A heating profile of a microwave oven is modified using microwaves at a plurality of frequencies. A power of transmission to a cavity of the microwave oven of microwaves is defined at each of the plurality of frequencies. A duration is defined for which the microwaves are transmitted at each of the plurality of frequencies. For each of the plurality of frequencies, a proportion of power input to the cavity that is not output from the cavity is measured. The measured proportions am used to modify the power of transmission at each frequency, the duration of transmission at each frequency or both.

A microwave heating package with a polarized shield includes a tray and a cover and at least one microwave energy interactive element. The microwave energy interactive element is dimensioned and arranged to extend along a peripheral region of a food item in an interior of the tray. The microwave energy interactive element reduces heating along the peripheral region of the food item when the microwave energy interactive element is exposed to microwave energy. The tray and the lid of the construct can each include at least one microwave energy interactive element.

Devices and methods for RF heating of food, using techniques which allow uniformity and/or controlled non-uniformity.

A container formed from a blank, a forming, tool and a method of forming a container are disclosed. The container includes features that are formed by a plurality of score lines in a marginal portion of the blank. The container has a bottom wall, a side wall, and a flange extending from the side wall. The flange has a thickness that is greater than a thickness of the blank.

Devices and methods for RF heating of food, using techniques which allow uniformity and/or controlled non-uniformity.

A microwave heating package with a polarized shield includes a tray and a cover and at least one microwave energy interactive element. The microwave energy interactive element is dimensioned and arranged to extend along a peripheral region of a food item in an interior of the tray. The microwave energy interactive element reduces heating along the peripheral region of the food item when the microwave energy interactive element is exposed to microwave energy. The tray and the lid of the construct can each include at least one microwave energy interactive element.