Heavy Metals Analysis and Physico-Chemical Properties of Brassica Campestris Seed Oil from Western Rajasthan

Abstract

Brassica campestris is an annual, erect and branched plant of the Brassicaceae family and a significant oil seed crop that plays a vital role in the agricultural sector. It is being consumed in enormous quantities across the world due to its nutritious values. Heavy metals impair crop growth and yield by interfering with other essential nutrients and impeding their uptake in plants. For our study, an industrially contaminated region in western Rajasthan was selected to collect seeds during the rabi season. Brassica campestris seed oil was extracted using an appropriate petroleum ether solvent in a Soxhlet extractor and then digestion of the seed oil was performed. Physicochemical characteristics such as percentage content of oil 39.32%, moisture 4.78%, ash content 3.88%, unsaponifiable matter 0.95%, saponification value 168.35 mg KOH/g, acid value 1.14 mg KOH/g and iodine value 107.27 g of I₂/100g of the seed oil were analysed. An Agilent 4210 MP-AES was used for the analysis of the concentration of heavy metals in the liquid digested Brassica campestris seed oil sample at different wavelengths. The transesterification process was used to prepare FAME and then GC-FID was used to scrutinise the quantitative analysis of the fatty acid methyl ester compositions. Seven major fatty acids were identified in Brassica campestris seeds oil which are erucic acid 45.28%, oleic acid 13.95%, α-linolenic acid 12.46%, linoleic acid 11.20%, eicosenoic acid 6.04%, palmitic acid 4.88% and stearic acid 1.35%. Erucic acid and oleic acid were the predominant fatty acids in it, so it can be utilised in lubricants, surfactants and a healthy human diet, but high and prolonged intakes of erucic acid may have a toxic effect on the heart.