Berry Drying: Mechanism, Pretreatment, Drying Technology, Nutrient Preservation, and Mathematical Models

Abstract

Fresh berries containing in bioactive compounds are perishable under natural conditions. Drying is one of the most effective processing techniques to extending the shelf life of berry products, and the nutrients and active components of berries can be retained to a great extent. However, the flavor and texture of the final product considerably correlate with drying techniques. Therefore, the present reviewed work summarizes the research progress of berry drying technology by the perspectives of traditional drying technology and innovative drying concepts and explores the research situation of convective drying, freeze drying, vacuum drying, microwave drying and innovative drying technology for berry drying. The dehydration mechanism, pretreatment methods, and drying technology of various berries were summarized. And the effects of different drying treatments on nutritional components of berry drying were presented; application status of mathematical modeling employed in berry drying was also discussed. Moreover, the research direction and development trend of berry drying techniques in the future were pointed out, which are aimed at improving the drying efficiency of berries, preserving the active components of berries to the greatest extent, and promoting the processing utilization of berries and economic benefits in the future to provide a reference for further research and utilization of drying technology.