[P058-P106] Poster Presentation Awards / International Poster Award for Young Researcher

[P098] Identification of Flavor-Contributing Components and Tenderizing Enzymes in Liquid Shio Koji

*Yui Toyama¹, Eisaku Yamamoto¹, Miho Suzuki², Yuji Miyaguchi² (1. Hanamaruki Foods Inc., 2. Ibaraki Univ.)

Keywords:

Liquid Shio Koji,Tenderizing effect,Aspartic protease,metabolomics

Purpose: Shio koji is a traditional Japanese fermented seasoning. Conventional paste types have usability issues (measuring, mixing, scorching). Patented "Liquid Shio Koji" offers improved handling, reduced scorching/odor, and wider applications. It enhances umami, provides sweetness, mellow saltiness, and tenderizes meat, likely via fermentation metabolites and enzymes. However, specific contributing components are unclear. This study aimed to analyze liquid shio koji's composition and identify key components responsible for its characteristics. Methods: Compositional analyses were performed. Low molecular weight metabolites were analyzed using GC-MS and CE-TOF-MS metabolomics. Proteins were analyzed by LC-MS/MS. Proteins potentially contributing to meat tenderization were purified and identified. Results: Major components identified included glutamic acid (amino acid), citric acid (organic acid), and glucose (reducing sugar), with significant isomaltose. GC-MS detected Benzaldehyde and 2,3-Butanediol. Metabolomics (CE-TOF-MS) identified 126 ionic metabolites; numerous non-proteinogenic amino acids, vitamins, and peptides likely contribute to the complex flavor. Protein analysis (LC-MS/MS) detected major enzymes (aspartic protease, glycosidase) and Aspergillus oryzae-derived proteins of unknown function. SDS-PAGE confirmed bovine myofibrillar protein degradation, indicating protease involvement in meat tenderization. Subsequent purification identified the aspartic protease Aspergillopepsin I as a contributing factor.