Spray drying of folic acid within nano-emulsions: Optimization by Taguchi approach

ABSTRACT

Research over recent decades has shown that inadequate folate concentrations may contribute to some disorders. Cereal flours have been a primary candidate for fortification by folic acid as they are consumed by most of the people but the main obstacle is destruction of this vitamin by the process and environmental deteriorating factors. So, it can be nano-encapsulated for protection and efficient delivery. Our main goal was to find the optimum conditions in spray drying of pectin–whey protein concentrate (WPC) double emulsions containing folic acid. Five independent variables including pectin and WPC content, dispersed phase content, pH, and surfactant type of span and polyglycerol polyricinoleate (PGPR) were considered along with water activity (a_w) and bulk density as the main responses. The experiment design was performed by Taguchi approach and 16 treatments were determined. The grand average of a_w and bulk density for folic acid powders was approximately 0.371 and 343 kg/m³, respectively. The main effect analysis with Taguchi technique revealed that pectin content was the most important factor affecting a_w (39.5%), and WPC had the minimum influence (6%). In terms of bulk density, it was found that the most important parameter was WPC (29.6%) and the minimum influence was related to surfactant system (8.1%). Finally, optimum conditions were determined as 0.5% pectin, 4.0% WPC, 10% dispersed phase, and pH 8, with a PGPR micro-emulsion, which resulted in a_w = 0.229, and 1.5% pectin, 8.0% WPC, 10% dispersed phase, and pH 9, with a PGPR nano-emulsion, which resulted in density = 245.45 kg/m³ for folic acid powders.

KEYWORDS:

• Folic acid
• optimization
• spray drying
• Taguchi