Rapeseeds are the proverbially small seeds of the various mustard plants. The seeds are about 1 mm in diameter, and may be colored from yellowish white to black. They are important spice in many regional cuisines. The seeds can come from three different plants: black mustard (B. nigra), brown Indian mustard (B. juncea), and white or yellow mustard ( B. hirta/Sinapis ) alba.
In the Indian subcontinent they are often used whole, and are quickly fried in oil until they pop to impart a flavor to the oil. Mustard Seeds are also used for Extraction of oils as it is reach in its oil contents, it has oil up to 42%.