Norfolk Kale Is Loaded With Powerful Antioxidants Like Quercetin and Kaempferol. Kale, like other leafy greens, is very high in antioxidants. These include beta-carotene and vitamin C, as well as various flavonoids and polyphenols ( 2 ). … But many substances that happen to be antioxidants also have other important functions. Norfolk Kale is now in our Norfolk Veg Boxes.