Unveiling Optimal Synthesis and Structural Insights of Starch Ferulate via the Mechanoenzymatic Method

Abstract

In this study, starch ferulate was synthesized employing a mechanoenzymatic method, specifically based on the twin screw extrusion technique and lipase catalysis. The research then primarily centered on optimizing process parameters and conducting structural analysis. Optimal conditions were determined to be 8.2% ferulic acid addition, 66 °C extrusion temperature, and 3.2% lipase (N435) addition. The enzyme-catalyzed time was 30 s. The degree of substitution for starch ferulate was quantified at 0.005581 under these specific conditions. The presence of C=O bonds in the synthesized starch ferulate proved that the synthesis process was efficient. Additionally, the crystal structure underwent reconstruction. Observations through Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) demonstrated that the mechanoenzymatic method led to an augmentation in the specific surface area of starch molecules, thereby facilitating the exposure of active sites. This breakthrough underscores the vast potential of mechanoenzymatic techniques to revolutionize the rapid and sustainable synthesis of starch ferulate, marking a pioneering stride in ester synthesis. The insights garnered from this study transcend theory, offering a visionary roadmap for the development and real-world deployment of advanced modified starch esters.