Dynamic maceration of Matricaria chamomilla inflorescences: optimal conditions for flavonoids and antioxidant activity

The aim of this paper was to study and optimize the dynamic maceration process to obtain Matricaria chamomilla L., Asteraceae, inflorescences extracts with optimum flavonoid content and antioxidant activity using a multivariate approach. Hydroalcoholic extracts were obtained by dynamic maceration in lab scale and the influence of extraction temperature, ratio of plant to solvent, ethanol strength; extraction time and stirring speed on the flavonoid content and antioxidant activity were unveiled using a fractional factorial design. The ethanol strength, ratio of plant to solvent and temperature were the three factors that influenced most the extract properties and were studied by a central composite design. Total flavonoid content and antioxidant activity were affected by the ethanol strength and ranged from 1.49 to 3.95% and 13.3 to 36.2 μg/ml, respectively. The desirability functions resulted in an optimal dynamic maceration condition using 1 h extraction at stirring speed of 900 rpm, ethanol 74.7%, temperature of 69 °C and using 36.8% of plant in solvent (w/v). Under this set of conditions, the extract had total flavonoid content of 4.11 ± 0.07%, in vitro antioxidant activity with IC50 of 18.19 μg/ml and apigenin and apigenin-7-glycoside contents of 2.0 ± 0.1 mg/g and 20.1 ± 0.9 mg/g, respectively. The results showed a low solvent consumption compared to previous works. The model was able to predict extract properties with maximum deviation of 12% and the extraction process developed herein showed to be reliable, efficient and scalable for M. chamomilla inflorescences, enriched with flavonoids, apigenin and apigenin-7-glycoside and high antioxidant activity.