Optimization of extraction parameters of bioactive components from defatted marigold (Tagetes erecta L.) residue using response surface methodology

Response surface methodology (RSM) was used to estimate the optimum extraction parameters, in which the antioxidant activity (AA) of the extract from the defatted marigold residue was the strongest. The AA of marigold extracts was investigated by the radical scavenging activity assays ((2,2-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)). Results demonstrated that AA was significantly affected by the content of total. phenolics (TP) and total flavonoids (TFA) (p<0.0001). The optimal extraction parameters of marigold extracts for the highest AA by ABTS method were ethanol concentration of 79.7%, extraction temperature of 74.2 degrees C and time of 8.1 h, and by DPPH assay with 89.3% of ethanol concentration at 81.5 degrees C for 11.1 h, AA values were 2.42 and 1.86 mmol TE/g, respectively. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.