Componentes do rendimento, teores de isoflavonas, proteínas, óleo e qualidade de sementes de soja

Abstract

Soybean seeds have been used not only for animal, but also for human nutrition because of the presence of proteins; lipids; some vitamins and polyphenolic compounds, such as isoflavones, in their chemical composition. The antioxidant activity of isoflavones may be considered a safe mechanism of seed quality. This is due to the deterioration theory which leads to a cellular detriment because of the action of free radicals on cell membranes. Experiments were carried out during the 2004/05 agricultural year in two different sowing locations (Maringá and Umuarama). The objective of this study was to evaluate the yield, physiological quality of seeds produced in two sowing locations; to determine oil, protein and isoflavone contents; as well as to correlate isoflavone contents to the yield, physiological quality and oil-protein contents of soybean seeds. The seed quality was evaluated by the germination test (first count and final count); the tetrazolium test (vigor and viability) and the concentration of oil, protein and isoflavone tests. Analysis of the isoflavone contents showed that the BRS 133 and EMBRAPA 48 cultivars presented the highest isoflavone contents whereas the BR 36 cultivar showed the lowest isoflavone contents in both places. Germination was above 80% in all cultivars tested in Maringá. The correlation between isoflavones and the weight of one thousand seeds was negative for both locations.