Ochratoxin A content in baby food

The purpose of this study was to investigate the ochratoxin A content in baby food. The analysis of ochratoxin A were performed by immunoaffinity column clean-up and HPLC with fluorescence detection. The detection limit was 0.2 mg/kg. Ochratoxin A was detected in 22.5% of 40 samples up to 1.2 mg/kg. Mean level was 0.15 and 0.31 mg/kg. Ochratoxin A level was higher in oat-based samples. Calculations made on the basis of the obtained means showed that the daily ochratoxin A dietary intake were up to 1.72 ng/kg b.w.     

Ochratoxin A in Wines

Mycotoxins are produced by fungi, commonly known as mold. Ochratoxins are a dangereous group of mycotoxins produced as secondary metabolites by several fungi of the Aspergillus or Penicillium families. Ochratoxin have been detected in foods and beverages, including grape juice and wine. Several analytical methods have been developed for detection of Ochratoxin A [OTA] in wine. In this article, the chemical structure, biosynthesis, formation, microorganisms, determination methods, regulations and the removal of OTA have been reviewed.     

Bestimmung von Ochratoxin A in Muttermilch

Zusammenfassung Es wird ein Analysenverfahren zur Bestimmung von Ochratoxin A in Milch beschrieben. Die Milch wird in einer Pufferlösung bei pH 1,6 homogenisiert, um an Proteine gebundenes Ochratoxin A freizusetzen. Ochratoxin A wird anschließend mit Chloroform extrahiert und der Extrakt über Natriumbicarbonat gereinigt. Der Nachweis des Toxins erfolgt nach hochdruckflüssigchromatographischer Trennung an einer Phasenumkehr-Trennsäule mit dem Fluorescenzdetektor. Die Nachweisgrenze der Methode liegt bei 0,1 ng/ml. Als durchschnittliche Wiederfindungsrate wurde im Bereich zwischen 0,5–10,0 ng/ml ein Wert von 83,1 % ermittelt. Die Absicherung der Ergebnisse ist durch die Analyse toxinhaltiger HPLC-Fraktionen mittels Massenspektrometrie (Direct Exposure Probe) bei chemischer Ionisation in Methan oder eines Enzymimmunoassays möglich. Mit dieser Methode wurden Rückstände von Ochratoxin A in 4 von 36 nach zufälligen Kriterien gesammelten Muttermilchproben nachgewiesen.

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Determination of ochratoxin A in human milk

Summary A method for the determination of ochratoxin A in milk is described. The milk is homogenized in a buffer solution at pH 1.6 to release ochratoxin A from its bond to proteins. Ochratoxin A is extracted with chloroform and the extract cleaned up using a base clean-up step. Analysis is performed by high-pressure liquid chromatography, using a reversed-phase column and fluorescence detection. The detection limit of the method is 0.1 ng/ml and the average recovery rate, tested in the range between 0.5 and 10.0 ng/ml, was found to be 83.1 %. Chemical ionization mass spectrometry (direct exposure probe) and an enzyme immunoassay were used as confirmatory tests. Using this method, trace amounts of ochratoxin A were found in 4 of 36 randomly collected human milk samples.

     

Ochratoxin A in human blood in relation to Balkan endemic nephropathy and urinary system tumours in Bulgaria

In continuing the effort to provide further evidence for the hypothesis that ochratoxin A might be involved in the aetiology of Balkan endemic nephropathy and the associated urinary system tumours, a survey to determine the occurrence of ochratoxin A in human blood was conducted in affected and unaffected areas of Bulgaria, where both diseases are prevalent. Ochratoxin A, positive samples, were present more often in blood from affected patients and the contamination levels were generally higher.     

葡萄酒中赭曲霉素A的研究进展

赭曲霉素A（OTA）是一种真菌毒素,常见于谷物、谷物产品、水果、咖啡、葡萄干、葡萄酒和啤酒中。由于OTA在食物中稳定且不易分解,对人体构成了一种潜在的危害,国际癌症研究机构（IARC）已将其定义为group2B类致癌物。欧洲各国已经对赭曲霉素A进行限量,也制定了相应的官方检测方法。对葡萄酒中赭曲霉素A的性质、毒性、污染现状、产生菌、影响因素和测定方法进行了综述。     

Ochratoxin A and aflatoxins in 1989 Saudi wheat

In a survey of aflatoxins B1, B2, G1, G2 and ochratoxin A in 209 ungraded and graded samples from the 1989 Saudi Arabian wheat crop, only one sample was found to contain ochratoxin (1.8 μg Kg^-1) and a trace of aflatoxin.     

Caffeine Inhibition of Ochratoxin A Production

The effect of caffeine and theobromine on growth and ochratoxin A production by Aspergillus ochraceus was determined using microbiological medium. Caffeine produced a small decrease in growth, while reducing ochratoxin production as much as 98%. Theobromine had relatively little effect on growth or ochratoxin production. Screening of caffeine for its effect on the growth of a number of Aspergillus and Penicillium species indicated that caffeine may have biological activity against a variety of mycotoxigenic molds.     

Survey: Ochratoxin A in European special wines

The occurrence of Ochratoxin A (OTA) was examined in 121 special wines made using different winemaking techniques and from many European origins. The wine groups with the highest OTA content and occurrence, above 90%, were those were the must was fortified before fermentation (mean: 4.48 μg/l) and those made from grapes dried by means of sun exposure (mean: 2.77 μg/l). Fortified wines with long aging in wooden casks were about 50% contaminated, with OTA levels below 1.00 μg/l. Wines affected by noble rot, late harvest wines and ice wines did not contain OTA. Overall, 19.8% of the wines studied contained OTA levels above the maximum permissible limit for the European Union (2 μg/kg) in wine (excluding liqueur wines).     

Ochratoxin A in pork kidneys--description of a method

A rapid procedure for the isolation and clean-up on a silica gel column is described for the determination of Ochratoxin A from pork kidneys. The detection limit is 0.3 microgram/kg.     

液相色谱-质谱联用技术测定葡萄酒中的赭曲霉毒素A残留

建立葡萄酒中赭曲霉毒素A的高效液相色谱-串联四极杆质谱联用测定方法,该方法经HLB固相萃取柱净化样品,以ZORBAX Eclipse XDB-C18柱(3.0×50 mm,1.8μm)分离,流动相为0.1%甲酸水溶液和甲醇(梯度洗脱),电喷雾正离子MRM模式检测.该方法的检出限0.20 μg/L,方法定量下限0.20 μg/L,线性范围0.20 μg/L～100 μg/L,加标回收率86.6%～91.0%,相对标准偏差为1.67%.     

Ochratoxin A in Brazilian roasted and instant coffees

Thirty-four samples of roast and ground coffee, 14 samples of instant coffee and two samples of decaffeinated instant coffee were collected in markets and supermarkets in the city of Campinas, Brazil, and analysed for ochratoxin A using immunoaffinity columns for clean-up and HPLC with fluorescence detection for quantification. The limit of detection was 0.2 ng/g ochratoxin A. Twenty-three samples of ground and roast coffee were found to be contaminated with the toxin at levels ranging between 0.3 and 6.5 ng/g. The average concentration in all 34 samples was 0.9 ng/g. All samples of instant coffee contained ochratoxin A at levels ranging from 0.5 to 5.1 ng/g, with an average figure of 2.2 ng/g. Roast and ground coffee is the type of coffee most used by Brazilians for the preparation of the beverage. Considering that an average Brazilian adult takes five cups of coffee per day, which corresponds to 30 g of roast and ground coffee, the probable daily intake of ochratoxin A by a 70 kg adult would be 0.4 ng/kg bw, which is far below the current Provisional Tolerable Daily Intake of 14 ng/kg bw for ochratoxin A as set by the Codex Alimentarius. To study the transfer of ochratoxin A into coffee brew, the beverage was prepared by two methods: (a) the drip method and (b) the Brazilian country style method. No significant difference was observed between the two methods in terms of extraction of the toxin using five contaminated samples containing between 0.8 and 6.5 ng/g ochratoxin A. The drip method extracted 86 +/- 15% and the Brazilian country style 74 +/- 20% of the ochratoxin A initially present in the roast and ground coffee.     

Ochratoxin A and Brewing Technology: A Review

Ochratoxins are a hazardous group of mycotoxins produced as secondary metabolites by several fungi of the Aspergillus and Penicillium families. Ochratoxins have been detected and determined in foods and beverages, including barley, malt and beer, at ppb levels. Varied analytical methods have been developed for the detection of ochratoxin A [OTA] in cereals and beer. Ochratoxin A has hazardous effects on health and has been classified within group 2B, as a possible human carcinogen by IARC. Scientists have expressed great concern about the presence of ochratoxin A in foods. In this article, chemical structure, biosynthesis by microorganisms, analytical methods for testing, regulations, changes during brewing, and detoxification of OTA, are reviewed. Beer poses very little risk as a source of ochratoxin in the diet.     

Ochratoxin A in red pepper flakes commercialised in Turkey

The aim of this study was to investigate the presence of Ochratoxin A (OTA) in red pepper flakes commercialised in Turkey. A total of 75 samples were collected from different supermarkets and traditional bazaars in Istanbul during 2012–2013. OTA analysis was performed by high-performance liquid chromatography equipped with fluorescence detection after immunoaffinity column clean-up. The method was linear in the range 0.05–40 μg kg^?1 (r² = 0.9997). Twenty-seven out of 31 (87.1%) packed red pepper flake samples contained OTA at concentrations ranging from 0.6 to 1.0 μg kg^?1, whereas 100% of the unpacked red pepper flake samples contained OTA, in the range 1.1–31.7 μg kg^?1. Overall, only 4 unpacked samples (5.3%) contained OTA, with a mean value of 23.4 μg kg^?1, which is higher than the European Union limit. It is suggested that OTA content should be carefully considered in red pepper flake samples especially marketed in unpacked form.     

Ochratoxin A in cocoa and chocolate sampled in Canada

In order to determine the levels of ochratoxin A (OTA) in cocoa and cocoa products available in Canada, a previously published analytical method, with minor modifications to the extraction and immunoaffinity clean-up and inclusion of an evaporation step, was initially used (Method I). To improve the low method recoveries (46-61%), 40% methanol was then included in the aqueous sodium bicarbonate extraction solvent (pH 7.8) (Method II). Clean-up was on an Ochratest? immunoaffinity column and OTA was determined by liquid chromatography (LC) with fluorescence detection. Recoveries of OTA from spiked cocoa powder (0.5 and 5 ng g(-1)) were 75-84%; while recoveries from chocolate were 93-94%. The optimized method was sensitive (limit of quantification (LOQ) = 0.07-0.08 ng g(-1)), accurate (recovery = 75-94%) and precise (coefficient of variation (CV) < 5%). It is applicable to cocoa and chocolate. Analysis of 32 samples of cocoa powder (16 alkalized and 16 natural) for OTA showed an incidence of 100%, with concentrations ranging from 0.25 to 7.8 ng g(-1); in six samples the OTA level exceeded 2 ng g(-1), the previously considered European Union limit for cocoa. The frequency of detection of OTA in 28 chocolate samples (21 dark or baking chocolate and seven milk chocolate) was also 100% with concentrations ranging from 0.05 to 1.4 ng g(-1); one sample had a level higher than the previously considered European Union limit for chocolate (1 ng g(-1)).     

谷物类食品中赭曲霉毒素A分析方法的研究进展

赭曲霉毒素A是由真菌产生的次级代谢产物,由于其具有极强的肾脏毒性、致癌性、致畸性,且对食品污染的范围广泛,许多国家对其制定了严格的限量标准。目前对谷物中赭曲霉毒素A的检测方法主要有薄层色谱分析法、高效液相色谱法、酶联免疫吸附法、毛细管电泳法和胶体金试纸条法等。随着检测水平的提高,对食品中的赭曲霉毒素A限量标准的要求也在不断地提高。建立安全、准确、灵敏度高、重现性好的检测体系将成为今后研究的重点。     

Ochratoxin A in liquorice as affected by processing methods

A study of the effect of several processing methods on the concentration of ochratoxin A (OTA) in liquorice and derived products was carried out. The effect of the sorting, washing and peeling of fresh liquorice roots was investigated; as well as the production at a laboratory scale of liquorice extract and block liquorice from dry roots. Finally, the thermal stability of OTA was assessed. The OTA content was analysed by high-performance liquid chromatography-fluorescence and confirmed by methyl ester formation. The OTA level in liquorice extract was stable to heat treatment at 150°C for 60 min. The OTA concentration was unaffected by sorting or washing, but it was much reduced by peeling (a 53.1% reduction). A great reduction in the OTA level was found during the production of liquorice extract (78.6%) and block liquorice (91.8%).