Physical and chemical properties of encapsulated rosemary essential oil by spray drying using whey protein–inulin blends as carriers

Summary The objective of this study was to evaluate the influence of whey protein isolate ( WPI ) and inulin blends on the properties of rosemary essential oil microencapsulated by spray drying. The following ratios (w/w) of WPI to inulin were evaluated: 1:1, 1:3 and 3:1. Increasing the WPI concentration increased the particle instantanisation times and decreased the moisture content. The samples did not differ significantly ( P > 0.05) in hygroscopicity and porosity. The microcapsules produced at higher inulin concentration showed the highest bulk density and tapped density and were significantly different from other treatments. WPI /inulin blends of 1:1 and 3:1 proved to be effective carriers to entrap rosemary essential oil. The encapsulated oil composition in particles proved to be quite similar to pure oil, and no interaction between wall matrix and encapsulated oil was demonstrated. The analysis of particle size distribution revealed that the particle size varied from 11.5 to 11.9 μm and that all samples had an amorphous structure.