Authors:E. Vamanu, A. Vamanu, D. Pelinescu, S. Niţă, N. Rusu, and N. Popa
The synthesis of exopolysaccharides was determined for the Streptococcus sp. IL5 strain in MRS and M17 medium, with carbon sources such as glucose, lactose and sucrose. According to the obtained results, by using glucose as carbon source, the highest quantity of exopolysaccharides was obtained, namely of 400 mg l−1. The influence of various glucose concentrations (5, 10, 15, 20%) on exopolysaccharide production was tested. It resulted in that, at a concentration of 15% glucose, a maximum quantity of synthesized exopolysaccharides was obtained. The influence of temperature and of pH on the exopolysaccharide synthesis capacity of the strain was tested as well. From the tests the temperature of 37 °C and pH 7 proved to be the ideal parameters for obtaining a maximum exopolysaccharides quantity. Based on chromatographic methods, the content of synthesized polysaccharide was determined, consisting of 31.87% anhydrous glucose with a degree of polymerization of 36.7%.
Authors:L.F. Pérez-Romero, F.T. Arroyo, C. Santamaría, M. Camacho, and A. Daza
The fruit quality parameters of Prunus armeniaca L. cv ‘Ninfa’ grafted on ‘Myrobalan 29C’ (Prunus cerasifera Ehrh.) and ‘Real Fino’ apricot seedling (Prunus armeniaca L.) were analysed in an experimental orchard under organic management. The study was performed between 2010 and 2012 in the province of Seville (SW Spain). Colour, fruit and stone weights, firmness, soluble solid concentration, and acidity were measured for fruit quality evaluation. Trunk cross-sectional area, main branches, and fruit yield were also determined. In general, ‘Myrobalan 29C’ rootstock produced fruit slightly larger in size and with a bigger weight. By contrast, apricots on ‘Myrobalan 29C’ had less firmness and a lower solid soluble concentration than on ‘Real Fino’. There was little difference in the colour, acidity, and stone dry weights. Trees on ‘Real Fino’ had larger areas of trunk and branches but no significant differences were obtained in relation to fruit yields.
The adsorption properties of natural zeolite (clinoptilolite) has been studied in order to determine its applicability for copper and zinc removal in acid mine drainage treatment process. For purpose of these experiments the determination of the sorption equilibrium and removal efficiencies were performed under batch conditions using single and dual-component solutions. The experiments were carried out under acidic conditions (pH approx. 4). In general, the obtained results from kinetic experiments showed rapid decrease of the metal concentration during the first 10 min, corresponding to ~80% total removal of ions from both single and dualcomponent solutions. This initial rapid period was followed by a further slow drop in metals concentration caused by ion-exchange in deeper structure of zeolite.Preliminary tests on the real samples of acid mine drainage from Smolnik mine, Slovakia, showed that natural zeolite has a potential as an alternative low cost adsorptive material for acid mine drainage treatment.
Our knowledge on the presence of mycotoxin producing fungi and mycotoxins in food commodities in the last decade in Hungary has been summarized in this review. Among the mycotoxin producing fungi, detailed data are available for Fusarium species in cereals, and mycotoxigenic Aspergillus species in different food commodities including coffee, raisins and spices. Ochratoxin concentrations above the tolerable limit have mostly been detected in imported products such as peanuts and coffee. Ochratoxin levels close to the tolerable limit have been observed in Hungarian red peppers. Besides, ochratoxin A has also been detected in Hungarian wine, beer and raisins. Aflatoxins are usually detected in considerable quantities only in imported agricultural products in Hungary, while patulin concentrations were usually below the allowable limit in Hungarian apple juice concentrates. In the future, continuous sampling and analysis of foods and feeds are required to ensure consumer safety in Hungary.
In this study, the
antibacterial and antioxidant activities of dried fruit extract of cranberry
(gilaburu, Viburnum opulus) were determined. The total phenolic content
was found to be 131.99±2.11 mg
gallic acid equivalent (GAE) g-1 in the cranberry fruit extract
(CFE). The antioxidant activity of the extract was found to be 315.50±8.2 mg g-1 in dried methanol extract. At 2,
5, 10 and 15% concentrations the extracts were tested for their antibacterial
effects by using the agar diffusion method against ten bacteria, some of them
pathogenic and some of them spoilage microorganisms. All bacteria were
inhibited by 10 and 15% concentrations of the CFE. Methanol (control) had no
inhibitory effect on all the tested bacteria. The most sensitive of the
bacteria was A. hydrophila, whereas the most resistant bacterium was Y.
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: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.
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.