Abstract

Background: Drying is one of the oldest preservation techniques used in the food industry. This technology has evolved and different drying systems have been applied, such as convection, conduction, or radiation, and combinations thereof. Scope and approach: This review studies the VMD process whose principle is based on the electromagnetic radiation emitted by the magnetron on a food matrix in a reduced pressure environment and which is transformed into heat. VMD is a promising, fast, and efficient process for reducing moisture content. Both research and industrial use have grown by 303% in the last 20 yr. The objective of this review is to provide an overview of major developments in VMD research and its application in various foods and other materials. Based on the characteristics and parameters of the VMD equipment in the drying process, it was possible to classify the effect VMD has on different food matrices. Key findings and conclusions: The review describes the phenomenological behavior of the drying process and how to optimize it using equipment modifications with computer simulations. The different VMD systems have been classified as static, rotary, continuous flow, and proprietary equipment. In addition to some characteristics of process efficiency and energy consumption, VMD exhibits energy consumption savings of approximately 50% compared with other drying systems. Finally, product quality is discussed under different conditions, such as equipment design and temperature uniformity. Thus, it is challenging to design and built new VMD systems with higher energy efficiency in food drying.