Effects of pH, kappa-carrageenan concentration and storage time on the textural and rheological properties of pea protein emulsion-gels

Abstract This study examined the rheological and textural properties of gels produced through emulsion gelation using pea protein isolate (PPI). Emulsions were prepared with varying PPI concentrations (2%–10%) and 0.25 oil fraction, followed by heat treatment. Higher PPI concentrations improved encapsulation efficiency (EE), but heat slightly reduced it, though EE remained above 90%. Droplet size decreased with higher PPI. The emulsion was then gelled with different kappa-carrageenan (KC) concentrations (1%–2%) and pH levels (4–7). Gel hardness increased with KC content, while adhesiveness decreased. Springiness, cohesiveness and water-holding capacity (WHC) rose with pH and KC, while meltability decreased. Rheological tests showed stronger gels with higher KC and lower pH. Storage time generally increased gel strength, except at pH 4. This work highlights the interplay between PPI, KC, pH and storage time in shaping the properties of pea protein-based emulsions and gels.