Recent advances on the improvement of quercetin bioavailability

Natural antioxidants, such as polyphenols, are finding increasing application in functional foods designed to improve human health, wellbeing, and performance. Quercetin is a flavonol-based polyphenol that exhibits a broad range of potentially beneficial health effects, including anti-hypertensive, anti-diabetic, anti-asthmatic, anti-carcinogenic, anti-viral and antioxidant activities. The types and amounts of quercetin found in different plant sources vary considerably. Onions have a particularly high quercetin content, mainly in the form of isoquercetin, whereas black teas and apples mainly contain quercetin in the form of rutin. Quercetin has been incorporated into different kinds of food matrices to improve their nutritional profiles, including baked goods and dairy products. However, the bioavailability of quercetin is often relatively low (