LAUSR

(1) Background: In this study, aiming at the problems of low efficiency and high energy consumption in the esterification reaction of OSA and starch, the jet milling technology was used to pretreat corn starch and starch raw materials with different pulverization strengths were obtained by controlling the speed of the classifier. (2) Methods: The starch obtained under different classification speeds was modified by esterification with OSA. Using CLSM, FTIR, XRD, NMR, FTIR, XPS, and other technologies, the modification effect was verified, and the physical and chemical properties of J-OSA-Starch such as DSC, RVA, transparency, and emulsifying properties were determined. (3) Results: Jet milling pretreatment significantly reduced the particle size of corn starch and improved the reaction efficiency and degree of substitution during esterification with OSA. After pretreatment, the corn starch granules were broken, and the relative crystallinity was significantly reduced. CLSM, FTIR, XPS, and NMR confirmed the esterification of corn starch with OSA, which increased with increasing crushing strength. The thermodynamic properties and viscosity of J-OSA-starch decreased with the increase in the classification speed. Jet milling pretreatment enhanced the clarity, emulsifying activity, and emulsifying stability of OSA-modified corn starch. (4) Conclusions: Jet milling pretreatment can effectively increase the esterification efficiency of starch and OSA. Therefore, jet milling can be used as a pretreatment to improve the esterification of starch OSA and produce modified starch for industrial applications.