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.     

Occurrence of ochratoxin A (OTA) in wines: influence of the type of wine and its geographical origin.

The results of more than 450 samples taken from the literature and 400 samples tested by our own investigations have been taken into account to quite extensively describe the situation of OTA contamination of wine. According to these data OTA is much more commonly detected in red wines than in rosé and white wines and the OTA concentration is remarkably higher than in the last two. Thus OTA could be detected in 25% of white wine samples whereas it was detected in 40% of rosé and 54% of red wine samples. The same result was found when comparing the wines from southern and northern regions. Here the red wine samples from the northern cultivating area showed a contamination of 12% in contrast to those from the southern area which showed a contamination of about 95%.     

A survey of ochratoxin A occurence in Greek wines

A total of 150 wines, including 123?dry wines (64 red, 49 white and 10 rosé) and 27 dessert wines (14 red and 13 white), were obtained from various viticulture and oenological practices across Greece during the period 1999–2006 and analyzed for ochratoxin a (OTA) using immunoaffinity clean-up and HPLC with fluorescence detection. There was a high frequency of OTA in commercially available wines (69% positive samples). However, the level of contamination was relatively low, with only one sample marginally reaching the EU permitted maximum level (2.0?µg?l^?1). A total of 91% of the samples had OTA concentrations <1.0?µg?l^?1. The higher concentrations were found in wines from the southern regions, especially in dessert-type wines. There were no significant differences based on wine color or production years. Furthermore, there was no difference between conventional or organic cropping systems in terms of OTA presence.     

Contribution to the study of ochratoxin A in Spanish wines.

With the aim of assessing ochratoxin A (OTA) contamination in wines from a Spanish northern region and the influence of harvest conditions, the following samples were analysed: 40 wines (28 red and 12 white) obtained from grapes cultivated in three different places of the northern Spanish region of Navarra, but in different years, 20 samples in 1997 and 20 in 1998. Wine samples were provided by a viticultural experimental station with very consistent and controlled cultural and enological practices. A high-performance liquid chromatography (HPLC) method with fluorescence detection and immunoaffinity columns was employed (LOD = 0.05 ng ml(-1); method recovery = 101%). Eighty five per cent of the samples from 1997 showed OTA levels >0.05 ng ml(-1) (range 0.056-0.316 ng ml(-1)) and 15% of the samples from 1998 showed OTA levels above the LOD (range 0.074-0.193 ng ml(-1)). Averages detected in 1997 positive samples were 0.185 ng OTA ml(-1) wine (SD = 0.023) in white wine samples (n = 6) and 0.160 ng ml(-1) (SD = 0.119) in the red wine samples (n = 11). These differences between contamination by OTA in the samples from the two different years were attributed to the different quality of the grapes, due to the bad climate in 1997. The possibility of the loss of the mycotoxin was excluded by the analysis of OTA in contaminated wine during 12 months. This study showed that OTA is stable in wine for at least 1 year.     

Determination of ochratoxin A in wine by immunoaffinity cleanup and liquid chromatography tandem mass spectrometry

A simple and accurate method has been developed for determining ochratoxin A (OTA), using an immunoaffinity column for cleanup and liquid chromatography-tandem mass spectrometry for identification and quantification. Wine samples were diluted with a solution containing polyethylene glycol 8000 and sodium hydrogen carbonate, filtered through a glass microfiber filter, and cleaned up on an immunoaffinity column. OTA was then eluted with methanol-acetic acid (98:2) and analyzed by liquid chromatography-tandem mass spectrometry. The average recoveries of OTA from red and white wines were 95 and 96.7% (spiked OTA level was 0.05 ng/ml) and repeatabilities (relative standard deviation) were 3.8 and 2.4%, respectively. The detection limit was 0.0003 ng/ml based on the signal-to-noise ratio in wine of 3:1. Analysis of 74 samples of domestic and imported wines showed OTA levels ranging from < 0.0003 to 0.82 ng/ml, with an incidence of contamination of 92.1% for red wines, and < 0.0003 to 0.51 ng/ml, with an incidence of contamination of 77.8% for white wines. These detection rates were higher than those rates of past reports of OTA contamination in wine, due to the high sensitivity of this method. However, all samples analyzed in this study complied with European Union regulations. It is concluded that this method is a useful tool for the quality assurance of wine.     

Ochratoxin A in wine and grape juice sold in Canada.

Ochratoxin A (OTA) was determined in 251 samples of wines and grape juice collected over 3 years in Canada. In total, 25/84 samples of red wine, 22/96 samples of white wine, 3/46 red grape juices and 1/25 white grape juices contained OTA levels above the limit of quantitation (LOQ). Canadian wines, when compared with imported products, showed both a lower OTA occurrence, noted as positive (19 versus 48% above the limit of detection (LOD) for wines), and a lower level of OTA contamination (upper bound mean of 17.5 versus 163pg ml(-1) for wines). Wines from the USA contained no quantifiable levels of ochratoxin A. OTA was found in Canadian and US grape juice samples, with 12.9% above the LOD and an upper bound mean of 13.3pg ml(-1). It was extracted from a wine or grape juice sample by passing it through an immunoaffinity column. The sample matrix was washed off the column with water. OTA was eluted from the column with methanol and quantitatively determined by liquid chromatography using a fluorescence detector. The presence of OTA was confirmed by esterification with boron trifluoride-methanol. The LOQ of OTA was estimated as 20 pg ml(-1) in white wine (S/N 10:1) and 40 pg ml(-1) in red wine, white grape juice and red grape juice (S/N 20.1). The LOD was estimated as 4pgml(-1) for white wine and 8pgml(-1) for red wine and white and red grape juices (S/N 3:1).     

An overview of ochratoxin A in beer and wine

Ochratoxin A (OTA) is a mycotoxin produced mainly by several fungal species of the genera Aspergillus and Penicillium. This mycotoxin has been shown to be nephrotoxic, hepatotoxic, teratogenic and carcinogenic to animals and has been classified as a possible carcinogen to humans. OTA occurs in a variety of foods, including beer and wine. Reports on OTA occurrence in beer indicate that this is a worldwide problem due to the widespread consumption of this beverage. At present, the European Union (EU) has not set a maximum allowable limit (MAL) for this mycotoxin in beer, although there is a limit in barley and malt. Studies carried out in different countries agree in the high proportion of samples contaminated with OTA although levels are, usually, below 0.2 ng/ml. OTA occurrence has been related to the contamination of malt barley with ochratoxigenic species, particularly Penicillium verrucosum. OTA produced in grains is carried to wort and, although fermentation decreases the concentration, the toxin is not eliminated. Reducing the fungal contamination of malt barley is the most promising strategy for reducing OTA in beer. With regard to wine, surveys on the presence of OTA have been conducted worldwide. The proportion of wines in which OTA is detected is very high (above 50%) in some countries (especially in the Mediterranean basin) although only a few wines contained concentrations exceeding the MAL laid down by the EU (2.0 ng/ml). A gradient of concentration is usually recognized; OTA levels decrease in the order red, rose, and white wine but also with increasing latitude of the producing countries. OTA presence in wines is due to the black aspergilli, mainly A. carbonarius, which can grow on grapes in the vineyards and produce the toxin. At grape crushing, the juice can be contaminated with the toxin which is carried over into wine, where it persists due to its stability. Pre- and post-harvest treatments are being investigated to diminish contamination of wines as much as possible.     

Detection of ochratoxin A and cis- and trans-resveratrol in red wines and their musts from Calabria (Italy)

The natural occurrence of ochratoxin A (OTA) and cis- and trans-resveratrols in red wines has been widely reported. The aim of this work was to evaluate the ochratoxin A (OTA) and both cis- and trans-resveratrol content of red wine (from must to wine) in a pilot-scale vinification process in Calabria (Italy). Eleven samples were collected at different stages of vinification and analysis was carried out by HPLC. Wine from manufacturer 3 contained the highest amount of trans-resveratrol (3.41 mg l(-1)). This wine was characterized by an Aglianico-Magliocco grape variety. Interestingly, data regarding OTA showed that the value of this contaminant was low in all analyzed samples and, in each case, below the legal limit (2.0 mg l(-1) (ppb)). Overall, the results demonstrated the high quality of wines produced in Calabria.     

Influence of yeast strain on ochratoxin A content during fermentation of white and red must

The aim of this work was to examine whether the yeast strains, responsible for alcoholic fermentation, have an influence on the concentration of ochratoxin A (OTA) in wine. Before the fermentation, OTA was added to musts up to a concentration of about 2 microg/l. OTA content was determined in white and red wines resulting from respective musts and in methanolic extract of the yeast lees (MEL). Data showed a significant reduction of OTA at the end of alcoholic fermentation. However, depending on the yeast strain involved in the fermentation, there was a difference in the content of OTA in the wines. The percentage of OTA removal during the fermentation was between 46.83% and 52.16% in white wine and between 53.21% and 70.13% in red wine. The absence of degradation products suggested an adsorption mechanism. OTA concentration in MEL resulting from red must fermentation was higher than in white. A significant amount of OTA was not recovered either from wine or from MEL.     

Occurrence of ochratoxin A in wine and grape juice marketed in Rio de Janeiro, Brazil.

Ochratoxin A (OA) is receiving attention world-wide because of the hazard it poses to human health. The aim was to test the distribution of OA in grape juice, pulps of frozen grapes, and national and imported table wine obtained from markets in Rio de Janeiro, Brazil. Analytical methodology using immunoaffinity column for OA extraction and clean-up with a final separation on a reversed-phase (C(18)) column and fluorescence detection in high-performance liquid chromatography showed a detection limit of 21 ng l(-1). The mean recovery was 91% for red wines and 82% for white wines; while the mean recoveries for juices and pulps of frozen grapes were 91.6 and 88%, respectively. Of 64 samples of grape juice and frozen pulps, 25% were positive for OA, being the mean content of 37 ng l(-1) with a maximum concentration of 100 ng l(-1). In wines, the mean concentration detected in 80 samples analysed was 34.4 ng l(-1) with 28.75% of positive samples. Red wines showed the highest percentages and levels of contaminated samples: 38% and 37 ng l(-1), respectively. The white wine contained levels above 26 ng l(-1) in 17.75% of the analysed samples. The levels of contamination detected in red wine sold in Río de Janeiro were not enough to surpass the virtually safe dose established as 5 n g kg(-1) body weight of daily intake.     

OCHRATOXIN A IN TURKISH WINES

In this research, 47 wine samples produced from 2001 to 2002 harvest period in four Turkish regions were analyzed for the presence of ochratoxin A (OTA). Based on the results, the OTA levels of red wines are generally higher than those of white and rose wines. However, the wines from two wine regions (Aegean and Thrace) are much more contaminated with OTA compared with the others.     

The role of processing on ochratoxin A content in Italian must and wine: a study on naturally contaminated grapes

Available data show that ochratoxin A (OTA) is a possible contaminant of wine and its concentration is higher in red wines than in white and rosé. The aim of this work was to study the fate of OTA during the main stages of the winemaking process (crushing, maceration, alcoholic fermentation, malo-lactic fermentation, bottle-aging) and the influence of technological treatments on OTA concentration in order to identify the critical process steps. Attention was focused on red winemaking, in different wineries in the south of Italy, with two naturally OTA contaminated grape varieties ('Negroamaro' and 'Primitivo') and on different vintages (2001-2002-2003). The results show that no OTA is produced during winemaking, but each operation during winemaking can modify OTA content. The OTA present in grapes to a certain degree is released to the juice during crushing. Maceration increases the OTA content, while alcoholic and malo-lactic fermentation cause a reduction in OTA in the wine.     

European research on ochratoxin A in grapes and wine

European wine production represents about 70% of world production and thus is an important export commodity. Ochratoxin A (OTA) was first detected as a wine contaminant in 1996 and the role of Aspergillus section Nigri and A. carbonarius in OTA production discovered in Europe in 1999. Subsequently Europe-wide surveys have shown that A. carbonarius is predominantly responsible for OTA contamination of grapes, wine and vine fruits. Analyses of wine samples throughout Europe have shown that there is a gradient in OTA concentration with a decrease from red, to rose and to white wines. The latitude of production is an important factor in determining risk from OTA contamination. Some geographic regions in Southern Europe are more prone to contamination with the toxigenic species and OTA. Ochratoxin A has also been found in much higher concentrations (max. 53 mug/kg) in dried vine fruit than in wine suggesting that A. carbonarius can dominate the drying vine fruit ecosystem. There is a significant lack of knowledge in Europe on conducive climatic conditions preharvest and their relationship with levels of risk from OTA contamination in grapes and their fate in wine production. This needs to be integrated with cultivation system to maximise the prevention of OTA entering this food chain.     

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: 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).     

Ochratoxin A in wines,musts and grape juices from Spain

A survey on the occurrence of ochratoxin A (OTA) in 240 grape‐based beverages was carried out. Red and white wines from four different Spanish Designations of Origin (n = 160), musts (n = 20), grape juices (n = 10), ordinary wines (n = 20), special wines (Malaga, muscatel, sherry, vermouth, etc) (n = 20) and sparkling wines (n = 10) were assayed for OTA content using immunoaffinity column clean‐up and high‐performance liquid chromatography with fluorimetric detection (detection limit 0.05 µg l^?1). Forty‐three (17.9%) of the samples tested contained detectable levels of OTA. The overall mean OTA concentration in red and white wines of Designations of Origin was 0.30 and 0.18 µg l^?1 respectively (ranges 0.05–3.19 and 0.05–1.13 µg l^?1 respectively). The percentage of wine samples with detectable amounts of OTA was higher for red (18.3%) than for white (10%) wines. OTA was also found in two of 10 red ordinary wines (0.68 and 4.24 µg l^?1), whereas none of 10 white ordinary wines contained OTA. The mean OTA amount detected in sparkling wines was 0.44 µg l^?1 (range 0.14–0.71 µg l^?1). Two of 20 must samples contained OTA at low levels (0.08 and 0.18 µg l^?1), while none of 10 grape juice samples contained OTA. Highest amounts of OTA were found in special wines (45%), with a maximum of 15.25 µg l^?1 in a muscatel sample. Copyright © 2004 Society of Chemical Industry     

Occurrence of Ochratoxin A in Chinese wines: influence of local meteorological parameters

A total of 119 wines, including 115 dry wines (77 red, 34 white, 4 rosé) and 4 ice wines, were obtained from four major regions around China (east, northeast, west, and northwest) from 1999 to 2009. Ochratoxin A (OTA) was detected by solid-phase extraction and high-performance liquid chromatography with fluorescence detection. The OTA levels ranged from <0.1 to 5.65 μg/L. The wines from the northeast area had the highest OTA level, with an average concentration of 2.18 μg/L. Analysis of the correlation between meteorological parameters and the OTA concentration in red wine revealed that the OTA concentration was positively correlated with rainfall in August, but negatively correlated with the average temperature. No significant correlation was found with the daily range of temperature and relative humidity. The results show that climate factors affect the OTA distribution in wines from the four major regions of China.     

Analysis of Ochratoxin A in Wine by High-Resolution UHPLC-MS

A method for determination of ochratoxin A (OTA) in wines using a new-solid phase extraction clean-up procedure followed with ultra performance liquid chromatography (UHPLC)-Orbitrap MS based on two scan events (full-scan Fourier transform mass spectrometer [FTMS] and higher energy-induced collision dissociation[HCD] data-dependent MS/MS) in positive ionization mode has been developed. The limit of detection (LOD) was estimated at 0.46 μg l^?1 for white wine, 0.53 and 0.54 μg l^?1 for rosé and red wines, respectively. The limit of quantification (LOQ) was estimated at 1.57 μg l^?1 in white wine, 1.77 and 1.81 μg l^?1 in rosé and red wines. Recovery experiments were carried out with spiked samples at three concentration levels (2, 5 and 10 μg l^?1). The OTA recoveries in spiked white wine samples varied from 69.6 % to 99.8 %, while the recoveries for rosé and red wine samples were in the range of 63.0–110.2 % and 63.6–103.2 %, respectively. Finally, based on the results, it is concluded that the combination of C18 cartridge with conventional particle packed columns and UHPLC LTQ-Orbitrap XL is an appropriate procedure for OTA analysis in wines.     

Detection of ochratoxin A and cis- and trans-resveratrol in red wines and their musts from Calabria (Italy)

The natural occurrence of ochratoxin A (OTA) and cis- and trans-resveratrols in red wines has been widely reported. The aim of this work was to evaluate the ochratoxin A (OTA) and both cis- and trans-resveratrol content of red wine (from must to wine) in a pilot-scale vinification process in Calabria (Italy). Eleven samples were collected at different stages of vinification and analysis was carried out by HPLC. Wine from manufacturer 3 contained the highest amount of trans-resveratrol (3.41?mg?l^?1). This wine was characterized by an Aglianico–Magliocco grape variety. Interestingly, data regarding OTA showed that the value of this contaminant was low in all analyzed samples and, in each case, below the legal limit (2.0?mg?l^?1 (ppb)). Overall, the results demonstrated the high quality of wines produced in Calabria.     

Occurrence of ochratoxin A in Rioja Alavesa wines

In this survey the influence of the geographical location and the kind of wine in the concentration of ochratoxin A (OTA) was studied. Forty percent of the Spanish wine market belongs to the Rioja Qualified Designation of Origen (DOCa Rioja) wines, which are already worldwide known. A total of 100 wines from the Rioja Alavesa (RA) production area of the DOCa Rioja were analysed, using immunoaffinity column clean-up and high-performance liquid-chromatography with fluorimetric detection (detection limit 0.002 μg/l). The presence of OTA was greater in wines produced in low rainfall and high temperature regions. The geographical location and kind of wine did not seem to have influence on the OTA concentration.