Optimization of Folic Acid Nano-encapsulation by A Taguchi Approach

Due to susceptibility of folic acid1 like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our main goal was to find the optimum conditions in pectin-WPC2 double emulsion preparations for nano-encapsulation of FA by spray drying. Five independent variables and their practical range including pectin and WPC content, dispersed phase content, pH, and surfactant type of Span and PGPR3 were considered along with encapsulation efficiency4 as the main response. The experiment design was performed by Taguchi approach and 16 treatments were determined. Final double emulsions were formulations containing an internal nano/micro-emulsion composed of a W/O system with FA present in the water phase, the whole dispersed within an aqueous phase of pectin-WPC complexes. The grand average of folic acid EE was approximately 88.3% in a range of 82.3 to 95.0%. The main effect analysis with Taguchi technique revealed that dispersed phase content of double emulsions was the most important factor affecting EE (36%) and surfactant had the minimum influence (5%). Also, it was revealed that the most important interaction between independent variables in terms of EE was between WPC and dispersed phase content while pectin-pH had the lowest interaction. Finally, optimum conditions were determined as 1.0% pectin, 4.0% WPC, 15% dispersed phase, pH=6, with a PGPR nano-emulsion which resulted in 99.0% EE of folic acid.