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Mycobiota and fumonisin contamination in dried fruits of different origin

TFumonisins are carcinogenic mycotoxins which were originally identified in Fusarium verticillioides. According to recent findings, fumonisins are also produced by some black Aspergillus species including Aspergillus niger and A. awamori. Aspergilli are able to produce fumonisins in high quantities on agar media with low water activities. Data on the occurrence and role of this species in fumonisin contamination of agricultural products with high sugar content are needed to clarify the importance of A. niger in human health. The mycobiota and fumonisin contamination of various dried fruit samples collected form different countries were examined to clarify the role of black Aspergilli in fumonisin contamination of such products. All except two of the examined raisin samples were contaminated with black Aspergilli. Species assignment of the isolates was carried out using sequence analysis of part of the calmodulin gene. The range of fumonisin isomers present in the raisin samples, and produced by A. niger and A. awamori isolates collected from dried vine fruits was also examined using reversed-phase high-performance liquid chromatography/electrospray ionization - ion trap mass spectrometry. Among the A. niger/A. awamori isolates identified, 67% produced fumonisins. The isolates produced several fumonisin isomers also present in the dried vine fruit samples, including fumonisins BM, 3-epi-FB,, 3- epi-FBj. iso-FB|, and two iso-FB;.j forms. Most of these isomers have previously only been identified in Fusarium species. The average fumonisin content of the 7 dried vine fruit samples which were found to be contaminated by potential fumonisin producing black Aspergilli was 7.22 mg kg'1 . Our data indicate that A. niger and A. awamori are responsible for fumonisin contamination of dried vine fruits worldwide. The observed levels of contamination are alarming and pose a new threat for food safety. Preliminary data also indicate that fumonisin contamination of other dried fruits including figs and dates, and that of onions are also caused primarily by black Aspergillus species. Further work is in progress to examine the role of black Aspergilli in fumonisin and ochratoxin contamination of agricultural products

Clay Mineralogy of Red Clay Deposits from the Central Carpathian Basin (Hungary): Implications for Plio/Pleistocene Chemical Weathering and Paleoclimate

Geochemical and mineralogical studies of palaeosols provide essential information for palaeoclimatic and palaeoenvironmental interpretation of continental deposits and can present a proxy for palaeoclimate. Red clays in the central Carpathian Basin (Hungary) (Tengelic Red Clay Formation; Kerecsend Red Clay Formation), overlain by loess-palaeosol sequences, were studied. Results from geochemical climofunctions applied to Upper Pliocene–Lower Pleistocene red clays and palaeosols located in the Carpathian Basin, and clay mineralogy, indicate that the palaeoclimate was considerably more humid and warmer during the Late Pliocene-Early Pleistocene in comparison to modern values

Multifractality beyond the Parabolic Approximation: Deviations from the Log-normal Distribution at Criticality in Quantum Hall Systems

Based on differences of generalized R\'enyi entropies nontrivial constraints on the shape of the distribution function of broadly distributed observables are derived introducing a new parameter in order to quantify the deviation from lognormality. As a test example the properties of the two--measure random Cantor set are calculated exactly and finally using the results of numerical simulations the distribution of the eigenvector components calculated in the critical region of the lowest Landau--band is analyzed.Comment: LaTeX 4 pages, 3 EPS included, to appear in Europhysics Letter