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Effect of rapeseed oil samples NAUKA
preparation
ON ANTIOXIDANT CAPACITY
The response surface methodology (RSM) based on a central compositional plan was used to determine optimum
conditions for extraction of antioxidant compounds from the refined rapeseed oil. Effects of two independent
variables, solvent polarity (dielectric constant = 20.6, 24.6 and 32.6 for acetone, ethanol and methanol, respec-
tively) and the ultrasound frequency-to-sonication time ratio on antioxidant capacity of the obtained extracts
were examined. The antioxidant capacity of rapeseed oil extracts was determined by three analytical methods:
ABTS, DPPH and CUPRAC. The predicted optimum solvent polarity of dielectric constant = 20.6 and ultrasound
frequency-to-sonication time ratio of 0.0 kHz/min resulted in an ABTS = 1760 µmol TE/100 g, DPPH = 305 mol
TE/100 g and CUPRAC = 638 mol TE/100 g, respectively. Therefore, conventional liquid-liquid extraction (LLE)
and acetone can be used for preparation of rapeseed oil to determine its antioxidant capacity.
ANALITYKA – NUMER 1, ROK (XVIII) 2017 33
