Alkaline conjugation of caseinate and propylene glycol alginate to prepare biopolymer complexes stabilizing oil-in-water emulsion gels

The current study describes an approach for creating covalently bonded complexes of sodium caseinate (NaCas) and propylene glycol alginate (PGA) without using a cross-linking agent. principle is based on transacylation reaction between the esterified carboxylic groups PGA amino NaCas during pH shift from alkaline (pH 12.0) to neutral condition 7.0). increased molecule weight at higher amount observed in SDS-PAGE indicated covalent bonding PGA. hydrodynamic diameter NaCas-PGA binary with increase concentration while no significant changes zeta-potential were observed. Compared alone, NaCas:PGA mass ratio 2:1 exhibited improved thermal stability was capable forming gel emulsions 80% (v/v) oil macroscopic phase separation. much greater storage modulus than loss gel-like structure emulsions, which agreed jammed droplets microscopy. studied may be improving quality oil-in-water emulsion products such as mayonnaises.