Occurrence of<Emphasis Type="Italic">penicillium expansum</Emphasis> and patulin in apples as raw materials for processing of foods — case study

The contamination of apples Gloster variety withPenicillium expansum was investigated in the case study. The apples serve as a raw material in thefood industry for processing of baby foodstuffs and other apple products. The core of 3 – 5 % apple samples has been contaminated with spores and mycelium of untested microfungi. The surface tissue of stored apples has not been damaged. Penicillium expansum was isolated in all tested apple samples. Patulin has been found at levels tens to hundreds of üg/kg in tested apple samples. Patulin was primarily associated with core and areas of decomposing tissue and can penetrate up to approx. 1 cm of the surrounding healthy tissue. The production of patulin after the experimental contamination of apples was tested after 14 days of storage (21 °C, dark). The maximum value of patulin was found 110 mg/kg of rotten part of apple sample.     

A HPTLC method for the determination of the mycotoxin zearalenone in cereal products

An HPTLC method for the quantification of zearalenone (ZEA) in cereals and cereal products (wheat flour and malt) has been developed. ZEA was extracted with 50 ml of acetonitrile-purified water (9+1) with addition of 2 g NaCl. The extracts were further purified on VICAM ZearalaTest^(tm) immunoaffinity columns, then analysed by instrumental high-performance thin-layer chromatography (HPTLC) on silica gel plates with fluorescence detection. Ethyl acetate - n-hexane (1+1) was used as the mobile phase. The chromatogram was scanned in fluorescence mode after excitation at λ=254 nm with λ=400 nm measuring filter: SENS and SPAN parameters were 195 and 20, respectively. TheR _F of ZEA under these conditions was 0.43. The recovery was 95% in the range 15–65 μg/kg cereal products; the mean relative standard deviation of repeatability (RSDr) was 7.6%. The limit of quantification (LoQ) of ZEA was 10 μg/kg. Validation of the method was performed according to the principles of the ICH for pharmaceutical analysis. Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003     

Occurrence of the toxigenic fungi (producers of aflatoxins and ochratoxin A) in foodstuffs in the Czech Republic 1999–2000

The occurrence of toxigenic fungi producing aflatoxins and ochratoxin A in foodstuffs was studied in the Czech Republic. Twenty five commodities were collected at twelve collection places in the Czech Republic (300 food samples). The presence of potentially toxigenicAspergillus flavus was observed in 28% of the sampled foods (black pepper, caraway seeds, fruit tea, black tea, oat flakes, fine flour, rolled oat flakes and semolina) in the year 1999, and in 25% of the sampled foods (black pepper, black tea, fine flour) in the year 2000.A tamarii (aflatoxins producer) was found in 3 black pepper samples (25%) in both years. Aflatoxins were detected in black pepper and caraway seed samples in the year 1999 and in sweet red pepper in the year 2000.A parasiticus andA nomius were not isolated. Aspergillus section Nigri (potential producer of ochratoxin A) was detected in some foodstuffs. Ochratoxin A was detected in raisins.Penicillium verrucosum andA ochraceus were not isolated from foodstuffs.     

Monitoring of mycotoxin biomarkers in the Czech Republic

AFM₁ was determined in 72 (72%) samples of human urine, range 19-6064 pg/g creatinine, mean 367 pg/g creatinine, median 158 pg/g creatinine and 90% percentile 755 pg/g creatinine in 1997. AFM₁ was determined in 46 (43.8%) samples of human urine, range 21-19219 pg/g creatinine, mean 414 pg/g creatinine, median 96 pg/g creatinine and 90% percentile 415 pg/g creatinine in 1998. OTA was determined in 2077 (94.2%) samples of human serum, range 0.1–13.7 μg/L, mean 0.28 μg/L, median 0.2 μg/L and 90% percentile 0.5 μg/L in 1994–2002. OTA was determined in 12 (40%) samples of human kidneys, range 0.1–0.2 μg/kg, mean 0.07 μg/kg, and median 0.05 μg/kg in 2001. Presented at the 26^th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004.     

Occurrence ofAlternaria andFusarium mycotoxins in winter wheat from domestic crop in year 2003

The aim of this study was a monitoring of the occurrence ofAlternaria andFusarium mycotoxins in winter wheat from domestic crop in the year 2003. Altenuene was determined in 56 (100%) samples of winter wheat, range 14.5–41 μg/kg, mean 25 μg/kg. Alternariol was determined in 16 (28.6%) samples of winter wheat, range 6.3–22.1 μg/kg, mean 5.7 μ/kg. DON was determined in 42 (100%) samples of winter wheat, range 250–3500 μg/kg, mean 330 μg/kg. T2-toxin was determined in 42 (100%) samples of winter wheat, range 25–337 μg/kg, mean 99 μg/kg. ZEA was not determined in samples of winter wheat. Presented at the 26^th Mykotoxin-Workshop in Herrsching, Germary, May 17–19, 2004 Financial support. Supported (one part of experiments, the determination of Fusarium mycotoxins) by the Ministry of Agricu ture of the Czech Rebublic (Propect No QF3121)     

The system approach to the identification of aflatoxigenic fungi in foodstuffs and feedstuffs

Aspergillus flavus, A parasiticus, A nomius, A tamarii andA pseudotamarii are important microorganisms capable of producing aflatoxins and further mycotoxins. Aflatoxigenic Aspergillus species are morphologically similar species belonging to the Aspergillus section Flavi. The aflatoxigenic fungal strains were isolated from foods (cereals, pulses, oilseeds, dried fruit, spices), soil, air and water. Mycological analyses are based on valid standards and recommendations of the International Commission for Food Mycology (ICFM). The identification of isolated aflatoxigenic fungi in foodstuffs and feedstuffs can be proved by using classical mycological cultivation methods, diagnostic nutrient media, chemotaxonomy and molecular biological methods (PCR). The system approach to the identification of aflatoxigenic fungi combines these four methods. Thirty strains of the aflatoxigenic fungi were tested.     

MYCOMON-monitoring project of toxigenic fungi in food in years 1999 – 2001

An occurrence of the toxigenic fungi producing aflatoxins and ochratoxin A in food was investigated in the study (“MYCOMON”) in years 1999–2001. Twenty five commodities were purchased from retail in twelve collection places in the Czech Republic (300 food samples together). The presence of potentially toxigenic fungiAspergillus flavus was observed in 28% of the sampled food (black pepper, black tea, caraway seeds, fine flour, fruit tea, oat flakes) in the year 1999, in 17% of the sampled food (black pepper, black tea, caraway seeds, fine flour, fruit tea, oat flakes) in the year 2000 and in 18% of the sampled food (black pepper, black tea, caraway seeds, fine flour, fruit tea, oat flakes) in the year 2001.Aspergillus tamarii (aflatoxins producer) was found in black pepper samples (25%) in year 1999, in black pepper samples and black tea (25%) in year 2000 and in black pepper samples and black tea (21%) in year 2001.Aspergillus parasiticus andAspergillus nomius were not isolated.Aspergillus sectionNigri (potential producer of ochratoxin A) was detected in some food (black pepper, black tea, caraway seeds, fine flour, fruit tea, raisins, sweet red pepper).Penicillium verrucosum and Aspergillus ochraceus were not isolated from the tested food.     

Raisins,ochratoxin A and human health

Raisins are one of the most nutritious dried fruits in the world. The occurrence of ochratoxin A (OTA) in raisins results from contamination and growth of ochratoxigenic fungi and short-term humid weather during drying. The estimation of the dietary exposure dose of OTA from raisins for the Czech population (children, adult) is presented. The risk of acute toxic effect of OTA was in the Czech Republic usually considered to be minimal. The risk of late toxic effects (particularly carcinogenic risk) after ingestion of very low single or repeated OTA doses from foodstuffs is very important     

A review on comparative data concerning <Emphasis Type="Italic">Fusarium</Emphasis> mycotoxins in Bt maize and non-Bt isogenic maize

The European corn borer reportedly promotes the infection of maize by Fusarium spp. Stalk and ear rots caused by Fusarium spp. are often related to mycotoxin accumulation in maize kernels. As a result, food and animal feed from maize are more severely contaminated with Fusarium mycotoxins: e.g. fumonisins (FUM), deoxynivalenol (DON) and zearalenone (ZEA). Bt maize is primarily an important potential tool for insect pest protection, both in the European Union and in other countries. Bt maize carrying the Bt genes is highly resistant to European corn borer larval feeding due to Bt toxin (δ toxin) production. Effective measures to combat pests therefore often have a positive side-effect in that they also reduce mycotoxin levels. Comparative analysis was used to the evaluation of the studies dealing with the reduction of Fusarium mycotoxins in Bt maize. Nineteen out of 23 studies on Bt maize came to the conclusion that Bt maize is less contaminated with mycotoxins (FUM, DON, ZEA) than the conventional control variety in each case.     

The experimental contamination of foodstuffs with the spores of toxigenic micromycetes and the production of mycotoxins

A study of experimental contamination of foods with spores of toxigenic micromycetes (Aspergillus flavus andPenicillium verrucosum) was realized. Samples of bread, apricot jam, Edam cheese, processed cheese and half-fat dried milk purchased on the market were used for experimental contamination. Aflatoxins and ochratoxin A were determinated in experimental contaminated foodstuffs.