Chemical Composition of Oil and Cake of Brassica juncea: Implications on Human and Animal Health

Abstract

AbstractOilseed Brassicas have become the third important edible oilseed crop next to soybean and palm in the world. The four main Brassica oilseed species, B. napus, B. rapa, B. juncea and B. carinata are widely cultivated for oil, condiment and vegetable purposes. B. juncea (L.) Czern, commonly referred to as Indian mustard is a major oilseed crop in South Asia, while B. napus and B. rapa are popular in Europe, Canada and Australia. Oil extracted from B. juncea using expeller/kachi ghani has always been favored as cooking oil in India due to its interesting chemical properties. Its oil is a perfect blend of saturated and unsaturated fatty acids along with bioactive components such as phytosterols and tocopherols. The meal or cake left after oil extraction from mustard seeds is rich in minerals, vitamins and high-quality proteins. Despite its nutritional richness, oil and meal of the traditional B. juncea varieties are considered inferior in quality as they contain a very high amount of undesirable long-chain fatty acids, namely erucic acid (C22:1) (40–57%) in oil and deleterious glucosinolates (GLSs) (50–120 µ moles/g) in seed meal. Intake of high erucic acid has been associated with cardiac injury in cattle and experimental rodents, whereas the presence of a high concentration of GLSs with goitrogenic effects limits the use of mustard meal to ruminants only. Based on animal trials, a statutory limit of < 2% erucic acid in oil and < 30 μmoles/g of GLSs in a meal has been set by many countries, initially for rapeseed varieties which have been registered under the trade name of ‘canola’ or ‘00’ quality and is also being implemented for mustard. The quantitative reduction of erucic acid is balanced by the increase in desirable oleic and linoleic acid in the mustard oil. In India, since 90% of the area under rapeseed-mustard is planted with B. juncea varieties, improvement of its oil and meal quality is of prime importance and hence, led to the development of canola or ‘00’ quality B. juncea varieties which have been fairly successful and can be considered excellent for food and feed purpose.KeywordsCanola oilErucic acidFatty acidsGlucosinolatesMustard mealMustard oilTocopherols