Effect of pH on the formation of electrostatic complexes between lentil protein isolate and a range of anionic polysaccharides, and their resulting emulsifying properties

Abstract

This research investigated the effect of pH on forming electrostatic complexes between lentil protein isolate (LPI) and a range of anionic polysaccharides [carboxymethyl cellulose (CMC), gum Arabic (GA), alginate (AL), and ι-carrageenan (CAR)] at 4:1 LPI-polysaccharide mixing ratio, and their resulting emulsifying abilities. Maximum optical densities were found to be 0.486, 0.716, 0.310, and 0.190 for LPI-CMC, LPI-GA, LPI-AL, and LPI-CAR, respectively indicating the level of aggregate size and growth. LPI-CAR emulsion displayed the highest emulsion stability (ES) because of its higher continuous phase and emulsion viscosities, lower mean droplet sizes, and negatively charged droplets. They also formed much smaller complexes within solution due to their high negative charge. All other LPI-polysaccharide systems formed less stable emulsions than LPI alone due to the larger sizes of both complexes and oil droplets.

Keywords: Anionic polysaccharides; Coacervation; Emulsification; Lentil protein.