This oil has a distinctive pungent taste, characteristic of all plants in the mustard (Brassicaceae) family (for example, cabbage, cauliflower, turnip, radish, horseradish or wasabi). It is often used for cooking in North India, Eastern India, Nepal, Bangladesh and Pakistan. In Bengal, Orissa, Assam, Manipur and Nepal, it is the traditionally preferred oil for cooking. The oil makes up about 30% of the mustard seeds. It can be produced from black mustard (Brassica nigra), brown Indian mustard (B. juncea), and white mustard (B. hirta).
The characteristic pungent flavour of mustard oil is due to allyl isothiocyanate. 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.
Effects on health
Mustard oil has high levels of both alpha-linolenic acid and erucic acid.
Based on studies done on laboratory animals in the early 1970s, erucic acid appears to have toxic effects on the heart at high enough doses. While no negative health effects of any exposure to erucic acid have been documented in humans, publication of those studies led to governments worldwide moving away from oils with high levels of erucic acid, and tolerance levels for human exposure to erucic acid have been established based on the animal studies. Mustard oil is not allowed to be imported or sold in the U.S. for use in cooking, due to its high erucic acid content.
Including oils in the diet that are high in alpha-linolenic acid has been thought to protect the heart and to prevent cardiovascular disease, but recent reviews have cast doubt on this, finding only slightly positive outcomes or even negative outcomes.
Two studies on health effects of mustard oil have been conducted in India, which had conflicting results. One found that mustard oil had no protective effect on the heart, and the authors reckoned that the benefits of alpha-linolenic acid were outweighed by the harm of erucic acid, while another study found that mustard oil had a protective effect, and the authors reckoned that the benefits of alpha-linolenic acid outweighed the harm of erucic acid.
The use of mustard oils in traditional societies for infant massage has been identified by one study as risking damaging skin integrity and permeability. Other studies over larger samples have shown that massaging with mustard oil improved the weight, length, and midarm and midleg circumferences as compared to infants without massage, although sesame oil is a better candidate for this than mustard oil.