Microencapsulation of Flaxseed Oil by Spray Drying: Effect of Oil Load and Type of Wall Material

Abstract

The objective of this work was to evaluate the effect of the type of wall material and the oil load on the microencapsulation of flaxseed oil by spray drying. Gum arabic, whey protein concentrate, and a modified starch were used to produce the microcapsules, each with four oil concentrations (10, 20, 30, and 40% oil, w/w, with respect to total solids), for a total of 12 tests. Initially, the feed emulsions were characterized for stability, viscosity, and droplet size. Then they were dried in a laboratory-scale spray dryer and the resulting particles were analyzed for encapsulation efficiency, lipid oxidation, moisture content, and bulk density. The increase in oil concentration led to the production of emulsions with larger droplets and lower viscosity, which directly affected powder properties, resulting in lower encapsulation efficiency and higher lipid oxidation. Among the three wall materials evaluated, the modified starch showed the best performance, with the highest encapsulation efficiency and lowest peroxide values.

Keywords:

• Emulsion properties
• Encapsulation efficiency
• Flaxseed oil
• Microencapsulation
• Spray drying

ACKNOWLEDGMENTS

The authors are grateful to FAPESP (processes 2009/52014-0 and 2009/54137-1) and CNPq (process number 474107/2010-8) for the financial support.

Notes

Different letters indicate significant difference at p ≤ 0.05 (capital letters: between different wall materials; lowercase letters: between different oil concentrations).

Different letters indicate significant difference at p ≤ 0.05 (capital letters: between different wall materials; lowercase letters: between different oil concentrations).

Different letters indicate significant difference at p ≤ 0.05 (capital letters: between different wall materials; lowercase letters: between different oil concentrations).