Mycotoxins in several Polish food products in 2004-2005.

In 2004-2005, samples of several selected Polish foods such as cereal products, nuts, dried fruits, coffee and culinary spices collected from Warsaw market and taken from food producers were analyzed on presence of aflatoxin B1, B2, G1, G2 (AF), ochratoxin A (OTA), zearalenone (ZEA) and deoxynivalenol (DON). After extraction and clean-up of extracts on immunoaffinity columns (IAC), mycotoxin analyses were carried out by HPLC using fluorescence and UV detectors. The concentrations of aflatoxins and ochratoxin A depending on the kind of sample ranged from 0.02 to 7.8 (one sample, of peanuts) and 0.02-11.9 µg/kg (one coffee sample), respectively. The levels of ZEA and DON were found to be below 50 °g/kg.

Ochratoxin A: an improvement clean-up and HPLC method used to investigate wine and grape juice on the Polish market.

A routine method appropriate for the determination of ochratoxin A (OTA) in wine, grape juice and grape juice drinks was described, and the occurrence of the mycotoxin was investigated in the most popular red wines, grape juice and grape juice drinks available on the Polish market. After clean-up on immunoaffinity column, samples were analysed by RP-HPLC using a fluorescence detector at 330 and 460 nm. The average OTA recoveries from spiked blank wine samples varied from 60 to 82%, and RSD% ranged from 5 to 14%. The OTA recovery for spiked grape juice and grape juice drinks were 80-100%, but the RSD% was between 7 and 10%. The limit of detection and limit of quantitation for all sample types were 0.5 and 2.0 ng l(-1), respectively. Fifty-three samples of red wine and seven samples of grape juice and grape drinks were assessed by means of this analytical procedure. OTA was detected in most wine samples (92%); its concentrations ranged from 2.2 to 6710 ng l(-1). In all grape juice and drink samples, OTA levels ranged from 1.6 to 64.7 ng l(-1).

Determination of deoxynivalenol in cereals by HPLC-UV.

A simple method for determination of deoxynivalenol (DON) in cereal samples is described. DON was extracted with methanol, the solvent evaporated, and the residue redissolved with water. This extract was purified on immunoaffinity columns. DON was determined by HPLC with UV-detection. The limits of detection (LOD) and quantification (LOQ) were 10 and 50 µg/kg, respectively.

On ochratoxin A and fungal flora in Polish cereals from conventional and ecological farms. Part 2: occurrence of ochratoxin A and fungi in cereals in 1998.

Over 200 samples of Polish cereal grain from the 1998 harvest obtained from conventional and ecological farms were investigated for the presence of ochratoxin A and for contamination by microscopic fungi. The frequency of contamination of rye and barley grains from conventional and ecological farms was similar in most cases; it varied from nearly 5 to 12%, respectively, for both types of farming. However, in samples from ecological farms, higher maximum concentrations of ochratoxin A were observed (35 micro g kg(-1), overall range 1.4-35.3 micro g kg(-1)) for both cereals rye and barley in comparison with rye and barley from conventional farms (maximum levels of 8.8 and 9.7 micro g kg(-1), respectively). However, wheat grain from the conventional farms showed ochratoxin A concentrations in a very wide range from 0.6 to 1024 micro g kg(-1) and the average frequency of contaminated samples was about 48%. In contrast, in wheat samples from ecological farming, the presence of ochratoxin A ranged from 0.8 to 1.6 micro g kg(-1) (mean 1.2 micro g kg(-1)) and the frequency of contamination was 23%. From samples containing detectable amounts of ochratoxin A, fungi producing ochratoxin A under laboratory conditions were isolated. They were classified as belonging to the species Penicillium cyclopium, P. viridicatum, Aspergillus ochraceus group, A. glaucus and A. versicolor. Penicillium strains-species known to be producers of ochratoxin A-were isolated from 71% of the samples; in 28% of samples, only Aspergillus strains (species known to be producers of this mycotoxin) were noted. These results have been compared with those obtained in 1997.

On ochratoxin A and fungal flora in Polish cereals from conventional and ecological farms - Part 1: occurrence of ochratoxin A and fungi in cereals in 1997.

Over 200 samples of Polish cereal grain from the 1997 harvest obtained from conventional and ecological farms were tested for the presence of ochratoxin A as well as for contamination by microscopic fungi. Ochratoxin A contamination of rye from ecological farms was over six times more frequent than that from conventional cultivation. The ochratoxin A content in wheat and barley samples from ecological farms was also higher. No wheat sample from conventional farms contained the mycotoxin. In the group of ecological farms, there were differences in the percentage of cereal samples containing ochratoxin A. The ochratoxin A levels ranged from 0.2 to 57 microg kg(-1). The mean concentration of ochratoxin A in investigated cereal grain was 5.7 microg kg(-1). From samples containing detectable amounts of ochratoxin A, fungi producing ochratoxin A under laboratory conditions were isolated. They were classified as belonging to the species Penicillium cyclopium, P. viridicatum, P. chrysogenum and also Aspergillus alliaceus, A. versicolor, A. glaucus and A. flavus. Penicillium strains - producers of ochratoxin A - were isolated from 93% of the samples; in 7% of samples, only Aspergillus strains producing this mycotoxin were noted. Rye samples mainly from one farm with an ecological type of cultivation and from one conventional farm were contaminated with both Aspergillus and Penicillium mycotoxigenic strains.

Ochratoxin A and other mycotoxins in Polish cereals and foods.

In 1990-2000 selected Polish cereals, cereal products and some different commodities collected in several regions of Poland were analysed for ochratoxin A (OTA) and aflatoxins. The frequency and the level of contamination of Polish cereals and cereal products by ochratoxin A seem to be similar as in most European countries. Aflatoxins in cereals and their products does not seem to be a problem in Poland, however the attention should be pay to some imported products like peanuts.

[Determination of vitamin C in selected fruit and vegetable products]. / Oznaczanie witaminy C w wybranych produktach owocowo-warzywnych.

A simple method was described to determine vitamin C as L-ascorbic acid (after reduction of dehydroascorbic acid by means of dithiothreitol) in fruit juices, fruit and vegetable-fruit nectars. Ascorbic acid was analyzed by RP-HPLC technique with UV detection (254 nm). The average recovery of ascorbic acid was 92-103% and limits of identification and detection were 0.003 and 0.009 mg/ml of products respectively.

[Determination of vitamins B1 and B2 in selected vegetable-fruit products]. / Oznaczanie witamin B1 I B2 w wybranych produktach owocowo-warzywnych.

A simple method was described to determine vitamins B1 and B2 in fruit and vegetable-fruit juices. Vitamins were extracted with perchloric acid and for their determination an ion pairing RP-HPLC technique with UV detection by 254 nm was applied. The average recovery for vitamin B1 was 85-104% and 94-105% for vitamin B2. The statistically estimated limits of identification and detection were respectively, for both vitamins: for B1: 0.008 and 0.0024, and for B2 0.0002 and 0.0007 mg/ml of product.

[Determination of selected mycotoxins in food. II. Selection of optimal conditions for the determination of fumonisin B1 and B2 in corn products using high performance liquid chromatography]. / Oznaczanie wybranych mikotoksyn w zywnosci. Cz. II. Dobór optymalnych warunków oznaczania fumonizyn B1 I B2 w przetworach z kukurydzy metoda wysokosprawnej chromatografii cieczowej.

The aim of this study was to perform a optimised method for determination of fumonisins B1 and B2 in corn products. The manner of extraction and clean-up of corn products extracts as well conditions of reaction of fumonisins with OPA was described. The main steps of optimised analytical procedure were: extraction of sample with methanol and water (3 + 1), clean-up of extracts on SAX column, derivatisation with OPA, and determination by means of RP-HPLC. The mobile phase was a mixture of methanol, water and acetic acid (75 + 24 + 1). Fluorometric detection was made at 370/440 nm. The mean recovery of fumonisins dependent on fortification level and product was 64-95%, limit of detection for each of fumonisins was 15 micrograms/kg.

[Determination of selected mycotoxins in food. I. Selection of optimal conditions for the determination of aflatoxin M1 in milk using high-performance liquid chromatography methods]. / Oznaczanie wybranych mikotoksyn w zywnosci. Cz. I. Dobór optymalnych warunków ozanaczania aflatoksyny M1 w mleku metoda wysokosprawnej chromatografii cieczowej.

The aim of this study was to perform a optimized method for determination of aflatoxin M1 in milk. The manner of extraction and clean-up of milk extracts as well conditions of reaction of aflatoxin M1 with TFA and HPLC was described. The main steps of optimized method were: extraction of samples with chloroform, clean-up of extracts on SPE C18 columns and by means of extraction with n-hexane, derivatisation of aflatoxin M1 with TFA (60 degrees C, 6 minutes) to acetal form--aflatoxin M2a and determination of aflatoxin by means of the RP-HPLC technique. The mobile phase was a mixture of methanol, isopropanol and water (18 + 7 + 75). Fluorometric detection was made at 370/418-700 nm. The mean recovery of aflatoxin M1 dependent on fortification level was 62-67%, limit of detection was 0.01 microgram/1 of milk.

[Use of HPLC technique for determination of aspartame and acesulfam-K in processed fruit products]. / Zastosowanie techniki HPLC do oznaczania aspartamu i acesulfamu-K w przetworach owocowych.

A liquid chromatographic method for the determination of the intense sweeteners--aspartame and acesulfam-K in fruit and vegetable nectars was described. Samples were extracted with water, then clarified with Carrez solutions. An aliquot of the extract was analyzed on C-18 reverse-phase column with UV detection. Mean recoveries ranged from 95.9 to 101.8%. The method is suitable for routine determinations of both sweeteners.

[Mycotoxins in enzyme preparations. III. Method of detection and determination of zearalenone]. / Mikotoksyny w preparatach enzymatycznych. Cz. III. Metoda wykrywania i oznaczania zearalenonu.

A simple method for the detection and semiquantitative determination of zearalenone in enzyme preparations was described. The method comprises extraction with chloroform and acetone (80 + 20), mini-column chromatographic purification of the crude extracts on silicagel, and two-dimensional thin-layer chromatography. The mean recovery by this method in from 74 to 80% and detectability of zearalenone is 50 micrograms/kg.

[Mycotoxins in enzyme preparations. Part II. Method of detection and determination of sterigmatocystin]. / Mikotoksyny w preparatach enzymatycznych. Cz. II. Metoda wykrywania i oznaczania sterygmatocystyny.

A simple method for the detection and semiquantitative determination of sterigmatocystin in enzyme preparations was described. The method comprises extraction with acetonitrile and a 4% aqueous KCL solution, column chromatographic purification of the crude extracts on silica gel, and two-dimensional thin-layer chromatography. The mean recovery by this method is from 71 to 79%, and the detectability of sterigmatocystin is 20 micrograms/kg.

[Mycotoxins in enzymatic preparations. 1. Method for the detection and determination of aflatoxins]. / Mikotoksyny w preparatach enzymatycznych. Cz. i. Metoda wykrywania i oznaczania aflatoksyn B1, B2, G1 i G2.

A simple method for detection and semiquantitative determination of aflatoxins B1, B2, G1 and G2 in enzymatic preparations is described. The method is based on extraction with a mixture of acetone with water, purification of extracts with lead acetate and on a column with aluminum oxide. The concentrated extracts were analysed by means of two-direction thin-layer chromatography. The mean recovery by this method was from 57 to 78% depending on the type of aflatoxin. The detection limit by this method was about 1 mcg/kg.

[Determination of trichothecenes in cereals]. / Oznaczanie trichotecenów w produktach zbozowych.

A simple method is described of identification and determination of deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS) and T-2 toxin in cereals. Chloroform-ethanol extracts were purified in columns filled with active charcoal, aluminium oxide and celite and were analysed by the method of thin-layer chromatography. The results were evaluated exposing fluorescent trichothecene derivatives to ultraviolet light, after they had been obtained on a chromatographic plate with aluminium chloride and sulphuric acid. The detectability of the method for various toxins was: DON--37, NIV--100, DAS--50, and T-2 toxin--100 mcg/kg.