It is fairly common to boil the oil to a high temperature, to its smoking point, and let it cool before use in cooking.
A finely blended mustard flavored oil. A pungent oil pressed from the seeds of the Indian mustard plant Brassica juncea, used both as a cooking medium and a hair and skin beautifying treatment in India. Mustard oil, called sarson ka tel in India, has good preserving qualities, so is used for pickles as well as curries. The mustard oil produced in the West is generally milder than the pungent Indian version. Mustard oil is the main cooking oil for centuries in the Eastern and Northern regions of India and in Bangladesh.
The pungent - tasting mustard oil seed qualifies as popular condiment in most parts of the globe. It can also claim a long and distinguished history as a traditional medicine.
Both the seeds and the oil have long been used in poultice, plaster, and other external formulation for upper respiratory tract congestion, joint pain, inflammation, and pain in lower back or lumbar region.
But the FDA requires imported mustard seed oil to be labeled 'for external use only,' so this is the label on this bottle. As the spice expert Gernot Katzer says:
''Because of the erucic acid and maybe also the isothiocyanates, mustard oil is not a legal foodstuff in most western countries, including the EU and the USA, and it must not be sold as a cooking oil. Nevertheless, Indian food shops often sell mustard oil, but to circumvent these paternalistic laws, their mustard oil is labeled ''For external use only''. There is no need to take that remark seriously, although mustard oil does have cosmetic use in India (e.g. as hair balm). In India, it is common to heat mustard oil initially to high temperature, up to the smoking point, and let it then cool down to regular cooking temperature, or even to room temperature, before the cooking proceeds. Although I don't know for sure, this heating procedure might be useful for detoxification (or, mayby, it just improves the taste, as does the toasting of dry spices); in any case, it's a good idea to follow that pracitice.''
Mustard oil serves as a flavoring in many beverages and foods.
According to the USDA database, this is the nutrition for 1 tablespoon of vegetable oil from mustard: Calories, 123; fat, 14g. The fatty acid composition is approximately 8 g monounsaturated, 3 g polyunsaturated, 1.6 saturated. This makes it higher in monounsaturated than corn or soyabean oil. It is similar to canola oil which also has 8 g monounsaturates and just a slightly higher polyunsaturated content (4 g/tsp for canola). It appears to be an oil that would be favorable because of the high monounsaturated fat content.