The aim of this work was to evaluated the
amounts of bioactive compounds in soybean and derived
products and the antioxidant activity (AA) assessed by the
methods of ABTS·+
, DPPH·
, FRAP and peroxidation of
linoleic acid (PLA). The micronized soy protein (MSP),
defatted soy flour (DSF) and textured soy protein (TSP)
had a higher content of phenolic compounds and higher
antioxidant activity (AA), than the other products. MSP
and tofus had the highest content of flavonoids and phytic
acid (PA), respectively. The AA correlated with total
phenolics and flavonoids, but the PA can act synergistically
chelating the pro oxidants ions iron and copper. The
highest concentration of copper was in soy protein isolate,
and of iron in an ingredient of soy fiber and soy germ.
Many compounds present in soy products contribute for
the AA, but the concentration and potential will depend
on final preparation of the grain or ingredients before
consumption