米曲霉对玉米浆中营养成分的降解规律及产物的吸收特性研究

Degradation of Nutrients in Corn Steep Liquor by Aspergillus oryzae and Absorption Characteristics of the Product

摘要:

【目的】探究米曲霉（Aspergillus oryzae）对玉米浆中营养成分的降解规律及产物的吸收特性。【方法】采用米曲霉对玉米浆进行发酵，分别在发酵1、3、5、7、9、11 d时探究玉米浆中营养物质的降解规律，并测定发酵7 d后玉米浆中的氨基酸质量分数及肽的相对分子质量分布；同时，利用黑木耳菌丝体静息细胞探究其对玉米浆发酵产物的吸收规律。【结果】当发酵时间为1~7 d时，随着发酵时间的延长，玉米浆中总糖和还原糖质量浓度显著下降，而可溶性蛋白质量浓度、氨基酸态氮质量浓度、氨基酸总量、米曲霉生物量及蛋白酶活性均显著升高。被黑木耳菌丝体静息细胞吸收的玉米浆发酵产物具有亲水性和两亲性，且相对分子质量分布均匀。【结论】在不添加任何辅料的条件下，米曲霉可高效发酵玉米浆，且其发酵产物能被食用菌吸收利用，为玉米浆源食用菌营养剂的开发奠定了基础。

Abstract:

[Objective]This study aims to explore the degradation patterns of nutrients in corn steep liquor by Aspergillus oryzae and the absorption characteristics of the product.[Method]Aspergillus oryzae was used for the fermentation of corn steep liquor, and degradation patterns of nutrients were studied after fermentation for 1, 3, 5, 7, 9, and 11 d. Changes in amino acid mass fraction and peptide molecular mass distribution in corn steep liquor after fermentation for 7 d were measured. Furthermore, the resting cells of Auricularia heimuer mycelia were used to explore the absorption characteristics of the fermentation product of corn steep liquor.[Result]As the fermentation time prolonged within 1~7 d, the mass concentrations of total sugar and reducing sugar in corn steep liquor decreased significantly, while the mass concentrations of soluble protein, amino acid nitrogen, and total amino acids, biomass of Aspergillus oryzae, and protease activity increased significantly. The fermented product absorbed by the resting cells of Auricularia heimuer mycelia had hydrophilic and amphiphilic properties, with a uniform relative molecular mass distribution.[Conclusion]Aspergillus oryzae could efficiently ferment corn steep liquor without any additives, and the fermentation product could be absorbed and utilized by edible fungi, which laid a foundation for the development of nutrients from corn steep liquor for edible fungi.