Characterisation of novel 1H,4H-quinolizinium-7-olate chromophores by application of colour dilution analysis and high-speed countercurrent chromatography on thermally browned pentose/L-alanine solutions

Citation
O. Frank et al., Characterisation of novel 1H,4H-quinolizinium-7-olate chromophores by application of colour dilution analysis and high-speed countercurrent chromatography on thermally browned pentose/L-alanine solutions, EUR FOOD RE, 213(1), 2001, pp. 1-7
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Food Science/Nutrition
Journal title
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
ISSN journal
1438-2377 → ACNP
Volume
213
Issue
1
Year of publication
2001
Pages
1 - 7
Database
ISI
SICI code
1438-2377(2001)213:1<1:CON1CB>2.0.ZU;2-H
Abstract
Thermal treatment of aqueous solutions of xylose and L-alanine at pH 5.0 re sulted in the formation of various coloured compounds. which were ranked ac cording to their colour impactsby application of the recently developed col our dilution analysis. High-speed countercurrent chromatography was then su ccessfully used for the first time to isolate colour-intense reaction produ cts from complex Maillard mixtures, amongst which the structures of 2-[(2-f uryl)methylidene]-4-hydroxy-5-methyl-2H-furan-3-one (1), and of the novel c ompounds 3-(2-furyl)-8-[(2-furyl)methyl]-4-hydroxy-methyl-1-oxo-1-HAH-quino lizinium-7-olate (2) and 3-(2-furyl)-8-[(2-furyl)methyl]-4,5-bis(hydroxy-me thyl)-1-oxo-1H,4H-quinolizinium-7-olate (3) were determined by LC/MS, 1D an d 2D NMR as well as UV/Vis spectroscopy. To measure the contribution of the se colorants to the overall colour of the browned Maillard mixture, colour activity values were calculated as the ratio of the concentration to the vi sual detection threshold of each colorant. By application of this colour ac tivity concept, 2.2% of the total colour of the thermally browned xylose/L- alanine solution was shown to be covered by the novel 1H,4H-quinolizinium-7 -olate chromophores 2 and 3.