两株米曲霉菌种的发酵性能研究

Comparison of the fermentation properties on two Aspergillus oryzae strains

将2株米曲霉扩大培养后用于生产试验,并将其发酵酱油的性能进行对比。结果表明,米曲霉1号酱油的氨基酸态氮、pH值、A_(530nm)、总氮低于米曲霉2号菌,总酸高于米曲霉2号;米曲霉2号酱油的游离氨基酸总含量为6.05 g/100 mL,是米曲霉1号(4.18 g/100 mL)的1.45倍;米曲霉1号酱油中醇类物质、酸类物质和醚类物质相对含量分别达61.53%、14.16%和1.26%,高于米曲霉2号的57.3%、13.07%和0.46%,而酯类物质(3.73%)、酮类物质(1.83%)和醛类物质(16.33%)低于米曲霉2号的3.96%、1.95%和21.31%;米曲霉1号酱油香气浓郁偏醇香味,米曲霉2号酱油香气浓郁偏酯香;米曲霉2号酱油的加热沉淀达到204 mm^2,远高于米曲霉1号酱油的25 mm^2。加热后过滤可去除米曲霉2号酱油中的沉淀。

Two strains ofAspergillus oryzae were used for scale-up production, and the properties of soy sauce fermented by the strains were com- pared. Results showed that the amino nitrogen contents, pH, A530nm and total nitrogen content in the soy sauce produced by A. oryzae No. 1 was lower than that by A. oryzae No. 2, but total acid content was higher. The free amino acid content in the soy sauce produced by A. oryzae No. 2 was 6.05 g/100 ml, which was 1.45 times that of A. oryzae No. 1 （4.18 g/100 ml）. There was a difference of volatile components between two strains. The relative contents of alcohols, acids and ethers in soy sauce by A. oryzae No. 1 were 61.53%, 14.16%, and 1.26%, respectively, which was higher than that in soy sauce by A. oryzae No.2 （57.3%, 13.07% and 0.46%）. However, the esters, ketones, aldehydes content in soy sauce by A. oryzae No. 1 were 3.73%, 1.83%, 16.33%, respectively, which was lower than that in soy sauce by A. oryzae No. 2 （3.96%, 1.95%, 21.31%）. Soy sauce by A. oryzae No. 1 was with alcohol fragrance, while soy sauce by A. oryzae No. 2 was with ester fragrance. Heating precipitation of soy sauce by A. oryzae No. 2 was 204 mm2, much more than that of soy sauce by A. oryzae No. 1 （25 mmZ）. Precipitation can be removed from soy sauce by A. oryzae No. 2 by ill- tration after heating.