White mustard (Sinapis alba) is an annual plant of the family Cruciferae. It is sometimes also referred to as Brassica alba or B hirta or yellow mustard. Grown for its seeds, mustard, as fodder crop or as a green manure, it is now wide spread worldwide although it probably originated in the Mediterranean region.
The yellow flowers of the plant produce hairy seed pods, with each pod containing roughly a half dozen seeds. These seeds are harvested just prior to the pods becoming ripe and bursting.
White mustard seeds are hard round seeds, usually around 1 or 2 millimeter in diameter, with a color ranging from beige or yellow to light brown. They can be used whole for pickling or toasted for use in dishes. When ground and mixed with other ingredients, a paste or more standard condiment can be produced.
The seeds contain sinalbin, which is a thioglycoside responsible for their pungent taste. White mustard has fewer volatile oils and the flavor is considered to be milder than that produced by black mustard seeds.
- http://www.maltawildplants.com/CRUC/Sinapis_alba.php Comprehensive profile for Sinapis alba.