Green extraction of silymarin from Milk thistle seeds and its encapsulation using the spray drying method

Silymarin was extracted from milk thistle seeds of Silybum marianum L. Gaertn through green extraction. Aiming at reducing energy power consumption by using renewable plant sources and environmentally friendly bio-solvents. A comparison study of extract yield, silymarin content and antioxidant activity of various extraction methods was studied. Green extraction was performed using two different polarities solvents (ethanol and ethyl acetate) using maceration extraction (ME) and the ultrasound-assisted extraction (UAE) method. The antioxidant activities of the resultant extracts were measured using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods. The highest yeiled, antioxidant activities (306.40 and 137.014 μM Trolox eq./mg for DPPH and ABTS, respectively) and silymarin content were found using ethanol solvent and UAE method compared to ethyl acetate and ME methods.Encapsulation was applied using the spray drying method using different ratio of Maltodextrin (MD) and Gum Arabic (GA). The results showed that by increasing the percentage of gum arabic, the size of the particles decreased but the encapsulation efficiency was increased to reach the maximum of 84.45% at 20:80, MD: GA. The results also indicated that the incorporation of MD and GA improved the encapsulation process, which agreed with the encapsulation efficiency.