Optimization of Production of Ferulic Oligosaccharides by Solid State Fermentation of Neurospora sitophila

The solid-fermented process conditions of producing feruloylated oligosaccharides (FOs) from corn bran were optimized in this study. The fungus Neurospora sitophila (generally recognised as safe, GRAS) was used as fermenting species, and FOs content was considered as the indicator, the single-factor and response surface experiments were performed to optimize the culture medium and culture conditions, including inoculation amount, fermentation time, fermentation temperature, and added amount of water. An FOs yield of 1.52 μmol/g was achieved under the following conditions: 5 g of corn bran and 2% of corn bran weight (w/w) of soybean meal in a 250 mL conical flask, an inoculation size of 1.17×10⁵ spores/flask, a fermentation time of 75 h, a fermentation temperature of 28 ℃, and added water mount of 15.2 mL. The observed yield value was close to the theoretical value predicted by the model (1.56 μmol/g), and increased by 60.83% compared with that of the pre-optimized process. Therefore, the FOs content of the product significantly increased by the optimization of the fermentation process, which offered a novel thought for enhancing the added value and expanding the routes for preparing maize bran-derived FOs.