Mixture Design Approach in Wall Material Selection and Evaluation of Ultrasonic Emulsification in Flaxseed Oil Microencapsulation

Abstract

Flaxseed oil, sensitive to oxidation, was systematically microencapsulated with six triple wall materials combinations [carbohydrate (maltodextrine and two different modified starches (N-Lok® and HiCap® 100)); protein (sodium caseinate, whey protein concentrate); and Arabic gum] for the highest microencapsulation efficiency and oxidation stability. Proportions of the triple wall materials were optimized in mixture design using the quadratic model. Effects of Ultra-Turrax and ultrasonic emulsifications on microencapsulation efficiencies were additionally characterized in the optimized wall material combinations. The microcapsules produced were investigated for particle size distribution, moisture content, water activity, bulk density, and oxidative stability. Results showed that the combination of modified starch (Hi-Cap® 100)/Arabic gum/whey protein concentrate (4/0/1, w/w/w) provided the highest efficiency in flaxseed oil microencapsulation. However, the only successful combination in preventing flaxseed oil oxidation was maltodextrine/Arabic gum/whey protein concentrate (4/0/1, w/w/w). The microcapsules produced by ultrasonic emulsification had higher microencapsulation efficiency than that of Ultra-Turrax emulsification.

Keywords:

• Flaxseed oil
• Microencapsulation
• Mixture design
• Spray drying
• Wall material

ACKNOWLEDGMENTS

The authors thank National Starch (New Jersey, USA) for providing the wall materials and the Research Administration Unit of Akdeniz University (Antalya, Turkey) for financial support (Project number: 2011.02.0121.008).

Notes

X₁: Carbohydrate, X₂: Arabic gum, X₃: protein.

X₁: Carbohydrate, X₂: Arabic gum, X₃: protein.

^a Selected combinations.

^b Values, obtained using optimal combinations, are expressed as mean ± standard deviation of triplicate analysis. Different letters within the same column indicate significant differences (P < 0.05).

Different capital letters within the same emulsification and different letters within the same combinations indicate significant differences (P < 0.05).

Different capital letters within the same emulsification and different letters within the same combinations indicate significant differences (P < 0.05).

Values are expressed as mean ± standard deviation of triplicate analysis. Different letters within the same column indicate significant differences (P < 0.05).