| Summary: |
Mycotoxins are toxic metabolites produced by various fungi growing in several foodstuffs. Ochratoxin A (OTA) is included in this group and it has been extensively studied in the last few years, regarding to risk assessment, toxicological effects and exposure assessment in different food matrices. OTA exposure assessment studies concluded that it comes from small amounts present in a large number of foodstuffs, rather than a localised or confined contamination of a single species. In the 90s, the sporadic detection of ochratoxin A in wines (1) made this a food safety problem.
During the last three years, this research team has investigated the occurrence of OTA in the wines from the Northern Region - Vinho do Porto and Vinho Verde, as an AGRO funded project (ending Fev.2005). A large surveillance has been performed (more than 600 samples), indicating that contamination in wines didn't significantly exist (3,4,5,6). OTA was detected in grapes at extremely low levels, but sufficiently high to question its fate during vinifications. Therefore microvinifications were performed and our team concluded that about 80% of OTA remained in the solid parts (wine lees and grape pomaces), seeming that degradation doesn't occur. The questions arising are - Does the toxin remain in vinification by-products? Does it suffer any kind of degradation? Does it return to environment or enter food chain, magnifying its toxic effects?
The Douro Demarcated Region includes 39,000 hectares of vineyards in northern Portugal and is responsible for the annual production of over 50 thousands of the winery by-products - wine lees and grape pomaces. Until now, any information exists about the final fate of ochratoxin A present in the by-products, reason why this project intends to solve, guaranteeing the prevention of its dissemination through the food chain.
It is intended to perform a large survey of ochratoxin content in by-products of vinification from Douro region, by me  |
Summary
Mycotoxins are toxic metabolites produced by various fungi growing in several foodstuffs. Ochratoxin A (OTA) is included in this group and it has been extensively studied in the last few years, regarding to risk assessment, toxicological effects and exposure assessment in different food matrices. OTA exposure assessment studies concluded that it comes from small amounts present in a large number of foodstuffs, rather than a localised or confined contamination of a single species. In the 90s, the sporadic detection of ochratoxin A in wines (1) made this a food safety problem.
During the last three years, this research team has investigated the occurrence of OTA in the wines from the Northern Region - Vinho do Porto and Vinho Verde, as an AGRO funded project (ending Fev.2005). A large surveillance has been performed (more than 600 samples), indicating that contamination in wines didn't significantly exist (3,4,5,6). OTA was detected in grapes at extremely low levels, but sufficiently high to question its fate during vinifications. Therefore microvinifications were performed and our team concluded that about 80% of OTA remained in the solid parts (wine lees and grape pomaces), seeming that degradation doesn't occur. The questions arising are - Does the toxin remain in vinification by-products? Does it suffer any kind of degradation? Does it return to environment or enter food chain, magnifying its toxic effects?
The Douro Demarcated Region includes 39,000 hectares of vineyards in northern Portugal and is responsible for the annual production of over 50 thousands of the winery by-products - wine lees and grape pomaces. Until now, any information exists about the final fate of ochratoxin A present in the by-products, reason why this project intends to solve, guaranteeing the prevention of its dissemination through the food chain.
It is intended to perform a large survey of ochratoxin content in by-products of vinification from Douro region, by means of the sampling provided by Sub-Vidouro, the Winery by-products Recycling Center of the Region. Physical and chemical characterization will be performed by UTAD, ochratoxin A will be analysed at LEPAE/FEUP and the degradation studies will be done at U.Minho. Final fate of ochratoxin A, degradation products and/or conditions favourable to its formation will be studied, in order to help prevention, as well as specific chemical reaction providing its elimination, if necessary, will also be investigated.
This project will contribute to improve knowledge on mycotoxins fate in environment, helping nature conservation and better quality of life. |
| Results: |
The multidisciplinary efforts of scientists, necessary to obtain the sustained conclusions from epidemiologists, toxicologists, analytical chemists and oenologists, require time and are often difficult to gather in useful time, once the gap between the detection of the contaminant and the product consumption is generally short, and decisions have to be taken rapidly. That is the main reason why concerns associated to the detection of some toxicological compounds recently found in wines have led to the imposition or the discussion to impose maximum legal levels in wine without consistent epidemiological research and interlaboratorial collaborative studies to uniform the methods of analysis. Examples are ethyl carbamate in the past and ochratoxin A nowadays. Although (and fortunately) for the majority of these compounds it is being concluded that there is no reason for concern, even the detection of a sporadic case of contamination urges the problem to be studied and strategies of control and prevention to be adopted. This project will contribute to help solving problems in the area of mycotoxins contamination by ensuring environmental safety and human and wildlife health, by supporting the scientific knowledge base of regulations and finally contributing to a decision-making process based on sound scientific evidence. The evaluation of final fate of the toxin, by means of a comprehensive monitoring programme, will influence strategies of prevention or elimination. Impacts resulting from this project will include ethics and social ones. Ethic impact will result from a correct, and reliable, analytically supported, management of information regarding the presence of OTA in national resources. Detected compounds will always have a chain of traceability, in order to allow the correct comparison with other studies or cases.
Expected results from each task are:
• To develop specific techniques of extraction/pre-treatment of samples according to its nature (grape pomaces, wine lees, brandies); to validate the analytical method(s) of determination of ochratoxin, regarding each solid (skin, stems, seeds, etc.) and liquid component of the by-products.
• To allow the identification/quantification of ochratoxin A in products derived from the by-products (brandies, alcohol, tartarates, etc.); To develop sampling routines that allow this procedure to be reproducible in view of the high quantities produced (20 - 30 thousand tons/year)
• To perform the physical-chemical characterization of the by-products and to conclude about the possibility of crossed contamination (other crops, sea products, etc.)
• To elucidate about reactions involved in order to define a possible degradation strategy in wineries by-products;
• To elaborate proceedings aiming effective quality control and safety procedures of by-products from wineries |