Thermal decomposition study of 4-methyloxybenzyl-glycoside by TG/DTA and on-line pyrolysis-photoionization mass spectrometry

TL;DR

This study examines how a flavor compound breaks down when heated, using specialized tools to track the process and identify breakdown products in real time.

Contribution

The study introduces a novel application of synchrotron VUV PIMS for analyzing thermal decomposition of glycoside flavor precursors.

Findings

The largest mass loss rate occurred at 246.7°C during thermal decomposition.

Key pyrolysis intermediates were identified at m/z 121 and m/z 347 using PIMS.

MBGL showed a distinct pyrolysis pathway compared to other glycosides.

Abstract

A flavor precursor of 4-methyloxybenzyl-2, 3, 4, 6-tetra-O-acetyl-β-d-glucopyranoside (MBGL) was synthesized via a modified Koenigs–Knorr reaction. The thermal decomposition behaviour and pyrolysis intermediate products of the glycoside were studied by simultaneous thermogravimetric/differential thermal analysis (TG/DTA) and synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry (PIMS). TG/DTA results showed that the largest mass loss rate appeared at a Tp of 246.7 °C. PIMS was used to identify the pyrolysis products of MBGL at 300 °C, 500 °C and 700 °C, respectively. The experimental apparatus had some advantages in real-time analysis and fewer secondary reactions. Some important pyrolysis intermediates, such as the ions of the 4-methyloxybenzyl group at m/z 121 and the glycone moiety at m/z 347, were detected by PIMS. The results indicate that the MBGL was probably showed a different pyrolysis way compared with the other glycosides. This work reports a useful application of synchrotron VUV PIMS in a thermal decomposition study of glycoside flavor precursors.

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