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Fifty-three different species of the genus Agaricus were collected in the Czech Republic during the period 1998-2001 and identified by an experienced mycologist. The samples were analysed for agaritine (N2-(γ-L-glutamyl)-4-hydroxymethylphenylhydrazine) content, a precursor to a suspected rodent carcinogen. There was a huge variation in agaritine content between species, but less variation between samples of a species. Whereas the cultivated mushroom Agaricus bisporus commonly contain 200-500 mg agaritine kg-1 fresh weight, no less than 24 of the 53 species contained agaritine levels above 1000 mg kg-1 fresh weight. The highest level was found in A. elvensis containing up to 10, 000 mg kg-1 fresh weight. Twenty species contained intermediate levels (100-1000 mg kg-1), and nine species were below 100 mg kg-1. Some of the species producing low levels of agaritine might be candidates for future strain development of Agaricus mushrooms for cultivation. No correlation could be observed between agaritine content and size of the mushroom, week of the year when collected, year of collection, or site of collection. Besides occurring in the genus Agaricus, some species of the genera Leucoagaricus and Macrolepiota were also shown to contain agaritine. [ABSTRACT FROM AUTHOR]

The fate of five Fusarium toxins — deoxynivalenol (DON), sum of 15- and 3-acetyl-deoxynivalenol (ADONs), HT-2 toxin (HT-2) representing the main trichothecenes and zearalenone (ZON) during the malting and brewing processes — was investigated. In addition to these 'free' mycotoxins, the occurrence of deoxynivalenol-3-glucoside (DON-3-Glc) was monitored for the first time in a beer production chain (currently, only DON and ZON are regulated). Two batches of barley, naturally infected and artificially inoculated with Fusarium spp. during the time of flowering, were used as a raw material for processing experiments. A highly sensitive procedure employing high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was validated for the analysis of 'free' Fusarium mycotoxins and DON-conjugate in all types of matrices. The method was also able to detect nivalenol (NIV), fusarenon-X (FUS-X) and T-2 toxin (T-2); nevertheless, none of these toxins was found in any of the samples. While steeping of barley grains (the first step in the malting process) apparently reduced Fusarium mycotoxin levels to below their quantification limits (5-10 µg kg-1), their successive accumulation occurred during germination. In malt, the content of monitored mycotoxins was higher compared with the original barley. The most significant increase was found for DON-3-Glc. During the brewing process, significant further increases in levels occurred. Concentrations of this 'masked' DON in final beers exceeded 'free' DON, while in malt grists this trichothecene was the most abundant, with the DON/DON-3-Glc ratio being approximately 5:1 in both sample series. When calculating mass balance, no significant changes were observed during brewing for ADONs. The content of DON and ZON slightly decreased by a maximum of 30%. Only traces of HT-2 were detected in some processing intermediates (wort after trub removal and green beer). [ABSTRACT FROM AUTHOR]

Toxic secondary metabolites produced by fungi representing Fusarium genus are common contaminants in cereals worldwide. To estimate the dietary intake of these trichothecene mycotoxins, information on their fate during cereal processing is needed. Up-to-date techniques such as high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (LC-MS/MS) was used for the analysis of seven trichothecenes (deoxynivalenol, nivalenol, HT-2 toxin, T-2 toxin, 15- and 3-acetyldeoxynivalenol, and fusarenon-X) in bread production chain (wheat grains, intermediate products collected during milling and baking process, breads). Regardless of whether the grains were naturally infected or artificially inoculated by Fusarium spp. in the field, the fractions obtained from the grain-cleaning procedure contained the highest mycotoxin levels. During milling the highest concentrations of deoxynivalenol were found in the bran, the lowest in the reduction flours. Baking at 210°C for 14 min had no significant effect on deoxynivalenol levels. The rheological properties of dough measured by fermentograph, maturograph, oven rise recorder, and laboratory baking test were carried out, and based on the obtained results the influence of mycotoxin content on rheological behaviour was investigated. [ABSTRACT FROM AUTHOR]

The level of agaritine was measured in fresh and canned cultivated mushroom (Agaricus bisporus) as well as in other food products containing A. bisporus , by reversed phase high performance liquid chromatography. The two fresh samples were purchased on the open market and contained 212 and 229mg/kg, respectively. Of the 35 different trademarks of canned mushroom products studied, 25 were based on cut mushrooms and 10 on whole mushrooms. On average, whole mushrooms contained 14.9 +- 6.7 mg agaritine per kg product whereas cut mushrooms contained 18.1 _ 7.8mg/kg. There was no statistically significant difference between these two values. Agaritine levels in brine were generally slightly lower than the levels detected in canned mushrooms. Thus, the level of agaritine in A. bisporus is reduced more than 10 times during the wet canning process, resulting in low levels in canned products. On a portion basis, somewhat higher amounts of agaritine may be found in some other food products (mushroom soup and pasta sauce) containing A. bisporus. [ABSTRACT FROM AUTHOR]

The influence of technological operations during rape-seed oil production on polycyclic aromatic hydrocarbon (PAH) concentrations in by-products, intermediate and final oils was evaluated. The decrease of light PAHs, benz(a)anthracene and benzo(a),pyrene during processing ofcrude oil to the deodorized product was significant at the 95% confidence interval in most batches analysed. Deodorization and alkali-refining were the steps contributing most to the PAH decrease. The relationship between PAH levels in rapeseed (and consequently in refined oil) and the duration of storage period was studied. The contaminationof raw material processed a short time after harvesting was significantly higher than that of the rapeseed stored in silos for several months. Analyses of rapeseed samples, which were re-purified in the laboratory, revealed that solid particles, which contaminate rapeseed during harvesting, initial treatment, transport and storage, contributed to PAH contamination to the extent of 36% (light PAHs) to 64% (heavy PAHs) on average . Further experiments demonstrated that PAHs in re-purified rapeseed were concentrated in the cuticular layer, because they were removed well from the whole seeds by simple rinsing with organic solvent in an ultrasonic bath without losses of rapeseed oil. Altenative expressions of total PAH contamination (e.g. various PAH groups and/or differently defined B(a)P toxic equivalents) are discussed and their effect on drawing conclusions about PAH elimination rate has been demonstrated. [ABSTRACT FROM AUTHOR]