Salad dressing have become a popular condiment in many countries. However, their high fat content may contribute to obesity and related health issues. In this study, mild and extensive purification were used to extract soybean oil body (SOB) with different protein compositions, and further modulated the interfacial charge interactions, thereby producing SOB self-aggregates for fat substitute in salad dressing. Mild purification of SOB increased extrinsic protein content, while extensive purification reduced extrinsic protein content. The mild purification system showed the largest particle size and segregated network structure close to the isoelectric point. However, the extensively purified system exhibited a charge reversal from negative to positive, forming a compact network. Both self-aggregates exhibited shear thinning and elastic properties. Increasing SOB self-aggregate concentration enhanced brightness, electrostatic repulsion and steric hindrance in salad dressing. SOB self-aggregates prepared with extensive purification at pH 5.0, formed a dense network structure that facilitated droplet arrangement, thereby imparting optimal viscoelasticity, enhanced interactions, and thixotropic recovery to salad dressing. This work presents a method based on different protein composition and charge modulation for incorporating oil body as ingredients in spreadable condiments without thickener as label-free products.