NATURAL OCCURRENCE OF DEOXYNIVALENOL IN SOYBEAN GROWN IN SERBIA - Soybean and Wheat Crops: Growth, Fertilization, and Yield - page 105

Soybean ( Glycine max ) represents an excellent source of high quality proteins; it has a
low content of saturated fats, it contains a great amount of dietary fiber, and its isoflavone
content makes it singular among other legumes [11]. Many researchers reported the benefits
of legumes: chickpeas, beans, lentils and soy, among others. The characterization and positive
health effects of soybeans have been studied recently and interest in this legume has increased
because of its functional components. Most of the studies have been focused on soybean
protein as a possible source of prevention against cardiovascular disease. This positive effect
may be due to a decrease in serum cholesterol concentrations. In addition, there are many
studies on isoflavones, non-nutritive substances, associated with prevention and treatment of
different chronic diseases. Moreover, some studies have shown the health properties of soy
dietary fiber. Therefore, it would be interesting to consider the replacement of animal-based
foods for soybean foods in order to obtain some nutritional benefits. Soy products are also a
good source of iron, and they contain vitamins B 1 and B 2 and an essential oil-linoleic acid,
one of the omega-3 fatty acids [12].
In Serbia, a strong increase in the soybean areas that was registered in the eighties and
beginning of nineties was followed by a significant drop to below 50,000 ha [13]. However,
in the last several years, a rise in the soybean-sown areas has been observed, so that a record
of 156,680 ha harvested area and the record yield of 429,639 metric tonas were registered in
2006 [14]. It is estimated that in Serbia in the year 2008 soybean was sown on about 145,057
ha [15], and the expected yield is 2.2-2.3 t/ha. Of the early-maturing soybean varieties prevail
Afrodita and Proteinka, of middle-maturing Balkan and Ravnica, and of late-maturing
varieties Vojvodjanka and Morava. Very early-maturing varieties Jelica, Krajina and Fortuna
are sown as stubble crops [13].
Today soybean represents the main source of proteins and practically an unlimited
component in the feedstuffs for all kinds of domestic animals. The proportion of soybean
meal and other soybean products in pig feed in developed countries such as the USA, Japan
and West Europe ranges from 14 to 25% and in poultry feed from 20 to 33%. In the West
European countries, soybean meal satisfies 60% of the protein needs in livestock feeding
[16].
In respect of the content of proteins and their biological value soybean represents the best
high-quality protein feed, which can serve as the main and only source of proteins for feeding
older pigs and poultry. The soybean amino acids composition is almost ideal and can satisfy
the needs of domestic animals for essential amino acids. The only prerequisite is that the
appropriate processing, involving not only oil extraction (sometimes oil is not extracted at all)
but also the inactivation of harmful and inhibiting components that have an adverse effect on
digestability and utilization of soybean proteins [16].
Mycotoxin contamination of soybeans has not been a significant problem as compared to
commodities such as corn, cottonseed, peanuts, barley and other grains. In surveys conducted
by the U.S. Department of Agriculture (USDA), 1046 soybean samples collected from
different regions of the United States, including all grades and different crop years, were
examined for aflatoxins. Aflatoxin was confirmed at low levels (7-14 μg/kg) in only two of
the test samples analyzed. These findings, along with other observations, suggested that
soybeans were not a good substrate for aflatoxin production. However, many of the test
samples showed evidence of contamination with Aspergillus flavus, a main contributor to
aflatoxin production under certain conditions. Therefore, the potential for aflatoxin formation
during adverse storage conditions does exist [17]. Low contamination of soybean with