Exploring the phase behavior of natural egg yolk-carboxymethyl cellulose concentrate: Impact on emulsification and gelling properties

Abstract

This study developed a dilution-phase diagram method to determine the phase behavior of concentrated egg yolk-carboxymethyl cellulose (EYCM). The results demonstrated that the strength of the electrostatic interaction (SEI) was within the strength limit (1314 mV2), and selective patch binding dominated the formation of soluble complexes. An SEI beyond the strength limit of electrostatic repulsion dominated the formation of alkaline co-solubility. The complex coacervates were formed due to strong electrostatic attraction at SEI > −100 mV2. The acidic co-solubility was formed due to the protonation of carboxymethyl cellulose (CMC). Spectroscopic analysis revealed that the stability of the EYCM spatial structure of the soluble complex was due to the stabilized hydrophobic core, the low content of unstable irregular coils (23.12%) and the high content of highly stabilized β-sheets (24.36%). The different phase behaviors of EYCM affected the emulsification and gelation properties. The acidic and alkaline environments led to co-solubility of the EYCM of a smaller particle size (<362.7 nm), which exhibited a better emulsifying activity. A suitable particle size and depletion attraction improved the emulsification activity and stability of the soluble complexes. Although the complex coacervates had a larger particle size (4160.1 nm), the free CMC-induced depletion attraction contributed to the favorable emulsion stability. In addition, for alkaline co-solubility, the intermolecular folding of LDL, lipid filling and CMC enhancement of the gel framework to form a strong gel. As acidification proceeded, protein unfolding was restricted, the role of lipids and CMC was reduced, and the gel structure gradually diminished.