Authors:V. Stehlik-Tomas, S. Grba, D. Stanzer, N. Vahčić, and V. Gulan Zetić
Procedures for the production of Saccharomyces cerevisiae biomass enriched with iron and the effects of the iron ions addition into the molasses medium on the yeast growth and the production of ethanol were studied. The growth of the yeast S. cerevisiae and the ethanol production in media with different concentrations of Fe were monitored in the batch process under semiaerobic and anaerobic conditions. The highest biomass concentration and ethanol production were achieved in the medium with 0.6-0.8 g l-1 of Fe under both (semiaerobic and anaerobic) conditions. Kinetics of the iron ions accumulation in yeast cells during 24 h of growth in the batch process under semiaerobic and anaerobic conditions were monitored. In anaerobic conditions the maximum uptake (10 mg g-1 d.m. yeast biomass) was obtained after 12 h of fermentation, while in semiaerobic conditions a four times lower uptake (2.5 mg g-1 d.m. yeast biomass) was obtained after 16 h of fermentation.
Authors:L. Körmendy, E. Zukál, I. Csapó, and N. Török
The aim of this study was a survey of relationships used for calculating ‘meat content’ with respect to the QUID regulation (Commission Directive
, 2001). The recommended equations are presented in a concise form. The advantages of a possible introduction of the meat equivalent concept are also treated [assessment of lean content of the meat ingredient(s)]. A non-negligible condition for applying the QUID equations is, in principle, the equality of the fat-free protein concentrations of the various tissue types in the raw meat materials. This needs an adjustment of the protein concentrations of the recipes to a reference value (PFFref), which can be achieved by effective or virtual addition of water to the formulation or ‘removal’ of water from it. The influence of moisture loss during meat processing on QUID is also discussed. The results of various calculation methods are presented with examples.
Authors:Cs. Mohácsi-Farkas, G. Kiskó, L. Mészáros, and J. Farkas
Laboratory batches of fresh tomato juices were treated in several experimental trials by high hydrostatic pressure alone or in combination with various concentrations of oregano, thyme or dill seed oils. Lactic acid bacteria formed the dominating component of the spoilage microbiota during post-processing storage at 15 °C causing spoilage of the untreated samples within 4 days. One tenth of a percent oregano or thyme oils at least doubled the microbiological shelf life, while their respective concentrations of 0.5% alone, or 400 MPa 5-20 min high hydrostatic pressure treatment alone resulted in microbial stability for at least two weeks. Two hundred MPa for 10 min resulted only in an approx. 3 days delay of spoilage, whereas 0.1% thyme oil increased the efficiency of this moderate UHP-treatment, resulting in a microbiologically stable product for at least 3 weeks at the storage temperature applied.
Authors:L. Simon-Sarkadi, É. Gelencsér, and A. Vida
A novel screening immunoassay for histamine was used for detection of histamine in different foodstuffs. The detection limit of this assay was 20 µg kg-1. The concentration of histamine varied between 182-982 µg kg-1 in sauerkraut, cheese and fish samples and 26-18433 µg l-1 in milk, sparkling wine and wines. The applied competitive enzyme immunoassay (ELISA) seemed a reliable technique for simple and rapid determination of histamine in food.
Authors:LJ. Glavaš-Obrovac, T. Opačak, V. Bareš, D. Šubarić, J. Babić, V. Ilakovac, and I. Karner
Recent studies performed on some tumour cell lines have given proof to the antiproliferative activity of compounds isolated from red wines against tumours. The purpose of this study was to evaluate potential cytotoxic activity of different concentrations of selected Croatian red and white wines on the growth of human normal and tumour cells in vitro. Effects on growth of cervical carcinoma (HeLa), colon carcinoma (Caco-2, HT-29), poorly differentiated cells from lymph node metastasis of colon carcinoma (SW-620), larynx carcinoma cells (HEp-2) and normal fibroblasts (WI38) were tested by MTT-assay. Radioactive substrate incorporation tests were used for assessing effects on DNA, RNAs and proteins syntheses. Concentration of polyphenols in wines was assessed according to the method of Singleton and Rossi. Ethanol in the wine concentrates was determined by MS-GC method. Results of the cytotoxicity test showed that colon carcinoma cells (Caco-2, HT-29), as well as colon carcinoma metastasis (SW620) were the most affected by dealcoholized red wines in concentrations 25% and 12.5% v/v. Amount of total phenols in the red wines was significantly higher (5-10 times) compared to the white wines. The red wine with the greatest polyphenol content was shown to be the most effective. Red wine samples in concentration 25% v/v statistically significantly inhibited the growth of all tested cell lines, including fibroblasts. Tested white wines showed no or negligible growth inhibitory effect against tumour and normal cells. Tumour cells, HeLa and Hep-2, treated by red wine V3 (12.5% v/v) and Hep-2 cells treated by red wine V4 (12.5% v/v) exhibited slightly growth-stimulatory effects. Biosynthesis assay of DNA, RNA and proteins indicated a standstill in the growth of treated cells. Our results indicate that polyphenol-rich domestic wine might have potential pro-therapeutic effect on transformed colonic cells.
Authors:J. Varga, R. Kiss, T. Mátrai, T. Mátrai, and J. Téren
Ochratoxin A is a mycotoxin produced by Aspergillus and Penicillium species. This mycotoxin is a common contaminant of various food products including cereal products, spices, dried fruits, coffee, beer and wine. Besides cereal products, beer and wine contribute significantly to ochratoxin exposure of humans. We examined the ochratoxin content of Hungarian wines and beers using an immunochemical technique. The detection limit of this technique is 0.01mg l-1. Altogether 65 wine and 25 beer samples were analysed. The presence of ochratoxin A was confirmed by HPLC in positive samples. Ochratoxin A was detected in 97.7% of wines, with ochratoxin concentrations ranging from 0 to 0.533mg l-1. The mean ochratoxin A concentration in wines was 0.110mg l-1. Only one of the Hungarian wines examined contained more than 0.5mg l-1ochratoxin A, the previously suggested EU limit for wine. Our data indicate that red wines are more frequently contaminated, and have higher mean ochratoxin contamination (0.117mg ml-1) than white wines (0.0967mg ml-1), in accordance with previous observations. A North-South gradient in wine ochratoxin concentrations is not evident from our data. For beers, all but one of the samples was found to be contaminated with small amounts of ochratoxin A with a mean concentration of 0.127mg l-1(range: 0.030-0.250mg l-1). Only one of the beers contained ochratoxin A above 0.2mg l-1, the anticipated European Community maximum allowable limit in beer. We could not detect correlation between the type and origin of beer and ochratoxin contamination.
Road traffic flows in intersections are modeled in this article. Cost of CO2, CO, CH, NOx, PM and value of travel time have been used in order to estimate the social costs arising at the intersections. The article presents assumptions for constructing the mathematical model, it describes the mathematical model and gives simulation results. Traffic flow parameters, as traffic flow concentration and traffic flow speed are presented as based on real traffic data.
Recently several studies have focused on the antioxidant activity of lycopene such as quenching of singlet oxygen and scavenging of peroxyl radicals. These properties may play a role in the prevention of different cancer and heart diseases. Tomato is one of the most important sources of lycopene. The main information on the effect of environmental parameters on quality and health-retaining constituents of tomato fruit is mostly related to temperature (air- and fruit canopy temperature) and light effects that might provide a stress to the fruit. Nowadays little is know about the direct effect of elevated CO2.The aim of the present work was to evaluate the effects of elevated CO2 in Perspex open top chambers (OTC) on the lycopene content of tomato fruit.Experiments on the effects of elevated CO2 concentrations showed mixed results. In this work it was found that concentrations of lycopene in a fruit decreased significantly when elevated CO2 was used. Elevated nitrogen sources generated only slight, but not significant difference in the lycopene concentration of tomato fruit.
A strain of Saccharomyces cerevisiae used in the food industry was propagated in the presence of zirconium ascorbate or zirconium citrate complex. The propagation of the yeast was slightly inhibited by zirconium (Zr) in a complex form, but it was not toxic. The Zr content in the fermentation medium decreased faster when using ascorbate complex than the citrate complex. The ascorbate complex was better accumulated by the yeast (4300 mg Zr g-1 dry mass) than the citrate complex (1600 mg Zr g-1 dry mass). The total amino acid content of the yeast cells decreased in the presence of both complexes. The concentration of some amino acids [threonine (Thr), proline (Pro), phenylalanine and cysteine (Cys)] was increased by 10-39% in the medium containing Zr ascorbate, while that of other amino acids [arginine (Arg), serine (Ser), methionine (Met) and glutamic acid (Glu)] decreased by 18-60%. As a result of the presence of zirconium citrate the concentration of Glu, aspartic acid (Asp), leucine (Leu), Thr, valine (Val), Ser, Arg, Pro and Met decreased by 19-32%, and the concentration of Cys increased by 59%.
Authors:Kalman Buzas, Peter Budai, and Adrienne Clement
One and a half year long field sampling was established in order to evaluate the contamination of storm water runoff. The event means (EMC) total petroleum hydrocarbons (TPH) concentration of the runoff was a function of the actual traffic intensity and the rainfall depth. It was concluded that this TPH, of which dominant component is the engine-oil (characteristically C28) does not form an ‘oil-in-water’ type emulsion in the condition of normal motorway-operation, but is interlocked to asphalt, rubber and soot particles of maximum some ten microns size. This condition influences the possibility, way and extent of separation alike. The separation equipments and their sizing applied so far are not suitable to achieve efficient surface water protection. Practical prevention method of accidental type environment pollution was also suggested. On the basis of the international literature evaluation, technical solutions capable to decrease the runoff pollution were summarized. Among these, useful calculation method was developed for designers to determine the sufficient storage capacity (water quality volume) of reservoirs applied for water quality protection. Monitoring technique of runoffs, which are characterized time dependent, variable pollutant concentrations by their nature, was proposed. It was stated that the administrative regulation should aim at the EMC instead of current concentration. Beside TPH information was gained on polycyclic aromatic hydrocarbons (PAHs), suspended solids, heavy metals, pH, and nutrient (N, P) pollution of the runoff, which are valuable for the grounding of further research results.