Extra-Virgin Olive Oil Extracted Using Pulsed Electric Field Technology: Cultivar Impact on Oil Yield and Quality.

Gianluca Veneziani,Roberto Selvaggini,Mauro Pagano,Roberto Tomasone,Agnese Taticchi,Luigi Daidone,Antonietta Lorefice,Beatrice Sordini,Sonia Esposto,Maurizio Servili

doi:10.3389/fnut.2019.00134

Gianluca Veneziani, Roberto Selvaggini + Show 8 more

Open Access

https://doi.org/10.3389/fnut.2019.00134

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Abstract

The main operators of the olive oil sector are continuously involved in the development of the olive oil mechanical extraction process with the common aim of increasing both the quality and the oil extraction yield coupled with the potential enhancement of the working efficiency of the olive mill. The pulsed electric field (PEF) is a recently studied technological innovation for the improvement of olive oil extraction technology. The impact of the PEF on the diffusion of oil and microconstituents, determined by the disruption effects on olive cell tissues carried out by the non-thermal method, was evaluated. A PEF can increase the permeability and breaking of the cell membranes with a consequent positive result on oil extractability and quality, mainly related to the compounds involved in the health and sensory properties of extra virgin olive oil. The PEF was tested on three Italian olive cultivars (Carolea, Coratina, and Ottobratica). The results showed a positive impact of the new technology on the oil yield, with an increase ranging from 2.3 to 6%, and on the concentration of hydrophilic phenols, with an increase ranging from 3.2 to 14.3%, with respect to the control tests. The data of the main compounds related to the health and sensory notes also showed high variability as a consequence of the genetic origins of the olive cultivars.

Highlights

The technological evolution of the olive oil mechanical extraction process in recent decades has been mainly based on the improvement of extra-virgin olive oil (EVOO) quality, which is strictly connected with compounds characterized by their health and sensory properties
A pulsed electric field (PEF) system was applied to the olive oil mechanical extraction process to evaluate its technological performance on the oil extractability and its impact on the main quality parameters of EVOO
The EVOOs obtained from the PEF-assisted extraction showed an increase in the oil yield for all of the processed cultivars, indicating the efficient degradation of the olive tissues to guarantee an improvement in the oil extractability of the mechanical extraction plant

Summary

Introduction

The technological evolution of the olive oil mechanical extraction process in recent decades has been mainly based on the improvement of extra-virgin olive oil (EVOO) quality, which is strictly connected with compounds characterized by their health and sensory properties (phenolic and volatile compounds). The application of the PEF system to the virgin olive oil extraction process, and to the valorization opportunities of by-product [26, 27], is still very limited, and there are only a few preliminary studies concerning its effects on oil yield and quality Both Abenoza et al [10] and Puértolas and Martínez de Marañón [14] analyzed the impact of the new technology on the oil extractability and chemical and sensory parameters by processing Arbequina and Arroniz olives and carrying out PEF treatment on the olive pastes before and after the malaxation phase, respectively. The nonthermal treatment resulted in an increase in the oil extraction yield and an improvement in the VOO quality related to the enhancement of the polyphenol, phytosterol and tocopherol contents Both studies highlighted the need for further research to evaluate the influences of external factors, such as the cultivar, maturity index, temperature, and other process parameters, on the performance of PEF applied to the olive oil mechanical extraction system

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