Integrated ultrasound-mechanical stirrer technique for extraction of total alkaloid content from Annona muricata

Abstract

Ultrasound-mechanical stirrer assisted extraction (UMSAE) of extraction yield, total alkaloid content (TAC) and antioxidant (DPPH) activity from Annona muricata leaves were optimized using response surface methodology. Five factors were screened using Plackett-Burman Design to investigate the variables that significantly influence the extraction yield, TAC and DPPH activity, namely solvent concentration, extraction time, ultrasound power, plant material to solvent ratio, and extraction temperature. According to statistical significance analysis, solvent concentration, ultrasound power, plant material to solvent ratio, and extraction temperature were selected for further optimization of the UMSAE extraction process using a Central Composite Design. ANOVA results exhibited that the obtained models were significant at 95 % confidence level. Satisfactory extraction yields (26.38 %) and TAC (39.73 mg AE/g) were obtained with relatively short extraction time under the optimum conditions compared with conventional Soxhlet extraction. The extract prepared under UMSAE displayed excellent DPPH activity (93.15 %). The optimized UMSAE promoted considerable yield increases 1.59-fold the yield extract, 2.32-fold TAC, and 1.19-fold antioxidant activity if compared to the Soxhlet extraction. This study provides the ideal integrated UMSAE settings for the maximum recovery of total alkaloid content with high antioxidant activity from A. muricata for possible utilization of their leaves in food applications.