Ultrasonic-Assisted extraction of bioactive compounds from hemp seeds: Process optimization, energy efficiency, and antioxidant activity evaluation

Hemp seed extract (HSE) was prepared using ultrasonic-assisted extraction (UAE) in an aqueous medium as a green solvent. The effect of ultrasonication factors including power, time, and temperature, was studied on the energy consumption (EC) of the ultrasonication, extraction yield (EY), antioxidant activity (DPPH free radical scavenging activity), total phenolic content (TPC), and total flavonoid content (TFC) of HSE. The ultrasonication factors showed a significant effect (p < 0.05) on the EC of ultrasonication, EY, TPC, TFC, and DPPH activity of HSE. The ultrasonication process was optimized at minimum EC and maximum TPC, EY, TFC, and DPPH activity of HSE and the ultrasonication power of 385 W for 30 min at 60 °C were obtained as optimum conditions. Moreover, a good association between predicted and experimental values was observed which validated the model. The response values at optimum conditions were 690.9 kj of EC, 13.2 % of EY, 85.4 mg GAE/mL of TPC, 106.1 mg QE/mL of TFC, and 79.4 % of DPPH activity. The thermodynamic analysis of the ultrasonication process revealed the endothermicity and spontaneity of the process. The ultrasonication process significantly improved the extraction of bioactive compounds from hemp seeds which can be beneficial for industrial applications.