Electrohydrodynamic encapsulation of probiotics in heat-resistant mMicrocapsules for applications in the food industry

Probiotics are an important part of functional foods and are defined as living microorganisms that confer health benefits to the host. Viable probiotics are, however, significantly destroyed during food thermal processing and in the stomach due to harsh digestive conditions. The challenge is to improve the survival of probiotic cells during manufacture, storage, and the passage through the gastrointestinal tract of the host in order to exert their health benefits. Various microencapsulation techniques have been used to protect probiotics against harsh conditions, however, these processes have low encapsulation efficiency, low yield and high energy consumption. On the other hand, electrospray microencapsulation can be used to produce capsules ranging from the micro to the sub-micron sizes, works at room temperature and has high encapsulation efficiency with narrow particle size distribution. The objective of this project was to create heat-resistant microcapsules (HRM) via electrospraying. To accomplish this, core and shell solutions were synthesized to perform encapsulation with metallic and 3D printed electrospray sources to increase the production rate. HRMs of 394.7±44.50 μm in diameter were obtained while physicochemical characterization shows a combination of parameters of both biopolymers, which is attributed to the formation of bonds between alginate and zein in the esterification process. The thermogravimetric analysis also shows an improvement in thermal properties, reducing weight loss due to material degradation at 250 ºC from 40% to 19%. This technology is a promising technology for probiotics encapsulation and fortification of foods thermally processed.