Effect of Zein Concentration on the Formation of Pectin-Zein Complexes

Biopolymeric particles can be formed by electrostatic complexes of globular proteins and anionic polysaccharides mixtures at pH values above pKa of anionic polysaccharide and under the isoelectric point of protein. The purpose of this study was to investigate the effect of protein (i.e., zein) concentration on the formation of complexes between zein and polysaccharide (i.e., amidated low methoxy pectin) in aqueous solution. The zeta potential, turbidity and morphology under different conditions were observed to provide insights into the physicochemical properties of zein-pectin complexes. The biopolymeric particles were obtained at pH 4 and concentration of zein and pectin of 0.001 and 1% w/w, respectively. As the zein concentration increased, the turbidity of zein-pectin solutions increased, resulting from the formation of zein-pectin complexes. The zeta potential of the systems became less negative when the zein concentration increased. The results suggested that concentration of zein primarily influenced the formation of zein-pectin complexes.