title: Autolysis of Aspergillus oryzae Mycelium and Effect on Volatile Flavor Compounds of Soy Sauce.
abstract: The autolyzed mycelia of Aspergillus oryzae are rich in proteins, nucleic acids, sugar, and other biomacromolecules, and are one of the main contributors to the flavor profile of commercially important fermented goods, including soy sauce and miso. We induced autolysis of the mycelia of A. oryzae over 1 to 10 d, and found that the maximum dissolved amounts of total protein and nucleic acid ratio accounted for 28.63% and 88.93%, respectively. The organic acid content, such as citric acid, tartaric acid, succinic acid, lactic acid, and acetic acid, initially increased and then decreased as autolysis progressed, corresponding to changes in pH levels. The main characteristic flavor compounds in soy sauce, namely, ethanol, 2-phenylethanol, and 2-methoxy-4-vinylphenol, were all detected in the autolysate. Subsequently, we tested the effect of adding mycelia of A. oryzae during the fermentation process of soy sauce for 60 d, and found that addition of 1.2‰ A. oryzae mycelia provided the richest flavor. Overall, our findings suggest that compounds found in the autolysate of A. oryzae may promote the flavor compounds of soy sauce, such as alcohols, aldehydes, phenols, and esters.
authors.affiliation: Hubei Cooperative Innovation Center for Industrial Fermentation, Research Center of Food Fermentation Engineering and Technology of Hubei, Hubei Univ. of Technology, Wuhan, 430068, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.affiliation: Hubei Cooperative Innovation Center for Industrial Fermentation, Research Center of Food Fermentation Engineering and Technology of Hubei, Hubei Univ. of Technology, Wuhan, 430068, China.
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Hubei Cooperative Innovation Center for Industrial Fermentation, Research Center of Food Fermentation Engineering and Technology of Hubei, Hubei Univ. of Technology, Wuhan, 430068, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Hubei Cooperative Innovation Center for Industrial Fermentation, Research Center of Food Fermentation Engineering and Technology of Hubei, Hubei Univ. of Technology, Wuhan, 430068, China.
authors.forename: Mengzhou
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Hubei Cooperative Innovation Center for Industrial Fermentation, Research Center of Food Fermentation Engineering and Technology of Hubei, Hubei Univ. of Technology, Wuhan, 430068, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Hubei Cooperative Innovation Center for Industrial Fermentation, Research Center of Food Fermentation Engineering and Technology of Hubei, Hubei Univ. of Technology, Wuhan, 430068, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Li
mesh_terms: D000143:Acids / Q000032:analysis; D001236:Aspergillus oryzae; D000431:Ethanol / Q000032:analysis; D005285:Fermentation; D005421:Flavoring Agents / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D005656:Fungal Proteins / Q000032:analysis; D006139:Guaiacol / Q000031:analogs & derivatives / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D025282:Mycelium / Q000378:metabolism*; D009696:Nucleic Acids / Q000032:analysis; D010626:Phenylethyl Alcohol / Q000032:analysis; D045730:Soy Foods / Q000032:analysis*; D013649:Taste; D014753:Vinyl Compounds / Q000032:analysis; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D000143:Acids; D005421:Flavoring Agents; D005656:Fungal Proteins; D009696:Nucleic Acids; D014753:Vinyl Compounds; D055549:Volatile Organic Compounds; D000431:Ethanol; D006139:Guaiacol; C526552:2-methoxy-4-vinylphenol; D010626:Phenylethyl Alcohol
keywords: Aspergillus oryzae; autolysis; mycelium; soy sauce; volatile compounds