Preparation and controlled release properties of heterocyclic flavor CS/Zein microcapsules

2,3-Diethyl-5-methylpyrazine (DEMP) is a highly volatile compound characterized by a strong nutty and roasted aroma. Due to its volatility, its application is limited, necessitating the development of suitable controlled-release techniques. In this study, composite wall materials comprising zein and chitosan (CS) were employed to encapsulate DEMP as the core material, forming heterocyclic flavor microcapsules via a coacervation method. The encapsulation efficiency was evaluated, and the preparation process was optimized using response surface methodology. Morphological characterization was performed using scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR), stability assessment, and release kinetics were analyzed using Thermogravimetric analysis (TGA). Results indicated that the microcapsules were successfully produced, with a maximum encapsulation efficiency of 82.27% under optimal conditions. Demonstrated excellent thermal stability, with high linearity in the thermal release kinetic model. Additionally, the microcapsules exhibited good storage stability, with release behavior at room temperature aligning with the Peppas model. Molecular dynamics (MD) simulations revealed that post-host-guest binding, the microcapsule molecules tend to contract and stabilize, with van der Waals forces being the primary intermolecular interactions. This research provides new insights into encapsulating flavor and fragrance compounds and broadens the application scope of heterocyclic flavor molecules.