Rheological properties and kinetics of pectin solutions of different mass concentrations (0.5, 1.0, 1.5, 2.0 g/100 mL) after microwave treatment at different times (0, 1, 3, 5, 8, 15, 20, 30 min) Inspection. The results showed that the apparent viscosity and intrinsic viscosity [η] of the samples decreased with the decrease of the mass concentration of pectin solution, the prolongation of microwave treatment time and the increase of shear rate. The Newtonian power law equation is used to describe the fluid behavior of the solution. The pectin solution is a shear-thinning pseudoplastic non-Newtonian fluid. At low mass concentrations, microwave treatment has the greatest influence on the fluid behavior of the solution.
The microwave degradation of pectin followed the first order kinetics according to the intrinsic viscosity. The degradation rate of pectin was the fastest at 0.5g/100mL concentration and the slowest at 1.5g/100mL concentration. Compared with the blank group without microwave in boiling water bath, it was found that there was non-thermal effect in the degradation of pectin by microwave.