Although yellow mustard, as we know it, has a spicy, slightly nutty taste, many people think that mustard seed lacks this flavor. This is because the typical taste develops only after the seed comes into contact with liquids, a step required to activate the enzyme myrosinase. This subsequently causes the release of the typical mustard flavor, which can often be quite sharp and spicy.
From Wikipedia: “Mustard seeds are the small round seeds of various mustard plants. The seeds are usually about 1 to 2 millimetres (0.039 to 0.079 in) in diameter and may be colored from yellowish white to black. They are important spice in many regional foods and may come from one of three different plants: black mustard (Brassica nigra), brown Indian mustard (B. juncea), or white mustard (B. hirta/Sinapis alba).
Grinding and mixing the seeds with water, vinegar, or other liquids, creates the yellow condiment known as prepared mustard.
An archaic name for the seed is eye of newt. Often misunderstood for an actual eye of a newt, this name has been popularly associated with witchcraft ever since it was mentioned as an ingredient to a witch's brew in Shakespeare's famous play Macbeth.”
“These mustard seeds are known in Hindi, Urdu, and Punjabi as sarson (Indian colza, Brassica rapa subsp. trilocularis, syn. Brassica campestris var. sarson), in Bengali as shorshe. These are used as a spice in Pakistan, Northern India, Nepal, and Bangladesh. The seeds are usually roasted until they pop. They are also planted to grow saag (greens) which are stir-fried and eaten as a vegetable preparation, called sarson ka saag in Urdu and Hindi (sarron da saag in Punjabi).
In Maharashtra, it is called as mohari, and is used frequently in Marathi recipes. Sarson ka tel (mustard oil) is used for body massage during extreme winters, as it is assumed to keep the body warm. In Bengali cuisine mustard oil or shorsher tel is the predominant cooking medium. Mustard seeds are also essential ingredients in spicy fish dishes like jhaal and paturi.
Raai (Gujarati), Mohari (Marathi: मोहरी ), aavalu (Telugu: ఆవాలు), kadugu (Tamil: கடுகு), or sasive (Kannada:ಸಾಸಿವೆ), kadugu (Malayalam: കടുക്) variety of Indian pickle consisting mainly of mangoes, red chilli powder, and aavaa pindi (powdered mustard seed) preserved in mustard oil, is popular in southern India with its origin in Andhra Pradesh.”
“Mustard seeds generally take three to ten days to germinate if placed under the proper conditions, which include a cold atmosphere and relatively moist soil. Mature mustard plants grow into shrubs.
Mustard grows well in temperate regions. Major producers of mustard seeds include India, Pakistan, Canada, Nepal, Hungary, Great Britain and the United States. Brown and black mustard seeds return higher yields than their yellow counterparts.
In Pakistan, rapeseed-mustard is the second most important source of oil, after cotton. It is cultivated over an area of 307,000 hectares with annual production of 233,000 tonnes and contributes about 17% to the domestic production of edible oil.
Mustard seeds are a rich source of oil and protein. The seed has oil as high as 46-48%, and whole seed meal has 43.6% protein.”
“Mustard seed contains about 20 to 36 % of a nutty, mild mustard oil, 28 % protein and the glycosides sinalbin (white mustard) and sinigrin (brown and black mustard), which are responsible for the spicy taste as well as for stimulating the appetite and digestion.*”
Note (italics): * = Translation from a German Wikipedia entry