Mustard oil can mean either the pressed oil used for cooking, or a pungent essential oil also known as volatile oil of mustard. The essential oil results from grinding mustard seed, mixing the grounds with water, and extracting the resulting volatile oil by distillation. It can also be produced by dry distillation of the seed. Pressed mustard oil is used as cooking oil in some cultures, but sale is restricted in some countries due to high levels of erucic acid. Varieties of mustard seed also exist that are low in erucic acid. Pressed oil Oil makes up about 30% of mustard seeds. It can be produced from black mustard (Brassica nigra), brown mustard (B. juncea), and white mustard (B. alba). Culinary use Having a distinctive pungent taste, the use of the oil is a feature of Bengali and North Indian cooking, as well as Bangladeshi cuisine. It is sometimes used as a substitute for ghee. Chemical composition Its pungent flavor is due to allyl isothiocyanate, a phytochemical of plants in the mustard family, Brassicaceae (for example, cabbage, horseradish or wasabi). Mustard oil has about 60% monounsaturated fatty acids (42% erucic acid and 12% oleic acid); it has about 21% polyunsaturated fats (6% the omega-3 alpha-linolenic acid and 15% the omega-6 linoleic acid), and it has about 12% saturated fats. Potential toxicity Mustard oil has high levels of erucic acid. Erucic acid may have toxic effects on the heart at high doses. An association between the consumption of dietary erucic acid and increased myocardial lipidosis, or heart disease, has not been established for humans, although given what is known about erucic acid, it can be a reason to expect that humans would be susceptible to this. The U.S. Food and Drug Administration prohibits the import or sale of expressed mustard oil in the U.S. for use in cooking due to its high erucic acid content. By contrast, the FDA has classified essential mustard oil, which has a much lower erucic acid content, as generally recognized as safe, and allows its use in food.Mustard and Mustard Oil Safety, National Capital Poison Center] (last accessed January 26, 2023). Expressed mustard oil is permitted in the U.S. as a massage oil, with a required "for external use only" label. Nutritional information According to the USDA, 100 grams of mustard oil contains 884 calories of food energy, and is 100% fat. The fat composition is