Abstract:

Using gum arabic and β-cyclodextrin as wall materials, blend microcapsules of phytosterol esters and puerarin
were prepared by a spray drying method. The influences of emulsifier composition, emulsifier dosage, solids content, core
material-to-wall material ratio, and gum Arabic-to-β-cyclodextrin ratio on emulsion stability were investigated as well as
the influences of inlet temperature, outlet temperature and homogenization pressure on microencapsulation efficiency. The
optimum processing parameters for the preparation of composite microcapsules were determined by combined use of single
factor and orthogonal array experiments as follows: emulsifier dosage (sucrose ester : monoglyceride = 6:4, g/g), 0.7%; solid
content, 20%; core material/wall material ratio, 0.25:1; wall material composition, acacia senegal:β-cyclodextrin = 5:5; inlet
temperature, 180 ℃; outlet temperature, 75 ℃; and homogenization pressure, 25 MPa. Under the optimum conditions, the
microencapsulation efficiency of phytostetol esters and puerarin were 89.04% and 80.15%, respectively. The composite
microcapsule was a milky white, uniform fine powder that smells pure. It had a moisture of 3.57%, density of 0.568 g/mL
and solubility of 95.11%, and exhibited high storage stability.

Key words: phytosterol ester, puerarin, microcapsules, spray drying