Microwave heating package, method and susceptor composition

A lossy susceptor device for microwave energy, which upon continued exposure to microwave radiation has a chemical susceptor portion which becomes substantially microwave transparent, said susceptor device comprising:

• a low lossy holder for said chemical susceptor, and a chemical susceptor in heat transfer association with said holder comprising an inorganic salt selected from Group IA and Group IIA salts in combination with water as a polar solvent for said salts, and a heating profile modifier, the amount of said salt being sufficient to depress the vapor pressure of water at least by 25% when compared to the vapor pressure of water at standard pressure, said holder including vent means which permits escape of solvent from the holder when said chemical susceptor is exposed to microwave radiation.

A method of microwave heating products which simultaneously heats internal portions of said product and selectively raises to a higher temperature pre-selected areas of said products, said method comprising:

• locating a lossy susceptor device in a microwave environment, said susceptor device including a chemical susceptor comprising a solute and a polar solvent for said solute, the amount of said solute being as a minimum an amount sufficient to provide a saturated solution of said solute in said polar solvent and an amount which will depress the vapor pressure of said solvent at least 25% when compared to the vapor pressure of said solvent at its boiling point at standard pressure, placing said product which is to be heated in heat transfer association with at least a portion of said susceptor device, and exposing said susceptor device to microwave radiation energy to heat said chemical susceptor, said chemical susceptor being heated to a higher temperature than said product until said polar solvent is driven off, and thereafter said chemical susceptor becoming substantially non-lossy.

A disposable package for use in microwave ovens, said package comprising:

• a container of substantially non-lossy material for holding of a product to be treated with microwave radiation, and a chemical susceptor for microwave energy associated with said container for thermal contact with at least one surface of a product which is to be placed in said container, said chemical comprising an inorganic salt selected from the group consisting of Group IA and Group IIA salts, and a polar solvent for said salt, and a low lossy substantially microwave transparent holder surface for said susceptor.

A method of microwave heating products which simultaneously heats the internal portions of said product and selectively raises to a higher temperature pre-selected areas of said products, said method comprising:

• locating a lossy chemical susceptor in a microwave environment, said chemical susceptor comprising a solute and a polar solvent for said solute, the amount of said solute being as a minimum an amount sufficient to provide a saturated solution of said solute in said polar solvent, and an amount which will depress the vapor pressure of said solvent at least 25% when compared to the vapor pressure of said solvent at its boiling point at standard pressure, placing said product which is to be treated in heat transfer association with at least a portion of said chemical susceptor and exposing said chemical susceptor to microwave radiation to heat said chemical susceptor, said chemical susceptor being heated to a higher temperature than said product, and a higher temperature than the fusion point of said solute portion of the chemical susceptor resulting in said solute portion changing to a liquid phase, and thereafter said solute portion continuing to heat in a steady state as long as said solute portion remains in said liquid phase and is exposed to sufficient microwave radiation energy to remain in said liquid phase.

A disposable microwave package comprising:

• a container of substantially non-lossy material for holding of a food product to be treated with microwave radiation energy, a chemical susceptor for microwave energy associated with said container for thermal contact with at least one surface of a product which is to be placed in said container, said chemical comprising an inorganic salt selected from the group consisting of Group IA and Group IIA salts, and a polar solvent for said salt, a low lossy substantially microwave transparent holder surface for said susceptor, a food product within said package, said food product having a low moisture content and a low density in order to change its heat load characteristics.