High internal phase Pickering emulsions stabilized by coconut pomace cellulose nanoparticle-based binary complexes:...

Plant-based particles are gaining prominence as food-grade stabilizers for HIPPEs in the food industry. Among them, coconut pomace cellulose, a major by-product of coconut milk processing, shows considerable potential as a Pickering emulsion stabilizer, offering opportunities for value-added utilization. However, the limited interfacial adsorption and viscoelasticity of single-component coconut pomace cellulose nanoparticles (CPCNPs) restrict their performance in HIPPE systems. This study developed three types of binary complexes by combining CPCNPs with tannic acid (CPCNPs-TA), sodium alginate (CPCNPs-SA), and xanthan gum (CPCNPs-XG), respectively, to enhance HIPPEs stability and functionality. Structural characterizations confirmed the formation of the complexes, while interfacial analyses (quartz crystal microbalance and dilatational rheology) revealed that CPCNPs-XG exhibited the highest interfacial adsorption and viscoelasticity. All binary complexes significantly improved emulsion rheology, gel hardness, cohesiveness, and lipid oxidative stability compared to CPCNPs alone. Notably, CPCNPs-XG-based HIPPEs showed the most robust resistance to oil droplet coalescence and oxidative degradation. Moreover, incorporating β-carotene into the oil phase or purple sweet potato anthocyanins into the aqueous phase further enhanced emulsion texture and stability. The HIPPEs also demonstrated superior 3D printability, with CPCNPs-XG-anthocyanins-based inks delivering the highest shape fidelity and structural recovery. These findings reveal the synergistic effect of CPCNP-based binary complexes and functional loadings in advancing the stability of HIPPEs and establish their application in developing bioactive food-grade inks for 3D printing.