Abstract: As an emerging nanoparticle, carbon dots (CDs) have been widely used in the fields of chemical sensing, biological imaging, drug delivery, photocatalyst and food detection due to its superior biocompatibility and photoluminescence. Food processing by-products come from a wide range of sources and are easy to obtain. Moreover, the surface of CDs prepared from food processing by-products is usually rich in functional groups and miscellaneous elements, imparting excellent photocatalytic, antioxidant and antibacterial properties to CDs. In recent years, CDs have been used as food packaging additives to enhance the ultraviolet (UV) shielding, mechanical, antioxidant and antibacterial properties of food packaging. In this paper, the types of food processing by-products that can be used to prepare CDs and natural polymer-based films added with CDs and the application of CDs in active and intelligent packaging are reviewed in order to provide guidance for the preparation of CDs from food processing by-products and its application in food packaging.

Key words: carbon dots; processing by-products; natural polymer; food packaging; food preservation