Bok choy, pak choi, or pok choi is a type of Chinese cabbage. Chinensis varieties do not form heads and have green leaf blades with lighter bulbous bottoms instead, forming a cluster reminiscent of mustard greens. Chinensis varieties are popular in southern China and Southeast Asia. Being winter-hardy, they are increasingly grown in Northern Europe. Now considered a subspecies of Brassica rapa, this group was originally classified as its own species under the name Brassica chinensis by Carl Linnaeus. They are a member of the family of Brassicaceae or Cruciferae, also commonly known as the mustards, the crucifers, or the cabbage family.
Spelling and naming variations
Other than the ambiguous term "Chinese cabbage", the most widely used name in North America for the chinensis variety is simply bok choy or siu bok choy. It can also be spelled pak choi, bok choi, and pak choy. In the UK and South Africa, the term pak choi is used. Less commonly, the descriptive English namesChinese chard, Chinese mustard, celery mustard, and spoon cabbage are also employed. In Australia, the New South Wales Department of Primary Industries has redefined many transcribed names to refer to specific cultivars. In addition, they have introduced the wordbuk choy to refer to a specific kind of cabbage distinct from pak choy. In China, the majority of Chinese speak Mandarin ; for them, the term used most commonly is 青菜 qīng cài. Although the term 白菜 is pronounced "baak choi" in Cantonese, the same characters are pronounced "bái cài" by Mandarin speakers and used as the name for Napa cabbage which they call "Chinese cabbage" when speaking English. In the Philippines, it is called péchay in Spanish and pichay or petsay in Tagalog. What is labelled Bok Choy may come in 2 forms: traditional true bok choy or Shanghai bok choy. Regular bok choy is usually more expensive and has a dark crinkly colored leaves and stem portions that are white and crisp texture that is more suitable to Cantonese style cooking, stir fries, and simple or raw preparations. Shanghai bok choy has greater availability in most American Markets and has mild tasting spoon shaped leaves that are lighter green with stems that are jade green instead of white. The texture of Shanghai bok choy is less crisp and gets slimy if overcooked for too long but can otherwise be substituted in many cooking applications when true bok choy is unavailable.
Bok choy contains glucosinolates. These compounds have been reported to prevent cancer in small doses, but, like many substances, can be toxic to humans in large doses, particularly to people who are already seriously ill. In 2009, an elderly diabetic woman who had been consuming 1 to 1.5 kg of raw bok choy per day in an attempt to treat her diabetes developed hypothyroidism for reasons relating to her diabetes, resulting in myxedema coma. According to the case study published by her treating physicians, raw bok choy releases an enzyme which can inhibit the uptake of iodine, when eaten in large amounts over extended periods.
History
Bok choy evolved in China, where it has been cultivated since the 5th century AD.
