Permits concentration of heat-sensitive solutions and slurries at relatively low temperatures. Also applicable to highly corrosive or viscous solutions. Microwaves cook relatively large pieces without high temperature gradients between surface and interior. Uniform, rapid heating throughout the product is ideal for bulk polymerization reactions which are heat-initiated. Also effective for glue-line curing of laminates without direct heating of the laminates themselves.
Microwaves selectively heat with little direct heating of most solids.
Rapid, uniform heating of the inactivation temperature can control and terminate enzymatic reactions. Almost any heat transfer problem can benefit from the use of microwaves because of their ability to heat in depth without high temperature. Microwaves heat a product rapidly and uniformly to pasteurizing temperature without the overheating associated with external, high temperature heating methods. Ultra-rapid internal heating by microwaves causes puffing or foaming when the rate of heat transfer is made greater than the rate of vapor transfer out of the product interior. Microwaves are ideal for producing puffed snack foods.