Pulsed electric field treatment improves the oil yield, quality, and antioxidant activity of virgin olive oil

Abstract

Pulsed electric field (PEF) is an innovative technique used to assist in the extraction of vegetable oils. There has been no research on the effects of PEF on virgin olive oil (VOO) quality and antioxidant activity to date. The present study aimed to analyze the effects of PEF on oil yield, quality, and in vitro antioxidant activity of “Koroneiki” extra virgin olive oil. The results show that the PEF treatment increased the oil yield by 5.6%, but had no significant effect on the saponification value, K232, K270, and ∆K value of the VOO. PEF treatment reduced the oleic acid content by 3.12%, but had no significant effect on the content of palmitic acid, linoleic acid, linolenic acid, arachidonic acid, stearic acid, oleic acid, and palmitic acid. After PEF treatment, the levels of total phenolics, total flavonoids, and oleuropein increased by 7.6%, 18.3% and 76%, respectively. There was no significant effect on the levels of 4 phenolic acids (vanillic acid, p-coumaric acid, ferulic acid and cinnamic acid), 2 lignans (lignans and apigenin), hydroxytyrosol, and 3 pigments (lutein, demagnetized chlorophyll, and carotenoids). In addition, PEF treatment significantly increased the content of tocopherols, with α, β, γ, and δ tocopherols increasing by 9.8%, 10.7%, 13.6% and 38.4%, respectively. The free radical scavenging ability of DPPH and ABTS was also improved. In conclusion, the use of PEF significantly increased the yield of VOO oil as well as the levels of total phenolics, total flavonoids, oleuropein, tocopherol, and in vitro antioxidant activity.

Keywords

• Virgin olive oil
• Pulsed electric field
• Oil yield
• Quality
• Antioxidant activity