Effects of the Ultrasound-Assisted Leaching Process on the Extraction Rate of Phenolic Compounds, Antioxidant Activity, and Extraction Productivity of Freeze-Dried Pomegranate Biowaste Extract

The Ultrasound-Assisted Leaching Process (UALP) was done through to improve the extraction process and recovery of biophenolic compounds (BPCs) from Dried Pomegranate Biowaste (DPB). In addition, the leaching process was optimized under the operating conditions of temperature (25-85°C), time (20-60 min), and ultrasonic wave amplitude (0-100%) to make the Freeze-Dried Pomegranate Biowaste (FDPB) extract based on the quality indicators of the extraction productivity ratio (TPC/EC50) and Tannin Concentration (TC). Accordingly, the ratio of (TPC/EC50) and the TC value of FDPB increased significantly, under the Conventional Leaching Process (CLP) and operating conditions (55°C and 60 min) to ~1.04 and 20.78 mg CyaE/[g DM], respectively. However, the mentioned parameter increased to ~1.65 and 25.77 mg CyaE/[g DM], respectively, after applying the UALP treatment under similar conditions. Furthermore, the HPLC injections of the FDPB extract indicated that the most abundant compounds isolated from the DPB were p-coumaric acid, Gallic acid, Ellagic acid, and Caffeic acid. Besides, the dominant chemical functional groups were identified by Fourier Transform InfraRed (FT-IR) spectroscopy. Generally, the UALP of BPCs from the FDPB extract used less energy than the one extracted using the CLP.