Document Detail


Incorporation of chlorogenic acids in coffee brew melanoidins.
MedLine Citation:
PMID:  18290625     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The incorporation of chlorogenic acids (CGAs) and their subunits quinic and caffeic acids (QA and CA) in coffee brew melanoidins was studied. Fractions with different molecular weights, ionic charges, and ethanol solubilities were isolated from coffee brew. Fractions were saponified, and the released QA and CA were quantified. For all melanoidin fractions, it was found that more QA than CA was released. QA levels correlated with melanoidin levels, indicating that QA is incorporated in melanoidins. The QA level was correlated with increasing ionic charge of the melanoidin populations, suggesting that QA may contribute to the negative charge and consequently is, most likely, not linked via its carboxyl group. The QA level correlated with the phenolic acid group level, as determined by Folin-Ciocalteu, indicating that QA was incorporated to a similar extent as the polyphenolic moiety from CGA. The QA and CA released from brew fractions by enzymes confirmed the incorporation of intact CGAs. Intact CGAs are proposed to be incorporated in melanoidins upon roasting via CA through mainly nonester linkages. This complex can be written as Mel=CA-QA, in which Mel represents the melanoidin backbone, =CA represents CA nonester-linked to the melanoidin backbone, and -QA represents QA ester-linked to CA. Additionally, a total of 12% of QA was identified in coffee brew, whereas only 6% was reported in the literature so far. The relevance of the additional QA on coffee brew stability is discussed.
Authors:
E Koen Bekedam; Henk A Schols; Martinus A J S Van Boekel; Gerrit Smit
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-02-22
Journal Detail:
Title:  Journal of agricultural and food chemistry     Volume:  56     ISSN:  0021-8561     ISO Abbreviation:  J. Agric. Food Chem.     Publication Date:  2008 Mar 
Date Detail:
Created Date:  2008-03-20     Completed Date:  2008-06-11     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0374755     Medline TA:  J Agric Food Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2055-63     Citation Subset:  IM    
Affiliation:
Laboratory of Food Chemistry and Product Design and Quality Management Group, Department of Agrotechnology and Food Science, Wageningen University, Wageningen, The Netherlands.
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MeSH Terms
Descriptor/Qualifier:
Caffeic Acids / analysis,  chemistry
Chlorogenic Acid / chemistry*
Chromatography, Ion Exchange
Coffea / chemistry
Coffee / chemistry*
Coumaric Acids / analysis
Hot Temperature
Molecular Weight
Polymers / analysis,  chemistry*
Quinic Acid / analogs & derivatives,  analysis,  chemistry
Seeds / chemistry
Chemical
Reg. No./Substance:
0/Caffeic Acids; 0/Coffee; 0/Coumaric Acids; 0/Polymers; 0/caffeoylquinic acid; 0/melanoidin polymers; 1135-24-6/ferulic acid; 327-97-9/Chlorogenic Acid; 331-39-5/caffeic acid; 77-95-2/Quinic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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