Application of chemometric methods in the evaluation of antioxidants activity from degreased chia seeds extracts

Abstract Samples of chia seeds ( Salvia hispanica L.) were degreased by cold pressing and the residue obtained named degreased chia seeds (DCS) had the antioxidants extract obtained. A 2 2 experimental design was employed in order to evaluate the factors ethanol concentration and extraction time. The optimized conditions were extraction time 15 min with ethanol 70% where the activity (RSA), evaluated by the DPPH (2,2-diphenyl-1-picryl-hydrazyl) method was 94.76%. For this extract, the total phenolics content was 359.64 mg EGA/100 g. A pseudo-univariate calibration model is proposed as an alternative methodology to determine the %RSA by using the relative concentration from multivariate curve resolution with alternating least squares (MCR-ALS) from near-infrared (NIR) spectra of the antioxidant extract from DCS. The results suggest the possibility of %RSA determination directly from NIR spectra from extracts from DCS by using the multivariate resolution method MCR-ALS.