Encapsulation of iron within whey protein-pectin nanocomplexes: Fabrication, characterization, and optimization

Iron is an important micronutrient that cannot be added directly into food products due to potential reactions with the food matrix, impact on color, and taste. Complexed biopolymeric nanocarriers can overcome these challenges particularly for oral delivery of iron, but selecting appropriate biopolymers, their ratio and pH of complexation is very important. In this study, whey protein concentrate (WPC)-pectin nanocomplexes were prepared at different concentrations (WPC 4, 6 and 8%; pectin 0.5, 0.75 and 1%), and pH (3, 6 and 9) to encapsulate iron. The smallest carriers were observed at pH 3; higher pH led to higher zeta potential (zero to -32.5 mV). Encapsulation efficiency of iron in nanocarriers formulated at pH = 3, 6 and 9 were 87.83, 75.92 and 20%, respectively. Scanning electron microscopy revealed the spherical particles at pH 3. To conclude, a WPC to pectin ratio of 4: 1 at pH 3 was the best conditions for loading iron.