Mechanisms behind the changes in zein colloidal composite nanoparticles under different mass ratios and pH conditions

Hydrophobicity of zein (Z) makes it a candidate for encapsulating hydrophobic compounds and stabilizing Pickering emulsions. However, the high aggregation tendency of Z colloidal particles has limited its applications. In this work, the aggregation of Z particles was modulated by incorporating Farsi gum (FG), as a less-known hydrocolloid with attractive characteristics, into the colloidal particles. Z/water-soluble portion of FG (WFG) particles were fabricated at 3-7 pH range and 10:1-1:2 mass ratios using anti-solvent procedure and then characterized. Zeta potential values indicated higer colloidal stability in the presence of WFG. At higher pH values, the Z:WFG (1:1) colloidal particles were smaller than the Z particles. Although WFG incorporation decreased the adsorption rate of particles, both Z and Z:WFG efficiently reduced interfacial tension. Z (pH 4) and Z: WFG (pH 4) as interfacial layers revealed non-Newtonian and dominant viscose characters. This work can help to design Pickering emulsions using alcohol soluble-based particles.