Optimization of water-based ultrasonic-microwave assisted extraction (UMAE) of bioactive compounds from Garcinia mangostana pericarp

Objectives: Garcinia mangostana (GM) pericarp extract recognizes for relieving skin disorders. It becomes a household fruit juice due to its high concentration of antioxidant compounds, including phenolic and α-mangostin. The purpose of this study was to optimize the conditions of Ultrasonic-Microwave Assisted Extraction (UMAE) of GM pericarp.

Methods: GM pericarp was extracted by UMAE and conventional decoction extraction. UMAE was created in nine different individuals and combined ultrasonic and microwave power. The amount of phenolic compound, "caffeic acid, ferulic acid", α-mangostin, and total phenolic content (TPC) were compared. The optimized parameters were particle size of grounded raw material, microwave power, and ultrasonic power during water extraction.

Results: The optimized UMAE conditions combined 200 W microwave power and 200 W ultrasonic power to extract raw material grounded to 22.6 μm diameter particles (p≤0.05). The synergistic effect of ultrasonic and microwave-assisted extraction significantly (p≤0.05) impacted on the TPC, the yield of caffeic acid, ferulic acid, and α-mangostin.

Conclusions: Overall, the synergistic effect of ultrasonic and microwave extraction resulted in a significantly higher amount of bioactive compounds when compared to conventional decoction extraction (p≤0.001). These results demonstrated the advantages of UMAE for preparing GM pericarp extract for the food, cosmetic and pharmaceutical industries.