Juthaporn Ponphaiboon, Wantanwa Krongrawa, Sontaya Limmatvapirat, Chutima Limmatvapirat
This study optimized ultrasound-assisted extraction (UAE) conditions to maximize bioactive compounds from Momordica charantia L. (Okinawan bitter melon) fruit using response surface methodology (RSM). A three-factor, three-level Box-Behnken design assessed the effects of acoustic intensity, duty cycle, and extraction time on extraction yield, total phenolic content (TPC), antioxidant activity (DPPH and FRAP assays), α-glucosidase inhibitory activity, and charantin content. Acoustic intensity had the greatest impact, followed by duty cycle and extraction time. The optimal conditions were 85 W·cm −2 acoustic intensity, 0.83 s −1 duty cycle, and 13.20 min extraction time, yielding 35.80 % extract, 847.91 mg GAE/100 g extract TPC, IC 50 of DPPH at 119.08 µg/mL, FRAP value of 148.76 mg AAE/g extract, α-glucosidase inhibition of 41.60 mg acarbose/g extract, and charantin content of 5.83 mg/g extract. Experimental values closely matched predictions, confirming model validity. This optimized UAE method provides an efficient approach for extracting bioactive compounds from M. charantia L., ensuring high yield and biological activity. The findings offer valuable insights for industrial-scale extraction and potential applications in functional foods, pharmaceuticals, and nutraceuticals.