title: Primary and secondary metabolite profiling of doenjang, a fermented soybean paste during industrial processing.
abstract: In this study, a comprehensive metabolite profile analysis of doenjang, a fermented soybean paste, at various steps of its industrial 5-step production process was conducted, by combining gas and liquid chromatography-mass spectrometry techniques with multivariate analysis. From the partial least squares discriminant analysis of primary and secondary metabolites, the patterns were clearly distinguishable between the various processing steps (step 1: steaming, step 2: drying, step 3: meju fermentation, step 4: brining, step 5: doenjang aging). Of the primary metabolites, most of the monosaccharides, amino acids, and fatty acids increased in steps 3-5. Isoflavone and soyasaponin derivatives were major secondary metabolites identified during the processing of doenjang. Isoflavone glycosides gradually decreased after step 1, while isoflavone aglycones distinctly increased in steps 4-5. Soyasaponins generally decreased during processing after step 2. Increased isoflavone aglycones, such as daidzein, glycitein, and genistein, were observed in steps 4-5 showed the strongest positive correlation with doenjang's antioxidant potential and total phenolic content.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Su Yun
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Sunmin
authors.initials: S
authors.lastname: Lee
authors.affiliation: Food Research Institute, CJ CheilJedang Corporation, Seoul 152-051, Republic of Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Oh
authors.affiliation: Food Research Institute, CJ CheilJedang Corporation, Seoul 152-051, Republic of Korea.
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Jeon
authors.affiliation: Food Research Institute, CJ CheilJedang Corporation, Seoul 152-051, Republic of Korea.
authors.forename: Hyung Seok
authors.initials: HS
authors.lastname: Ryu
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea. Electronic address: chlee123@konkuk.ac.kr.
authors.forename: Choong Hwan
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D019149:Bioreactors; D005285:Fermentation; D013058:Mass Spectrometry; D010636:Phenols / Q000032:analysis*; D013025:Glycine max / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010636:Phenols
keywords: Antioxidant; Doenjang; GC–TOF-MS; Metabolite profile; Processing steps; UPLC–Q-TOF-MS