Fructose occurs in
foods and as a metabolite in vivo. It can be
degraded, leading to the formation of reactive carbonyl compounds,
which may influence food properties and have an impact on health.
The present study performed an in-depth qualitative and quantitative
profiling of fructose degradation products. Thus, the α-dicarbonyl
compounds 3-deoxyglucosone, glucosone, methylglyoxal, glyoxal, hydroxypyruvaldehyde,
threosone, 3-deoxythreosone, and 1-desoxypentosone and the monocarbonyl
compounds formaldehyde, acetaldehyde, glycolaldehyde, glyceraldehyde,
and dihydroxyacetone were detected in fructose solutions incubated
at 37 °C. Quantitative profiling after 7 days revealed 4.6–271.6-fold
higher yields of all degradation products from fructose compared to
glucose. Except for 3-deoxyglucosone, the product formation appeared
to be metal dependent, indicating oxidative pathways. CaCl2 and MgCl2 partially reduced fructose degradation. Due
to its high reactivity compared to glucose, particularly toward metal-catalyzed
pathways, fructose may be a strong contributor to sugar degradation
and Maillard reaction in foods and in vivo.