Optimisation of soy flour fermentation parameters to produce β-glucosidase for bioconversion into aglycones.
The solid state fermentation (SSF) parameters of defatted soybean flour (DSF) with Aspergillus oryzae IOC 3999/1998 or Monascus purpureus NRRL 1992 was evaluated using a rotational central composite experimental design to optimise the production of β-glucosidase and convert glycosidic isoflavones in aglycones. Variables investigated were initial pH of DSF, volume of water added to 10 g of DSF and incubation temperature. β-Glucosidase activity was measured using the synthetic substrate, p-nitrophenyl-β-D-glucoside. The content of isoflavones was determinate by ultra performance liquid chromatography. The highest production of β-glucosidase for both strains occurred when adding 10 mL of water to the DSF, incubating at 30 °C and using 6.0 as the initial DSF pH. A. oryzae IOC 3999/1998 expressed β-glucosidase activity at 10.7 times higher than M. purpureus NRRL 1992. The DSF fermentation was more efficient in converting isoflavones with M. purpureus NRRL 1992.
Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, 86057-970 Londrina, Paraná, Brazil.
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Handa
Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, 86057-970 Londrina, Paraná, Brazil.
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Couto
Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, 86057-970 Londrina, Paraná, Brazil.
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Vicensoti
Departamento de Ciências Farmacêuticas, Universidade Estadual de Londrina, 86057-970 Londrina, Paraná, Brazil.
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Georgetti
Departamento de Ciência e Tecnologia de Alimentos, Universidade Estadual de Londrina, 86057-970 Londrina, Paraná, Brazil. Electronic address: elida@uel.br.
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D001236:Aspergillus oryzae / Q000201:enzymology* / Q000378:metabolism; D001711:Biotransformation; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D005433:Flour / Q000032:analysis / Q000382:microbiology*; D005656:Fungal Proteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000295:instrumentation / Q000379:methods*; D007529:Isoflavones / Q000378:metabolism*; D032741:Monascus / Q000201:enzymology* / Q000378:metabolism; D013025:Glycine max / Q000378:metabolism / Q000382:microbiology*; D001617:beta-Glucosidase / Q000378:metabolism*
D003470:Culture Media; D005656:Fungal Proteins; D007529:Isoflavones; D001617:beta-Glucosidase
Isoflavones; Solid state fermentation; Soybean flour; β-Glucosidase