I suggest you ti read the application of PEF on virgin olive oil:

Abenoza, M., Benito, M., Saldaña, G., Álvarez, I., Raso, J., & Sánchez-Gimeno, A. C. (2013). Effects of pulsed electric field on yield extraction and quality of olive oil. Food and Bioprocess Technology, 6(6), 1367-1373.

or:

Guderjan, M., Töpfl, S., Angersbach, A., & Knorr, D. (2005). Impact of pulsed electric field treatment on the recovery and quality of plant oils. Journal of Food Engineering, 67(3), 281-287.

Guderjan, M., Elez-Martínez, P., & Knorr, D. (2007). Application of pulsed electric fields at oil yield and content of functional food ingredients at the production of rapeseed oil. Innovative food science & emerging technologies, 8(1), 55-62.

Effects of Pulsed Electric Field on Yield Extraction and Quality of Olive Oil

An overview of emerging techniques in virgin olive oil extraction process

Mpact of pulsed electric field treatment on the recovery and quality of plant oils

Application of pulsed electric fields at oil yield and content of functional food ingredients at the production of rapeseed oil

Thanks a lot Maria...maybe we can discuss later...

you may read this (and cross references):

Pulsed electric elds - Influence on physiology, structure and extraction processes of the oleaginous yeast Waltomyces lipofer

vorgelegt von

Diplom-Biologe

Dennis Raschke

Abstract

The main aim of this thesis was the investigation of pulsed electric field (PEF) treatment effects on the oleaginous yeast Waltomyces lipofer. The focus was laid on the application of PEF treatment on the extraction of proteins and fatty acids as well as on the development of suitable processing strategies. The basis for these investigations was provided by experiments aiming on the development of methods for rapid vitality and lipid droplet measurement, media optimization, growth monitoring as well as investigations on the inuence of PEF on the structure and physiology of W.lipofer.

Moreover, alternative processing strategies including the use of ultra sound instead of PEF treatment were applied. Extraction processes were tested, which are sustainable and environmental friendly by using microorganisms, energy saving treatment technologies and an extraction without organic solvents. By using microorganisms, the desired product can be produced in large amounts independent from natural resources, such as fish oils or oil seeds.

Rapid methods for flow cytometry and flow particle image analysis (FPIA) for the monitoring of vitality, cell size and lipid droplet development were successfully developed or adapted. Growth monitoring revealed a maximum optical density of 21.8, a doubling time of 7.1 h, a slightly decreasing vitality, which was always above 96.5%, and a constant accumulation of lipid droplets starting with late exponential phase was determined. Moreover, a correlation between the cell size of W. lipofer, the lipid droplet development, the pH and the growth rate was demonstrated. The influence of PEF on the physiology as well as on extraction processes was analyzed. A critical field strength of 2-3.75 kV/cm was determined. Depending on the treatment conditions a strong impact on vitality, cell size and structural integrity of the yeast cells was observed. At 3.75 kV/cm a constant decrease of vitality and cell size was seen with increasing energy input (1-15 kJ/kg). At a low electric field strength no influence on cell size and vitality was observed, while at a high electric field strength, i.e. 25 kV/cm, even the lowest energy input used, i.e. 1 kJ/kg, led to a maximum decrease of these parameters. The composition of fatty acids remained unchanged after PEF treatment. In both PEF treated and untreated samples, the predominant fatty acids were C16, C18 and C18:1 as well as small amounts of C16:1, C18:2, C18:3, C22 and C24. As far as extraction processes are concerned it was shown, that PEF treatment can be used for the extraction of hydrophilic substances e.g proteins (22.1 % of total protein at 10 kV/cm, 10 kJ/kg) and DNA (70.9 % of total DNA at 5 kV/cm, 10 kJ/kg). Moreover, it was demonstrated that PEF treatment can be used for the mechanical de-watering of cells. The dry weight was increased from 21.7% in untreated IX samples to 26.6% at 5 kV/cm and 15 kJ/kg. The extraction of lipophilic substance using the gentle extraction solvent Miglyol®812 after PEF treatment did not allow significant lipid extraction yields. In these experiments both batch and continuous treatment strategies, varying electric field strength (0-25 kV/cm) and different energy inputs (0-30 kJ/kg) were applied. However, the application of ultra sound treatment instead of PEF led to extraction yields of 29.2% of total lipids at 25 kJ/kg. By applying PEF treatment and subsequent gentle heat drying at 60, it was possible to enhance mechanical de-watering and the drying process. No negative influence of the increased temperature on the fatty acid pattern was seen. Two different options for the integration of PEF treatment into fermentation concepts were tested. As soon as the desired treatment conditions allow high vitalities of the microorganisms after treatment a continuous concept is applicable. It was shown that the cells do not adapt to repeated PEF treatment. In this case the amount of viable cells did not decrease below 63 % after treatment at 1.5 kV/cm and 2.8 kJ/kg every 24 h over a period of 4 days. As soon as the treatment conditions do not allow high vitalities after treatment a semi-contiuous fed-batch approach was tested. The removal of cell suspension from the fermenter and subsequent refilling with fresh media still allowed high cell vitalities above 88%.

Thanks a lot Mr Shanker. Can I get full paper this journal ?

Dear Mr Arie,

The desired article is attached.

Best wishes.