Effect of Homogenization Pressure and Oil Load on the Emulsion Properties and the Oil Retention of Microencapsulated Basil Essential Oil (Ocimum basilicum L.)

Abstract

The objective of this work was to evaluate the influence of oil concentration and homogenization pressure on the emulsion and particle properties during the microencapsulation of basil essential oil by spray drying, using gum arabic as the wall material. Experiments were planned according a 2² rotational central composite design. The independent variables were oil concentration with respect to total solids (10–25%) and homogenization pressure (0–100 MPa). Emulsions were analyzed for droplet mean diameter, stability, and viscosity, and particles were analyzed for oil retention, moisture content, particle size, and morphology. Emulsion viscosity was not affected by any of the independent variables. The increase in the homogenization pressure from 0 to 100 MPa resulted in smaller emulsion droplet size (down to 0.40 µm) and, consequently, higher oil retention (up to 95%). On the other hand, higher oil loads (25%) resulted in poorer oil retention (51.22%). Microencapsulation of basil essential oil using gum arabic as the wall material proved to be a suitable process to obtain powdered basil essential oil, presenting great oil retention with the use of lower oil concentration and higher homogenization pressure.

Keywords:

• Basil essential oil
• Emulsion properties
• Gum arabic
• Microencapsulation
• Spray drying

ACKNOWLEDGMENTS

The authors thank CNPq and FAPESP for financial support.

Notes

Note: Information provided by Linax Essential Oil Extraction.

^a Particle mean diameter was not a variable studied in the experimental design for response surface methodology. Means with the same lowercase letter did not differ significantly at P ≤ 0.05. Means with the same uppercase letter did not differ significantly at P ≤ 0.05.

NS = Nonsignificant.