## 3 Results and Discussion  
### Process and Olive Oil Extraction Yield  
The impact of applying treatment (PEF) on olive paste in combination with a reduced malaxation stage (30 min) was compared to the standard industrial protocol (control) with longer malaxation times (45 min) for 'Galega Vulgar' fruits at the turning stage. The proposed PEF treatment led to a significant 33% reduction in malaxation time, corresponding to a 9.4% reduction in the overall process time. These results can be important to industrial olive oil production.  
PEF treatment resulted in a slightly higher oil yield (1.7% increase) than the standard industrial protocol (Table 2). Thus, the oil content of the olive pomace obtained after PEF treatment was reduced by about 5.3% compared to the standard industrial protocol. Previous studies using the Spanish, Italian, and other cultivars of olive fruit at a lab scale had beforehand emphasized that PEF could increase the oil yield [6]. However, there is still a challenge in expanding the process that might come from the apparent non-linearity in scalability, optimization of several process factors, or cost involvement.  
Thus, this study was carried out on a pilot scale, and therefore, it is difficult to control the parameters related to the overall process, such as product variability, residence time in each stage, and product losses. However, the significance of these findings lies in their applicability to industrial-scale operations and mass production. Conducting the study on a pilot scale provides valuable insights that closely mirror real-world scenarios, enhancing the relevance and practicality of the results.  
[PERSON] et al. (2022) [9] observed 89.19% extractability using the \"Picholine\" variety, applying PEF treatment at 26 \({}^{\circ}\)C in the same stage of the process with the same time of malaxation in an industrial olive oil plant. [PERSON] et al. 2022 [6], who performed pilot and industrial trials using \"Manzanilla\" and \"Hojiblanca\" cultivars, observed generally higher yields by applying PEF treatment in combination with reduced malaxation time (30 min), with extraction yields ranging between 53.4% and 64.4% in control samples and 56.4% and 72.1% in PEF samples, in terms of oil in olive and oil in pomace. As presented, the extraction yield depends on many variables, from the variety of olives and the state of ripeness at harvest to the production conditions. Therefore, the results must be carefully compared.  
Regarding malaxation temperature, it was observed a slight increase in temperature from 31.2 \({}^{\circ}\)C to 33.4 \({}^{\circ}\)C without significance after PEF treatment of olive paste. However, at the end of malaxation, the temperature decreased to 32.6 \({}^{\circ}\)C, resulting in a minor impact on the process and being non-relevant.  
PEF treatment induces modifications in cell membranes, causing an increase in transmembrane potential, leading to the formation of pores and facilitating mass transfer during extraction processes [22]. The effects caused by PEF may explain the results obtained in this study, in which an increase in extraction efficiency was observed through the application of the treatment. The product processed by PEF achieved the same extraction yield as the control, with a 33% reduction in malaxation time. In the olive oil industry, production efficiency is a crucial factor for the company's profitability. Furthermore, given that the fruit harvest season is very short and the fruit is quite perishable, it is essential to make the most of olive oil extraction, minimizing losses associated with spoilage.