CHEMICAL COMPOSITION AND SOLUBLE IRON CONTENT IN SOYBEAN [Glycine max (L.) Merrill]

Soybean is a grain which possesses one of the highest contents of protein and iron among the foods of plant origin and had its use greatly increased in the latest years, in the eastern countries mainly by lactents who have problems of intolerance to bovine's milk. Due to its great concentration of iron, soybean has been investigated as to its capacity of recovering anemic individuals. In the past, the investigation was based only on its concentration of total iron, not taking into account the soluble fractions (greater bioavailability) from the insoluble (which are less bioavailable). This work was designed to accomplish chemical analyses on four soybean cultivars Glycine max (L.) Merrill (IAC PL-1; IAC 22; IAC 8-2 and IAC 15-2), as well as their respective contents of soluble iron. Protein contents in the grains, that were on average 34,46% were statistically similar; oil content was greater for the cultivar IAC PL-1, with 20,07% (P<0,01), the same cultivar which presented the lower fiber content, with 5,24% (P<0,01) in the ground grain and heat-treated at 95 C for one hour. The amount of total iron was higher for the cultivar IAC 8-2 with 110,27 ppm, followed by IAC PL-1 which presented the mean of 101,93 ppm of iron. Concerning their contents of soluble iron and polyphenols, there were no statistic differences among the treatments (P<0,01), their average contents of soluble iron of about 2,52 mg/100g and of tannin about 5,51 mg/100 of ground and heat-treated soybean. The results of those analyses indicate that the soybean IAC PL-1 would be the most adequate for a possible treatment for ferropriva anemia of rats for having good contents of total iron and content of soluble iron statistically equal to that of the soybean IAC 8-2, which presented the greatest content of total iron and for presenting the poorest contents of fiber.