Encapsulation of bioactive compounds using competitive emerging techniques: Electrospraying, nano spray drying, and electrostatic spray drying

This review is primarily focused on the comparison of three emerging techniques: electrospraying, nano spray drying, and electrostatic spray drying techniques. There are persistent advances to develop efficient drying technique for sensitive bioactives and to overcome their hurdles. These processes involve electrostatic forces as a promising factor for better encapsulation and stability of dried particles. Their potential differences in experimental setup, influencing factors and recent applications are listed. Introduction of electrostatic interaction between the components during atomization allows electrospraying and electrostatic spray drying as an advanced drying technique for heat-sensitive and labile products. Electrospraying and nano-spray drying demonstrated an effective drying with different solvent systems (organic or non-organic solvents) and also, achieved to encapsulate complex food ingredients (vitamins, minerals, phenolic compounds, probiotics etc.). These electric-assisted technologies showed higher encapsulation efficiency, uniform particle morphology and longer stability of dried powders than classical technologies. Nano-spray dryer with spray mesh technology and electrostatic collector brings out difference in dried powders in terms of particle size and product yield when compared to conventional spray drying. Electrospraying and nano-spray drying have been beneficial for highly valued research products (such as cells, enzymes, genes, etc.) but the scaling up of these processes is still currently in process. • Three emerging spray drying technologies using electric fields have been reviewed. • Electrospraying, nano-spray & electrostatic spray drying works at lower temperature. • These processes involve electrostatic forces allowing droplets & particle repulsion. • Overall technical considerations, advantages and limitations are discussed. • Industrial set up of electrostatic spray drying is commercially available.