Abstract:
Drying is one of the foremost and important steps during the processing of agricultural
crops, medicinal plants and herbs to preserve their properties. The present review provides
a detailed overview regarding the effect of drying techniques on the physio-chemical prop-
erties (microstructure, color, aroma composition) and bioactive compounds (phenolic com-
pounds, carotenoids, essential oils, etc.) of plant materials. Factors affecting different drying
processes and their optimization strategies have also been discussed. Furthermore, current
trends in the development of drying techniques for plant materials in terms of the retention
of their bioactive compounds are critically analyzed. Based on the published research
articles, oven drying, and microwave drying are the preferable techniques for most plant
parts; while for drying the plant extract, freeze/spray drying methods have gained higher
interest. Finally, recommendations are made considering the better use of drying techniques
for both plant materials and retention of their bioactive compounds.
