Mustard is one of the first spices known to humans. Mustard is a common spice used in the United States. All parts of the mustard plant are edible, including seeds, leaves, and flowers. Mustard works well with all types of meats, pork, poultry, and seafood.

Mustard refers to several Brassica species that are valued for their spicy and pungent dried seeds. Black mustard, Brassica nigra, seeds are used in table mustard. Brown mustard, Brassica juncea is also known as Indian mustard, leaf mustard, and mustard greens. Seeds of this mustard species are used for table mustard and leaves are used as salad greens. White mustard, Brassica hirta is cultivated for seeds used in table mustard and leaves used as salad greens. Rape refers to Brassica rapa whose seeds are the source of rapeseed or colza oil, used as industrial lubricating oil and edible salad oil.

Mustard Seed Oil
The pungent taste of mustard seeds results from an oil that is not actually present in the seeds. When mixed with water (or chewed), a chemical reaction occurs between an enzyme and a glucoside from the seeds, resulting in the production of the oil allyl isothiocyanate.

Mustard Seed
Mustard seed actually refers to the seeds of several related species of plants: black mustard seed (brassica nigra), brown mustard seed (brassica juncea), and white mustard seed (brassica hirta or brassica alba). Others categorize it as yellow, brown and oriental.

Mustard Research
Pityriasis rosea-like eruptions due to mustard oil application.
Indian J Dermatol Venereol Leprol. 2005 Jul-Aug;71(4):282-4.
Nashik, Maharashtra, India.
A young man employed in a construction company, presented with cutaneous lesions clinically simulating pityriasis rosea. Satisfactory and complete response to corticosteroids and antihistamines was followed by recurrence. Multiple recurrences within a short span of time arose a suspicion of alternative diagnosis. Site visit helped us to rule out occupational contact dermatitis. Further history taking revealed that he was recently using mustard oil for body massage. Subsequent patch testing confirmed contact hypersensitivity to mustard oil. Avoidance of the contact with mustard oil arrested appearance of further skin lesions.