In commercial terms, Extra Virgin Olive Oil (EVOO) is considered an exceptional food with excellent sensory and nutritional quality due to its taste, odor, and bioactive compounds; as such, it is of great health interest. This quality can be affected by the oxidative degradation, both chemical and enzymatic (the activity of oxidative, endogenous enzymes from the polyphenol oxidase and peroxidase olive fruit type), of essential components during the extraction and conservation of EVOO. In the bibliography, oxygen reduction during the malaxation process and oil storage has been studied in different ways. However, research concerning oxygen reduction in the crushing of the olive fruit or the malaxation of the paste, or both, in the “real extraction condition” is scarce. Oxygen reduction has been compared to control conditions (the concentration of atmospheric oxygen (21%)). Batches of 200 kg of the olive fruit, ‘Picual’ cultivar, were used and the following treatments were applied: Control (21% O₂ Mill–21% O₂ Mixer), “IC-NM”: Inerted crushing -Normal malaxation (6.25% O₂ Mill-21% O₂ Mixer), “NC-IM”: Normal crushing-Inerted malaxation (21% O₂ Mill-4.39% O₂ Mixer) and “IC-IM”: Inerted crushing -Inerted malaxation (5.5% O₂ Mill-10.5% O₂ Mixer). The parameters of commercial quality covered by regulation (free acidity, peroxide value and absorbency in ultra-violet (K₂₃₂ and K₂₇₀)) did not suffer any change concerning the control, and so the oils belong to the commercial category of “Extra Virgin Olive Oil”. The phenolic compounds of the olives involved in the distinctive bitter and pungent taste, health properties, and oxidative stability are increased with the downsizing amounts of oxygen in the IC-NM, NC-IM, and IC-IM treatments with an average of 4, 10, and 20%, respectively. In contrast, the total amount of volatile compounds decreases by 10–20% in all oxygen reduction treatments. The volatile compounds arising from the lipoxygenase pathway, which are responsible for the green and fruity notes of EVOO, also decreased in concentration with the treatments by 15–20%. The results show how oxygen reduction in the milling and malaxation stages of olive fruit can modulate the content of phenols, volatile compounds, carotenoids, and chlorophyll pigments in the EVOO to avoid the degradation of the compound with sensorial and nutritional interest.

The influence of altitude on the chemical composition of extra virgin olive oil (EVOO) remains incompletely characterized despite its critical importance for geographical authentication and Protected Designation of Origin (PDO) certification. This study investigated the altitude-driven effects on the fatty acid and triacylglycerol (TAG) profiles of 25 EVOO samples collected across 21 distinct altitudes ranging from 450 to 1045 m above sea level in a mountainous olive-growing region. Chromatographic analyses (GC-FID and HPLC-RID) quantified 37 lipid parameters including 13 individual fatty acids and 24 TAG species. Correlation analysis revealed that higher altitudes were significantly associated with decreased saturated fatty acid (SFA) content (r = −0.417, p = 0.038), increased monounsaturated fatty acid (MUFA) content (r = 0.401, p = 0.047), and an elevated MUFA/polyunsaturated (PUFA) ratio (from 16.3 at 450 m to 22.7 at 1045 m). Palmitoleic acid (C16:1; r = −0.695, p < 0.001) and oleic acid (C18:1; r = 0.434, p = 0.030) exhibited the strongest individual correlations with altitude. Among the TAGs, OOO+PoPP (1,2,3-trioleoylglycerol and 1-palmitoleoyl-2,3-dipalmitoylglycerol; co-eluting fraction) increased with altitude (r = 0.469, p = 0.018), whereas polyunsaturated TAG species decreased significantly. Linear discriminant analysis (LDA) achieved a classification accuracy of 96.0% (24/25 samples correctly classified), with the first two discriminant functions explaining 91.1% of the between-class variance. These findings demonstrate that altitude exerts a systematic and quantifiable effect on EVOO lipid composition, providing an analytical framework for geographical authentication, PDO verification, and quality differentiation of mountain-origin olive oils.

Virgin olive oil (VOO) extraction requires technologies that maximize yield while preserving bioactive compounds and sensory quality. Pulsed electric field (PEF) pretreatment enhances cell membrane permeabilization, facilitating oil release, yet its interaction with malaxation time remains underexplored. This study investigated the synergistic effects of PEF intensity (Low, Mid, High) and malaxation time (15, 30, 60 min at 25 °C) on extraction yield and quality parameters of ‘Picual’ and ‘Arbequina’ virgin olive oils. PEF was applied to olive paste before malaxation. Extraction yield, quality indices (acidity, peroxides, K₂₃₂, K₂₇₀), phenolic content, pigments (chlorophylls, carotenoids), and volatile organic compounds were analyzed. Sensory evaluation was performed by trained panels. Results: Mid-intensity PEF reduced pomace oil content by 33–35% in ‘Picual’ at 30 min malaxation, while ‘Arbequina’ showed limited yield improvements. All oils maintained extra virgin quality standards. PEF increased phenolic content up to 53% in ‘Arbequina’ (Low-intensity, 15–30 min). Pigment concentrations increased with PEF and malaxation duration. LOX-derived volatiles exhibited cultivar-specific responses: Low-intensity PEF reduced C6 aldehydes in ‘Picual’ but enhanced C6 esters (+58%) in ‘Arbequina’. PEF pretreatment optimizes VOO extraction in a cultivar-dependent manner, improving phenolic retention and modulating aroma profiles without compromising extra virgin classification.