Brassica (rapeseed-mustard) is the second most important edible oilseed crop in India after groundnut and accounts for nearly 30% of the total oilseeds produced in the country. When compared to other edible oils, the rapeseed mustard oil has the lowest amount of harmful saturated fatty acids. It also contains adequate amounts of the two essential fatty acids, linoleic and linolenic, which are not present in many of the other edible oils. However, it contains high amount of erucic acid (which may cause cardiac problems) and glucosinolates (sulphur compounds present in oil cake which are harmful to animals as feed). Consequently, despite high production, the Indian rapeseed mustard varieties have limited export market as they do not match up to the requisite international standards, namely "Canola" quality, which must have less than 2% erucic acid in the seed oil and less than 30 micromoles of glucosinolate for every gram of oil free cake. Although exotic varieties are available that meet the quality requirements, these varieties were not found suitable to grow under Indian agroclimatic conditions. Moreover, crossing with exotic cultivars is difficult due to incompatibility, poor seed set, seed inviability, etc.
GLC analysis of Indian rapeseed-mustard to study the variability of fatty acid composition
Kaushik N and Agnihotri A. 2000
Biochemical Society Transactions 28(6): pp. 581-583
Rapeseed mustard is one of the economically important oilseed crop in India. Speciality oils having high amounts of a specific fatty acid are of immense importance for both nutritional and industrial purposes. High oleic acid oil has demand in commercial food service applications due to long shelf life and cholesterol lowering properties. Both linoleic and linolenic acids are essential fatty acids, however, less than 3% linolenic acid is preferred for oil stability. High erucic acid is beneficial for polymer industry, while low erucic acid is recommended for edible purposes. Therefore, it is mandatory to undertake systematic characterization of the available genepool for its variable fatty acid profile to be utilized for specific purposes. In the present study the Indian rapeseed-mustard germplasm and some newly developed strains were analyzed by GLC to study the variability of fatty acid composition in these lines. The GLC analysis revealed that the rapeseed mustard varieties being popularly grown in India are characterized by high erucic acid content (30-51%) in the oil having lower levels of oleic acid (10-23%). However, from among the recently developed strains, several lines were identified having high oleic acid (60-70%), moderate to high linoleic (9-38%) and low linolenic acid (4-7%) content. Work is in progress at TERI to utilize these lines for development of strains having particular fatty acid composition for specific purposes.