A sensitive and selective method for the quantitative determination of fatty acid tryptamides as shell indicators in cocoa products

Citation
M. Munch et P. Schieberle, A sensitive and selective method for the quantitative determination of fatty acid tryptamides as shell indicators in cocoa products, Z LEBENSM U, 208(1), 1999, pp. 39-46
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Food Science/Nutrition
Journal title
ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND-FORSCHUNG A-FOOD RESEARCH AND TECHNOLOGY
ISSN journal
1431-4630 → ACNP
Volume
208
Issue
1
Year of publication
1999
Pages
39 - 46
Database
ISI
SICI code
1431-4630(1999)208:1<39:ASASMF>2.0.ZU;2-F
Abstract
Tetracosanoyl-2-(3-indolyl)ethane amide (lignocerinic acid tryptamide; LAT) and docosanoyl-2-(3-indolyl)ethane amide (behenic acid tryptamide; BAT) we re identified as the most prominent tryptamides in cocoa shells based on el ectrospray ionisation mass spectrometry and H-1 NMR measurements. The struc ture of LAT, which is reported for the first time in cocoa shells, and also that of BAT were confirmed by synthesis. By using synthesised heptadecanoy l-2-(3-indolyl)ethane amide as the internal standard, a sensitive and repro ducible method was developed for the quantification of LAT and BAT in the p icogram range by means of HPLC/fluorescence detection. The detection limit was determined to be 30 pg/run. In authentic shell samples, 50-fold higher concentrations of both tryptamides were determined compared to the cocoa co tyledons. In 15 commercial chocolate samples, concentrations of 23.1-63.0 m u g of the tryptamides (sum of both) per gram of fat were found. A first ex periment attempted to correlate the tryptamide content with the amounts of shells in a model chocolate showed that the method is a promising tool to d etermine the shell content in the quality assessment of cocoa products.