Roasting process of coffee beans as studied by nuclear magnetic resonance: time course of changes in composition.
In this paper, we report a (1)H and (13)C nuclear magnetic resonance (NMR)-based comprehensive analysis of coffee bean extracts of different degrees of roast. The roasting process of coffee bean extracts was chemically characterized using detailed signal assignment information coupled with multivariate data analysis. A total of 30 NMR-visible components of coffee bean extracts were monitored simultaneously as a function of the roasting duration. During roasting, components such as sucrose and chlorogenic acids were degraded and components such as quinic acids, N-methylpyridinium, and water-soluble polysaccharides were formed. Caffeine and myo-inositol were relatively thermally stable. Multivariate data analysis indicated that some components such as sucrose, chlorogenic acids, quinic acids, and polysaccharides could serve as chemical markers during coffee bean roasting. The present composition-based quality analysis provides an excellent holistic method and suggests useful chemical markers to control and characterize the coffee-roasting process.
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Feifei
F
Wei
Kazuo
K
Furihata
Masanori
M
Koda
Fangyu
F
Hu
Takuya
T
Miyakawa
Masaru
M
Tanokura
D002726:Chlorogenic Acid / Q000032:analysis; D040503:Coffea / Q000737:chemistry*; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D015999:Multivariate Analysis; D011134:Polysaccharides / Q000032:analysis; D011801:Quinic Acid / Q000032:analysis; D012639:Seeds / Q000737:chemistry*; D013395:Sucrose / Q000032:analysis; D013997:Time Factors
D011134:Polysaccharides; D011801:Quinic Acid; D002726:Chlorogenic Acid; D013395:Sucrose