Supercritical carbon dioxide is an ideal solvent to synthesize particulate delivery systems suitable for food applications. However, regulations require solvents and ingredients are either generally-recognized-as-safe or approved by FDA. We utilized unique features of the supercritical anti-solvent process to synthesize systems suitable for delivering antimicrobials in foods. The polymer we used was zein, prolamines, that is a category of alcohol-soluble corn proteins, and lysozyme was used as a model antimicrobial. Zein is insoluble in aqueous solutions and is ideal for a sustained delivery of antimicrobials into food products that have a long shelf-life. Our results showed that lysozyme was gradually released from particles for more than 30 days. A sustained release is required to inhibit microorganisms over a long period of time because free antimicrobials lose their biological activity in a few days. Our work therefore exemplified a system suitable to enhance the microbial safety of food products.