Role of octenyl succinic anhydride in tuning structural and surface properties of Pueraria lobata starch: A novel stabilizer for particle-stabilized emulsion gels.

Pueraria lobata starch (PLS) is a promising botanical starch; however, its strong hydrophilicity limits its application as an effective particulate emulsifier. In this study, PLS was esterified with octenyl succinic anhydride (OSA) to enhance its amphiphilic properties, and the structure-function relationships governing its performance in particle-stabilized emulsions and emulsion gels were investigated. Structural characterization confirmed the successful incorporation of OSA and significant changes in granule surface properties. Starch modified with 7% OSA exhibited the most favorable emulsifying performance, with a degree of substitution (DS) of approximately 0.022. The resulting starch particle-stabilized emulsions showed high stability under acidic and high-salinity conditions and readily formed emulsion gels. Rheological analysis indicated predominantly elastic behavior (G' > G″), together with enhanced structural recovery and thermal stability. These results demonstrate the potential of OSA-modified PLS as a food-grade particulate stabilizer for emulsified food systems.