Electrostatic spray drying: Advantages for thermosensitive actives

Abstract

Spray drying (SD) and freeze drying (FD) represent common methods utilized across various industries to achieve powdered final products. Electrostatic spray drying (ESD) is an emerging alternative as a continuous process to dry sensitive products without degradation, challenging the established drying techniques. This study aims to explore the efficacy of this process (ESD) in preserving the integrity of active components like oils, lactic acid bacteria (LAB), and enzymes. Additionally, a life cycle assessment (LCA) of these three drying technologies was conducted for a comprehensive evaluation. In oil encapsulation, the study showed that oxidation was significantly influenced by the formulation and the drying processes employed, where higher encapsulation efficiency resulted in lower degradation. This was observed, for instance, in the saponin composition dried with ESD. For LAB encapsulation, the results demonstrated higher preservation using FD and ESD. However, the impact of climate change using FD is twice superior to the ESD process. Finally, for enzyme application, β-gal activity was retained maximally while encapsulating using skim milk or maltodextrin. Specifically, regardless of drying technique, maltodextrin exhibited a maximum retention of β-gal activity, exceeding 30%. In all the case studies, ESD proved to excel in encapsulating thermosensitive actives, highlighting superior retention of native viability and properties compared to SD. Additionally, ESD generated results comparable to those achieved with FD. Therefore, ESD appears to be a promising method for high powder quality and a more sustainable process than FD and SD.