Search Results (149)

The large and hard olive pit adversely affects oil quality during traditional crushing, as seed- and pit-derived enzymes modify phenolic profiles and volatile compounds. Polyploid breeding offers a potential means to reduce pit size and improve processing traits, yet cultivated olive (Olea europaea L. subsp. europaea) is a strictly diploid species, and natural polyploids have not been previously documented. To evaluate the potential of triploids in olive improvement, we screened seed-derived progeny from multiple cultivars for polyploidy using flow cytometry and chromosome observation. One naturally occurring triploid seedling (‘Olive-3x’) was identified from a mixed lot of open-pollinated seeds. Whole-genome resequencing was used to develop 64 polymorphic InDel markers, and three markers indicated ‘Koroneiki’ as one putative parent of the triploid. Morphological and cytological analyses showed that the triploid exhibited typical polyploid characteristics, including thicker leaves and enlarged epidermal and palisade mesophyll cells compared with diploid controls. These findings provide the first evidence of a naturally occurring triploid in cultivated olive and show that triploids can arise within seed-derived progeny. The identified triploid plant and the developed markers offer useful resources for future studies on olive polyploidy and provide foundational resources for future research on olive polyploidy and cultivar improvement. Full article

Olive (Olea europaea L.) cultivars often exhibit genotype-specific responses to micronutrient management. In this study, we investigated the metabolic leaf fingerprinting of three cultivars ‘Rošinjola’, ‘Leccino’, and ‘Istarska bjelica’ at two sampling periods (SP-I = 64 days after treatment (DAT) and SP-II = 118 DAT), following boron foliar fertilisation (+B = 41.62 mM B; −B = 0 mM B) applied 50 days after anthesis. To our knowledge, this is the first study to provide such a detailed evaluation of boron-induced shifts in phenolic metabolism in olive leaves. At harvest (SP-II), all three cultivars showed higher concentrations of total identified phenolic compounds in +B plants compared with the −B controls. Notably, the concentration of verbascoside at harvest was higher in +B plants of ‘Istarska bjelica’ and ‘Leccino’, but not in ‘Rošinjola’. Oleuropein content increased in +B plants at harvest to a level higher than 4870 mg/100 g DW, irrespective of cultivar. Conversely, apigenin-7-glucoside declined from SP-I to SP-II in ‘Leccino’ regardless of treatment, whereas in ‘Istarska bjelica’, this decrease occurred only in control plants, with boron preventing the seasonal decline. These findings confirm the prolonged effect of boron foliar fertilisation on phenolic metabolism in olive leaves and highlight cultivar-specific differences in metabolic responses. Further research is needed to clarify how these metabolic shifts relate to primary plant metabolism and how they influence olive oil quality traits among cultivars grown under Croatian conditions. Full article

The Olea europaea L., commonly known as the European olive, has been recognized for centuries as one of the most valuable species among useful plants. In contemporary applications, the olive tree provides a wide array of raw materials utilized in the food, pharmaceutical, and nutraceutical industries. Extracts derived from the leaves, bark, and fruits of O. europaea have also gained significant relevance in dermatological and cosmetic formulations. The aim of this paper was to review scientific studies published between 2019 and 2025 concerning the application of olive oil and other derivatives of the European olive in the care of skin, hair, and nails. The analysis underscores the role of olive-derived bioactives in wound healing, stretch mark management, and skin regeneration, highlighting compounds such as oleocanthal and oleuropein in hydration, elasticity, wrinkle reduction, and photoprotection relevant to skin aging. The evidence for olive oil in hair and nail care mainly highlights their moisturizing and strengthening effects, though studies remain limited. O. europaea derivatives show a favorable safety profile with low allergenic potential, and their availability and minimal sensitization risk support use in home cosmetics. The importance of the European olive and its products is expected to grow in the coming years. However, the availability of technologies for processing waste materials obtained from this plant, as well as the associated technological costs, remain significant limitations. Full article

Olive (Olea europaea L.) is an important woody oil crop worldwide, and accurate estimation of leaf chlorophyll content is critical for assessing nutritional status, photosynthetic capacity, and precision crop management. Unmanned aerial vehicle (UAV) remote sensing, with high spatiotemporal resolution, has increasingly been applied in crop growth monitoring. However, the small, thick, waxy leaves of olive, together with its complex canopy structure and dense arrangement, may reduce estimation accuracy. To identify sensitive features related to olive leaf chlorophyll and to evaluate the feasibility of UAV-based estimation methods for olive trees with complex canopy structures, UAV multispectral orthophotos were acquired, and leaf chlorophyll was measured using a SPAD (Soil Plant Analysis Development) meter to provide ground-truth data. A dataset including single-band reflectance, vegetation indices, and texture features was built, and sensitive variables were identified by Pearson correlation. Modeling was performed with linear regression (LR), Random Forest (RF), Extreme Gradient Boosting (XGBoost), Partial Least Squares Regression (PLSR), and Support Vector Machine (SVM). Results showed that two spectral bands (green and red), one vegetation index (TCARI/OSAVI), and twelve texture features correlated strongly with SPAD values. Among the machine learning models, XGBoost achieved the highest accuracy, demonstrating the effectiveness of integrating multi-feature UAV data for complex olive canopies. This study demonstrates that combining reflectance, vegetation indices, and texture features within the XGBoost model enables reliable chlorophyll estimation for olive canopies, highlighting the potential of UAV-based multispectral approaches for precision monitoring and providing a foundation for applications in other woody crops with complex canopy structures. Full article

Increasing the tocopherol content in plant-derived foods not only improves their nutritional quality but may also enhance plant resilience against abiotic stress factors. Tyrosine catabolism is the origin of homogentisic acid, which constitutes the core aromatic ring in the structure of tocopherols. Two olive tyrosine aminotransferase genes, OeTAT1 and OeTAT2, have been cloned, and the corresponding recombinant proteins have been functionally validated. Both proteins showed significant differences in substrate specificity and catalytic efficiency. OeTAT1 protein exhibited a marked substrate preference for tyrosine (K_m 0.57 mM and V_max of 47.61 U mg⁻¹), forming 4-hydroxyphenyl pyruvic acid, which is the direct precursor of homogentisic acid. On the contrary, OeTAT2, with significantly lower catalytic activity, displayed broad substrate specificity and was less efficient with tyrosine (K_m 6.80 mM and V_max 5.72 U mg⁻¹). The expression analysis of OeTAT1 and OeTAT2 during the development and ripening of fruits in seven olive cultivars, as well as in olive trees grown under water stress, suggests different roles for both genes. The data suggest that OeTAT1 seems to play a key role in tocopherol biosynthesis during olive fruit development, while OeTAT2 may be more closely associated with other metabolic pathways unrelated to tocopherol biosynthesis. Furthermore, both genes were found to be upregulated under water stress conditions in olive. Full article

Background/Objectives: Olive leaf (Olea europaea L.), a by-product of olive oil production, is rich in bioactive phenolics but limited in application due to poor solubility and stability. To improve their bioavailability, this study presents a comparative encapsulation strategy using three phospholipid-based liposomal systems (AL, PG90, and PH90) loaded with ethanolic olive leaf extract. Methods: Liposomes were characterized by physicochemical parameters, encapsulation efficiency (EE), antioxidant activity, morphology, release kinetics under simulated physiological conditions, and 60-day stability. To the best of our knowledge, this is the first direct comparison of AL, PG90, and PH90 matrices for olive leaf extract encapsulation. Results: HPLC and GC-MS confirmed successful encapsulation, with oleuropein showing the highest EE (up to 76.18%). PH90 favored retention of non-polar triterpenes, while AL and PG90 preferentially encapsulated polar flavonoid glycosides. FT-IR analysis verified extract integration into phospholipid bilayers. Antioxidant activity remained high in all loaded formulations, with negligible activity in empty liposomes. Extract-loaded systems exhibited reduced particle size, higher viscosity, and more negative electrophoretic mobility, enhancing colloidal stability. PG90 liposomes displayed the most stable mobility profile over 60 days. Transmission electron microscopy and nanoparticle tracking analysis revealed formulation-dependent vesicle morphology and concentration profiles. Release studies demonstrated significantly prolonged polyphenol diffusion from PG90 liposomes compared to the free extract. Conclusions: Phospholipid composition critically governs encapsulation selectivity, stability, and release behavior. Tailored liposomal systems offer a promising strategy to enhance the stability and delivery of olive leaf polyphenols, supporting their application in bioactive delivery platforms. Full article

The olive tree has exceptional agricultural and economic importance in Mediterranean regions due to its fruit, which is used to produce olive oil. However, the olive oil industry generates a significant amount of waste, including leaves from Olea europaea L. These leaves contain a high concentration of bioactive compounds, predominantly phenolic ones, which are well known for their antioxidant properties and health benefits. Determining antioxidant capacity involves the use of different assays based on absorbance (DPPH, 2,2-diphenyl-1-picrylhydrazyl; and ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and fluorescence (ORAC, Oxygen Radical Absorbance Capacity), which require reagents and long waiting times. Therefore, having a non-destructive technique capable of providing this information would be useful. To explore this, 120 olive leaf samples were analyzed using the three antioxidant assays to quantify their total antioxidant capacity. Predictive models were successfully developed for each of the three methods, achieving coefficients of determination (R²) between 0.9 and 1 across calibration, validation, and prediction. Additionally, high residual predictive deviation (RPD) values were obtained, indicating that the models exhibit strong reliability and predictive performance. Full article

The olive tree (Olea europaea L.) has been cultivated for millennia, with olive oil representing both a cornerstone of the Mediterranean diet and a major agricultural commodity. Its composition, rich in monounsaturated fatty acids, polyphenols, tocopherols and squalene, supports well-documented cardioprotective, antioxidant and anti-inflammatory benefits. Olive oil production generates substantial secondary streams, including pomace, leaves, pits and mill wastewater, which are rich in phenols, triterpenes and fibers. This review consolidates recent advances in their phytochemical characterization, innovative extraction technologies and health-promoting effects, while highlighting the economic and regulatory prospects for industrial adoption. Comparative analysis shows that olive leaves can produce up to 16,674.0–50,594.3 mg/kg total phenolics; oleuropein 4570.0–27,547.7 mg/kg, pomace retains 2.24 g GAE/100 g dried matrix (DM)total phenolics; oil 13.66% DM; protein 6.64% DM, and wastewater contains high concentration of phenolics content of olives. Innovative extraction techniques, such as ultrasound and microwave-assisted methods, allow for a recovery, while reducing solvent use and energy input. The analysis highlights opportunities for integrating these by-products into circular bioeconomy models, supporting the development of functional foods, nutraceutical applications and sustainable waste management. Future research should address techno-economic feasibility, regulatory harmonization and large-scale clinical validation to accelerate market translation. Full article

Climate change poses serious challenges to Mediterranean crops such as the olive tree (Olea europaea L. subsp. europaea), underscoring the need for cultivars with improved drought tolerance and disease resistance. This study investigates variability in leaf and wood traits among Moroccan and introduced olive cultivars and their crossbreed genotypes grown under similar conditions. Specifically, we assessed (1) variation in key functional traits, (2) the effects of crossbreeding combinations, and (3) trait syndromes shaped by selection. Results showed substantial intraspecific variation in leaf traits, including specific leaf area (SLA), specific leaf water content (SLWC), stomatal size (SS), and density (SD), indicating diverse strategies for resource use and plasticity. Crossbreed genotypes generally displayed higher SLWC and lower SLA, reflecting adaptation to water stress. Wood traits, particularly vessel size (SVS) and number (NVS), also varied, revealing trade-offs between hydraulic efficiency and safety. Notably, an increase in vessel size and hydraulic conductivity was correlated with oil content (OC%), while OC% increased with higher vessel and stomatal densities. Larger stomata increased conductance and fruit growth, while lower SLA was linked to higher yield. Multivariate analysis distinguished two genotype groups, consistent with parental combinations. Overall, crossbreeding generated novel functional diversity that may enhance adaptive potential. These findings highlight the value of integrating functional and anatomical traits into olive breeding programs to improve resilience and productivity under climate change. Full article

Olive leaves (Olea europaea) are the most abundant agricultural by-product of olive tree cultivation, generating substantial waste each year. Their disposal is deemed an environmental challenge, particularly in Mediterranean countries that dominate the olive oil sector, yet their rich bioactive profile makes them promising candidates for functional food development. This study aimed to determine the total antioxidant capacity (TAC) and total phenolic content (TPC) of olive leaf powder extracts using different extraction solvents and methods to identify the most efficient strategy for possible incorporation into functional food systems. Extractions were performed with distilled water, 70% ethanol, 80% methanol, and 50% acetone using three methods: stirring, soaking, and ultrasound-assisted extraction (UAE). TAC and TPC were quantified using the FRAP and Folin–Ciocalteu assays, respectively. Among solvents, acetone consistently yielded the highest values across most methods (TAC: 19.02 mmol Fe²⁺/L, TPC: 1289.95 mg GA/L), while ethanol also showed strong extraction performance (TAC: 15.35 mmol Fe²⁺/L; TPC: 1214.76 mg GA/L), offering a safer and more scalable option for food applications. Method-wise, UAE achieved the greatest phenolic recovery, while both UAE and stirring proved effective for antioxidant extraction. Overall, these findings provide quantitative evidence supporting possible incorporation of olive leaf powder as a valuable ingredient in functional foods and other sustainable applications, while also contributing to the circular economy through the sustainable valorization of agricultural waste. Full article

Olive (Olea europaea) leaves, a by-product of olive oil production, represent a promising source of bioactive peptides. In this study, the peptidome of an olive leaf protein hydrolysate (OLPH) obtained via enzymatic hydrolysis with Alcalase was identified and analyzed for the first time. Liquid Chromatography coupled to Trapped Ion Mobility Spectrometry and Tandem Mass Spectrometry (LC-TIMS-MS/MS) analysis revealed over 7000 peptide sequences. Peptides with PeptideRanker scores above 0.79 were selected for in silico evaluation of antimicrobial potential, including physicochemical characterization and molecular docking. Several peptides—such as NYPAWGY, SSKGSLGGGF, QWDQGYF, and SGPAFNAGR—exhibited strong predicted antimicrobial potential, supported by favorable interactions with bacterial, viral, and fungal targets in docking simulations. Correlation analysis revealed that physicochemical features, such as net hydrogen, amphipathicity, and isoelectric point, were positively associated with predicted antimicrobial activity. These findings highlight the potential of olive leaf-derived peptides as natural antimicrobial agents and support the valorization of olive by-products as a sustainable source of functional ingredients for applications in food safety and health. Further experimental validation is needed to confirm the efficacy and mechanism of action of the identified peptides. Full article

Increasing the shelf-life of fruits and vegetables using edible natural substances after harvest is economically important and can be useful for human health. Postharvest techniques help maintain the quality of edible tissues resulting in extended marketing periods and reduced food waste. The edible coating on perishable commodities is a common technique used by the food industry during the postharvest supply chain. The objective of this research was to study the effect of edible oil to minimize the loss of postharvest physio-chemical and nutritional attributes of bananas. The study selected two banana cultivars (Musa, ‘Cavendish’ and ‘Milk’) to conduct this experiment, and two edible oils (olive oil (Olea europaea) and moringa oil (Moringa peregrina)) were applied as an edible coating under two different storage conditions (15 and 25 °C). The fruit’s physio-chemical properties including weight loss, firmness, color, total soluble solids (TSS), pH, titratable acidity (TA), TSS: TA ratio, and mineral content were assessed. The experiment lasted for 12 days. The physicochemical properties of the banana coated with olive and moringa oils were more controlled than the non-coated (control) banana under both storage temperatures (15 °C and 25 °C). Coated bananas with olive and moringa oils stored at 15 °C resulted in further inhibition in the ripening process. There was a decrease in weight loss, retained color, and firmness, and the changes in chemical parameters were slower in banana fruits during storage in the olive and moringa oil-coated bananas. Minerals were highly retained in coated Cavendish bananas. Overall, the coated samples visually maintained acceptable quality until the final day of storage. Our results indicated that olive and moringa oils in this study have the potential to extend the shelf-life and improve the physico-chemical quality of banana fruits. Full article

The paper describes the application of mono-dimensional high-resolution nuclear magnetic resonance (NMR) spectroscopy to extra virgin olive oil (EVOO) samples to extract the chemical composition reasonably featured by specific genotype (cultivar) and detailed environmental conditions (terroir). To achieve this goal, we designed a suitable spectroscopic protocol made up of four NMR experiments: (I) standard ¹H{¹³C}, (II) multiple pre-saturated ¹H{¹³C}, (III) ¹H selective excitation at 9.25 ppm, and (IV) ¹³C{¹H} acquisition. The three ¹H-NMR experiments (I–III) were merged into a single informative ¹H-NMR trace. This “Restored Intensities from Customized Crops” (RICC-NMR) allowed us to extract, in just one ¹H-NMR dataset, combined information about (a) main components, (b) less-represented components, and (c) minor but key-ruling secoiridoid species, respectively. Selected integrations of the RICC-NMR trace, together with selected integrations gathered from the ¹³C-NMR profile, led, for each sample, to the quantification of variables able to sort out distinct EVOOs. In this paper, this original methodology was applied to rationalize eighteen EVOOs from Sicily and nineteen from Sardinia, which were chemometrically compared and discussed. Full article

Organic agriculture has few tools against pests and diseases and is constantly looking for effective and sustainable products such as geomaterials, i.e., zeolite. This study evaluates the physiological and morphological responses of olive plants (Olea europaea) to foliar applications of different geo-materials, specifically kaolin, natural zeolite, and ammonium-enriched zeolite. The research examines leaf anatomical modifications, including internal tissue structures, trichome and stomatal density, chlorophyll content, and gas exchange parameters, alongside the impact on fruit development and extra virgin olive oil (EVOO) quality. Results indicate that kaolin application negatively influenced transpiration and stomatal conductance, an effect corroborated by increased xylem vessel wall thickness. However, the reduction in stomatal conductance was attributed to a functional rather than morphological adaptation, as no significant changes in stomatal density or size were observed. Both geo-material treatments altered leaf surface properties, particularly peltate trichome characteristics. Notably, ammonium-enriched zeolite application enhanced photosynthetic rate during early olive development, likely due to its nutritional role, and contributed to increased fruit size and oil yield. These findings highlight the potential of geo-material-based foliar treatments as an effective strategy to optimize plant physiological performance and improve olive oil production in sustainable agricultural systems. Full article

Environmental conditions during olive fruit development and genotype have shown to be important sources of variability in final fruit weight and oil concentration. There are fewer studies concerning how the environment and genotype modulate growth dynamics. Thus, the present study aimed to evaluate the timing of fruit growth, pit hardening, and oil accumulation in several olive cultivars under different air temperatures along a latitudinal gradient (29°–33° S) with a range of altitudes (450–1250 masl) in Western Argentina; determine parameters derived from the dynamics of fruit growth and oil accumulation along the same gradient; and explore possible relationships between derived parameters and air temperatures. The cultivars evaluated were Arbequina, Arbosana, Coratina, Changlot, and Picual. Pit hardening occurred 20 days earlier in warmer locations, leading to an earlier onset of oil synthesis. The final fruit dry weight was mainly influenced by the cultivar, which was explained by differences in fruit growth rates. Cooler locations had 39% higher average final fruit dry weight and 22% higher oil concentration than warmer ones. Differences in final oil concentration between genotypes × environments were primarily associated with the oil accumulation rate rather than the duration of the oil accumulation period. However, changes in this rate seem to be cultivar-dependent. Interestingly, the rate and oil accumulation duration showed a negative relationship. These results highlight the need to explore genetic variability in temperature response to limit the detrimental impacts of global warming on olive fruit growth and oil concentration. Full article