Abstract: Quercetin, a natural bioactive substance that is widely found in foods, has a broad range of functions such as antioxidant, anti-inflammatory and anti-tumor functions, as well as preventive effect on cardiovascular diseases. Delivery systems for quercetin have been developed to tackle its poor water solubility and low stability. In this article, the physicochemical properties, biological activity, stability, human metabolism and delivery systems of quercetin are summarized. Furthermore, the safety aspects of quercetin and its delivery systems are also reviewed to provide a theoretical basis for expanding its applications in the food field.

Key words: quercetin; physicochemical properties; biological activities; stability; absorption and metabolism; delivery systems; safety