Safety Aspect in Soybean Food and Feed Chains: Fungal and Mycotoxins Contamination

Soybean (Glycine max L. Merr.) is an Asiatic leguminous plant cultivated in many parts of the world for its oil and proteins, which are extensively used in the manufacture of animal and human foodstuffs (FAO, 2004a; Hepperly, 1985). The production reached 47.5 million tons during the 2006/2007 harvest season ranking Argentina third as soybean producer in the world. In Argentina, during the last quarter of the century, soybean production has increased at an unprecedented rate from a cultivated area of 38.000 hectares in 1970 to 16 million hectares today. Around 70% of the soybean harvested is processed, providing 81% and 36% of the world's exported soybean oil and meal, respectively (SAGPyA, 2010). Soybean is often attacked by fungal infections during cultivation, or post-harvest (in transit or in storage), significantly affecting its productivity. Seeds and infected harvest debris are the main sources of primary infections, and the level of seed damage depends on environmental conditions such as high relative humidity, dew, and temperatures above 25 oC. These species can be potential mycotoxin producers. Mycotoxins (from “myco” fungus and toxin) are relatively low-molecular weight, fungal secondary metabolic products that may affect exposed vertebrates such as animals in a variety of ways. Mycotoxins are considered secondary metabolites because they are not necessary for fungal growth and are simply a product of primary metabolic processes. The functions of mycotoxins have not been clearly established, but they are believed to play a role in eliminating other microorganisms competing in the same environment. They are also believed to help parasitic fungi invade host tissues. The amount of toxins needed to produce adverse health effects varies widely among toxins, as well as within each person’s immune system (Brase et al., 2009). Some mycotoxins are carcinogenic, some are vasoactive, and some cause central nervous system damage. The mycotoxins can be acutely or chronically toxic, or both, depending on the kind of toxin, the dose, the health, the age and nutritional status of the exposed individual or animal, and the possible synergistic effects between mycotoxins. The most frequently studied mycotoxins are produced by species of Aspergillus, Penicillium, Fusarium and Alternaria. There is an increasing world consumer demand for high quality and inocuous food and drink products with the lowest possible level of contaminants such as mycotoxins. As a result, the food industry in the developed world demands raw ingredients of the best