Microwave-assisted guar gum conjugation improvement in stability of pea protein high internal phase Pickering emulsion and its application in zeaxanthin delivery

Microwave pre-treatment enhanced PPI-GG glycation degree and shortened reaction time. • Conjugate nanoparticles had smaller particle size and higher interfacial stability. • Microwave-assisted GG conjugation synergistically modified PPI nanoparticle structure. • Rheology and stability of conjugate HIPPEs were improved by microwave pre-treatment. • Microwave-conjugation enhanced protection and delivery of zeaxanthin by HIPPEs. Glycation conjugate nanoparticles of pea protein isolate (PPI) and guar gum (GG) were prepared with microwave pre- and post-treatment for 4 and 6 min. Effect of microwave-assisted GG conjugation on stability and delivery function of high internal phase Pickering emulsions (HIPPEs) constructed by PPI nanoparticles were investigated. Microwave pre-treatment promoted covalent binding of GG to PPI with smaller particle size (99.02 nm) and higher interfacial stability. The secondary structure of conjugate nanoparticles was more flexible, and their tertiary conformation was looser. Microwave pre-treatment improved appearance, microstructure and rheological properties of conjugate HIPPEs, enhancing their physical, thermal, pH and ionic strength stability. Furthermore, encapsulation efficiency of conjugate HIPPEs with microwave pre-treatment for 4 min was 95.88%, and improved its controlled release effect, resulting in the highest bioaccessibility (62.79%). Therefore, microwave-assisted PPI-GG glycation modified physicochemical properties and structure of conjugate nanoparticles, which enhanced stability of HIPPEs and their delivery function for zeaxanthin. Download: Download high-res image (224KB) Download: Download full-size image