Mycotoxins, the invisible evil. The dreaded natural contaminants, which are highly toxic to humans, are a permanent alert. How to prevent its formation and manage related food safety risks? From June 10-12, 2019, Rome will host the international conference on the topic (poster attached). An event that has been bringing together leading experts for 20 years to share updates on the state of the art, scientific evolution and legislation. This is followed by an interview with Carlo Brera, one of the leading international experts on mycotoxins, a researcher at the Istituto Superiore di Sanità as well as the organizer of the congress.
Dr. Brera, is there a real risk to the population from the consumption of common foods such as pasta, bread, cookies?
From the scientific evidence to date, the general population is to be considered not particularly at risk, except for children of post-infantile age (3-10 years) and partly adolescents, based on their unfavorable body weight and the consumption of foods not dedicated to this group.They eat, in fact, foods designed and suitable for consumption by adults, since there is no differentiation as there is for baby food (intended for infants and children up to 3 years), which is subject to lower limits for the presence of contaminants.
What factors are responsible for the formation of mycotoxins?
The main factors to refer to as a source of risk are mainly those related to environmental conditions that cause stress to both the plant and the mold itself. In particular, thermal, nutritional and water stress undoubtedly represent favorable conditions for the development of fungal colonies in the field with probable consequent production of mycotoxins.
Are mycotoxins still a serious threat to crops?
Compared with 20 years ago, farmers-as well as all operators in the feed food system-have improved their attention to the problem, but still a satisfactory level of prevention has not been achieved. The risk remains high under certain climatic conditions. 2014 did not go well, but the last high-risk condition was in 2012 and was repeated as in 2003. Evidently the lesson has not been learned. There have been signs of a strong mold attack in the field again this year.
16 years ago, the year was characterized by 6 months of drought, with no rainfall from May to October. Ideal conditions for strong aflatoxin B1 growth. Farmers were unable to intervene then, as irrigation is never sufficient to compensate for such a level of aridity. The grain dried in the field prematurely, was then harvested prematurely with moisture below 22 percent, promoting mold growth that led to frightening aflatoxin levels. All contaminated crops were segregated in silos. The biogas industry took off right then, when it disposed of 30-40% of those contaminated crops.
In case of contamination, are there effective treatments to remove mycotoxins from food? Toasting and drying, for example?
Mycotoxins cannot be eliminated. They are natural contaminants produced by molds or fungi due to favorable climatic conditions. They are ubiquitous, growing at all latitudes, and are also highly thermostable. Prevention is the only way to counteract them, but this is where the biggest obstacle stands.
What preventive measures can be taken?
On measures to be taken in the field to combat mycotoxin formation in corn and wheat there are good practices codified in official acts. Such as the 1996 Recommendation of the European Commission, the Codex Alimentarius Recommendation, and the guidelines of the Ministry of Agriculture (drafted by Professor Amedeo Reyneri, who will be present at the conference).
What do good agricultural practices involve?
Best practices recommend adopting a holistic approach characterized by many components such as crop precession (crop rotation, ed.), which makes it possible to contain the propagation of mycotoxins. This is in fact more likely when species that are palatable to the fungi that originate these toxins are grown in succession, such as maize and soon after sorghum. Biological control must then be employed, including using antagonistic insects. And resort, where appropriate, to seed tanning.
Sowing should be done on plowed, not firm soil. Weed and ‘pests’ control, use of fungicides, and proper irrigation are also recommended. And the control of harvest mechanization, to prevent grain damage by mechanical tools, as any injury to the grain or caryopsis becomes nourishment for mold growth during storage. Other preventive measures refer to the final stage, namely immediate drying of the crop and careful handling of silos.
Are there also innovative law enforcement measures?
The best solution is plants that are resistant to fungal attack and mycotoxin production. Varieties obtained by isogenic lines, from maize or wheat (non-GMO, ed.), created by Italian universities, by CREA, and by the Institute of Cereal Farming in Bergamo. Although there are numerous studies and seed varieties registered as resistant to fungal attack, such solutions are not yet being adopted systematically. The problem is that the farmer, at the time of planting, does not know what the weather conditions will be in the following months. And he is unwilling to pay more for a hardy variety in the absence of guarantees on the return on the increased investment.
A good practice that has also been gaining ground in Italy for about three years is biocontrol, which was developed in the United States in the 1980s. It involves spraying the cultivated field with fungal strains identical to those that produce mycotoxins but characterized by being nontoxic. By playing with quantity, the nontoxic fungal species is induced to prevail over the other, resulting in reduced growth of toxigenic mold congenial to the production of aflatoxin B1, which is highly toxic.
Another possible solution, adopted in several countries outside our own, is the use of genetically modified (GM) corn varieties, which inhibit the formation of certain mycotoxins (fumonisins). Spain grows them; Italian farmers, on the other hand, cannot. Both because of the planting ban in Italy and the fragmentation of our agriculture into small lots that would make it impossible to avoid contamination between GMO and conventional crops. A ban on planting but not consumption. In fact, as is well known, our country still imports GMO feed to feed the farms from which the raw materials of such excellences as Parmigiano Reggiano cheese or Parma ham originate. (A paradox already on this site highlighted, ed.).
With so many prevention measures available, why do mycotoxins in the field remain a constant threat?
It takes little to describe good practices, but a lot to implement them. And the farmer must first of all secure an income. I have always said this in the international arena as well, we would need agricultural policies aimed at supporting farmers, otherwise there is no prevention that holds, because no one recognizes the farmer for the increased costs involved.
Adopting agronomic practices that result in a mycotoxin-free crop costs more, has a plus, but the crop is still paid the same price. If it is contaminated, however, it is paid even less. In this situation, it is logical for the farmer to try his best to protect his production, but without exceeding a certain level, otherwise he would have no economic return.
Do the same considerations apply to organic farming?
Organic farming foods should be better protected, with respect to the risk of mycotoxin contamination, because the mentioned good agronomic practices are provided by ‘default’.
The frequency of contamination is far higher in conventional. But any contamination on an organic field can reach much higher levels than on a conventional one because no pesticides, herbicides or insecticides are used.
In a recent survey of reports to the RASFF of food consignments contaminated with mycotoxins, we noticed that the countries of origin of the risk are always the same. And among these excel the United States, home of ‘biocontrol’. How come?
In Europe we have very strict and restrictive regulations based on the precautionary principle, while the United States relies on risk assessment and prioritizes the marketability of the product.
In addition, despite advanced research and the use of mycotoxin-resistant GMO crops, the U.S. has climatic conditions that do not guarantee compliance with the limits in place in Europe. However, this should not frighten us, because we enjoy a very good European border control system.
How are border controls regulated in the European Union?
The European Commission has issued two specific regulations to modulate controls in consideration of risk factors. Both regulations – reg. EC 669/09 on pathogenic contaminants and reg. EU 884/14 on aflatoxins- bear a table with country, matrix, frequency of controls according to risk and parameters to be controlled (salmonella, aflatoxins, ochratoxin, etc.). They are updated every 4 months, and the percentages of matches to be checked may change.
Fifteen years ago, for example, problems emerged on Iranian pistachios, which were contaminated with aflatoxin B1. The European Commission, then DG SANCO, decided that 100 percent of incoming consignments should be subjected to controls. A delegation of inspectors was later sent to Iran to verify the origin of the problem. Within a few years, the situation improved and controls dropped first to 50 percent, then to 20 percent. Precisely because of the remedies shared with European mission experts and their effective adoption by local producers.
Currently, reg. EU 884/14 requires, in some cases, the control of 1 in 2 consignments when the origin is at risk of aflatoxins. What is not screened at the European borders is still subject to controls on the territories of the member states.
Why does Italy appear infrequently in the RASFF as a reporter of mycotoxin-contaminated batches?
Historically, Italy has always been at the top for alerts because we have a network of controls that is unique in Europe in terms of organization and efficiency. Therefore, it is highly likely that importers will not land mycotoxin-contaminated food consignments in Italy. And as a result, not finding any, Italy does not often appear in the RASFF for this type of alert, despite being generally among the European countries that send the most alerts.
In the national territory, so with priority on Italian productions, what is the level of controls and mycotoxin risk?
In 2016, I asked the Ministry of Health to organize a national plan to control mycotoxin risk on food. Together we drafted the plan, which lasted until 2018 and is still in place. All regions contributed. Now I–risk assessor–have at my disposal a database that is well organized in terms of quantity and quality of information.
6 thousand data, sorted according to the standard required by EFSA, allow me to make a survey of mycotoxin exposure risk in Italy. A volume that also makes us competitive at the European level. When the Commission asks the member states for data on the level of internal risk, it is important to provide a good amount of it, in order to have more weight in the decision-making process.
The risk of exposure of the Italian population to mycotoxins still presents some problems. But no major critical issues emerge, based on the analysis I will bring to the congress.
Dr. Brera, tell us something about the mycotoxin congress you organized in Rome.
The first day, June 10, is entirely devoted to analytical methodologies on mycotoxins and plant toxins. This year it takes place in a prestigious venue, the Noble Pharmaceutical Chemical College, Via in Miranda 10, inside the Roman Forum. We will be inside a consecrated church. A green back door opens in front of the only temple still intact. Instead, the other two days-which are devoted to risk management and risk assessment, respectively-take place, as is traditional, at the National Institute of Health.
Prominent among the many international keynote speakers is Dr. Frans Verstraete of DG SANTE of the European Commission, who will present the very latest news on the subject. Representatives of all major organizations active in the mycotoxin field are also present. CEN, European Committee for Standardization, the reference body for the procurement of reference methods for mycotoxin analysis. The Ministry of Health, EFSA, CREA, vil CNR in Bari and various universities (Turin, Piacenza), the Association of Milling Technologists, Coldiretti and others.
ANNEX Program_VI National Mycotoxin Congress
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".