Analysis of food oligosaccharides using MALDI-MS: quantification of fructooligosaccharides.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a powerful new technique that will have a great impact on food analysis. This study demonstrates the applicability of MALDI-MS performed directly on an aqueous food extract for qualitative and quantitative analysis of food oligosaccharides. 2', 4',6'-Trihydroxyacetophenone was found to be the best matrix for analysis of oligosaccharides in the foods examined. The relationship between laser strength, resolution, and the response factors of individual oligosaccharides using MALDI-MS was investigated. A MALDI-MS method for quantitative analysis of fructooligosaccharides with standard addition of a pure fructooligosaccharide was developed. High performance anion exchange chromatography with pulsed amperometric detection was compared to MALDI-MS for the analysis of fructooligosaccharides. The fructooligosaccharide analyses were performed on red onions, shallots, and elephant garlic.