Avaliação de compostos bioativos produzidos por fungos do gênero Rhizopus sp. por fermentação em estado sólido utilizando diferentes substratos agroindustriais

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 ...