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).     

Optimisation of the Amido Black assay for determination of the protein content of grape juices and wines

While the heat/chill stability of white wines cannot be predicted from the total protein concentration, this information is useful in assessing the effectiveness of fining treatments. We have adapted the Amido Black assay for use in grape juice and wine. The response of bovine serum albumin (BSA) was similar in water, model wine and model juice. The linear range of the assay (<100 mg l^?1) extends beyond protein concentrations typically found in grape juices and wines. The limit of quantification was 11.1 mg l^?1 for BSA in model wine and 7.6 mg l^?1 in model juice, while the limit of detection was found to be less than 3 mg l^?1 in either solution. In contrast to other methods of protein determination, this assay is not affected by common wine phenolic and pectic compounds or by glutathione. The mean response of BSA was similar in model juice and red and white grape juices. The mean response of BSA in red wine was lower than in white wine and model wine (p < 0.001), and there was considerable variation in response among wines. Protein concentrations determined using this method were reproducible (CV < 10%). This optimised assay can be used to monitor protein levels in grape juices and wines. © 2001 Society of Chemical Industry     

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.     

Determination of residues of propamocarb in wine by liquid chromatography-electrospray mass spectrometry with direct injection.

A simple, sensitive and reliable liquid chromatography-mass spectrometry method with direct injection of diluted samples is reported for the determination of propamocarb residues in wine. Red and white wines were diluted 40- and 20-fold, respectively, using water. Liquid chromatography was performed with a mobile-phase gradient and detection was by electrospray mass spectrometry in a positive ionization mode. Propamocarb was detected as the protonated molecular species at m/z 189. Using matrix-matched calibrant solutions, a calibrated range equivalent to 0.05-2.0 mg kg(-1) in red and white wines and limits of detection of 0.025 mg kg(-1) for white wine and of 0.05 mg kg(-1) for red wine (0.00125 microg ml(-1) of sample solution injected) were readily achievable. Recovery of propamocarb hydrochloride from wine spiked before dilution was in the range 91-115%. The chromatograms were free of isobaric interferences. In a small wine survey (72 samples), no residues of propamocarb were detected above 0.1 mg kg(-1).     

Detection of ochratoxin A in tropical wine and grape juice from Brazil

BACKGROUND: Ochratoxin A (OTA) is the main mycotoxin found in grapes, wines and grape juices and is considered one of the most harmful contaminants to human health. In this study, samples of tropical wines and grape juices from different grape varieties grown in Brazil were analysed for their OTA content by high‐performance liquid chromatography. RESULTS: The detection and quantification limits for OTA were 0.01 and 0.03 µg L^?1 respectively. OTA was detected in 13 (38.24%) of the samples analysed, with concentrations ranging from < 0.03 to 0.62 µg L^?1. OTA was not detected in any of the grape juice samples. Most of the red wine samples proved to be contaminated with OTA (75%), while only one white wine sample was contaminated. However, the OTA levels detected in all samples were well below the maximum tolerable limit (2 µg L^?1) in wine and grape juice established by the European Community and Brazilian legislature. CONCLUSION: The results of this study indicate a low risk of exposure to OTA by consumption of tropical wines and grape juices from Brazil. © 2012 Society of Chemical Industry     

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).     

Statistical optimization of ethanol fermentation parameters for processing local grape cultivars to wines

Grape juice from two local grape cultivars viz. Punjab MACS purple and H‐144 was subjected to prefermentation skin treatment. Ethanol fermentation w.r.t agitation rate, temperature, inoculum size, and nutrient supplementation were optimized using Triple M medium following response surface methodology (RSM). RSM results were numerically optimized keeping temperature “in range” for red wine and “low” for white wine which showed agitation rate of 80 ± 1 rpm for 24 hr, diammonium hydrogen orthophosphate supplementation @ 150 mg/100 ml, inoculum size of 6.1 and 6.5% (vol/vol), and fermentation temperature of 24.6 and 21 °C as optimum for ethanol fermentation of red and white wines, respectively. Optimized results were validated on grape juice of Punjab MACS purple and H‐144 cultivars that lead to 12.0 and 11.2 (%vol/vol) ethanol production, respectively. Gas chromatography mass spectrometry analysis revealed the presence of 41 volatile compounds in the form of phenols, alcohols, terpenes, esters, ketones, and amines that add to the nutraceutical and antioxidant value of the wines.

Practical applications

Present study provides the statistical optimized fermentation parameters for red and white wine production separately. Optimization of an efficient processing technology to produce local grape wines will help to reduce the price of wines so that they are available to common masses at affordable costs besides improving the economic status of grape growers in the state and providing valuable information to wine makers to establish winery under North Indian conditions. Use of synthetic grape juice (Triple M media; during off season of grapes) lead to optimization of ethanol fermentation parameters in two separate fashions considering fermentation temperature as key parameter. Gas chromatography mass spectrometry analysis showed the presence of flavonoids, terpenes, and esters increasing nutritive value of product, providing antioxidants to the consuming person.     

The multi-element determination and regional discrimination of Australian wines

Concentrations were determined for 56 elements in 1397 samples of Australian wine, using solution based inductively coupled plasma mass spectrometry and emission spectroscopy. Interpretation of the data indicated that, within red and within white wines, the vintage and grape variety had little effect on the multi-element composition of the wine, although significant differences were observed between red and white wines.     

Simple determination of main organic acids in grape juice and wine by using capillary zone electrophoresis with direct UV detection

An accurate, simple and rapid capillary zone electrophoresis (CZE) method with direct UV detection has been set up for the determination of main organic acids in grape juice and wine. The determination of tartaric, malic, and citric acids in grape juices and tartaric, malic, succinic, acetic, lactic and citric acids in wines can be achieved in less than 3 min with only a simple dilution and filtration treatment of the sample. Validation parameters of the method as detection and quantification limits, linearity, precision (intraday and interday analysis) and recovery were also studied in grape juice, white wine, rose wine and red wine, separately. The proposed method decreases the analysis times of the previous reported CZE methods and allows the rapid control of the grape maturity, the winemaking processes and the detection of wine alterations and/or illnesses.     

中国野生刺葡萄（Vitis davidii Foex）及其单品种葡萄酒中花旗松素含量分析

利用高效液相色谱-串联质谱联用技术对原产中国的野生刺葡萄果实的果皮、果肉、种子及单品种葡萄酒中的花旗松素含量（以鲜质量计算）进行测定与分析。结果表明：刺葡萄果实果皮中花旗松素含量最高,其含量在刺葡萄黑、白果实中分别为（2.44±0.18）、（2.03±0.14） mg/kg,在种子中分别为（1.66±0.13）、（1.38±0.12） mg/kg,果肉中含量最低,分别为（0.36±0.02）、（0.25±0.02） mg/kg。刺葡萄黑、白果实中各个部位花旗松素含量均无明显差异,但对照品种黑色果实果皮中的花旗松素含量显著高于白色果实,这说明花旗松素含量的高低与葡萄果皮颜色并无直接关系。在单品种酒中,白葡萄酒由于酿造工艺不同,果皮和种子中的花旗松素无法进入酒中,花旗松素含量仅为红葡萄酒的20%;葡萄酒中的花旗松素含量略低于果实是因为提取果实中花旗松素的溶剂是甲醇,而葡萄酒中只是水和乙醇的自然浸渍。     

新疆葡萄酒中赭曲霉毒素A含量分析

赭曲霉毒素A（OTA）是葡萄及其深加工产品中主要的真菌毒素,同时也被国际癌症研究机构（IARC）定为2B类致癌物。 采用 酶联免疫法（ELISA）商业试剂盒对新疆四大产区葡萄酒中OTA含量进行调研分析,研究不同产区葡萄酒中OTA含量的差异;同时, 对不同葡萄品种酿造葡萄酒过程中发酵葡萄汁和葡萄酒的OTA含量进行测定,分析酿造过程中OTA的变化规律。 结果显示,34份葡 萄酒样品中OTA含量均未超过2 μg/L;其中,焉耆盆地和吐哈盆地葡萄酒中OTA含量较低,平均含量分别为0.19 μg/L、0.20 μg/L;在 白葡萄酒酿造过程中OTA含量呈显著的下降趋势,而红葡萄酒酿造中OTA含量呈先升高后降低的趋势。     

Occurrence and stability of inorganic and organic arsenic species in wines, rice wines and beers from Central European market

We investigated in total 80 wine samples of different types and seven grape juice and 23 beer samples purchased from markets in Central Europe in order to understand the arsenic (As) speciation and help assess the potential As toxicity via intake of alcoholic beverages. Generally, total As concentrations in most samples investigated were below the drinking water limit 10 μg l(-1) published by the World Health Organization (WHO); ranging from 0.46 to 21.0 μg l(-1) As in red and white wines and from 0.75 to 13.4 μg l(-1) As in beers. In addition, concentrations of total As in rice wine and in rice beer were 0.63-6.07 and 3.69-8.23 μg l(-1) As, respectively. The total As concentrations in ice wine ranged from 7.94 to 18.8 μg l(-1) As, significantly higher than in white and red wine. Arsenite predominated as the As species in most of the wine samples, whereas arsenate was the dominant species in rice wine, beer and rice beer. Methyl As components were usually minor components in all wine and beer samples. Monomethylarsonic acid, dimethylarsinic acid and two additional unknown As species were frequently found in grape juice, late harvest and ice wine with higher sweetness. After air exposure, arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid were stable at 4°C for months, probably due to the acidic conditions of wine and beer samples. The presence of sulfite had little influence on As speciation in wine. Despite the predominance of more toxic arsenite and arsenate in wine and beer, the estimated weekly exposure to As (via consumption of beer, wine and rice wine) is low. The As intake per capita is 6.81 μg from beer, <1.93 μg from wine and 0.88 μg from rice wine, estimated using the median of total As concentration multiplied by the average consumption per capita of the corresponding beverage.     

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     

Fate of three insect growth regulators (IGR) insecticides (flufenoxuron, lufenuron and tebufenozide) in grapes following field application and through the wine-making process

The dissipation of three insecticide flufenoxuron, lufenuron and tebufenozide residues in grapes after field treatments and during the wine-making process was assessed. Residues were determined in grape, must, centrifuged must and wine samples by HPLC-UV after cyclohexane extraction and clean-up on silica-phase cartridges. Vines in vineyards with white and red grapes located in Central Greece were sprayed once with commercial formulations of each insecticide at the recommended doses in experiments carried out in 2004 and repeated in 2006. The insecticide residues in grapes showed slow reduction for a period of 42 days after application following first-order kinetics with dissipation rates ranged from 0.011 to 0.018 mg kg?1 day?1. However, at the recommended pre-harvest interval (PHI) residues did not exceed 0.27 ± 0.03 mg kg?1 for flufenoxuron and lufenuron and 0.68 ± 0.07 mg kg?1 for tebufenozide, and they were clearly lower than the maximum residue limits (MRLs) set by the European Union for grape (2 mg kg?1 for flufenoxuron, 1 mg kg?1 for lufenuron and 3 mg kg?1 for tebufenozide). Grape processing into wine caused an almost complete reduction for flufenoxuron and lufenuron as their residues in wine were below the method LOQs (<0.01 mg l?1), but only a moderate reduction for tebufenozide with concentrations from 0.13 to 0.26 mg l?1 measured in the produced wines. Mean transfer factors for tebufenozide of 0.45 for white 'Roditis' and 0.34 for red 'Cabernet Sauvignon' were found from grapes into wine for the wines processed without maceration. The wine-making technique (with or without maceration) had the same influence on tebufenozide residues in wine. Of the various clarifying agents studied, charcoal was found to be the only one effective in removing tebufenozide residues from wine.     

Determination of flavan-3-ols and trans-resveratrol in grapes and wine using HPLC with fluorescence detection

Concentrations of trans-resveratrol, catechin and epicatechin were analyzed in musts and wines produced from seven red and four white grape cultivars from various wine growing regions of Turkey. Phenolics were quantified using an HPLC method optimized for the separation of wine phenolics. Wine samples contained higher phenolics levels than the corresponding musts. With the exception of Semillion, white wines and musts contained lower concentrations of phenolics than red wines and musts. However, the white cultivar Semillion had the highest concentrations of catechin and epicatechin among all wine and must samples. Semillion wine catechin and epicatechin were 13.7 and 11.8 mg/L, respectively. The highest level of trans-resveratrol among the white cultivars was found in Narince wine (1.93 mg/L). Within the red wine and must cultivars, Bo?azkere, Öküzgozü, and Cabernet contained the highest concentrations of flavan-3-ols and trans-resveratrol. Catechin was the major phenolic in all wines and most musts. Epicatechin was the major phenolic in 6 of the 11 must samples, but none of the wine samples. trans-Resveratrol was generally found in lowest concentrations in both wines and musts.     

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.     

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.     

Anthocyanin pattern of several red grape cultivars and wines made from them

A high-performance liquid chromatography (HPLC) method with in-line photodiode array detection was applied to separate anthocyanins from red grape skin extracts of several Spanish cultivars, before and after winemaking, and from finished red wines. Data show that, for every cultivar studied, the anthocyanin pattern of the three materials considered (fresh grape skins, crushed grape skins after winemaking, and finished red wines) is quite different. These results may be explained by taking into account the different chemical structures of each anthocyanin and the degradation reactions that should take place during winemaking. On the other hand, the HPLC fingerprint of every material (fresh grape skins, crushed grape skins after fermentation, and wines) is related to cultivar characteristics. Thus, HPLC determination of the anthocyanin pattern of wines may be used to predict the grape cultivar from which wine was made.     

Effect of refermentation conditions and micro-oxygenation on the reduction of volatile acidity by commercial S. cerevisiae strains and their impact on the aromatic profile of wines

Herein, we evaluate the applicability of previously characterized commercial and indigenous Saccharomyces cerevisiae strains and non-S. cerevisiae species for the deacidification of white and red wines at a pilot scale. The effect of the refermentation process (mixture of acidic wine with musts from freshly crushed grapes or with residual marc) as well as micro-oxygenation (MO) on acetic acid removal efficiency and wine aromatic composition was also assessed in a red wine. The commercial strains S26 and S29 efficiently reduced both acetic acid (43 and 47%, respectively) and sugar (100%) after 264 h of refermentation of an acidic white wine that was supplemented with grape must. Similar results (60-66% of acetic acid removal) were observed for red wine deacidification using grape must, independently of MO. When residual marc was used for deacidification, strain S26 removed 40% of acetic acid, whereas strain S29 did not initiate refermentation with or without MO. Wines obtained by refermentation with the must had significantly lower acetic acid and a higher total SO₂ concentration in comparison to the wines deacidified by the grape marcs. The volatile aroma compound's composition of deacidified red wines was dependent on the refermentation process used, rather than on MO. The marc-deacidified wine obtained by the use of strain S26 and without MO achieved the best sensory classification. When data from all analytical and sensory evaluation were combined, Principal Component Analysis (PCA) separated the wines into three distinct groups according to the strain and the refermentation process independently of MO. We successfully established an efficient and cheap enological solution for the rectification of volatile acidity of wines.     

Occurrence and stability of inorganic and organic arsenic species in wines,rice wines and beers from Central European market

We investigated in total 80 wine samples of different types and seven grape juice and 23 beer samples purchased from markets in Central Europe in order to understand the arsenic (As) speciation and help assess the potential As toxicity via intake of alcoholic beverages. Generally, total As concentrations in most samples investigated were below the drinking water limit 10?µg?l^?1 published by the World Health Organization (WHO); ranging from 0.46 to 21.0?µg?l^?1 As in red and white wines and from 0.75 to 13.4?µg?l^?1 As in beers. In addition, concentrations of total As in rice wine and in rice beer were 0.63–6.07 and 3.69–8.23?µg?l^?1 As, respectively. The total As concentrations in ice wine ranged from 7.94 to 18.8?µg?l^?1 As, significantly higher than in white and red wine. Arsenite predominated as the As species in most of the wine samples, whereas arsenate was the dominant species in rice wine, beer and rice beer. Methyl As components were usually minor components in all wine and beer samples. Monomethylarsonic acid, dimethylarsinic acid and two additional unknown As species were frequently found in grape juice, late harvest and ice wine with higher sweetness. After air exposure, arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid were stable at 4°C for months, probably due to the acidic conditions of wine and beer samples. The presence of sulfite had little influence on As speciation in wine. Despite the predominance of more toxic arsenite and arsenate in wine and beer, the estimated weekly exposure to As (via consumption of beer, wine and rice wine) is low. The As intake per capita is 6.81?µg from beer, <1.93?µg from wine and 0.88?µg from rice wine, estimated using the median of total As concentration multiplied by the average consumption per capita of the corresponding beverage.