The crystallization of lactose usually causes the structural collapse and core material escape of flavor encapsulations. The objective of this study was to investigate the effects of different grafting degrees of WPI-inulin Maillard reaction products on the lactose crystallization and the subsequent release behaviors. Ethyl acetate was chosen as the model volatile flavor and the encapsulations were prepared by freeze-drying. The results found that the encapsulation efficiency was significantly increased from 30% to over 80% by using MRPs as wall materials. Those microparticles showed the greater flavor retention and lower moisture adsorption. In addition, the encapsulations produced by the proper Maillard reaction times (e.g., 48 h and 72 h) could effectively delay the lactose crystallization and thus improve the structural stability of the matrix. This innovation finding aims to use the Maillard reaction to control the crystallization behaviors and enhance the usefulness of high-lactose containing products in encapsulation systems.