Optimization of onion oil microencapsulation by response surface methodology

摘要

Using agar and gelatin as wall materials, onion oil was microencapsulated using the extrusion spraying technology. A sensitive methodology was developed for quantitative determination of the microencapsulation yield through ethyl acetate extractionand gas chromatographic analyses. Optimal conditions for the microencapsulation process consisting of the ratio of [core material, Cm] to [wall material, Wm] (X_1), temperature of dispersion fluid (X_2), detergent concentration in dispersion fluid (X_3),and concentration of emulsifier (X_4) were determined using response surface methodology. The regression model equation for the yield of microencapsulation (Y, percent) of onion oil could be predicted as Y = 97.028571-0.775000 (X_1)-0.746726 (X_1) centre dot (X_1)-1.100000 (X_3) centre dot (X_2). The optimal conditions for the microencapsulation of the onion oil were determined as the ratio of [core material] to [wall material] of 4.5 : 5.5 (w/w), the temperature of dispersion fluid of 17.1 deg C, detergent concentration in dispersion fluid of 0.03 percent, and the concentration of emulsifier of 0.42 percent. Results revealed the most stable microcapsule of onion oil could be formed with the highest yield of microencapsulation (more than 95 percent) under optimal conditions.