Optimization of Solid State Fermentation Conditions Using a Mixture of Bean Curd Residue and Marc with Bacillus natto

Objective] The aim was to optimize the appropriate solid state fermentation(SSF)conditions.Method] The optimization of solid state fermentation using a mixture substrate of bean curd residue and the marc with Bacillus natto was developed.Result] The best fermentation condition optimized by the test of single factor and the orthogonal design respectively was mixing ratio of bean curd residue to marc 2∶1,substrate pH value 6,fermentation temperature 39 ℃,inoculum volume 10% and fermentation time 48 h.Under this optimized fermentation condition,the content of crude fiber in the substrate decreased from 107.8 mg/g before SSF to 56.2 mg/g after SSF,and the degeneration rate of crude fiber was 47.87%.Conclusion] The bean curd residue in its palatability was enormously improved by SSF with Bacillus natto strain,which could be expected to be widely used as raw material of health foodstuff.