The phenolic extract assessed in this study could be considered as an alternative for inhibiting toxigenic fungi and as a substitute for synthetic compounds in food preservation. © 2018 Society of Chemical Industry.

This study evaluated the effect of Rhizopus oryzae, on essential amino acids and fatty acid profile on lignocellulosic substrates soybean, wheat and rice bran. R. oryzae was isolated from crop of Brazilian south region, genetically characterized and solid-state fermentation was carried on tray reactors during 120 h/30°C. The profile of amino acids and fatty acids was conducted every 24 h by high performance liquid chromatography with fluorescence detector (HPLC-FL) and gas chromatography (GC)-flame ionization detector, respectively. Fatty acids found on rice, wheat and soybean bran biomass showed an increase in the ω3 acids (72%, 64% and 58%, respectively); however, ω6 level was not affected. Fungal biomass on soybean and wheat bran present the most complete essential amino acids profile from a nutritional point of view, increased in Val (34%), Leu (19%), Lys (6%) and Phe (2%) after 96 h of cultivation. The cultivation with R. oryzae triggers changes on essential nutrients of the agro-industrial by-products.

The phenolic extracts obtained from rice bran cultivated with Rhizopus oryzae were evaluated about their abitily to inhibit the production of trichotecenes and emerging mycotoxins by Fusarium strains on sweet corn cobs (Zea mays L.). The rice bran was cultured with R. oryzae for 48 h at 30 °C. The phenolic compounds were extracted, clarified, lyophilized and ressuspend as water solution with different concentrations. The phenolic acid extracts were applied on sweet corn inoculated by F. cerealis, F. graminearum and F. poae incubated by 15 days at 25 °C and afterward the fermented corn was autoclaved and frozen. The mycotoxins were quantified by LC-MS/MS. The mycotoxin production by all Fusarium strains evaluated was reduced in relation to the control. F. poae was the most sensitive, because its production of the toxins T-2 and HT-2 and BEA was inhibited by phenolic extract 0,5% (p/v), while extract 1% (p/v) inhibited 96% of the DON production. DON, 3ADON and 15ADON production by F. graminearum and F. cerealis was also reduced. Therefore, the extract is a promising antimicotoxinogenic against Fusarium toxins production on sweet corn cobs and should be a good alternative to reuse wastes from agroindustry.