Interfacial and emulsion-stabilizing properties of zein nanoparticles: differences among zein fractions (α-, β-, and γ-zein)

According to the solubility in the binary solvent of ethanol water, zein can be classified into alpha-, beta-, gamma-, and delta-zein, and the difference in amino acid compositions of these fractions is believed to affect their physicochemical properties and functionalities. This research comparatively analyzed main zein fractions, namely the alpha-zein fraction, beta-zein fraction, and gamma-zein fraction, on the formation, surface adsorption, and emulsifying properties of their anti-solvent-induced particles. Results showed that all zein fractions were able to form spherical particles through an anti-solvent procedure, and formed particles possessed different surface charge and surface hydrophobicity. gamma-Zein fraction particles had the biggest size and lowest surface hydrophobicity, the highest interfacial adsorption speed, and formed the strongest viscoelastic interfacial film, as analyzed through the interfacial rheology results, while beta-zein fraction particles exhibited the poorest interfacial activity. These physicochemical differences were reflected in their emulsifying properties, whereby the gamma-zein fraction particle-stabilized emulsion had the maximum tolerance to salt (50, 100, and 200 mM NaCl) and pH (4.0, 7.0, and 9.0). The excellent interfacial properties of the gamma-zein fraction presented in this research would afford a new strategy for the effective application of zein.

Automated summary

This research compared the main zein fractions and found differences in their formation, surface adsorption, and emulsifying properties of anti-solvent-induced particles. The gamma-zein fraction displayed superior interfacial properties and emulsifying capabilities, making it a potential new application strategy for zein.