The soybean and its products are rich in isoflavonoids, these have the increased
concentration after the microbial fermentation, due to the release of phenolics, through
the conversion of the glycosidic forms into aglycones. The solid state fermentative
process by filamentous fungi has been widely used as a biotechnological strategy in
the search of aggregating values to agroindustrial products and byproducts, mainly
raising the levels of bioactive compounds. In the present study, the increase of these
antioxidant and anti-inflammatory properties in different substrates using fungal strains
of the genus Rhizopus sp. The 17 lines tested were able to raise the antioxidant
potential of the soybean grains. The fermentation of soybean and rice using R.
oligosporus NRRL 2710 resulted in an increase of 26.5 times the antioxidant potential
and 9.33 times the content of phenolic compounds in the ethanolic extracts, in 72 hours
of process. In addition, they showed a positive response to anti-inflammatory activity,
with a maximum inhibitory capacity of 70.75% and an inhibitory concentration of 4.2
mg mL. The products fermented by R. oligosporus NRRL 2710 were submitted to
different extraction processes: Soxhlet with different solvents and supercritical CO2 +
ethanol (scCO2 + EtOH), which allowed to verify the relationship between polarity and
extraction yield. Soxhlet extractions were performed using dry and wet fermented
samples, the highest values of yield obtained were 42.09% and 32.84%, respectively.
This type of extraction allowed to obtain values of antioxidant activity at the inhibitory
concentration (IC50) of 0.55 and 0.67 g g-1 and phenolic compounds of 1.30 and 1.05
mg GAE g-1. Different conditions were tested in the compressed fluid extraction
process (scCO2 + EtOH) to study the influence of pressure and temperature on
extraction yield. The results showed that both variables influence the yield of the
process. The extracts from this procedure had an IC50 value of 0.17 g g-1, inhibiting
94.05% of the DPPH radical. As for phenolic compounds, these extracts presented
1.39 mg GAE g-1.
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