Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Record number 349092
Title High Molecular Weight Melanoidins from Coffee Brew
Author(s) Bekedam, E.K.; Schols, H.A.; Boekel, T. van; Smit, G.
Source Journal of Agricultural and Food Chemistry 54 (2006)20. - ISSN 0021-8561 - p. 7658 - 7666.
DOI https://doi.org/10.1021/jf0615449
Department(s) Food Chemistry Group
Product Design and Quality Management Group
VLAG
Publication type Refereed Article in a scientific journal
Publication year 2006
Keyword(s) chemical-characterization - maillard reaction - liquid-chromatography - espresso coffee - roasted coffee - arabica coffee - foam stability - amino-acids - hot-water - green
Abstract The composition of high molecular weight (HMw) coffee melanoidin populations, obtained after ethanol precipitation, was studied. The specific extinction coefficient (Kmix) at 280, 325, 405 nm, sugar composition, phenolic group content, nitrogen content, amino acid composition, and non-protein nitrogen (NPN) content were investigated. Results show that most HMw coffee melanoidins are soluble at high ethanol concentrations. The amino acid composition of the HMw fractions was similar, while 17% (w/w) of the nitrogen was NPN, probably originating from degraded amino acids/proteins and now part of melanoidins. A strong correlation between the melanoidin content, the NPN, and protein content was found. It was concluded that proteins are incorporated into the melanoidins and that the degree of chemical modification, for example, by phenolic groups, determines the solubility of melanoidins in ethanol. Although the existence of covalent interaction between melanoidins and polysaccharides were not proven in this study, the findings suggest that especially arabinogalactan is likely involved in melanoidin formation. Finally, phenolic groups were present in the HMw fraction of coffee, and a correlation was found with the melanoidin concentration
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