Occurrence of ochratoxin A in Italian wines.

A total of 96 red wines and 15 white dessert wines produced mostly in the years 1995-97 in 19 Italian regions were analysed for ochratoxin A (OTA). The amount of OTA ranged from < 1 to 3856 ng/l the median (mean) was found to be 90 (419) ng/l for the red wines and 8 (736) ng/l for the white dessert wines. Our survey shows that the geographic region of origin has a strong influence on OTA contamination, both for red and for dessert wines: in fact, wines produced in southern Italy were markedly more contaminated. The overall median (mean) OTA concentration in the red wines produced in the four Italian areas (northwest, northeast, centre and south) was 2 (11), 90 (81), 134 (295) and 1264 (1233) ng/l. The same trend was observed for the white dessert wines: OTA concentrations of over 1000 ng/l were found in four out of five samples from southern Italy (1185, 2454, 3477, 3856 ng/l), while central and northern samples showed very low contamination. The contribution of wine to mean daily OTA intake can be considered negligible in the case of people drinking wine manufactured in northern and central Italy; this is not true if a medium drinker constantly consumes red wine produced in southern Italy in this case wine alone could supply the diet with an amount of OTA equal to or even above the tolerable daily intake of 5 ng/kg body weight recommended by the Scientific Committee on Food of the European Commission.     

Occurrence of ochratoxin A in Greek wines

The presence of ochratoxin A in foods and wines is of current interest owing to its toxic effects. Ochratoxin A is a widely distributed mycotoxin with nephrotoxic activity. It constitutes a new restrictive agent for the export of vinicultural products and is thus important from an economic as well as a scientific point of view. In this study the determination of ochratoxin A in Greek wines was made by means of commercial immunoaffinity columns for purification followed by HPLC with fluorescence detection for quantification of the toxin. The method was applied to 28 dry wines (14 red, 13 white, one rosé) and seven sweet wines (three red, four white) obtained by various viticultural and oenological practices. The levels of ochratoxin A ranged from <0.02 to 3.2 ng ml^?1, with sweet wines containing higher levels than dry wines. Most of the wines contained relatively low concentrations of ochratoxin A (0.02–0.5 ng ml^?1), which do not represent a serious risk to consumer health. © 2003 Society of Chemical Industry     

Factors affecting the presence of ochratoxin A in wines

Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines.     

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.     

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.     

Natural co-occurrence of ochratoxin A,ochratoxin B and aflatoxins in Sicilian red wines

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂ (OTA, OTB, AFB₁, AFB₂, AFG₁, AFG₂) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l^–1, well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG₁, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB₁, AFB₂, AFG₁ and AFG₂ at two different levels. The limits of detection (LODs) in wines were 0.02 µg l^–1 for OTA, 0.04 µg l^–1 for OTB, 0.03 µg l^–1 for AFG₁, AFG₂ and AFB₂, and 0.05 µg l^–1 for AFB₁. A good correlation was found, with good performances in term of precision for the method.     

胶体金技术快速测定葡萄酒中赭曲霉毒素A

目的利用胶体金免疫层析技术建立葡萄酒中赭曲霉毒素A的快速筛查方法。方法样品经过层析、孵育,通过i Check-单卡单测快检仪的图像分析进行定量检测,同时对进口与市售国产葡萄酒进行筛查。结果赭曲霉毒素A在添加水平为2.0、5.0μg/L时,红葡萄酒的平均回收率分别为92.5%、72.0%;相对标准偏差(RSD,n=6)分别为5.84%、2.59%;桃红葡萄酒的平均回收率分别为87.0%、76.6%;相对标准偏差(RSD,n=6)分别为7.70%、5.56%;白葡萄酒的平均回收率分别为84.0%、78.4%;相对标准偏差(RSD,n=6)分别为5.67%、3.54%。该方法定量限为1.0μg/L。同时与酶联免疫方法和液相色谱方法比较,通过t检验表明胶体金法不存在系统误差。市售葡萄酒赭曲霉毒素A的含量低于欧盟的限量标准(2.0μg/L)。结论胶体金的方法具有快捷、灵敏、特异性等特点,适合于大批量葡萄酒样品的现场快速筛查。     

Occurrence of ochratoxin A in sweet wines produced in Spain and other countries

A survey for the presence of ochratoxin A (OTA) was undertaken from 2001 to 2005 in 188 samples of sweet wines produced in Spain and in 102 samples originating from other countries: France (n = 49), Austria (9), Chile (9), Portugal (9), Greece (6), Italy (5), Germany (3), Hungary (2), Slovenia (2), Switzerland (2), Canada (1), Japan (1), New Zealand (1), Ukraine (1), South Africa (1) and the USA (1). The analytical method was based on immunoaffinity chromatography clean-up and high-performance liquid chromatography (HPLC) with fluorescence detection. The limit of detection (defined as a signal-noise ratio = 3) was estimated to be 0.01 µg l^-1. The limit of quantification (0.02 µg l^-1) was checked as being the lowest measurable concentration. OTA was detected in 281 out of 290 samples analysed (96.9% positive) at concentrations ranging from 0.01 to 4.63 µg l^-1. The overall mean and median levels were estimated to be 0.50 and 0.14 µg l^-1, respectively. In Spanish sweet wines OTA was found in 99% of the samples, with mean and median values of 0.65 and 0.19 µg l^-1, respectively. The mean value obtained in this study for OTA in the Spanish sweet wines would result in an intake of about 37.5 and 3.2 ng day^-1 of OTA for regular consumers and for the overall population, respectively. These figures represent a minor contribution to the provisional tolerable weekly intake (PTWI) or TWI established by the Joint Expert Committee on Food Additives (JECFA) and the European Food Safety Authority: 3.8 and 3.1% for regular consumers; and 0.4 and 0.3% for the whole adult population, respectively.     

Arsenic content in some Spanish wines. Influence of the wine-making technique on arsenic content in musts and wines

All of the essential technological means of treating grapes, must and wine were examined systematically. The main reasons for the differences in the arsenic (As) content of rosé and red wines are explained. In this study a relationship has been found between the As level and the wine-making technique. Rosé wines contain more As than red wines because they require a shorter period of contact with the skins. In order to prove this, the average values for the rosé and red wine samples from the same winery were compared.     

The use of high-performance liquid chromatography to detect ochratoxin A in dried figs from the Spanish market

BACKGROUND: Detection and quantification of ochratoxin A (OTA) in dried fig samples purchased in Spain has been carried out using high‐performance liquid chromatography with fluorescence detection after extraction with methanol and sodium bicarbonate, and clean‐up by using an immunoaffinity column. RESULTS: The detection limit of the method was 0.06 ng g^?1, and the limit of quantification 0.18 ng g^?1. OTA was detected in 31 (88.6%) out of 35 samples of dried figs analysed, with concentrations that ranged from < 0.1 to 277 ng g^?1. However, only three samples contained OTA concentrations above the tolerable level set by European Commission regulations for dried vine fruits (10 ng g^?1). CONCLUSION: The results of this survey show the value of monitoring OTA in dried figs especially if they are home grown. Copyright © 2011 Society of Chemical Industry     

Mycobiota and ochratoxin A producing fungi from Spanish wine grapes

Grapes from three different regions with a long winemaking tradition in Spain were analysed at different growth stages in order to identify the ochratoxigenic mycobiota during three consecutive seasons. The correlation between meteorological parameters and ochratoxigenic fungi was studied and revealed a significant positive correlation between black aspergilli infection and temperatures in the month preceding each sampling date. No significant correlation was found with either relative humidity or rainfall. Biodiversity indexes were also calculated in this study. Black aspergilli species were the most abundant in grapes before harvest, and among them, Aspergillus carbonarius was the main ochratoxin A (OTA) producer species and represented 78-100% of the isolates tested. The results obtained support the key role of A. carbonarius as the main source of OTA contamination in grapes.     

A survey of phenolic compounds in Spanish wines of different geographical origin

 The phenolic composition of red and white wines from four Spanish Appellations of Origin (official classification of Spanish wines) was investigated. Different hydroxybenzoic and hydroxycinnamic acids, catechins, procyanidins, alcohols, stilbenes and flavonols were identified. Additionally, the ketone 2,3-dihydroxy-1-guaiacylpropan-1-one was identified for the first time in red wines aged in oak barrels. The concentration of most of the phenolic compounds quantified was higher in red wines than in white wines, as would be expected from the different methods of vinification and the grape varieties used. These differences could also contribute to differences in the antioxidant ability of these wines. The multivariate analysis applied to the phenolic compounds quantified allowed the relationships among these compounds to be examined and the origin of the wines to be distinguished. Received: 31 May 1999 / Revised version: 16 August 1999     

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 cDNA-AFLP approach to study ochratoxin A production in Aspergillus carbonarius

Aspergillus carbonarius is responsible for the majority of mycotoxin contaminations in grapes and its derivatives. Most of A. carbonarius strains are ochratoxin A (OTA) producers, even though at very different levels. This broad variability was used to identify genes whose expression is linked with the ability of producing OTA. A cDNA-AFLP differential display screening was performed in two strains of A. carbonarius, antagonists for the ability of producing OTA, allowing the identification of 119 differentially expressed sequences putatively involved in the regulation of OTA biosynthesis. A likely connection was pointed out between the biosynthesis of the toxin, vegetative growth and sexual/asexual developmental progression, along with common signalling pathways involving G protein and Ca(2+)/calmodulin dependent phosphorylation and dephoshorylation cascades.     

Presence of quercetin-3-O-glucuronoside in Spanish table wines

Quercetin-3-O-glucuronoside has been identified in several Spanish table wines by thin-layer (t.l.c.) and high-performance liquid (h.p.l.c.) chromatographic methods. This is thought to be the first report of its occurrence in wine.     

Arsenic content in some Spanish wines Influence of the wine-making technique on arsenic content in musts and wines

Summary All of the essential technological means of treating grapes, must and wine were examined systematically. The main reasons for the differences in the arsenic (As) content of rosé and red wines are explained. In this study a relationship has been found between the As level and the wine-making technique. Rosé wines contain more As than red wines because they require a shorter period of contact with the skins. In order to prove this, the average values for the rosé and red wine samples from the same winery were compared.

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Arsen-Gehalt in einigen spanischen Weinen. Beeinflussung des Arsengehaltes von Most und Weinen durch kellertechnische Maßnahmen

Zusammenfassung Durch systematische Überprüfung aller wesentlichen kellertechnischen Schritte der Most- und Weinbehandlung wurden die Hauptursachen der großen Unterschiede im Arsengehalt von Weinen aufgeklärt. Dieser vermindert sich schon beim ersten Abstich nach der Gärung und weiterhin durch die Entfernung der Trübstoffe. Bei starkstreuenden Gehalten zeigte sich, daß die Rotweine geringere Werte als die Roséweine aufwiesen. Außerdem unterschieden sich vergleichbare Weine aus verschiedenen Betrieben deutlich im Arsengehalt.

     

Study of ochratoxin A content in South Moravian and foreign wines by the UPLC method with fluorescence detection

In 2009–2010, 72 wine samples of Moravian and foreign origin were analysed for ochratoxin A contamination. A fast analytical method based on immunoaffinity column clean-up and followed by the ultra performance liquid chromatography coupled to fluorescence detection was used. LOD and LOQ values were 0.3 and 1.0 ng/L. Ochratoxin A was detected in 11% of Moravian wines and the detected OTA level ranged from 1.2 to 71.2 ng/L. In foreign wines, OTA level ranged from 1.6 to 227.0 ng/L. The values of OTA in all studied samples were significantly below the maximum allowable limit, 2.0 μg/kg, set by the European Union.