Premium
The phenolic substances of manufactured tea. III. —ultra‐violet and visible absorption spectra
Author(s) -
Roberts E. A. H.,
Williams D. M.
Publication year - 1958
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740090406
Subject(s) - theaflavin , gallic acid , chemistry , absorption (acoustics) , absorption spectroscopy , salt (chemistry) , chromatography , nuclear chemistry , organic chemistry , polyphenol , materials science , antioxidant , physics , quantum mechanics , composite material
Abstract The absorption spectra of thearubigin fractions are all very similar and differ appreciably from those of the theaflavins. Theaflavin and theaflavin gallate have similar absorption spectra, which also resemble that of purpurogallin. Substances A, B and C have absorption bands at 275 mμ. The spectrum of Q differs from that of purpurogallincarboxylic acid. The identification of P as a 5:7:3′:4′:5′‐pentahydroxyflavylium salt is suggested. Substance 1C absorbs similarly to gallic acid, and the presumed p ‐coumarylquinic acids to p ‐coumaric acid.