Effect of ultrasound, microwave, and enzymatically pre-treated Terminalia chebula pulp on extraction of bioactive compounds using supercritical CO2

Terminalia chebula fruit pulp was subjected to three different pre-treatments viz. microwave (360 and 720W), ultrasound (50 and 100% amplitude) and cellulase (200 and 400U) and their combinations then subjecting the best pre-treated pulp to supercritical CO2 (ScCO2) for extraction of bioactive compounds. It was observed that ultrasound at 50% amplitude, microwave at 360 Watts, and enzyme with 400 Unit resulted in maximum yield bioactive compounds for the different pre-treatments. The selected levels of the pre-treatments were now evaluated for combined treatment. In the combined pre-treatment, microwave-assisted ultrasound extraction resulted in maximum extraction of bioactive compounds. The total phenolic compounds (TPC), total flavonoid content (TFC), and antioxidant capacity (DPPH) were found to be 346.05 mg GAE/g, 116.93 mg QE/g and 91.57% respectively. This best pre-treated pulp was then subjected to ScCO2 extraction, which further increased the recovery. The final extract was characterized and analysed using LC-MS.