-274 | DOI: 10.17221/3324-CJFS Solid-phase microextraction coupled with gas chromatography was used for the analysis of volatile aroma compounds in Niva cheese. The extraction conditions were very mild, which minimises thermal, mechanical, or chemical modification of the sample; the method is rapid, simple, and cheap. In total, 54 compounds were identified in Niva cheese using this method: 3 hydrocarbons, 5 aldehydes, 11 ketones, 18 alcohols, 3 esters, 10 fatty acids, and 4 sulphur compounds. These aroma compounds were quantified and subsequently the changes in the concentrations of them were studied throughout the ripening period. Most of the volatile compounds identified were present at all stages of the cheese ripening, their amounts changing significantly, however, in most cases the final concentration in the ripe cheeses was similar to the initial concentration in the unripe cheese. |
Phthalic acid esters (PAEs) in the food chainAlžbeta JarošováCzech J. Food Sci., 2006, 24(5):223-231 | DOI: 10.17221/3318-CJFS Phthalic acid esters (PAEs) rank among the primary risk pollutants and their adverse effects may endanger the environmental balance and affect the ontogenetic development of live organisms and their body functions. Therefore, the aim of this study was to monitor the occurrence of PAEs in packaging materials and plastics (infusion sets), to evaluate the accumulation and distribution of the most common phthalates such as DEHP (di-2-ethylhexyl phthalate) and DBP (di-n-butyl phthalate) in body tissues and organs of pigs and broiler chicks having been administered the phthalates per os, to assess the occurrence of PAEs in pig and cattle farms in the district of Hodonín (1997-1999), and to propose precautionary measures to mitigate the risk of PAE penetration into the food chain and the environments. DEHP and DBP contents in packaging materials ranged from 0.1 to 4259 mg DEHP, and from 0.1 to 1298 mg DBP per 1 kg printed packaging material, respectively. In haemodialysis patients, over 0.5 mg DEHP per 1 kg blood was found after three hours of haemodialysis. In combined feeds for farm animals (pigs, cattle, poultry), DEHP and DBP concentrations ranging from 0.07 to 1.77 and from 0.06 to 2.36 mg/kg feed, respectively, were detected. In all the food samples investigated, measurable levels of DEHP (less than 0.01-0.22 mg/kgsample) and DBP (less than 0.01 to 1.31 mg/kgsample) were found. In the experimental pigs and broilers, phthalates were distributed in all the organs monitored and the highest accumulation was found in adipose tissue as expected. All the samples withdrawn from farms in the Hodonín district had measurable phthalate concentrations; the hygienic limit (4 mg/kg) was exceeded in 2 samples of swine adipose tissue (4.26 and 6.92 mg/kgfresh sample) and in 1 sample of cattle adipose tissue (4.75 mg/kgfresh sample). |
Winter Wheat MarkolaF. Ondrejčák, D. MuchováCzech J. Genet. Plant Breed., 2006, 42(1):23-24 | DOI: 10.17221/6053-CJGPB |
The RAPD analysis of several cultivars of grapevine (Vitis viniferaL.) and their clonesH. Vlastníková, K. Moravcová, M. PidraHort. Sci. (Prague), 2004, 31(4):136-139 | DOI: 10.17221/3807-HORTSCI Nine identification RAPD markers (Moravcová et al. 2003) were used to distinguish 24 clones and grapevine cultivars. No polymorphism was detected among all the tested clones of Chardonnay, Pinot gris and Zweigeltrebe from Polešovice. Pinot noir, Pinot gris, Pinot blanc and Pinot Meunier were indistinguishable within clones, they also showed the identical RAPD profile within cultivars (except discussed sample No. 26). On the other hand, Auxerrois as a relative to cultivars of Pinot group showed unique patterns and may be classified as a different cultivar. Some irregularities within the cultivars of Pinot family from Oblekovice were also found, several of them gave different results from those expected: Pinot blanc sample 26 has the RAPD profile typical of Chardonnay. A new abnormal RAPD pattern as a marker of typical Chardonnay and Pinot profiles was observed in two cases. While RAPD banding patterns could not distinguish between the known clones, they were useful for distinguishing between phenotypically similar cultivars and for assessing the origins of cultivars thought to have originated as sports. |
Mapping spatial variability of soil properties and yield by using geostatic methodM. Kroulík, M. Mimra, F. Kumhála, V. ProšekRes. Agr. Eng., 2006, 52(1):17-24 | DOI: 10.17221/4875-RAE The Czech University of Agriculture in Prague (CUA) Farm at Lány started with precision farming technology several years ago. In the first step the yield and nutrients content were monitored. For precision application development, detailed description of soil conditions and interrelationship will be necessary. Pulling force and soil electric conductivity measurement as indirect measuring methods were used for mapping spatial soil variability. These methods demonstrate other ways for description of complex soil media. |
Occurrence, development and natural enemies of Pemphigus spyrothecae (Homoptera, Pemphigidae)Original PaperJ. UrbanJ. For. Sci., 2002, 48(6):248-270 | DOI: 10.17221/11883-JFS In 2001, galls were analysed of Pemphigus spyrothecae Pass. taken in one- to three-week intervals from Populus nigra and P. nigra var. italica at 4 localities in Brno. Fundatrices matured in the first half of June and during the first half of summer produced about 50 offsprings. Virgines produced about 10 offsprings which grew up in winged sexuparae. The winged individuals started to occur in galls from the beginning of August. In galls with intact development, on average 500 aphids developed. Galls with intact development on P. nigra var. italica reached larger average dimensions and contained at least by 4% more aphids than galls on P. nigra. About 5% of fundatrices died already in the 1st instar and other 3 to 6% in higher instars by the beginning of reproduction. At localities under investigation, 7.5 to 39.0% of galls on P. nigra and 3.9 to 13.7% of galls on P. nigra var. italica were occupied by the fly Leucopis puncticornis Meig. (Chamaemyiidae). About 24.3 to 32.2% of galls on P. nigra and 23.3 to 49.3% of galls on P. nigra var. italica were occupied by the bug Anthocoris minki Dohrn (Anthocoridae). Hover flies Heringia heringi (Zett.) and Pipiza festiva Meig. (Syrphidae) killing aphids in 3.8 to 30.4% of galls on P. nigra and 6.5 to 6.8% of galls on P. nigra var. italica were an important regulator. In August (i.e. at the beginning of the formation of winged sexuparae), the majority of galls opened through primary slit-shaped or oval emergence holes. A part (7.8 to 19.5%) of galls with so far intact development, however, remained closed and all aphids contained in them died. Diseases (particularly mycoses) often participated in the accelerated dying of aphids. The effect of mortality factors on the gall size differentiation was evaluated in details. The galls do not cause any leaf area reduction. In the case of mass outbreak, they decrease decorativeness of poplars in street alleys. In August and September, liquid excrements fall out from the galls (honeydew) polluting the environment in villages and housing estates. |
Fungal contamination and the levels of mycotoxins (Don and Ota) in cereal samples from poland and east slovakiaEva Čonková, Anna Laciaková, Igor Štyriak, Ludwik Czerwiecki, Grażyna WilczyńskaCzech J. Food Sci., 2006, 24(1):33-40 | DOI: 10.17221/3291-CJFS The cereal samples were taken immediately after harvest from the selected localities of Poland(45 samples) and East Slovakia(60 samples). Fungal contamination of these samples was investigated and subsequently the presence of two important mycotoxins, deoxynivalenol (DON) and ochratoxin A (OTA), was quantitatively examined. Concerning mould contamination, no difference was observed between the samples from Polandand East Slovakia. The highest incidence was observed of Fusarium, Aspergillus, and Penicillium genera. However, most of the investigated samples of wheat, rye, and barley contained less than 104 cfu/g. The limit 750 ppb for DON in cereals and their products, recommended by the European Mycotoxin Awareness Network (EMAN), was exceeded only by one wheat sample (4.5%) fromPoland, but by seven wheat samples (14.6%) fromSlovakia. None cereal sample investigated for OTA exceeded the allowed limit - 5 µg/kg. |
Effect of enzymatic activity of diesel oil contaminated soil on the chemical composition of oat (Avena sativa L.) and maize (Zea mays L.)M. Wyszkowski, J. WyszkowskaPlant Soil Environ., 2005, 51(8):360-367 | DOI: 10.17221/3611-PSE The aim of the study was to determine the effect of soil contamination with diesel oil (3, 6, 9, 12 and 24 g/kg soil) on the yield and the content of macroelements in oat and maize cultivated in soil supplemented with nitrogen and sawdust. The correlation between the content of macroelements in the crops and the soil enzymatic activity was also determined. High doses of diesel oil had a definite negative effect on the content of all macroelements in oat, excluding phosphorus. The presence of diesel oil had a favourable effect on the accumulation of most of macroelements in the above-ground parts of maize. Nitrogen application to the soil caused an increase in the content of nitrogen and in the accumulation of calcium and magnesium in the above-ground parts of both crops as well as an increase in sodium content in maize. Sawdust applied to the soil had a considerably lower effect (several to less than 20%) on the content of macroelements in plants. A correlation between the activity of urease and acid and alkaline phosphatase in the soil and the content of macroelements in plants cultivated in diesel oil contaminated soil was observed. This correlation was positive only in the case of alkaline phosphatase activity and phosphorus content in oats. |
Effects of pectin and carrageenan on thermophysical and rheological properties of tapioca starchJurislav Babić, Drago Šubarić, Đurđica Ačkar, Vlasta Piližota, Mirela Kopjar, Nela Nedić TibanCzech J. Food Sci., 2006, 24(6):275-282 | DOI: 10.17221/3325-CJFS The effects of hydrocolloids pectin, carrageenan, as well as of pectin/carrageenan mixtures on gelatinisation, retrogradation, rheological characteristics, and swelling power of tapioca starch were studied with Brookfield rotational viscometer and differential scanning calorimeter (DSC). The results showed that hydrocolloids retarded the retrogradation of tapioca starch. Enthalpy and temperatures of gelatinisation, as well as solubility, did not vary significantly in starch-hydrocolloid systems. Viscosity of tapioca starch increased on the addition of hydrocolloids: the effect of carrageenan on viscosity was more remarkable than that of pectin. |
Comparison of in vitro gas production technique with in situ nylon bag technique to estimate dry matter degradationA. Kamalak, O. Canbolat, Y. Gurbuz, O. OzayCzech J. Anim. Sci., 2005, 50(2):60-67 | DOI: 10.17221/3996-CJAS Dry matter (DM) degradation of wheat straw (WS), barley straw (BS), lucerne hay (LH) and maize silage (MS) was determined using two different techniques: (i) in vitro gas production and (ii) nylon bag degradability technique. In vitro gas production and in situ DM disappearance were measured after 3, 6, 12, 24, 48, 72 and 96 hours of incubation. In situ and in vitro DM degradation kinetics was described using the equation y = a + b (1 - ect). In all incubations there were significant (P < 0.001) correlations between gas production and in situ DM disappearance or estimated parameters ((a + b)gas and (a + b)is or (a + b)gas and EDMDis) whereas there were no significant (P > 0.05) correlations between cgas and cis or bgas and bis. Gas production from the insoluble fraction (b) alone explained 98.3% of the variation of EDMD. The inclusion of gas production from the quickly soluble fraction (a) and rate constant (c) of gas production in the regression equation improved the accuracy of EDMD prediction. The correlations between the results of both methodologies seem to be sufficiently strong to predict degradability parameters from gas production parameters. It was concluded that the in vitro gas production technique has good potentiality to predict in situ DM disappearance and some DM degradation parameters. |
Monitoring of pesticide residues in apples from Slovakia for baby food productionMilena Dömötörová, Andrea Hercegová, Eva MatisováCzech J. Food Sci., 2006, 24(2):84-92 | DOI: 10.17221/3303-CJFS 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. |
