Optimization of high-intensity pulsed electric field-assisted extraction of procyanidins from Vitis amurensis seeds using response surface methodology

Abstract

Procyanidins (PC) from Vitis amurensis seeds was extracted using high-intensity pulsed electric field (PEF). The process parameters including pulse number, electric field strength, ratio of material to liquid and ethanol concentration were studied using response surface methodology, and extraction yield of the extracts were determined. Antioxidant activity of the extracts by PEF, ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and ethanol extraction (EAE) were compared based on total antioxidant capacity, DPPH radical scavenging capacity and ferrous ion chelating activity. The results revealed that the optimization of conditions of PEF are: pulse number 10; electric field strength 25 kV/cm; ratio of material to liquid 1:21 g/mL; ethanol concentration 63% (v/v), and the PC yields reached 8.23% under this condition. The PEF resulted in a highest extraction yield of PC among the four extraction methods. There was no significant difference in total antioxidant capacity of PC obtained by four methods, the DPPH radical scavenging capacity and ferrous ion chelating activity of PC extracted by PEF were close to that of UAE and MAE, which were superior to EAE. These showed that PEF was an effective method for extracting PC.