Abstract:

In order to investigate the pyrolysis behavior of the flavor precursor of
geranyl-β-D-glucopyranoside, the glycoside was pyrolyzed at 200, 300, 400 ℃ in an on-line
pyrolyzer under anaerobic conditions and in an off-line mode separately. Gas chromatography-mass
spectrometry (GC/MS) was used for the qualitative and quantitative analysis of the pyrolysis
products. The thermal degradation mechanism of geranyl-β-D-glucopyranoside was discussed according
to the results. Little geranyl-β-D-glucopyranoside was pyrolyzed at 200 ℃ and there were a large
amount of geraniol and little by-products produced at 300 ℃. With the increasing temperature to 400
℃, both the pyrolytic products and by-products were significantly increased. Therefore, it
indicated that the optimized temperature of pyrolysis was 300 ℃. The main pyrolysis product of the
glycoside was geraniol. It showed the primary decomposition reaction took place with the breaking of
glycosidic linkage, the cleavage of O-glycosidic bond as expected. The on-line mode experiment was a
rapid and good qualitative method for the pyrolysis, and the off-line mode can be used as a
quantitative method based on the qualitative analysis.

Key words: flavor
precursors , geraniol, glycoside, pyrolysis, gas chromatography-mass spectrometry (GC/MS)