In Asia, Europe, and America, the brown mustard is grown mainly grown for the extraction of vegetable oil. The oil content of brown mustard varies from 28.6 to 45.7 per cent. However, the oil is high in erucic acid content and is thus not popular in most Western countries. The oil is used as hair oil, lubricant, or used for industrial purposes. Also known as Indian mustard or Rai, this oilseed crop is grown in Asia and Europe for its leaves as well. Leaves are eaten as vegetable – they are shredded, cooked, and served as side dish. Young tender leaves, called ‘mustard greens’ are used in salads or used in pickles. Interestingly, brown mustard oil is used to retard the fermentation process when making apple cider. The seeds of brown mustard are used as condiment; they are also used in birdseed mixtures. The seed meal is very high in protein content, but it cannot be used for human consumption because of high glucosinolate content.
Botanical name: Brassica juncea
English name: Brown mustard, Indian mustard
Hindi name: Rai, Sarashapa
Rayi is a glabrous annual herb with a few bristles at the base with long, erect or patent branches.
Leaves: lower leaves petioled, green, sometimes with a whitish bloom, ovate to obovate, variously lobed with toothed, scalloped or frilled edges, with 1–2 lobes or leaflets on each side, upper leaves subentire, short petioled.
Flowers: yellow in racemes.
Fruits: linear silique, often constricted between the seeds, with a conical beak usually longer than 6 mm, dehiscent, up to 20-seeded.
Seeds: globose, 1–1.5 mm in diameter, finely reticulate, pale to dark brown.
Parts used as medicine: Seeds and oil.
Rai is bitter and pungent in taste with a hot potency. It is acrid, thermogenic, anti-inflammatory, carminative, digestive, and tonic in quality and is recommended in vitiated conditions of Vata and Kapha, malarial fevers, colic pain, anorexia, dyspepsia, intestinal worms, flatulence, inflammations, sin diseases, spleen and liver diseases and persistent vomiting.
Ayurveda recommends application of B. juncea oil for chest affections in children.
In Indian traditional medicine, the oil is used with camphor as an effective combination for rheumatic pain and swellings.
In Ayurveda, mustard seed powder is used as emetic in poison and other stomach disorders.
In Ayurveda, the mustard leaf is applied externally to combat glandular swellings in conditions such as elephantiasis.
It is a folk remedy for arthritis, foot ache, and rheumatism.
The seed is used in Chinese medicine to treat tumor, lumbago, and stomach disorders.
In China, the leaves are eaten in soups for inflammations or hemorrhages.
In Africa, the root is used as galactagogue.
Side effects: No well documented contraindications. Patients hypersensitive to mustard need to avoid its use. Topical application of mustard oil may induce skin inflammation. Injection into joints may induce allodynia, hyperalgesia, and neuroinflammation.