Effect of Extraction Solvent on Oil and Bioactives Composition of Commercial Indian Niger (Guizotia abyssinica (L.f.) Cass.) Seed

Abstract

Commercially available niger (Guizotia abyssinica (L.f.) Cass.) seed was investigated to evaluate the effect of extraction solvent on oil and bioactives composition. For this purpose, niger seeds were subjected to solvent extraction using solvents of different polarity, viz., hexane, petroleum ether, chloroform, acetone, methanol and ethanol. The oil content of niger seeds obtained after extraction with solvents of different polarities was in the range of 31.8-41.3 g/100 g. The extracted oil was characterized by the following parameters: color (40.0-95.0 Lovibond units), free fatty acids (3.6-12.3 g/100 g), peroxide value (3.2-7.8 mequiv O 2 /kg), iodine value (137.6-140.3 cg I 2 /g), saponification value (177.3-185.9 mg KOH/g) and unsaponifiable matter (1.3-4.3 g/100 g). Among fatty acids, linoleic acid (69.4-73.2 %) was the major fatty acid and trilinolein (31.2-33.4 %) was the major triacylglycerol. The composition of bioactive molecules was 171.9-345.8 ppm of total tocopherols; 247.1-2,647.7 ppm of total phenolics; 1,249.6-6,309.3 ppm of total sterols and 18.9-181.0 ppm of total carotenoids. Among the tocopherols, a-tocopherol was the major component with 154-276 ppm. Of the total phenolics, vanillic acid with 176-1,709 ppm was the major phenolic compound in the oil extracted using different solvents. Ethanol-extracted oil showed a 13.9-fold better oxidative stability and a higher radical scavenging activity (IC 50 value of 9.2 mg/mL) compared to hexane-extracted oil (IC 50 value of 40.3 mg/mL). This is probably the first report of its kind on solvent extractability of bioactives of niger seed.

Impact of Extraction Method on Physicochemical Characteristics and Antioxidant Potential of <i>Adansonia digitata</i> Oil

“…It is known that, n-hexane usually extracts only non-polar lipids and very little polar lipids. Acetone, a renewable organic solvent with a very low boiling point, would be miscible with all oils except palm [30]. Moreover, the results obtained are in agreement with those reported by Mani et al [23] when optimizing the extraction of oil from Moringa oleifera seeds which were 33.47% and 30.33%, respectively with hexane and acetone.…”

“…The quality of the oil extracted with acetone is better than other oils. Indeed, the combination of the peroxide value with the extinction coefficients (k 232 and k 270 ) shows that the oxidative stability of the oil extracted with acetone is relatively better, which could be explained by the presence of natural antioxidants such as tocopherols, sterols, carotenoids and phenolic compounds [30] [44] [61]. Moreover, these results suggest that the oil extracted with acetone would be less oxidized and less sensitive to deterioration than those extracted by pressing or with chloroform and n-hexane.…”

Stability of Cold‐Pressed Oil from Commercial Indian Niger (Guizotia abyssinica (L.f.) Cass.) Seed as affected by Blending and Interesterification

“…This also confirms the theory that the greater the amount of unsaturation, the higher the amounts of natural antioxidants [26,27]. The natural antioxidants content of NSO and CNO agreed well with our previous reports [9,10,16], while the natural antioxidants content of OO agreed well with the literature [25].…”

“…This also showed a direct correlation between the SV and USM of the oils. The FFA, PV, Iv, SV and USM of NSO, CNO and OO agreed well with previous reports in the literature [9,10,16,25].…”

“…The average oil content of niger seed has been reported to be in the range of 40-44 % [1][2][3][4][5][6]. Niger seed oil, like sunflower and safflower oils, contains a high content of omega-6 PUFA (63-75 %) [1][2][3][4][5][6][8][9][10].…”