Extraction of biologically active compounds from Aronia melanocarpa: Comparison of techniques and multiple response optimization

The presented paper deals with the selection of most efficient extraction method for obtaining biologically active compounds (mainly antioxidants) from the black chokeberry (Aronia melanocarpa) fruits. Two conventional methods (maceration and Soxhlet extraction) as well as a more recent accelerated solvent extraction (ASE) were employed. The extracts were evaluated by means of their overall yield, antioxidant activity (TEAC assay), total phenolic content (TPC), ascorbic acid (AA), and malic acid (MA) content. Both Soxhlet extraction and ASE led to the highest overall yields (42 %) of the extract; however, in terms of TEAC and TPC, the extracts obtained by ASE were usually superior. The highest TEAC value (227.7 mg TE/g) as well as the highest TPC (67.9 mg GAE/g) were obtained by ASE using 40 % (v/v) ethanol at 140 degree celsius after 30 min. The ASE method was further analyzed using a 23-factorial design where the effect of temperature (40-140 degree celsius), extraction time (5-30 min), and solvent composition (40-96 % ethanol) was investigated. While temperature and solvent composition significantly affected the extract properties, the effect of extraction time was small or even insignificant. The regression model obtained from ANOVA was further used for multiresponse optimization of ASE conditions using the global desirability function as a criterion for overall extract quality.