Ochratoxin A in dried vine fruits from Chinese markets

A total of 56 dried vine fruits, including 31 sultanas and 25 currants, were selected from Chinese markets in 2012. All samples were analysed for Ochratoxin A (OTA) using solid-phase extraction and high-performance liquid chromatography (HPLC) with fluorescence detection. It turned out that 58.9% of the samples were positive and the OTA amount ranged from <0.07 to 12.83 μg/kg, with a mean level of 0.99 μg/kg. Only one sample exceeded the European Union (EU) maximum level of 10 μg/kg. Meanwhile, it was shown that OTA contamination increased among north-western, northern and southern China, which showed OTA means of 0.08, 0.99 and 2.01 μg/kg, respectively. Moreover, in samples of products sold in sealed plastic bags, i.e. consumer-size packages (n = 19, mean = 0.30 μg/kg) less OTA was detected when compared with sampled bulk packages (n = 37, mean = 1.67 μg/kg). In addition, sultanas (mean = 0.92 μg/kg) had less OTA contamination than currants (mean = 1.22 μg/kg).     

Ochratoxin A in beverages from Morocco: a preliminary survey

In a preliminary study, samples of Moroccan wines (n = 30), beers (n = 5) and fruit juices (n = 14) were assayed for ochratoxin A (OTA) by HPLC with fluorimetric detection, followed by confirmation by cleavage of the OTA molecule using carboxypeptidase with HPLC-fluorimetric determination of ochratoxin alpha (OT alpha). All the wine samples were contaminated, and the overall median OTA concentration was 0.65 microg/l (range 0.028-3.24 microg/l). One of the 14 samples of fruit juices was contaminated with a concentration of 1.16 microg/l, whereas none of the five beer samples was contaminated. This is the first report on the occurrence of OTA in various beverages from Morocco.     

Ochratoxin A in dried vine fruits on the Canadian retail market

Between 1998 and 2000, 151 samples of raisins and sultanas and two samples of currants were collected from retail outlets across Canada and analysed for ochratoxin A. Samples were extracted with methanol-sodium bicarbonate, and the extracts were cleaned-up by immunoaffinity column chromatography. Ochratoxin A was quantified by liquid chromatography with fluorescence detection. The minimum quantifiable level was 0.1 ng g^-1. Ochratoxin A was present, above the minimum quantifiable level, in 67 (79%) of 85 samples of raisins, in 39 (59%) of 66 samples of sultanas, and in both samples of currants. The overall mean level of ochratoxin A was 1.8 ng g^-1 in both the raisins and sultanas, and 2.8 ng g^-1 in the currants.     

Ochratoxin A concentrations in Greek domestic wines and dried vine fruits.

A survey for the presence of ochratoxin A (OTA) was conducted from 1995 to 1999 on 268 locally produced commercial wines, and on 81 samples of domestic dried vine fruits (currants and sultanas) collected between 1998 and 2000 from sites of primary storage and processing. The OTA concentration in red dry wines (n = 104, median = 0.09 microgram l(-1)) was not significantly different from that for white (n = 118, median = 0.06 microgram l(-1)) and rosé (n = 20, median = 0.08 microgram l(-1)) wines. Eighteen samples of dessert wines (sweet, semi-sweet, semi-dry) and eight samples of retsina wine showed larger OTA concentrations with medians of 0.33 and 0.27 microgram l(-1), respectively. Our data indicate that the geographic region of origin influences OTA contamination for the red dry wines. In fact, a trend of increasing OTA contamination was observed for red wines from northern to southern Greece. Regarding the OTA levels in dried vine fruits, sultanas (n = 27, median = 0.6 microgram kg(-1)) were less contaminated than currants (n = 54, median = 1.3 microgram kg(-1)). Also, sultanas produced in 2000 and currants produced in 1999 showed the lowest incidence of OTA contamination, with medians of 0.3 and 0.9 microgram kg(-1), respectively.     

High-performance liquid chromatography-tandem mass spectrometry method for simultaneous detection of ochratoxin A and relative metabolites in Aspergillus species and dried vine fruits

A simple, sensitive and reliable quantification and identification method was developed for simultaneous analysis of ochratoxin A (OTA) and its related metabolites ochratoxin alpha (OTα), ochratoxin B (OTB) and mellein. The method was assessed by spiking analytes into blank culture media and dried vine fruits. Performance was tested in terms of accuracy, selectivity and repeatability. The method involves an ultrasonic extraction step for culture samples using methanol aqueous solution (7:3, v/v); the mycotoxin is quantified by high-performance liquid chromatography coupled with electrospray ionisation and triple quadrupole mass spectrometry (LC-ESI-MS/MS). The recoveries were 74.5–108.8%, with relative standard deviations (RSDs) of 0.4–8.4% for fungal culture. The limits of detection (LODs) were in the range of 0.03–0.87 μg l^–1, and the limits of quantification (LOQs) ranged from 0.07 to 2.90 μg l^–1. In addition, the extraction solutions and clean-up columns were optimised specifically for dried vine fruit samples to improve the performance of the method. Methanol–1% sodium bicarbonate extraction solution (6:4, v/v) was determined to be the most efficient. Solid-phase extraction (SPE) was performed as a clean-up step prior to HPLC-MS/MS analysis to reduce matrix effects. Recoveries ranged from 80.1% to 110.8%. RSDs ranged from 0.1% to 3.6%. LODs and LOQs ranged from 0.06 to 0.40 μg kg^–1 and from 0.19 to 1.20 μg kg^–1, respectively. The analytical method was established and used to identify and quantify OTA and related compounds from Aspergillus carbonarius and Aspergillus ochraceus in cultures and dried vine fruits. The results showed that A. carbonarius produced OTα, OTB and OTA, whereas A. ochraceus produced OTB, OTA and mellein after 7 days of cultivation. Of 30 commercial samples analysed, 10 were contaminated with ochratoxins; OTB, OTα and mellein were also detected in different samples.     

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.     

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.     

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).     

Occurrence of ochratoxin A in cocoa by-products and determination of its reduction during chocolate manufacture

This work reports an investigation carried out to assess the natural occurrence of ochratoxin A in 168 samples from different fractions obtained during the technological processing of cocoa (shell, nibs, liquor, butter, cake and cocoa powder) and the reduction of ochratoxin A during chocolate manufacture. Ochratoxin A analyses were performed with immunoaffinity columns and detection by high performance liquid chromatography. Concerning the natural ochratoxin A contamination in cocoa by-products, the highest levels of ochratoxin A were found in the shell, cocoa powder and cocoa cake. The cocoa butter was the least contaminated, showing that ochratoxin A seems to remain in the defatted cocoa solids. Under the technological conditions applied during the manufacture of chocolate in this study and the level of contamination present in the cocoa beans, this experiment demonstrated that 93.6% of ochratoxin A present in the beans was reduced during the chocolate producing.     

FTIR-ATR infrared spectroscopy for the detection of ochratoxin A in dried vine fruit

A method of screening sultanas for ochratoxin A (OTA) contamination, using mid-infrared spectroscopy/Golden Gate single-reflection ATR (attenuated total reflection), is described. The main spectral characteristics of sultanas from different sources were identified in a preliminary acquisition and spectral analysis study. Principal component analysis (PCA) showed that samples of various origins had different spectral characteristics, especially in water content and the fingerprint region. A lack of reproducibility was observed in the spectra acquired on different days. However, spectral repeatability was greatly improved when water activity of the sample was set at 0.62. A calibration curve of OTA was constructed in the range 10-40 µg OTA kg^-1. Samples with OTA levels higher than 20 µg kg^-1 were separated from samples contaminated with a lower concentration (10 µg OTA kg^-1) and from uncontaminated samples. The reported methodology is a reliable and simple technique for screening dried vine fruit for OTA.     

Incidence of patulin in fruits and fruit juices marketed in Campinas, Brazil

One hundred and eleven samples of processed fruit juices (apple, grape, pineapple, papaya, guava, banana and mango) and 38 samples of sound fruits (apple, papaya, mango, pear and peach) produced and marketed in Brazil, were analysed for patulin by HPLC. Only one out of 30 samples of apple juice was found positive at 17 mug/l. Patulin was not detected in the other foodstuffs. It was found in 14 samples of spoiled fruit samples of apple (150-267 mug/kg), pear (134-245 mug/ kg) and peach (92-174 mug/kg). Confirmation of the identity of patulin was based on the UV spectrum obtained by the HPLC diode array detector, compared with thatof standard patulin, TLC developed by several solvent systems and sprayed with 3-methyl-2-benzothiazolinone hydrazone , and by acetylation with acetic anhydride.     

Validation of a UHPLC-FLD method for the simultaneous quantification of aflatoxins,ochratoxin A and zearalenone in barley

A fast and simple UHPLC-FLD method has been developed for the simultaneous determination in barley of aflatoxins (B1, G1, B2 and G2), ochratoxin A (OTA) and zearalenone (ZEA), some of the most important mycotoxins due to their toxicity and occurrence. The procedure is based on the extraction of the six mycotoxins with a mixture of acetonitrile and water, and the purification of the extract with immunoaffinity columns before analysis. Detection of AFB1 and AFG1 is improved using a photochemical reaction. The method has been validated with satisfactory results. Limits of detection were 340 ng kg⁻¹ for ZEA, 13 ng kg⁻¹ for OTA and varied from 0.5 to 15 ng kg⁻¹ for aflatoxins. Recovery percentages were between 78.2% and 109.2%. After being validated, the method has been successfully applied to 20 barley samples cultivated in a region of northern Spain (Navarra).     

Ochratoxin A in cereal-based baby foods: occurrence and safety evaluation

Ochratoxin A is a typical cereal contaminant with strong nephrotoxic activity. To estimate the quantity of ochratoxin A that can be taken in by a child in the weaning period, several samples of cereal-based baby foods were analysed. Although most samples analysed contained ochratoxin A in undetectable amounts or below the Italian legal limit of 0.5 μg kg -1 , some irregular products were found. In particular, the analyses of the 119 batches (338 samples) of baby foods considered indicated that: 20 batches (16.8%) contained detectable quantities of ochratoxin A and four of these (3.4% of the total) contained ochratoxin A above the Italian permitted value. All samples coming from agricultural practices based on integrated pest management contained undetectable amounts of ochratoxin A, while ~5% of batches coming from conventional and organic agricultural practices were above the legal limit. On the basis of the established provisional tolerable weekly intake (PTWI), there is no significant toxicological risk for a child who occasionally consumes a formula with ochratoxin concentration slightly above the permitted level. However, stricter controls have to be applied to reject the batches containing irregular concentrations of ochratoxin A.     

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。     

浙江省5大类食物中赭曲霉毒素A暴露评估

目的 评价浙江省居民膳食赭曲霉毒素A(OTA)暴露风险。方法 收集2018—2019年浙江省居民消费食物5大类24种共518份,结合浙江省2015—2016年膳食消费量调查数据,对居民OTA膳食暴露进行评估。结果 OTA只在谷物及其制品中检出,而水果、茶叶、膨化食品、婴幼儿谷类辅食中均未检出OTA。燕麦及其制品OTA检出率最高为16.1%(5/31);OTA阳性样本含量范围为0.53～4.00μg/kg,其中燕麦及其制品检出含量最高,为4.00μg/kg;OTA含量均未超过我国限量标准（5μg/kg）。暴露评估显示,浙江省全人群中绝大多数消费情景下谷物及其制品膳食OTA暴露量为0.004～7.360 ng/kg BW,在OTA的安全摄入范围内（14 ng/kg BW）;少数高污染高消费情景下,稻谷OTA摄入量为19.627 ng/kg BW,是安全摄入量的140.19%。不同年龄组人群以1～6岁组每日摄入量最高,为0.014～34.644 ng/kg BW,是安全摄入量的0.10%～247.46%。本研究中稻谷是浙江省居民膳食OTA的主要贡献食物,不同消费人群贡献率达到87.22%～9...     

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 at nanomolar concentrations: a signal modulator in renal cells

Ochratoxin A (OTA) is a ubiquitous fungal metabolite with nephrotoxic, carcinogenic, and apoptotic potential. Toxicokinetics make the kidney the primary target organ for OTA. Due to its widespread occurrence in improperly stored foodstuff the complete and safe avoidance of OTA for humans is impossible. There are several reports showing a significant correlation between OTA exposure and certain forms of nephropathies. At nanomolar concentrations OTA leads to specific changes of function and phenotype in renal cells. The toxin interacts with certain cellular "key-molecules" (e. g., mitogen-activated protein (MAP) kinases, Ca2+), thereby disturbing cellular signalling and regulation events as well as mitochondrial function. Moreover, OTA has the ability to modulate physiological signals (e. g., angiotensin II or TNFalpha) and thereby influences cell function and cell growth and may even stable re-program the cells (e. g., altered distribution of chromosomes). This review concentrates on the effects of OTA in the nanomolar range and its interactions with cellular signalling networks in different renal cells proposing OTA to act as a signal modulator.     

Ochratoxin A and Human Health Risk: A Review of the Evidence

Ochratoxin A (OTA) is a mycotoxin produced by several fungal species including Aspergillus ochraceus, A. carbonarius, A. niger, and Penicillium verrucosum. OTA causes nephrotoxicity and renal tumors in a variety of animal species; however, human health effects are less well-characterized. Various studies have linked OTA exposure with the human diseases Balkan endemic nephropathy (BEN) and chronic interstitial nephropathy (CIN), as well as other renal diseases. This study reviews the epidemiological literature on OTA exposure and adverse health effects in different populations worldwide, and assesses the potential human health risks of OTA exposure. Epidemiological studies identified in a systematic review were used to calculate unadjusted odds ratios for OTA associated with various health endpoints. With one exception, there appears to be no statistically significant evidence for human health risks associated with OTA exposure. One Egyptian study showed a significantly higher risk of nephritic syndrome in those with very high urinary OTA levels compared with relatively unexposed individuals; however, other potential risk factors were not controlled for in the study. Larger cohort or case–control studies are needed in the future to better establish potential OTA-related human health effects, and further duplicate-diet studies are needed to validate biomarkers of OTA exposure in humans.     

粮食中赭曲霉毒素A的快速定量检测-超高效 液相色谱法

建立了免疫亲和柱净化-超高效液相色谱法快速定量测定粮食中赭曲霉毒素A(Ochratoxin A, OTA)的检测方法。样品经提取后,用免疫亲和柱净化、浓缩, Waters Acquity UPLC BEH C₁₈(50 mm?2.1 mm, 1.7 μm)色谱柱分离,以乙腈∶水∶冰醋酸(体积比 100∶98∶2)为流动相,流速为0.2 mL/min,进样量为1μL,用Acquity荧光检测器激发波长为310nm,发射波长为465 nm处进行检测,赭曲霉毒素A的保留体积小于1.15mL,从样品前处理到分析整个过程小于45 min。根据3倍信噪比的峰响应值,确定赭曲霉毒素A的检出限为0.25pg,在1～50.0 pg范围内呈线性相关,相关系数R₂值为0.998;在小麦、玉米、稻谷样品中加标回收率分别为81.5%～101.2%,81.3%～85.5%,87.8%～97.5%,精密度为3.3%～6.4%。本方法简便快速、灵敏度高、重现性好、溶剂用量少,适用于粮食中赭曲霉毒素A的快速测定。