Structural and rheological modulation of low-oil emulsions by deamidated pea protein–gum arabic coacervates for reduced-fat applications

Increasing GA transformed flocculated oil droplets into dense networks. • Higher GA increased droplet size and enhanced emulsion viscoelasticity. • DPPI-GA ratios of 8:1–10:1 yielded low-oil emulsions with mayonnaise-like rheology. • GA enhanced emulsion networks but excess GA (5:1–3:1) reduced interfacial activity. This study investigates low-oil-phase emulsions formed by deamidated pea protein isolate (DPPI) and gum arabic (GA) coacervates at pH 3.0 as a low-fat food system. The impact of varying the DPPI-to-GA ratio (1:0–3:1) on 28% oil emulsions was examined. DPPI and GA formed coacervates via electrostatic, hydrogen bonding, and hydrophobic interactions. Increasing GA ratio shielded hydrophobic regions of DPPI, reducing surface hydrophobicity and interfacial activity, leading to larger emulsion droplets. GA also acted as a bridging agent, promoting aggregation of coacervates and shifting the microstructure from flocculated droplets to dense networks, with oil droplets more uniformly embedded. This structural change enhanced emulsion viscoelasticity, with higher GA ratios showing stronger nonlinear rheological behavior. At DPPI-GA ratios of 8:1–10:1, emulsions exhibited viscoelastic properties and large-strain responses comparable to traditional mayonnaise (70% oil). This study suggests a plant-based method for reduced-fat emulsified foods with conventional-like structural and rheological properties. Download: Download high-res image (185KB) Download: Download full-size image