Dielectric loss mediated promotion of microwave heating in the Maillard reaction

Abstract

Dielectric loss (ε″) represents the ability to convert electromagnetic energy into heat, which may further affect the degree of Maillard reaction (MR). Based on the differences in electromagnetic response between lysine (Lys) and glucose (Glu), this study aims to verify the ε″ -mediated intervention of microwave heating (MW) on different stages of MR by using different reaction solvents. Compared to conventional heating (CV), the systems with MW showed greater ε″ and absorbance at both 294 nm (A294nm) and 420 nm (A420nm). Changing the solvent from pure water to a mixture (1:1 vol ratio of water to glycerol), thereby dramatically increasing ε″ (by 6.02), compared to pure water (CV), the systems treated with the mixture under MW demonstrated large increases at both A294nm and A420nm, increasing by 0.35 at 10 min and 1.35 at 60 min, respectively. These results suggest that increasing ε″ contributes to the promotion of MW during different stages of the MR.