where does quercetin come from
Quercetin is highly concentrated in apples, onions (especially red onions), and green tea. It is also in red grapes, citrus fruit, tomato, broccoli, leafy greens, cherries, raspberries, cranberries, and many other fruits and vegetables.One vine ripened apple, for example, contains 50 mg of quercetin.uercetin is highly concentrated in apples, onions (especially red onions), and green tea. It is also in red grapes, citrus fruit, tomato, broccoli, leafy greens, cherries, raspberries, cranberries, and many other fruits and vegetables.