Bok choy

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 (Cantonese for "white vegetable") or siu bok choy (Cantonese, for "small white vegetable"; as opposed to dai bok choy meaning "big white vegetable" which refers to the larger Napa cabbage). 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 names Chinese 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 word buk choy to refer to a specific kind of cabbage distinct from pak choy.

In China, the majority of Chinese speak Mandarin (about 955 million people), and for them, the term used most commonly is 青菜 qīng cài (literally "green vegetable"). 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 (Chinese: 小白菜; lit.: 'small white vegetable') or Shanghai bok choy (Chinese: 上海青; lit.: 'Shanghai green'). 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.

Nutritional value

Raw bok choy is 95% water, 2% carbohydrates, 1% protein and less than 1% fat (table). In a 100 gram amount, raw bok choy supplies 13 calories and is a rich source (20% or more of the Daily Value, DV) of vitamin A (30% DV), vitamin C (54% DV) and vitamin K (44% DV), while providing folate, vitamin B6 and calcium in moderate amounts (10–17% DV) (see table).

Bok choy was ranked #2 for nutrient density out of 41 nutrient-rich plant foods.

Toxic effects

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.