85 Comparison of MALDI-TOF mass spectrometry and HPAEC-PAD analysis of debranched amylopectin from different sources.

K. KOCH (1), S. Broberg (2), and P. Åman (1). (1) Dept. of Food Science, Swedish University of Agricultural Sciences, Box 7051, 750 07 Uppsala, Sweden; (2) Dept. of Chemistry, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden.

Knowledge of the fine structure of starch is an important parameter for understanding the relationship between structure and functional properties. High-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) is a commonly used technique for the chain length analysis of amylopectin. Matrix-assisted laser-desorption ionization–time of flight (MALDI-TOF) mass spectrometry is another interesting method for the analysis of the chain length since it gives detailed information about the molecular weight of the individual chains. The two techniques have been compared using debranched amylopectins from wheat and potato. Differences between the chain length distribution profiles obtained by chromatography and mass spectrometry are discussed. Furthermore, mass spectra from debranched amylopectin and debranched whole starch have been compared since amylose and amylopectin need not be separated prior to analysis with MALDI-TOF. The fast MALDI-TOF method is a complement to the quantified HPAEC-PAD technique.