Improving Microwave Heating using Polysaccharides as Thickeners

Abstract

The aim of this work was to improve microwave heating in white sauces using different polysaccharides in their formulation; ι-, λ- and κ-carrageenan and native and modified starches were used as thickeners. Five model systems were prepared, each one with a different polysaccharide, salt, and water. Dielectric loss factor (ε'') was measured and penetration depth of the electric field was calculated at 20 and 40°C at 2450 GHz. The results showed that ε'' increased significantly (P < 0.05) when temperature rose in all the model systems. Moreover, ε'' decreased significantly (P < 0.05) when the polysaccharide concentration rose in the systems elaborated with starch (both native and modified). The penetration depth increased significantly at 40°C when native starch concentration rose. Not significant differences due to the thickener concentration were found in the depth penetration values in the other model systems, both at 20 and 40°C.

Keywords

• polysaccharides
• salt
• starch
• carrageenan
• sauces
• microwaves
• microstructure
• dielectric properties