A Teaching Laboratory for Comprehensive Lipid Characterization from Food Samples

Autor: Benjamin Weber, Kestutis Bendinskas, Hoangvy V. Nguyen, Vadoud Niri, Tamara Nsouli, Carolyn Joyce, Thorsten W. Jaskolla
Rok vydání: 2014
Předmět:
Zdroj: Journal of Chemical Education. 91:1697-1701
ISSN: 1938-1328
0021-9584
DOI: 10.1021/ed400586z
Popis: Traditional and state-of-the-art techniques were combined to probe for various lipid classes from egg yolk and avocado qualitatively and quantitatively. A total lipid extract was isolated using liquid–liquid extraction. An aliquot of the total lipid extract was subjected to transesterification to form volatile fatty acid methyl esters suitable for gas chromatography to quantify fatty acyl residues in both food samples. Another total lipid aliquot was separated into two lipid fractions of higher and lower polarity using silicic acid column chromatography. All fractions were analyzed using thin-layer chromatography and were checked for cholesterol using the Liebermann-Burchard test. In addition, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using 2,5-dihydroxybenzoic acid and 4-chloro-α-cyanocinnamic acid matrixes was performed to analyze the composition of separated lipid fractions. Egg yolk exhibited phosphatidylcholines and phosphatidylethanolamines in the more polar fracti...
Databáze: OpenAIRE