title: Comprehensive NMR analysis of compositional changes of black garlic during thermal processing.
abstract: Black garlic is a processed food product obtained by subjecting whole raw garlic to thermal processing that causes chemical reactions, such as the Maillard reaction, which change the composition of the garlic. In this paper, we report a nuclear magnetic resonance (NMR)-based comprehensive analysis of raw garlic and black garlic extracts to determine the compositional changes resulting from thermal processing. (1)H NMR spectra with a detailed signal assignment showed that 38 components were altered by thermal processing of raw garlic. For example, the contents of 11 l-amino acids increased during the first step of thermal processing over 5 days and then decreased. Multivariate data analysis revealed changes in the contents of fructose, glucose, acetic acid, formic acid, pyroglutamic acid, cycloalliin, and 5-(hydroxymethyl)furfural (5-HMF). Our results provide comprehensive information on changes in NMR-detectable components during thermal processing of whole garlic.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo , 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Tingfu
authors.initials: T
authors.lastname: Liang
authors.forename: Feifei
authors.initials: F
authors.lastname: Wei
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kodani
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Nakada
authors.forename: Takuya
authors.initials: T
authors.lastname: Miyakawa
authors.forename: Masaru
authors.initials: M
authors.lastname: Tanokura
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D003116:Color; D003296:Cooking; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000737:chemistry; D005737:Garlic / Q000737:chemistry*; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015416:Maillard Reaction; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D010936:Plant Extracts; C008046:5-hydroxymethylfurfural; D005662:Furaldehyde
keywords: Maillard reaction; NMR; black garlic; multivariate statistical analysis; thermal process