Ochratoxin A in Grape and Wine

Ochratoxin A (OTA) is dangerous to human health, and its legal limits in grape and wine are fixed. The molecule consists of an isocoumarin derivative linked to phenylalanine through a carboxyl group (structure reported in Fig. 8.1). 

This toxin is a secondary metabolite of Penicillium verrucosum, Aspergillus ochraceus, A. carbonarius, and A. niger fungi, whose development is promoted by favorable environmental conditions, 

Mass Spectrometry in Grape and Wine Chemistry, by Riccardo Flamini and Pietro Traldi 

In general, a satisfying method for quantitative analysis has to provide high sensitivity, low limits of detection (LOD), low limits of quantification (LOQ), a linearity range of at least three to four orders of magnitude, high precision (repeatability and reproducibility of data), and accuracy (experimental data as close as possible to the true value ). 

In particular, methods for analysis of OTA in wine, including both sample preparation and analysis, have to provide LOQ of at least 0.6gg/L (the legal limit is 2ppb), LOD 0.2gg/L, a linearity range of 0.1-100 ppb, and an extraction yield from red and white wines at least 84.6 and 88.4%, respectively (International Organization of Vine and Wine, 2006). Solid-phase extraction (SPE) sample preparation coupled with LC/MS analysis provides the performances required. Recently, LC/MS methods by direct injection of the sample were developed as well. 

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Flamini, R., Dalla Vedova, A., De Rosso, M. and Panighel, A. (2007) A New Sensitive and Selective Method for Analysis of Ochratoxin A in Grape and Wine by direct liquid chromatography/surface activated chemical ionization-tandem mass spectrometry, Rapid Commun. Mass Spectrom. 21(22), 3737-3742. 

Figure 8.4. The SACI/MS3 spectra of the OTA daughter ion at m/z 358 (above) and of the ZAN daughter ion at m/z 303 (below). The OTA m/z 239+341 and ZAN m/z 163+189+207 signals are used for quantitative analysis. (Spectra acquired in positive-ion mode collision energy applied to the parent ion 80% of maximum value MS3 of daughter ions at 100% of maximum collision energy). (Reprinted from Rapid Communications in Mass Spectrometry 21,Flamini et al., A new sensitive and selective method for analysis of ochratoxin A in grape and wine by direct liquid chromato-graphy/surface activated chemical ionization-tandem mass spectrometry, p. 3740, Copyright 2007, with permission from John Wiley Sons, Ltd.)...

Ochratoxin A in grape and wine (OTA) 241 Octapolar fields 62 Octenone 258 Oligomeric anthocyanins 200 Orbitrap 69,86... 

Atoui, A., Mitchell, D., Mathieu, F, Magan, N., Lebrihi, A. (2007). Partitioning of ochratoxin A in mycelium and conidia of Aspergillus carbonarius and the impact on toxin contamination of grapes and wine. J. Appl. Microbiol, 103, 961-968. 

The various contaminations in foods are due to the presence of compounds dangerous for consumer health or that affect organoleptic characteristics of the product. Ochratoxin A (OTA) and biogenic amines are dangerous for human health, and their legal limits are fixed in grape and wine. Due to their negative sensory properties and very low sensory thresholds, 2,4,6-trichloroanisole and ethylphenols have to be practically absent in wine, or present at as low a level as is possible. 

Serra, R., Mendoca, C., and Venancio, A. (2006). Fungi and ochratoxin A detected in healthy grapes and wine production. Lett. Appl. Microbiol. 42, 42 7. 

B Zimmerli, R Dick. Ochratoxin A in table wine and grape-juice occurrence and risk assessment. Food Add Contain 13(6) 655-668, 1996. 

The mycotoxin ochratoxin A (AAA) (7), which is a possible human carcinogen, continues to receive extensive attention due to its presence in a myriad of foods and beverages (1520, 1521) and its well-established toxicity (teratogenicity, mutagenicity, immunotoxicity, genotoxicity, and carcinogenicity) (1522-1524). Major sources of ochratoxin A are grapes, must, and wine (1525-1533), cereals (1534), beer (1535,1536), dried fruit (1537), roasted coffee (1538), and cocoa products and chocolate (1539). 

Zimmerli B, Dick R (1996) Ochratoxin A in Table Wine and Grape-Juice Occurrence and Risk Assessment. Food Addit Contam 13 655... 

Leong, L.S., Hocking, A.D., Scott, E.S. (2006b). The effect of juice clarification, static or rotary fermentation and fining on ochratoxin A in wine. Aust. J. Grape Wine Res., 12, 245-252. 

Burdaspal, P.A. and Legarda, T.M. (1999) Ochratoxin A in wine and grape musts and juices produced in Spain and other European countries, Alimentaria (Madrid), (299), 107-113. 

Serra, R., Mendonqa, C., Abrunhosa, L., Pietri, A. and Venancio, A. (2004) Determination of ochratoxin A in wine grapes comparison of extraction procedures and method validation, Anal. Chim. Acta, 513 (1), 41 -47. 

Flamini, R. and Larcher, R. (2008). Grape and Wine Contaminants Ochratoxin A, Biogenic Amines, Trichloroanisole and Ethylphenols, In Hyphenated... 

Pantazopoulos P, uncertainty estimate for Procedure ONT-FCL-0024, Determination of ochratoxin A in Wine and Grape Juice by High Performarwe Liquid Chromatography with Fluorescence Detection, 2001 (available at http //www.measurementuncertainty.org/mu/ examples/pdf/EncertaintyEstimateExampleFood LaboratoryDivisionOntarioRegion.pdf accessed 8/11/10). 

Ng W, Mankotia M, Pantazopoulos P, Neil RJ, Scott PM, Ochratoxin A in wine and grape juice sold in Canada, Food Addit. Contam. 2004 21(10) 971-981. 

Belli, N., S. Marin, A. Duaigues, A.J. Ramos, and V. Sanchis. 2004. Ochratoxin A in wines, musts and grape juices from Spain. /. Sci. Food Agric. 84 591-594. 

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