Kale or borecole (Brassica oleracea Acephala Group) is a vegetable with green or purple leaves, in which the central leaves do not form a head. It is considered to be closer to wild cabbage than most domesticated forms. The species Brassica oleracea contains a wide variety of vegetables, including broccoli, cauliflower, collard greens, and brussels sprouts. The cultivar group Acephala also includes spring greens and collard greens, which are extremely similar genetically. Pieris rapae is one of the most well known pests of the plant.
Kale freezes well and actually tastes sweeter and more flavourful after being exposed to a frost. Tender kale greens can provide an intense addition to salads, particularly when combined with other such strongly flavoured ingredients as dry-roasted peanuts, soy sauce-roasted almonds, red capsicum flakes, or an Asian-style dressing. When combined with oils or lemon juice, kale's flavor is noticeably reduced. When baked or dehydrated, kale takes on a consistency similar to that of a potato chip. Curly kale varieties are usually preferred for chips. The chips can be seasoned with salt or other spices. Kale is very high in beta carotene, vitamin K, vitamin C, and rich in calcium. Kale is a source of two carotenoids, lutein and zeaxanthin. Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical with potent anti-cancer properties.