Mycotoxins: effects on cereals & proposals for reducing their presence.
Mycotoxins top the worlwide list of the most common natural contaminants in food. Until a few years ago mycotoxins were not given much attention, but lately their relevance has been increasing. In 2013, especially in Andalusia, a lot of animal feed was thrown out after a high level of mycotoxins was detected; although no damage to human health occurred, concern among farmers increased.
What are mycotoxins?
Mycotoxins are toxic secondary metabolites produced by fungi of certain types, such as Alternaria, Aspergillus, Claviceps, Fusarium and Penicillium. The type and number of mycotoxins produced by each type varies from year to year, depending mainly on environmental factors, crops and storage. Given the right conditions, fungi can develop without mycotoxins, because these secondary metabolites are produced as a response of the fungus to an adverse condition as a way to adapt the environment to their needs in a stressful situation.
The presence of mycotoxins can affect both human and animal health. To consumers, they represent a silent danger: their consumption is in small doses, thus no obvious clinical signs are apparent; however, over time they may pose a grave danger.
For example, in making bread, the degraded gluten proteins negatively affect the elasticity of the dough, the color of the crumbs and the size of the loaf.
Why should we worry?
An estimated 25 % of all crops worldwide are affected by mycotoxins, especially by aflatoxins, according to the United Nations Food and Agriculture Organization (FAO). That fact under no circumstances violates the European legislation for controlled substances; there are, however, two areas of concern: the high percentage of products with some type of mycotoxin residues, and the presence of some newer mycotoxins that are not yet controlled by law.
High levels of mycotoxins in the diet can have acute and chronic adverse effects on human health, as well as on a great variety of animal species. Those adverse effects can appear on various organs, especially the liver and kidneys, but also on the nervous, endocrine and immune systems. The symptoms caused by mycotoxins are often as different from each other as are the chemical structures of those toxins.
However, in general terms, the risk of acute mycotoxin poisoning in man is low or moderate, compared to poisoning derived from microbiological or chemical contaminants.
What types of mycotoxins are there, and what crops do they affect?
The genus Fusarium is made up of a large number of species, some of which are pathogens of plants, especially of cereals, and cause a disease known as Fusarium head blight. This feature results in a greater concern regarding the presence of these fungi in cereals, since on the one hand they cause a decrease in performance (by reducing the weight and size of the grains), and on the other hand the infected grains affect the functional properties of the gluten and the quality of the final product (bread, pasta, etc.).
DON is the most common Fusarium mycotoxin; it is present in various cereals, especially in corn and wheat. That mycotoxin appears usually before the harvest, when the crops are affected by species such as F. graminearum and F. culmorum. Its importance lies in the serious consequences that the DON has for agriculture. The contamination by this mycotoxin threatens crops and feed and, consequently, also food products. The appearance of DON causes significant economic losses and affects productivity and trade, both domestic and international.
Other relevant mycotoxins are Ochratoxin A (OTA), produced by fungi of the genera Aspergillus and Penicillium, which grow naturally not only in grains but also in coffee, beer or wine.
Patulin, another mycotoxin present in food, is synthesized from Aspergillus and Penicillium, and can be detected in feed, vegetables, grains and fruits. It is common in wheat, lettuce, radishes and apples, particularly in non-fermented apple juice.
Fumonisins are a group of mycotoxins only recently identified; they are produced by F. moniliform, a mold present throughout the world that is often found in corn. The presence of fumonisin B1 has been reported in corn (and related products) in several agro-climatic regions in several countries. These toxins are particularly pervasive when the corn is grown in a hot and dry environment.
What can we do?
We must realize that it is NOT possible to get rid of mycotoxins, but rather that their levels must be below those set by regulation. The advice for reducing mycotoxins in cereals are:
> Best practices in agriculture (BPAs) and best practices in manufacturing (BPMs).
> Additional management systems such as Hazard Analysis Critical Control Points (HACCP).
To avoid the presence of these substances before the processing of foods is the only way to prevent their further development. Therefore, prevention during the harvest as well as providing care after the harvest are both just as critical.
During the harvest itself, the biggest problem is the increase of mycotoxins. Preventive measures include maintaining the appropriate harvest schedules, avoiding moisture higher than 15%, and removing foreign material from crops. During the post-harvest, the problem is the continuing increase of mycotoxins, hence the necessity to protect the stored products through strict humidity controls, to watch out for the appearance of pathogens, and to store all products on clean and dry surfaces.
Other important pillars in the control and prevention of mycotoxins are de-contamination (removal or neutralization of mycotoxins in food) and de-toxification (reducing or eliminating the toxic properties of mycotoxins). The fact that mycotoxins are heat resistant makes it necessary to apply temperatures higher than 100°C to destroy them in raw materials, and this turns out to be impractical because it may have an organoleptic and nutritional impact on the final product.
What do we do at IDEAGRO, and what are our lines of work?
Currently all measures and proposals for action by the players involved are based on actions over products that have already been collected. At IDEAGRO we believe that at that stage, the best we can do is to try to maintain the quality; but to really reduce the impact of the mycotoxins, we must act upon their source, which is none other than the growth phase. Therefore, at IDEAGRO we have spent years developing BPAs tailored to different growing areas; the implementation of these BPAs allows us to reduce the mycotoxin content exponentially over a period of years. These programs are the result of many studies done in collaboration with the research departments of universities and bio-stimulant manufacturers, and they are based on improvements in soil health, on changes in nutrition, and on inducing resistance in plants against adverse effects.
For more information: firstname.lastname@example.org, or call +34 968 118 086 // @ideagro & @palazonpedro