General areas of the use of a microwave radiation for processing of plant raw materials (review)

Abstract

In the last decade, the use of a microwave radiation in the chemistry of plant raw materials has attracted the attention of a growing number of scientists. This review is devoted to an analysis of recent publications in this area, the number of which is exponentially increased. The main fields of application of microwave radiation in the chemistry and technology of plant raw materials have been discussed, including extraction of the low-molecular weight compounds of different classes both in an individual state and in compositions (for example, essential oils) from natural plant objects; an isolation of high-molecular weight structural biopolymers (cellulose, lignin, and hemicelluloses); processes of drying of plant materials; wood pyrolysis; hydrolysis of high-molecular weight components of plant raw materials; chemical modification of plant biopolymers with the aim to obtain ethers, esters, and other derivatives; chemical modification of plant raw materials without prior separation into individual components; and other processes. Microwave radiation was shown to be efficient for these processes. In general, microwave radiation was found to considerably accelerate processes and significantly reduce energy costs. Examples of implementation of the described processes in industry were given. At present, processes and mechanisms that occurred under the action of the microwave radiation on a plant material has been little studied and requires further investigation.