Migration of bisphenol a into food simulants and meat rations during initial time of storage

The aim of this work was to assume the amount of BPA that can migrate to food packed into the cans coated by epoxy-phenolic lacquer. The assumption was made by determining the amount of BPA which migrates from the inner can coating to different food simulants: 3% acetic acid, 10% ethanol, their mixture (3% acetic acid +10% ethanol), and 50% ethanol. The examined tinplate cans were made by the special requirements of the Serbian Armed Forces. Further, the effect of the sterilization process and the very initial time of storage (15–105 days), on the level of BPA in the canned meatballs in tomato sauce, which are in the regular use of the Serbian Armed Forces, was examined. The BPA content was determined by the high performance liquid chromatography-mass spectrometry (HPLC–MS), and compared with BPA content found in the food simulants.     

Glycoalkaloid content of potatoes sold in Czechia

Glycoalkaloid levels in different cultivars collected from three regions were monitored during two years. With the exception of Karin, one of the most widely grown cultivar in the Czech Republic, none of the cultivars used for human consumption exceeded the levels considered safe. The average of total glycoalkaloids content for tested cultivars ranged from 31 to 166 mg/kg fresh weight. There were no significant differences between glycoalkaloid levels in tubers from different regions. Attention was paid to the adequate sampling procedure.     

Use of UV photography to identify aflatoxin-producing strains ofAspergillus flavus andA. parasiticus

UV photography in glucose, yeast extract (GY) agar medium was tested as a simple and rapid method for the distinction of afiatoxin-positive from aflatoxin-negative strains ofAspergillus flavus andA. parasiticus. In the UV photographs aflatoxin-producing moulds were identified as grey or black colonies, whereas aflatoxin-non-producing moulds appeared as white colonies. Of the afiatoxin-positive strains detected by the UV photographic method, 10% was confirmed by extraction of the GY agar medium and mould mycelium in chloroform, extracts which were analysed subsequently using thinlayer chromatography. Confirmation of aflatoxigenic strains was achieved by biosynthesis on liquid medium yeast extract sucrose (YES) broth.     

Immobilization of silver nanoparticles on polyethylene terephthalate

Two different procedures of grafting with silver nanoparticles (AgNP) of polyethylene terephthalate (PET), activated by plasma treatment, are studied. In the first procedure, the PET foil was grafted with biphenyl-4,4′-dithiol and subsequently with silver nanoparticles. In the second one, the PET foil was grafted with silver nanoparticles previously coated with the same dithiol. X-ray photoelectron spectroscopy and electrokinetic analysis were used for characterization of the polymer surface at different modification steps. Silver nanoparticles were characterized by ultraviolet-visible spectroscopy and by transmission electron microscopy (TEM). The first procedure was found to be more effective. It was proved that the dithiol was chemically bonded to the surface of the plasma-activated PET and that it mediates subsequent grafting of the silver nanoparticles. AgNP previously coated by dithiol bonded to the PET surface much less.     

Bioaccumulation of Arsenic Species in Rays from the Northern Adriatic Sea

The difference in arsenic concentration and speciation between benthic (Pteromylaeus bovinus, Myliobatis aquila) and pelagic rays (Pteroplatytrygon violacea) from the northern Adriatic Sea (Gulf of Trieste) in relation to their size (age) was investigated. High arsenic concentrations were found in both groups with tendency of more efficient arsenic accumulation in benthic species, particularly in muscle (32.4 to 362 µg·g⁻¹ of total arsenic). This was attributed to species differences in arsenic access, uptake and retention. In liver most arsenic was present in a form of arsenobetaine, dimethylarsinic acid and arsenoipids, whereas in muscle mainly arsenobetaine was found. The good correlations between total arsenic/arsenobetaine and size reflect the importance of accumulation of arsenobetaine with age. Arsenobetaine is an analogue of glycine betaine, a known osmoregulator in marine animals and both are very abundant in mussels, representing an important source of food for benthic species P. bovinus and M. aquila.