Response surface methodology optimization of α-mangostin extraction using betaine-1,2-propanediol deep eutectic solvent

Mangosteen pericarp contains α-mangostin, the most abundant xanthone that is useful as an antioxidant. Deep eutectic solvent (DES) was used in this study as a green solvent for extraction of α-mangostin. Our previous study shows that a DES, consisting of betaine as the hydrogen bond acceptor and 1,2-propanediol as the hydrogen bond donor, having the highest extraction yields compared to other betain-based DESs. In this study, the operating condition of the solvent extraction process has been optimized using the response surface methodology approach, based on the Box-Behnken design. The highest calculated α-mangostin extraction yield obtained was 4.2% (w/w), corresponding to an extraction temperature of 56.5 °C, mangosteen powder to DES mass ratio of 0.12, and extraction time of 6.9 hours. The optimum temperature was found to be the combined effect of enhanced leaching of the mangosteen pericarp matrix by the DES and α-mangostin degradation at higher temperatures.