Changes in fatty acids in <i>Brassica juncea</i> L. oil grown under two simulated conditions of fluoride contamination

Rapeseed, the second-most-important vegetable oil source, is cultivated in various areas of India where both groundwater and soil are contaminated with fluoride (F^–). Furthermore, the frequent use of F^– contaminated groundwater for irrigation leads to accumulation of F^– in surface and sub-surface soil. The study aims to compare the morphological and biochemical changes in <i>Brassica juncea</i> L., the variations in its fatty acids (FAs) composition and oil yield, under two regimes of F^– contaminated soils: (i) pre-contaminated soil (Tr) and (ii) irrigation with F^– contaminated water (Ir). The level of F^– (µg g⁻¹) in the plant tissues (root, leaf, and grain) was significantly higher in Ir_10 (18.3, 14.7, and 2.8, respectively) than in Tr_10 (4.3, 2.6, and 0.77, respectively), while the oil yield was significantly lower with Ir_10 (19.5%) than with Tr_10 (44.9%). The phytoremediation potential of F^– by <i>Brassica juncea</i> L. is greater in Tr regime than in the Ir regime. The erucic acid content (%), which is detrimental to cardiac health, increased to 67.37% (Ir_10) and 58.3% (Tr_10) from 57.73% (control). Thus, the present study shows that irrigation with F^– contaminated water results in greater toxicity and accumulation in plants and is not safe for human health. Irrigation with F^– contaminated water results in a greater accumulation of F^– in mustard than cultivated on pre-contaminated soil. The level of erucic acid in mustard oil enhances against F^– exposure.