Preparation of Antioxidant Concentrates from Edible Vegetable Oilseed Cakes and Estimation of their Antioxidant Activity using DPPH.

Since there is a growing interest to replace the
synthetic antioxidants in foods and vegetable oils by
natural counterparts, oilseed cakes like sesame, flax,
niger, groundnut, mustard and sunflower seed cakes
were utilized to isolate natural antioxidant concentrates
for this purpose. The above oilseed cakes were
totally defatted and subjected for methanol extraction
to yield 3.1, B.8, 6.1, 7.5, 14.3 and 9.6% of antioxidant
concentrate respectively. Screening of these
concentrates using UV-visible spectra and FT-IR
frequencies revealed the presence of lignan,
glucosides, tocopherols and carotenoids. Sesame
and niger seed cake concentrates contained sesamo!
up to 18,463 and 17,680 ppm respectively. Whereas
polyphenol was found to be ranging between 5.8 to
32.3% among alt the concentrates. The antioxidant
activity of these concentrates were studied using 2,2·
diphenyl·l·picrythydrazyl radical (DPPH). The percent
antiradical activity and ICSO (mg) value were in the
decreasing order for sesame (65.4, 0.045), sunflower
(52.9, 0.094), niger seed (44.4, 0.11), groundnut (39.5,
0.13), mustard (19.1, 0.16) and flax (13.3, 0.19) seed
cake concentrates respectively. Study showed that
sesame cake concentrate was most potent and
flaxseed cake concentrate was least potent. Sesame
cake concentrate was better than BHt Hence,
sesame-sunflower and niger seed cake concentrates
can be used to replace synthetic antioxidant up to a
larger extent.