Dual-role ultrasonication in fabricating a zein-resveratrol/pectin complex: From particle engineering to interface activation for superior pickering emulsion stability.

Abstract

This study introduces a two-step ultrasonic strategy for fabricating zein-resveratrol-pectin ternary complexes as Pickering emulsion stabilizers. The novelty lies in two aspects. First, resveratrol serves as both a structural modulator and an antioxidant. Second, ultrasonication plays a distinct dual role, with primary ultrasonication optimizing nanoparticle assembly (encapsulation efficiency 86.0%, particle size ∼180 nm) and secondary ultrasonication activating interfacial complexation with pectin to yield complexes with superior emulsifying performance (emulsifying activity index 15.94 m2/g). The resulting emulsion exhibited solid-like gel behavior (storage modulus ∼100 Pa), minimal creaming (20.01%), and exceptional stability under thermal, pH, and ionic stresses, with minimal creaming even at 85 °C. Raman spectroscopy confirmed the formation of a dense interfacial layer, which underpinned the enhanced oxidative resistance (peroxide value 0.25 mmol/L after 5 days). This work demonstrates that integrating polyphenol modification with dual-stage ultrasonication offers a green and effective approach for developing high-performance, clean-label food colloids.