Solid-state fermentation for the enrichment and extraction of proteins and antioxidant compounds in rice bran by Rhizopus oryzae

The objective of this work was to evaluate the solid-state fermentation with Rhizopus oryzae CCT 7560 of rice bran for the enrichment of proteins and the antioxidant compounds in the fermented biomass. Fermentation was performed in tray bioreactors at 30ºC for 120 h. Protein extraction was done at alkaline pH, followed by precipitation with acetone. Phenolic compounds were extracted with cold methanol. The maximum protein was recovered from after 120 h (26.6%). The content of total phenolic compounds increased during the fermentation and was maximum after 96 h, which inhibited the DPPH radical by 87%. The promising characteristics of the protein and phenolic extracts of the biomass suggested the application in the coating composition for vegetal tissues preservation.

Estudo das condições de extração de compostos fenólicos de cebola (Allium cepa L. ) / Study on the extracting conditions of phenolic compounds from onion (Allium cepa L)

O objetivo deste trabalho foi estabelecer as melhores condições para efetuar extração de compostos fenólicos totais de diferentes classes comerciais de cebola (Allium cepa L.). Por meio de Planejamento Experimental Fatorial foram determinadas as variáveis que influenciam significativamente nas etapas de extração. As variáveis estudadas foram: natureza do solvente, procedimento de agitação, tempo de extração e tempo de agitação com e sem interrupções. A melhor combinação resultou em um modelo preditivo, empregando semetanol como solvente, agitação de 120 minutos a 200 rpm. O maior conteúdo fenólico em diferentes classes de cebola foi 2275 μg/g, 88% de recuperação e o limite de quantificação foi de 31 μg fenóis/g.