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Polychlorinated biphenyls (PCBs) and phytoestrogens were found to affect contractions of bovine uterus. Prostaglandins (PG) F_2á and E₂ are also involved in the uterine contractility. Hence the aim of these studies was to investigate the effect of PCBs and some phytoestrogens on PG secretion from endometrial cells obtained on days 1-5 of the oestrous cycle. Cells were incubated in aerated atmosphere at 38°C for 24 h, separately with the mixture of PCBs - Aroclor 1248 (10 ng/ml), with individual congeners -77, -126 or -153 (each at the dose 100 g/ml), coumestrol, daidzein or genistein (each at the dose 10^-6M) or jointly each PCB with each of the phytoestrogens. Using the TOX1-kit neither Aroclor 1248 (Ar 1248) nor individual congeners were found to affect the viability of cells compared to the control (P > 0.05). All used PCBs markedly increased the metabolite of PGF_2á(PGFM) concentrations (P < 0.05) but not PGE₂ (P > 0.05). Hence the ratio of PGF_2á to PGE₂ was also increased by PCBs. However, when these cells were incubated with each of the phytoestrogens, there was a decrease in both PGF_2á and PGE₂ secretion compared to the control (P < 0.05) but without altering the PGF_2á : PGE₂ ratio. Moreover, phytoestrogens could clearly reduce the concentrations of PGFM elicited by PCBs, and they reduced PGE₂ secretion compared to that evoked by PCB-126 and -153 only. Thus phytoestrogens can restore the proper ratio of PGF_2á : PGE₂ secreted by the bovine endometrium.

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.

A PCR method previously developed for typing Mycobacterium avium was used to characterize the genetic diversity of M. avium strains isolated from swine (n = 90) and humans (n = 24). The strains were identified with IS901 PCR and IS1245 PCR: 38 strains were of IS901+ and IS1245+ genotype (M. avium subsp. avium) and 76 strains were of IS901- and IS1245+ genotype (M. avium subsp. hominissuis). All human isolates were IS901 negative. IS1245-IS1311 spacer typing was successfully accomplished for 59 isolates while 55 isolates gave no amplification signal. The isolates with negative typing results were additionally tested for the presence of IS1311 and all with the exception of one gave positive results. IS1245-IS1311 spacer typing failed in all IS901+ isolates as they yielded no bands. A high degree of heterogeneity among isolates was observed: 59 isolates demonstrated 43 different patterns comprising up to 6 bands.

The correlations between longevity, functional longevity, stayability and selected milk, reproductive and type traits were estimated; it was done on the basis of estimated breeding values for longevity, functional longevity, dairy traits, reproductive traits and stayability rates at the age of 60, 72, 84, and 96 months. The correlation between breeding values for longevity and functional longevity was 0.69. The correlations between longevity and stayability at 60, 72, 84, and 96 months of age were around 0.75 (from 0.73 to 0.76) whereas the correlation with stayability at 48 months was considerably lower (0.64). The breeding values for dairy traits showed a positive relationship with longevity (from 0.37 to 0.46) and a slightly negative correlation with breeding values for functional longevity (from -0.10 to -0.20). A low relationship was found between longevity and reproductive traits. Between the type traits and longevity traits only the conformation score for the form (0.18) and for the udder showed a positive correlation (0.24). The correlation between the form and functional longevity remained approximately on the same level whereas the correlation with the main udder score decreased to 0.08, which indicated a positive relationship between milk traits and udder scores.

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.

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.

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).

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.

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.

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.

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.

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⁺).

In 1995-1997 seven varieties of potatoes were cultivated in field trials in twelve localities in the Czech Republic. Six of the twelve localities were situated in lower, warmer and drier areas with fertile, predominantly loamy soils. The other localities were situated in higher, colder and more humid areas. They represent traditional potato-growing areas in the Czech Republic. After harvest potato tubers of all varieties were analysed for resistance to mechanical damage, dry matter content, reducing sugar (RS) content, nitrate content, polyphenol content. Glycoalkaloid (GA) content was analysed only in Karin variety. In all experimental years potatoes cultivated at lower altitudes contained less RS (by 22%), less polyphenolic compounds (by 5.8%), higher percentage of tubers not mechanically damaged with the rebound pendulum (by 12.7%), compared to tubers from higher localities. On the other hand, tubers grown at lower altitudes contained more nitrates (by 26.8%) in all three years. Over the three years, the average of results in Karin variety did not demonstrate the influence of environmental conditions of the areas on GA content in tubers.

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.

The analysis of the trace elements has been shown to be a valuable tool to discriminate wines according to their region of origin. As, Ba, Ca, Co, Cr, Li, Mg, Rb, Sn, Sr, and V were selected as specific markers indicating the origin of Slovak wines according to the vineyard regions. Several factors, such as the environmental contamination, agricultural practices, climatic changes, and others, may markedly change the multielement composition of the wine and may endanger the relationship between the wine and the soil composition. The effect was studied of the viniculture process on the distribution of selected markers in the winemaking products. The main markers pass from the vineyard soil to the grape, and the main portion leaves the winemaking process in the press cake and yeast lees. Very significant correlation of the wine origin markers was found between changed the wine making products and the vineyard soils. The sugar addition to grape juice to some extent the total element compositions of wines but did not result in substantial changes of the markers determining the wine origin.

The formation of 3-chloropropane-1,2-diol (3-MCPD) released from its esters with higher fatty acids was studied using the recognised precursors of 3-MCPD (tripalmitin, 1,3-dipalmitin, 1-monopalmitin and soybean oil) in the presence of sodium chloride. The precursors were reacted with sodium chloride in an emulsion stabilised with an emulsifier under conditions which modelled the thermal treatment of foods during processing. The highest amount of bound 3-MCPD (released from its esters) was formed from 1-monopalmitin followed by 1,3-dipalmitin, whereas tripalmitin and soybean oil yielded the lowest levels of bound 3-MCPD. Four sets of experiments were then carried out aimed at monitoring the influence of various factors (soybean oil amount, NaCl content, water content, and temperature) on the yield of bound 3-MCPD. The formation of bound 3-MCPD was directly proportional to the concentration of either oil or NaCl. The highest amount of bound 3-MCPD was formed in media containing approximately 20% water. The amount of bound 3-MCPD decreased with increasing temperature over the range 100-230°C and reached its highest value at 100°C. Models with 1,2-dipalmitoyl-3-chloropropane-1,2-diol showed that the decomposition rate of this ester rapidly increased with increasing temperature over the range 100-230°C being the lowest at 100°C and the highest at 230°C.

This review article gives a survey of principal pathways that lead to the biosynthesis of the proteinogenic amino acids of the glutamic acid group (glutamic acid, glutamine, proline, arginine) and aspartic acid group (aspartic acid, asparagine, threonine, methionine, lysine, isoleucine) starting with oxaloacetic acid from the citric acid cycle. There is an extensive use of reaction schemes, sequences, and mechanisms with the enzymes involved and detailed explanations using sound chemical principles and mechanisms.

The aim of the present study was to develop a rapid and inexpensive method for the determination of methylmercury in fish tissues based on GC/ECD instrumentation. The new method is based on acidic digestion in hydrochloric acid and subsequent extraction with toluene. Methylmercury is determined by the GC/ECD technique using a DB-608 capillary column. The following parameters of the method were established: detection limit 13 μg/kg, limit of quantification 22 μg/kg, linearity 0.2-200 ng/ml, reproducibility 9.4%, and recovery 90%. The method was developed and verified using CRM 464 reference material and was successfully tested in inter-laboratory comparisons IMEP - 20 "Trace elements in tuna fish" organised by the Joint Research Centre - Institute for Reference Materials and Measurements (Belgium), with the success rate of E_n=0.43.

Sensory profiles of saccharin, acesulfame K, aspartame, and neotame were compared with that of sucrose in three different types of water (tap water, commerical Crystalis water, and distilled water) under the conditions of the respective ISO standards. The intensities of off-flavours, especially bitter and metallic tastes, were higher in the solutions of synthetic sweeteners than in that of sucrose. The aspartame solution was the sample closest to the sucrose solution, and the intensity of off-flavours was significantly higher in acesulfame solution. Ratings of the bitter taste were related to those of the metallic taste, the relation being semilogarithmic. The performancies of different assessors were nearly the same in all ratings, and the absolute values of the ratings of sweetness and different off-flavours had the same repeatabilities. The relative accuracy was, naturally, much higher in off-flavours than in the case of sweetness.

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.

This review article gives a brief survey of the principal pathways that lead to the biosynthesis of the most important non-protein amino acids occurring in foods and feeds. These amino acids have been divided into the following groups: 3-amino acids and 4-amino acids, N-substituted amino acids, alicyclic amino acids, hydroxyamino acids, sulfur-containing amino acids, basic amino acids, and taurine.

This review article gives a survey of the principal biosynthetic pathways that lead to the most important food glycerolipids, i.e. triacylglycerols, glycerophospholipids, and glyceroglycolipids as reported in recently published papers. Glycerophospholipids are further subdivided to phosphatides, lysophosphatides, and plasmalogens. The subdivision of the topics is predominantly via biosynthesis. Reaction schemes, sequences, and mechanisms with the enzymes involved are extensively used as well as detailed explanations based on chemical principles and mechanisms.

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.

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.

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.

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.

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.

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 L_1,2 = 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.

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.