Optimization of Ultrasonic-Assisted Extraction of Antioxidant Compounds from Starfruit (Averroha carambola L)Leaves

Extracts of starfruit leaves (SL) were used with a response surface methodology (RSM) to optimize experimental conditions for ultrasonic-assisted extraction (UAE). A 33-1 fractional factorial design (extraction-time XET, pulse-cycle XPC and sonication-amplitude XSA) was employed for UAE, and SL extracts were characterized by total soluble polyphenols (TSP) content and antioxidant capacity (1,1-diphenyl-2-picryl-hydrazyl [DPPH],...