[1] The process is known as MVH because the microwaves penetrate uniformly throughout the volume of the product being heated, thus delivering energy evenly into the body of the material.
This is in contrast to traditional thermal processing, which relies on conduction and convection from hot surfaces to deliver energy into the product.
[2] Processing temperatures can be very accurately controlled by varying the flow rate of the product through the MVH treatment chamber.
Flowing liquids move continuously through a unique treatment chamber, thereby heating the product.
Because microwaves transfer electromagnetic energy at a molecular level, and the vibration of the molecules creates heat through friction, it is difficult to properly check for this highly localized 'micro'-thermal effect or create conditions where study of the putative 'athermal' effect is possible.