Influence of Process Conditions on the Physicochemical Properties of Pequi Powder Produced by Spray Drying

Abstract

Microencapsulation of extract pequi pulp by spray drying, using Arabic gum as a microencapsulating agent, was studied. Tween 80 was used as a secondary emulsifier. A factorial design was conducted with the following independent variables: inlet air temperature (140 to 200°C), surfactant concentration Tween 80 (0 to 5%), and microencapsulating agent concentration (10 to 20%) on the responses; moisture content (0.3 to 1.9%), hygroscopicity (10.7 to 14.3 g adsorved water/100 g solids), process yield (25.8 to 56.1%), water activity (0.07 to 0.17), vitamin C (113.0 to 306.6 mg ascorbic acid/g pequi solids), and carotenoids content (10.9 to 74.3 mg carotenoids/g pequi solids). Only powder moisture content, hygroscopicity, water activity, and vitamin C content were statistically influenced by independent variables. Spray drying was optimized for maximum vitamin C and carotenoids content and minimal water content and hygroscopicity. Powder obtained under optimum conditions was characterized as to particle morphology, bulk, absolute density, and particle size distribution.

Keywords:

• Caryocar brasiliense
• Composite central rotatable design
• Microencapsulation
• Optimization
• Scanning electron microscopy

ACKNOWLEDGMENTS

The authors acknowledge the Foundation of Research Support of São Paulo–FAPESP (process number 2009/54170-9) and the Faculty of Agricultural Engineering of the University of Campinas for financial support.

Notes

AOAC = Association of Analytical Chemists.

N.S. = non-significant at p > 0.10.