Citral: Bioactivity, Metabolism, Delivery Systems, and Food Preservation Applications

Citral is a monoterpene aldehyde with a lemon flavor, comprising two isomers: geranyl aldehyde and neura. Citral's unique biological activities and lemonlike aroma have contributed to its widespread use in the food preservation industry. However, citral exhibits instability under various conditions, necessitating the development of several delivery systems to enhance its physicochemical stability and retard degradation. This article provides a comprehensive review of citral's structure, biological activities (including antimicrobial, antioxidant, anti-inflammatory, diabetes prevention, anticancer, and insect repellent properties), metabolism, stability, and delivery systems (such as spray drying, Pickering emulsions, nano-emulsions, and self-assembly), as well as its applications in food preservation. The advantages and limitations of these delivery systems are also discussed. Future research should explore opportunities to develop biopackaging films by integrating advanced technologies to achieve better monitoring and regulation of food freshness.