ISOLATION OF A ZINC-CHELATING COMPOUND FROM INSTANT COFFEE BY THE TETRAMETHYL MUREXIDE METHOD

Authors
NAKAMURTAKADA Y SHATA H MINAO M OGAWA H SEKIGUCHI N MURATA M HOMMA S
Citation
Y. Nakamurtakada et al., ISOLATION OF A ZINC-CHELATING COMPOUND FROM INSTANT COFFEE BY THE TETRAMETHYL MUREXIDE METHOD, Lebensmittel-Wissenschaft + Technologie, 27(2), 1994, pp. 115-118
Citations number
12
Categorie Soggetti
Food Science & Tenology
Journal title
Lebensmittel-Wissenschaft + Technologie → ACNP
ISSN journal
00236438
Volume
27
Issue
2
Year of publication
1994
Pages
115 - 118
Database
ISI
SICI code
0023-6438(1994)27:2<115:IOAZCF>2.0.ZU;2-D
Abstract
Tetramethyl murexide, which is a chelating reagent that shows a shift in the absorption maximum due to the formation of a complex, was used as an indicator for the purification of a zinc-chelating compound in i nstant coffee. A soluble coffee solution was purified principally by i on exchange, gel filtration, and reversed-phase column chromatographic methods. An active compound was isolated and identified as citric aci d by nuclear magnetic resonance and mass spectroscopic analyses. One m ole of citric acid bound 1 mol of zinc, and its apparent dissociation constant was 3.5 x 10(-8) mol/L.