Thymol loaded zein microparticles obtained by spray-drying: Physical-Chemical Characterization

The use of thymol in the food industry may be restricted due to its high instability to temperature, oxygen, light and humidity. This disadvantage may be postponed by microencapsulation. Microparticles were obtained by spray-drying technique at a drying temperature of 130 degrees C and 0.385 g per 100 g of zein for thymol concentration. In these conditions, 49.5% encapsulation efficiency was achieved and microparticles featured an average size of 14.3 mu m measured by laser beam diffraction on a Mastersizer 2000 equipment. Morphologically they revealed a spherical shape with smooth surface and mild roughness. Thermal analysis showed protection to thymol at a temperature above the degradation temperature of the compound (200 degrees C). Delivery tests presented a release of thymol at 90% on the first day, classified as burst release according to Fick's second law.

Automated summary

The high instability of thymol in the food industry can be addressed through microencapsulation, which delays its degradation. Microparticles obtained by spray-drying technique show good encapsulation efficiency and release properties, making them suitable for food additives.