The term mustard oil is used for three different oils that are made from mustard seeds:
- A fatty vegetable oil resulting from pressing the seeds,
- An essential oil resulting from grinding the seeds, mixing them with water, and extracting the resulting volatile oil by distillation.
- An oil made by infusing mustard seed extract into another vegetable oil, such as soybean oil
The pungency of mustard oil is due to the presence of allyl isothiocyanate, an activator of the TRPA1 channel