Rheological properties and microstructure of a novel starch-based emulsion gel produced by one-step emulsion gelation: Effect of oil content

A high elastic starch-based emulsion gel was fabricated by one-step heat-set gelation of the emulsion stabilized by octenylsuccinate starch for the first time. The effect of oil content on the linear and nonlinear rheological behavior and microstructure of the novel emulsion gel was investigated. The role of oil as inactive or active filler in the system shifted depending on content. The oil at low content of 10% did not integrate well into gel matrix and manifested as defects to gel network, playing as inactive filler, which was further confirmed by its decreased rheological modulus and viscoelastic properties compared with pure starch gel. Increasing the oil from 20% to 70% enhanced the gel strength related to a denser packing of oil droplets and starch aggregation, performing as active filler. This work provided a new strategy for structuring liquid oil, and the gel could find applications in food structuring and fat replacer.