Ultrasound-assisted extraction of bioactive compounds from ciriguela (Spondias purpurea L.) peel: Optimization and comparison with conventional extraction and microwave

The ciriguela (Spondias purpurea L.) residue resulting from its pulp and juice processing stands out due to the high content of bioactive compounds. This study aimed to optimize the ultrasound-assisted extraction (UAE) process of phenolic compounds from ciriguela peel. The response surface method was used to investigate the effects of process-independent variables (ultrasonic amplitude, UA): 20%, 60% and 100%, and ultrasonic exposure time (T): 5, 10 and 15 min on the dependent variables (content of total phenolic compounds (TPC), DPPH - 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (IC50) and ferric reducing-antioxidant power (FRAP) of ciriguela peel extract. The UA and time influenced TPC, IC50 and antioxidant activity by FRAP. However, the antioxidant activity of DPPH had no significant influence on the variables used. Ideal conditions were set at UA = 100% (200 W) and T = 15 min. The extract of phenolic compounds from the ciriguela peel obtained by optimized ultrasound was compared with other extraction techniques (conventional and microwave-assisted). UAE showed better results concerning the extraction yield of phenolic compounds and high antioxidant activity (35.15 mg GAE/g, IC 50 = 0. 19 mg/mL), compared to conventional extraction (30.10 mg GA/g and IC 50 = 1.68 mg/mL) and microwave-assisted (23.31 mg GA/g and IC 50 = 4.29 mg/mL). These results demonstrate the efficacy and better usefulness of the ciriguela residue in obtaining the extracts of bioactive compounds using the ultrasound-assisted extraction technique. (C) 2021 Published by Elsevier B.V. on behalf of King Saud University.