Pectin-induced quality improvement of pea protein emulsion template oleogels and their application as fat replacers in sponge cakes.

Abstract

In this study, high-quality oleogels based on pea protein isolate and high-methoxyl pectin were prepared using an emulsion-templated approach. The role of high-methoxyl pectin in oleogel formation under different pH (6 and 7) and concentrations (0-1.5%) was investigated by analyzing emulsion stability and the resulting oleogel structure. Furthermore, their feasibility as butter substitutes in sponge cakes was evaluated. The results showed that pectin interacted with pea protein through hydrogen bonding and hydrophobic interactions, inducing slight conformational rearrangements, which in turn led to the strengthening of the interfacial film and reinforcement of the continuous-phase network. Consequently, emulsions showed smaller (10.91 μm) and more uniform droplets, lower zeta potential (-42.78 mV), higher contact angle (72.53°), and greater viscosity. Oleogels obtained at 1.5% pectin and pH 7 displayed the strongest solid-like structure with highest oil-binding capacity (99.49%), hardness (8.71 N) and gel strength (G' > 105 Pa). When fully replacing butter, oleogels produced sponge cakes showed no significant difference in specific volume (4.02 vs. 4.17 mL/g) and hardness (0.72 vs. 0.58 N) compared to the butter group (p > 0.05), highlighting their potential as saturated fat-free fat substitutes.