Konjac glucomannan enhances the thermal and freeze-thaw stability of rennet-modified caseinate high internal phase emulsions via viscoelastic structuring and interfacial modulation

Konjac glucomannan markedly enhanced the heat and freeze-thaw stability of RM-NaCas HIPEs. • KGM promoted the formation of dense viscoelastic networks with increased viscosity and elastic dominance. • Reduced interfacial tension and improved wettability induce by KGM reinforced interfacial layer. • Enhanced stability is primarily attributed to bulk structuring and interfacial reinforcement. High internal phase emulsions (HIPEs) often exhibit limited resistance to thermal processing and freeze-thaw treatments, restricting their practical applications. This study demonstrated that konjac glucomannan (KGM) significantly enhanced the stability of rennet-modified sodium caseinate (RM-NaCas) HIPEs under heating (60–100 °C for 20 min) and repeated freeze-thaw cycles. Emulsions containing 0.8% KGM maintained structural integrity after heating at 100 °C and exhibited reduced crystallization temperature. KGM also increased the viscosity and viscoelasticity and promoted the formation of a denser droplet distribution and network structure. In addition, interfacial tension and contact angle measurements indicated improved interfacial properties, while FTIR analysis suggested the presence of intermolecular interactions between KGM and NaCas, such as hydrogen bonding. Overall, the enhanced stability is primarily attributed to viscoelastic structuring of the continuous phase and interfacial reinforcement. This study provides an effective and clean-label strategy for designing thermally and freeze-thaw stable HIPEs for food applications. Download: Download high-res image (113KB) Download: Download full-size image