13 - Electrostatic spray drying of high oil load emulsions, milk and heat sensitive biomaterials

Abstract

Electrostatic spray drying (ESD) is a low temperature drying technique that combines gas–liquid atomization and electrostatic charge in a streamlined one-step process for conversion of liquid feed to powder. Traditional spray drying uses high temperatures (inlet: 180–230 °C, and outlet: 80–100 °C) that often degrade the activity of biological materials and lower the quality of powders. Low ESD operating temperatures (inlet: <100 °C, and outlet: <60 °C) coupled with electrostatic charge promotes the agglomeration of dried particles and eliminates the need for post drying agglomeration steps. ESD is used successfully in drying heat sensitive biological materials in agricultural, food, and pharmaceutical applications and includes products such as probiotic microorganisms, microorganisms associated with the human microbiota, heat sensitive proteins, microalgae, and other pharmaceutical products. ESD not only offers an alternative approach to drying heat sensitive biological materials but also excels in drying of high oil load emulsions. In this chapter we explore the principles of ESD and present examples emphasizing the value adding benefits of this technology.