3.5. Viscosity
Viscosity of the pectin extracted at different microwave energy levels is shown in Fig. 5. Viscosity of 1 g/100 g pectin solution ranged from 60.5 to 98.2 mPa s. Viscosity increased significantly after 15 min of extraction at all the energy levels studied. The increase in viscosity was higher at the microwave energy of 660W to 1000 W for 20 min. Viscosity of pectin decreased at 25 min at all energy levels demonstrating the effect of temperature for long heating periods.