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MicroRNAs (miRNAs) are key regulators of gene expression in plants, influencing various biological processes such as oil quality and seed development. Although, our knowledge about miRNAs in olive (Olea europaea L.) is progressing, with several miRNAs being identified in previous studies, but most of these reported miRNAs have been predicted without the aid of a reference genome, primarily due to limited genome accessibility at the time. However, significant knowledge gaps still need to be improved in this area. This study addresses the complexities of miRNA detection in olive, using a high quality reference genome and a combination of genomics and machine learning-based methods. By leveraging random forest and support vector machine algorithms, we successfully identified 56 novel miRNAs in olive, surpassing the limitations of conventional homology-based methods. Our subsequent analysis revealed that some of these miRNAs are implicated in the regulation of key genes involved in oil quality. Within the context of oil biosynthesis pathways, the novel miRNA Oeu124369 regulates fatty acid biosynthesis by targeting acetyl-CoA acyltransferase 1 and palmitoyl-protein thioesterase, thereby influencing the production of acetyl-CoA and palmitic acid, respectively. These findings underscore the power of machine learning in unraveling the complex miRNA regulatory network in olive and provide a high quality miRNA resource for future research aimed at improving olive oil production by exploring the target genes of the identified miRNAs to understand their role and their biological processes., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Pakdel et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The phenolic composition of virgin olive oil (VOO) primarily depends on the phenolic content of the olive fruit. The purpose of this work was to characterize the first metabolic step in the synthesis of tyrosol (Ty) and hydroxytyrosol (HTy), whose derivatives are by far the predominant phenolics in both olive fruit and VOO. To this end, two genes encoding tyrosine/DOPA decarboxylase enzymes, OeTDC1 and OeTDC2 , have been identified and functionally and physiologically characterized. Both olive TDC proteins exclusively accept aromatic amino acids with phenolic side chains, such as tyrosine and 3,4-dihydroxyphenylalanine (DOPA), as substrates to produce tyramine and dopamine, respectively. These proteins exhibited a higher affinity for DOPA than for tyrosine, and the catalytic efficiency of both proteins was greater when DOPA was used as a substrate. Both olive TDC genes showed a fairly similar expression profile during olive fruit ontogeny, with OeTDC1 consistently expressed at higher levels than OeTDC2 . Expression was particularly intense during the first few weeks after fruit set, coinciding with the active accumulation of Ty and HTy derivatives. The data suggest that both olive TDCs are responsible for the initial step in the synthesis of the most important phenolics, both quantitatively and functionally, in VOO.

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.

The Mediterranean diet includes virgin olive oil (VOO) as the main fat and olives as snacks. In addition to providing nutritional and organoleptic properties, VOO and the fruits (olives) contain an extensive number of bioactive compounds, mainly phenolic compounds, which are considered to be powerful antioxidants. Furthermore, olive byproducts, such as olive leaves, olive pomace, and olive mill wastewater, considered also as rich sources of phenolic compounds, are now valorized due to being mainly applied in the pharmaceutical and nutraceutical industries. The digestive system must physically and chemically break down these ingested olive-related products to release their phenolic compounds, which will be further metabolized to be used by the human organism. The first purpose of this review is to provide an overview of the current status of in-vitro static digestion models for olive-related products. In this sense, the in-vitro gastrointestinal digestion methods are widely used with the following aims: (i) to study how phenolic compounds are released from their matrices and to identify structural changes of phenolic compounds after the digestion of olive fruits and oils and (ii) to support the functional value of olive leaves and byproducts generated in the olive industry by assessing their health properties before and after the gastrointestinal process. The second purpose of this review is to survey and discuss all the results available to date.

Background: Olive, as a non-climacteric fruit, is presumed to be ethylene independent with regard to ripening triggering/coordination. Nevertheless, studies have demonstrated that postharvest ethylene treatments induce changes in composition and properties also of non-climacteric fruits, including aroma profiles, a key quality parameter of extra virgin olive oils. Olive fruit of cv. 'Leccino' harvested at two distinct ripening stages (less advanced ripening, LAR; and more advanced ripening, MAR, with Jaén index of 4.58 and 5.10, respectively) were subjected to ethylene (1000 ppm in air) treatment for 24 h before oil extraction., Results: Based on multivariate analysis of volatile organic compound (VOCs), the effect of ethylene treatment appeared to be more pronounced in MAR samples. However, differences in organoleptic analysis were also detected in ethylene-treated LAR olive oils. Ethylene seems to selectively affect linolenic/linoleic acid metabolism, particularly concerning the C5 pathway, and reduce specific defect-associated compounds., Conclusion: Exogenous ethylene applied to cv. 'Leccino' olives before processing was effective in inducing specific changes in the VOC profiles of the resulting oil. The effect was different depending on the ripening stage of the harvested olives. The lipoxygenase pathway (including the production of C5 compounds) and fermentative-related compounds appeared to be affected by the treatment. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

High vacuum technology has been incorporated into a new assisted extraction system applied to virgin olive oil (VOO) processing, which was tested at a lab-scale pilot plant to evaluate its impact on the physicochemical properties of the olive paste and oil. The vacuum system induced changes in the mechanical and structural properties of the olive cells, improving the coalescence of the oil droplets due to substantial cellular and intracellular mass transfer during the process, as shown by cryo-scanning electron microscopy (Cryo-SEM) analysis. The effects on the quality characteristics of VOOs extracted from three cultivars at different malaxation temperatures were evaluated. A significant increase in the phenolic content, from 25.2% to 48.6%, was observed. The content of volatile compounds responsible for the VOO flavor decreased as a function of malaxation temperature. The reduction of some volatile molecules related to the VOO off-flavor (ethanol, ethyl acetate and acetic acid) was also shown., (Copyright © 2020. Published by Elsevier Ltd.)

Phenolic compounds in virgin olive oil (VOO) contribute to its health properties, organoleptic features and oxidative stability. In this study, a total of 44 olive tree cultivars categorized by the International Olive Council to be among the most internationally widespread varieties were exhaustively and homogenously evaluated by analysis of the VOO phenolic profile during three consecutive crop seasons. Differences among cultivars resulted in up to 15-fold variations in the total phenol concentration. The 'cultivar' factor contributed the most to the variance (66.8% for total phenolic concentration) for almost all the phenols. However, the 'interannual variability' factor and the interaction 'cultivar x interannual variability' exhibited significant influences on specific phenols. According to the phenolic profile of the VOOs, we determined the presence of three groups of cultivars marked by the predominance of secoiridoid derivatives, which supports the phenolic profile as a criterion to be considered in olive breeding programs., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Calcium is a preservative and firming agent largely used in the table olive industry. Foliar applications of calcium (as calcium chloride, CaCl 2 ) before harvest have been proposed in other fruits to increase firmness and reduce physiological disorders or internal damage. However, there is still a shortage of information regarding the source, the concentration, the number, and the period of calcium application onto the canopy to get an effective response of olive quality. In this study, we aimed to investigate the effect of two concentrations of CaCl 2 foliar treatments (0.5% and 1.0%), applied at different stages of fruit development (at the end of fruit set, end of pit hardening, and prior to harvesting), on olive quality for two varieties ('Manzanilla de Sevilla' and 'Ascolanta tenera'), cultivated in two different geographical areas (Spain and Italy respectively)., Results: The calcium concentrations applied enhanced the fruit calcium content and decreased sodium and potassium. They also improved the mechanical properties without modifying fruit morphology or cuticle thickness; nor did they cause phytotoxicity. Foliar treatments increased the oil content in the pulp (dry weight basis) and the amount of hydroxytyrosol, tyrosol, and oleuropein, among other phenols., Conclusion: Calcium foliar applications during fruit development effectively increase olive quality. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Many studies demonstrated that olive oil (especially extra virgin olive oil: EVOO) phenolic compounds are bioactive molecules with anti-cancer, anti-inflammatory, anti-aging and neuroprotective activities. These effects have been recently attributed to the ability of these compounds to induce epigenetics modifications such as miRNAs expression, DNA methylation and histone modifications. In this study, we systematically review and discuss, following the PRISMA statements, the epigenetic modifications induced by EVOO and its phenols in different experimental systems. At the end of literature search through "PubMed", "Web of Science" and "Scopus", 43 studies were selected.Among them, 22 studies reported data on miRNAs, 15 on DNA methylation and 13 on histone modification. Most of the "epigenomic" changes observed in response to olive oil phenols' exposure were mechanistically associated with the cancer preventive and anti-inflammatory effects. In many cases, the epigenetics effects regarding the DNA methylation were demonstrated for olive oil but without any indication regarding the presence or not of phenols. Overall, the findings of the present systematic review may have important implications for understanding the epigenetic mechanisms behind the health effects of olive oil. However, generally no direct evidence was provided for the causal relationships between epigenetics modification and EVOO health related effects. Further studies are necessary to demonstrate the real physiological consequences of the epigenetics modification induced by EVOO and its phenolic compounds.

Olives affected by active and damaging infestation (olive fruit fly Bactrocera oleae (Rossi)) were assayed for their chemical composition. Biophenols were determined by HPLC, sterols, triterpenic dialcohols, and fatty acids by gas chromatography analysis. The acquired data were statistically analyzed. Oils produced from "Istrska belica" fruit affected by active infestation compared to the oils made from fruit affected by damaging infestation showed higher amounts of total oleuropein biofenols (377.3 versus (vs.) 106.6 mg/kg), total biophenols (755 vs. 377 mg/kg), lignans (85.3 vs. 32.9 mg/kg), the dialdehydic form of decarboxymethyl oleuropein aglycone (DMO-Agl-dA) (148.3 vs. 49.0 mg/kg), its oxidized form (DMO-Agl-dA)ox (35.2 vs. 8.5 mg/kg), the dialdehydic form of oleuropein aglycone (O-Agl-dA) (61.1 vs. 8.0 mg/kg), the dialdehydic form of ligstroside aglycone (L-Agl-dA) (63.5 vs. 28.0 mg/kg), the aldehydic form of oleuropein aglycone (O-Agl-A) (40.6 vs. 8.4 mg/kg), and lower amounts of tyrosol (Tyr) (6.0 vs. 13. 9 mg/kg) and the aldehydic form of ligstroside aglycone (L-Agl-A) (13.8 vs. 40.3 mg/kg). Higher values of stigmasterol (2.99%) and lower values of campesterol (2.25%) were determined in oils affected by damaging infestation; an increase in triterpenic dialcohols was also observed (3.04% for damaging and 1.62% for active infestation). Oils affected by damaging infestation, compared to active infestation, showed lower amounts of oleic acid (73.89 vs. 75.15%) and higher amounts of myristic (0.013 vs. 0.011%), linoleic (7.27 vs. 6.48%), and linolenic (0.74 vs. 0.61%) acids.

In the oil sector, a novelty in the centrifugal extraction system is represented by the multi-phase decanters (DMF) that work without adding process water and with the advantage of recovering a dried pomace and a by-product, called "pâté", consisting of the pulp and its vegetation water, without traces of stone. The pâté has a high content of phenolic compounds, mainly represented by secoiridoids and verbascoside. The present work investigated the efficacy of two different ways of debittering (by sequential filtrations and spontaneous fermentation) of DMF pâté from three olive cultivars ( Olea europaea L. "Leccino", "Carboncella" and "Tortiglione") to make the pâté edible, and, contemporary, investigated also the effect of its phenolic bioactive extracts on pathogenic bacteria and colon cancer cell model. Daily filtrations of pâté of the three cultivars have been shown to be more efficient in phenolic degradation. The activity of the indigenous microflora on the other hand takes a longer time to degrade the phenolic component and therefore to de-bitter it. None of pâté showed antibacterial activity. Colorimetric assay MTS for cell viability and metabolic activity tested on colon cancer cells CaCo2 and HCT116 suggest a potential beneficial effect of the dried extracts probably related to the modulation of gene expression under these treatments.

The two-phase technology for olive oil extraction generates large amounts of patè olive cake (POC), a by-product that is rich in bioactive health-promoting compounds. Here, response surface methodology (RSM) was used to maximize supercritical-CO 2 oil extraction from POC, while minimizing operative temperature, pressure and time. Under the optimal parameters (40.2 °C, 43.8 MPa and time 30 min), the oil yield was 14.5 g·100 g -1 dw (~65% of the total oil content of the freeze-dried POC matrix), as predicted by RSM. Compared with freeze-dried POC, the oil contained more phytosterols (13-fold), tocopherols (6-fold) and squalene (8-fold) and was a good source of pentacyclic triterpenes. When the biological effects of POC oil intake (20-40 µL·die -1 ) were evaluated in the livers of BALB/c mice, no significant influence on redox homeostasis was observed. Notably, a decline in liver triglycerides alongside increased activities of NAD(P)H:Quinone Oxidoreductase 1, Carnitine Palmitoyl-CoA Transferase and mitochondrial respiratory complexes suggested a potential beneficial effect on liver fatty acid oxidation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The awareness of the functional and nutraceutical properties of olives and olive oil bioactive constituents contributed to oliviculture recent increase. Olives' metabolism and nutritional quality are determined by how the olive-tree is coping to climate change-related episodes, which increasingly occur in the Mediterranean. We characterize the most relevant lipophilic and phenolic compounds of olives from Olea europaea cultivars [Cobrançosa, Cordovil de Castelo Branco and Cordovil de Serpa (C.Serpa)] exposed to drought + heat. Olives from the three cultivars presented a similar qualitative profile but differed in their relative richness. Cobrançosa olives are richer in organic acids, esters and carbohydrates, while C.Serpa olives have higher levels of phenolic compounds, particularly under control conditions. Drought + heat changed the quantitative profile of olives, in a way dependent on the cultivar, and C.Serpa olives showed the highest stress susceptibility. Climate change-related conditions stimulate the accumulation of relevant bioactive compounds in olives, contributing to increasing its nutritional value., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The health advantages of extra-virgin olive oil (EVOO) are ascribed mainly to the antioxidant ability of the phenolic compounds. Secoiridoids, hydroxytyrosol, tyrosol, phenolic acid, and flavones, are the main nutraceutical substances of EVOO. Applications of beneficial microbes and/or their metabolites impact the plant metabolome. In this study the effects of application of selected Trichoderma strains or their effectors (secondary metabolites) on the phenolic compounds content and antioxidant potential of the EVOOs have been evaluated. For this purpose, Trichoderma virens (strain GV41) and Trichoderma harzianum (strain T22), well-known biocontrol agents, and two their metabolites harzianic acid (HA) and 6-pentyl-α-pyrone (6PP) were been used to treat plants of Olea europaea var. Leccino and var. Carolea. Then the nutraceutical potential of EVOO was evaluated. Total phenolic content was estimated by Folin-Ciocalteau's assay, metabolic profile by High-Resolution Mass spectroscopy (HRMS-Orbitrap), and antioxidant activity by DPPH and ABTS assays. Our results showed that in the cultivation of the olive tree, T22 and its metabolites improve the nutraceutical value of the EVOOs modulating the phenolic profile and improving antioxidants activity.

Global warming is predicted to have a negative effect on plant growth due to the damaging effect of high temperatures. In order to address the effect of high temperature environments on olive oil yield and quality, we compared its effect on the fruit development of five olive cultivars placed in a region noted for its high summer temperatures, with trees of the same cultivars placed in a region of relatively mild summers. We found that the effects of a high temperature environment are genotype dependent and in general, high temperatures during fruit development affected three important traits: fruit weight, oil concentration and oil quality. None of the tested cultivars exhibited complete heat stress tolerance. Final dry fruit weight at harvest of the 'Barnea' cultivar was not affected by the high temperature environment, whereas the 'Koroneiki', 'Coratina', 'Souri' and 'Picholine' cultivars exhibited decreased dry fruit weight at harvest in response to higher temperatures by 0.2, 1, 0.4 and 0.2 g respectively. The pattern of final oil concentration was also cultivar dependent, 'Barnea', 'Coratina' and 'Picholine' not being affected by the high temperature environment, whereas the 'Koroneiki' and 'Souri' cultivars showed a decreased dry fruit oil concentration at harvest under the same conditions by 15 and 8% respectively. Regarding the quality of oil produced, the 'Souri' cultivar proved more tolerant to a high temperature environment than any other of the cultivars analyzed in this study. These results suggest that different olive cultivars have developed a variety of mechanisms in dealing with high temperatures. Elucidation of the mechanism of each of these responses may open the way to development of a variety of olives broadly adapted to conditions of high temperatures., Competing Interests: The authors have declared that no competing interests exist.

Extra virgin olive oil (EVO) is among the most counterfeit foodstuffs in the present market. The Italian production is with no doubt one of the most valuable and therefore mostly counterfeit, due to the difficulty in checking the geographic provenance of olives. In order to provide a way for verifying the provenance of EVO, the role of microelements and, in particular, of lanthanides in the oil production chain has been studied. The distribution of lanthanides as determined by means of ICP-MS analysis appeared to provide a good tool for tracing the EVO production chain. Lanthanides and other microelements were then used for distinguishing a particularly prised EVO production from Liguria (northwestern Italy) made from Taggiasca olive variety, verifying that this production can be easily authenticated on the base of these chemical descriptors., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Three factors for the extraction of extra virgin olive oil (EVOO) were evaluated: diameter of the grid holes of the hammer-crusher, malaxation temperature, and malaxation time. A Box-Behnken design was used to obtain a total of 289 olive oil samples. Twelve responses were analyzed and 204 mathematical models were obtained. Olives from super-intensive rainfed or irrigated crops of the Arbequina, Koroneiki, and Arbosana cultivars at different stages of ripening were used. Malaxation temperature was found to be the factor with the most influence on the total content of lipoxygenase pathway volatile compounds; as the temperature increased, the content of volatile compounds decreased. On the contrary, pigments increased when the malaxation temperature was increased. EVOO from irrigated crops and from the Arbequina cultivar had the highest content of volatile compounds. Olive samples with a lower ripening degree, from the Koroneiki cultivar and from rainfed crops, had the highest content of pigments.

Ultrasound-assisted extraction is an innovative technique applied to the extraction process for virgin olive oil (VOO), which is generally employed to increase plant efficiency and improve product quality. A high-power ultrasound (US) device was introduced at an industrial plant that can process at 2 tons/h to evaluate the technique's physicochemical impact on quality parameters of VOO that was caused by an intensive mass transfer induced by acoustic cavitation process and shockwaves. The impact on oil yield was also evaluated with respect to the ripening stage and malaxation time. No significant effects on the legal and commercial parameters of VOO (including quality indices, sterols, triterpene dialcohols, waxes and diacylglycerols) were found for olives at medium-early ripening stage. Significant physical changes, increased extraction yield (22.7%), enhanced phenol content (10.1%) were observed in US-VOO compared to control (C) oil extracted with a traditional process at an early maturity index., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Acrylamide and phenolic compounds on both fresh and cooked olives were monitored by HPLC/MS-MS and reversed-phase-HPLC methods along different procedures: elaboration process, high hydrostatic pressure (HHP), cooking treatment and bioavailability evaluation. Acrylamide was not detected during the elaboration process and after HHP treatment. Hydroxytyrosol, tyrosol, oleuropein and verbascoside were the most important phenols after HHP treatment. The frying and baking processes on olives enhanced the formation of acrylamide and a significant reduction in the phenolic compounds. The frying process produced lower acrylamide concentration and less reduction of phenolic compounds than the baking process, while in the gastrointestinal digestion these compounds were slightly reduced if compared to the initial stage. As a conclusion, the best way to ingest high quantities of phenols and reduce acrylamide consumption is by ingesting the olives when they are fresh. In case the olives need to be cooked, specific time and temperature conditions shall be applied., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The aim of this study was to prove the usefulness of multielements as provenance markers of olive oils by evaluating their link with soil composition and their discriminatory power. Eleven elements in twenty-one olive oils and their paired soils from four Tunisian regions were characterized. Chemometrics have been implemented for ICP-MS data processing. Principal component analysis identified the predominant geochemical source of the elements in the oils based on their associations according to Goldschmidt's rule. Although a clear correlation was not proven, correspondence was identified between the discriminating elements for both the soils and olive oils, which included Fe, Rb, Mg, and Pb. Linear discriminant analysis achieved classification and prediction rates of 92.1% and 87.3%, respectively. Our study substantiates the validity of multielements as markers of the olive oils' provenance, and that an elemental fingerprinting approach can be successfully applied in the construction of a database of Tunisian olive oils., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The pattern of olive oil accumulation is of paramount importance in olive because its influence in determining final oil yield and optimal harvesting date. In this work, we have evaluated the genetic and environment influence on the olive oil accumulation pattern. For that purpose, a set of cultivars and breeding selections planted in a multi-environment trial was evaluated in two consecutive harvest seasons. Significant effect of the environment, genotype and their interaction were observed for the maximum oil content reached and the rate of oil accumulation. On the contrary, the date of maximum oil content seems to depend only on the environment. The two breeding selections evaluated showed, in general, high stability and adaptability in oil accumulation parameters. Among the potential environmental factors that could affect oil accumulation, PLS analysis suggests that temperature could play a determinant environmental effect in the oil accumulation parameters tested in this study. These results underline the relevance of using multi-environment trials for adequate characterization of genotypes showing either good behaviour in variable environments or only under specific environmental conditions., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Extra virgin olive oil (EVOO) is the main source of fat in the Mediterranean diet. Phenolic compounds of EVOO, in particular, secoiridoids, are minor components that have generated special interest due to their positive effects on human health, supported by several clinical trials. This review summarizes the most recent findings on the pharmacological properties and action's mechanisms of secoiridoid oleocanthal, focusing attention on inflammation, oxidative stress, cancer, neurodegenerative processes, and rheumatic diseases. Being of relevance to the clinical effects of EVOO intake, the bioavailability and biotransformation of EVOO polyphenols are addressed. Moreover, this review summarizes the factors that may influence the oleocanthal concentration in EVOO. With the growing incidence of age- and lifestyle-related diseases, the current data indicated that the administration of EVOO rich in secoiridoids may be helpful in the prevention or treatment of different pathologies with an inflammatory component. Although promising, the future raises several questions and challenges, which are discussed here. The real beneficial effects of olive oil phenols on human health need to be clarified in new, well-designed clinical studies.

Olive oil phenolic compounds are receiving increased attention due to its influence on sensory characteristics and to scientific evidences of positive health effects. In this work, 28 ancient olive trees were selected and, during four consecutive seasons (2014-2017), oils were extracted and their phenolic fraction characterized. Hydroxytyrosol and tyrosol secoiridoids were the predominant groups, with contents between 32 and 496 mg of tyrosol equivalents/kg. Based on principal component analysis it could be concluded that the individual phenolic contents enabled the unsupervised grouping of olive oils by crop year. Furthermore, linear discriminant analysis allowed achieving sensitivities greater than 90%. It was shown that some specimens consistently allowed obtaining oils with high phenolic contents (≥500 mg tyrosol equivalents/kg). The identification of centenarian specimens for breeding based on their potential to produce oils with high levels of healthy compounds is of utmost interest, contributing to preserve the genetic heritage., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A single out-line HPLC-GC (FID) analytical method is applied to acquire the chromatographic fingerprint characteristic of the TMS-4,4'-desmetylsterol derivative fraction of several marketed edible vegetable oils in order to identify and discriminate the most valuable extra-virgin olive oils from the other vegetal oils (canola, corn, grape seed, linseed, olive pomace, peanut, rapeseed, soybean, sesame, seeds (non-specified composition but usually a blend of corn and sunflower) and sunflower). The natural structure of the preprocessed data undergoes a preliminary exploration using principal component analysis and heat map-based cluster analysis. A partial least squares-discriminant model is first trained from 53 oil samples (only 3 latent variables) and externally validated from 18 test oil samples. No classification errors are found and all the test samples are correctly classified. Additional classification models are also built in order to discriminate among vegetables-oil families and excellent results have been also achieved., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Olive oil, a functional food, is increasingly produced from trees irrigated with water containing high concentrations of salts. We studied the effects of irrigation-induced salinity on quality and health-related compounds in olive oil. Trees (cv Barnea) were grown in lysimeters with continuous control and monitoring of root-zone salinity. Salinity in the root zone was altered by changing irrigation solution salinity or by changing the extent of leaching. Extracted oil was analyzed for quality parameters including free fatty acid content, polyphenol, tocopherol, sterol and carotenoid levels, fatty acid (FA) profile, and antioxidative capacity., Results: While not all parameters changed, fruit water percentage and fruit oil content significantly decreased with increasing exposure to salt. As salinity increased, there was a desirable rise in measured polyphenol and tocopherol levels and a contrasting undesirable reduction in a number of important compounds, including 16:1 and 18:3 FA., Conclusion: The possible negative effects on olive oil quality due to FA-related parameters should concern producers dependent on, or considering, irrigation with high-salinity water sources. A number of important quality parameters were differentially influenced by the method of inducing the root zone salinity, suggesting that additional environmental variables leading to oxidative responses were affected by the treatments. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Hydrothermal pretreatments including steam explosion and subcritical water (SCW) facilitate hydrolyses of plant cell wall materials and supply environmentally friendly extraction solvents to recover value added compounds. In this study, effect of steam and SCW and temperature (160, 180 and 200 °C, 5 min) on yield and β-sitosterol content of pomace oil and phenolics were compared for value added utilization of olive pomace. Compared to acid hydrolysis, hydrothermal pretreatments yielded similar oil recovery. 54-76% of the bound oil and 18-32% of the bound β-sitosterol of the pomace were recovered by hydrothermal pretreatments. Steam pretreatment was more effective than SCW pretreatment at lower temperatures, however SCW showed increasing trend on oil yield related to steam pretreatment. As further research on process development, use of sequential temperature might be investigated, starting with steam explosion (<180 °C), followed by SCW pretreatment (>200 °C) to obtain multiple, aqueous and meal, fractions for total valorization of olive pomace., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In order to understand the distribution of the main secondary metabolites found in Olea europaea L., eight different samples (olive leaf, stem, seed, fruit skin and pulp, as well as virgin olive oil, olive oil obtained from stoned and dehydrated fruits and olive seed oil) coming from a Picudo cv. olive tree were analyzed. All the experimental conditions were selected so as to assure the maximum coverage of the metabolome of the samples under study within a single run. The use of LC and GC with high resolution MS (through different ionization sources, ESI and APCI) and the annotation strategies within MetaboScape 3.0 software allowed the identification of around 150 compounds in the profiles, showing great complementarity between the evaluated methodologies. The identified metabolites belonged to different chemical classes: triterpenic acids and dialcohols, tocopherols, sterols, free fatty acids, and several sub-types of phenolic compounds. The suitability of each platform and polarity (negative and positive) to determine each family of metabolites was evaluated in-depth, finding, for instance, that LC-ESI-MS (+) was the most efficient choice to ionize phenolic acids, secoiridoids, flavonoids and lignans and LC-APCI-MS was very appropriate for pentacyclic triterpenic acids (MS (-)) and sterols and tocopherols (MS (+)). Afterwards, a semi-quantitative comparison of the selected matrices was carried out, establishing their typical features (e.g., fruit skin was pointed out as the matrix with the highest relative amounts of phenolic acids, triterpenic compounds and hydroxylated fatty acids, and seed oil was distinctive for its high relative levels of acetoxypinoresinol and tocopherols).

The growing of microbial resistance leads to a great interest about some natural alternatives to synthetic compounds. This study was carried out in two olive orchards (Olea europaea L., cv. Coratina) South Italy (Basilicata region), one located in a polluted area near a fertilizers factory releasing Zn and the other in a control unpolluted site, both managed with similar cultivation techniques. Olive oil samples were studied from both areas during 2014 and 2015. The soil microbiological status of the polluted and unpolluted orchards has been characterized and the antimicrobial effects of olive oils extracted from polluted plants (PP) and control plants (CP) against some phytopathogens have been explored. Results showed that the antibacterial activity of PP oil was significantly higher than CP and this could be due to the high content of some phenolic compounds elicited by air and soil Zn pollution (especially in the layer 0-20 cm). There is no detectable antifungal activity of the studied oils. The metabolic activity (both total and for each carbon substrate group), diversity and evenness of PP soil bacterial communities were significantly different from CP soil, while the effects of soil depth was negligible. The same parameters measured on soil fungal communities are lower in PP soil at 0-20 cm soil depth. The current research clarified the impact of atmospheric Zn pollution on the antimicrobial activity of olive oil and the soil microbial metabolic profiles. The bioactive substances extracted from olive oils growing in Zn-polluted area might be used as antibiotics., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

The natural antioxidants of olive oil have phenolic structure and their activities are related to the formation of stable derivatives. In this study, the single components of the phenolic fraction of olive oil (1,4-hydroquinone, Semiquinone and 1,4-benzoquinone) have been studied as theoretical by using DFT (Density functional Theory). The behaviors of phenolic compounds of olive against to the alkyl peroxy radicals were investigated. Our data show that 1,4-benzoquinone is the best electron transfer agent in primary metabolic processes to human life. The frontier orbital gap, namely HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital) gap is the smallest for 1,4-benzoquinone. Hence, it is more stable than the others in blood. The natural phenolic compound's mechanism of many plants can be explained by using DFT method without consuming time and money. In this study, we have indicated the behaviors of natural antioxidants of olive oil's single components phenolic structure in blood phase., (Copyright © 2017. Published by Elsevier B.V.)

Heating operation has been applied to Chétoui extra-virgin olive oils (EVOOs) extracted from fruits with several ripening stages (RS). The studied samples, were subjected to microwave and conventional heating. Results showed that heated VOOs after 2.5 h and 7 min of conventional and microwave heating, respectively, gave rise to a drastically decrease of LOX products and allowed the detection of toxic new formed aldehydic volatiles (alkanal: nonanal, alkenals: (Z)-2-heptenal and (E)-2-decenal, and alkadienals: (E.E)-2.4-decadienal), which can be used as markers of VOO degradation. Their abundance in the VOO headspaces depends on their boiling points, the rate of their possible degradation to yield other compounds, on the heating processes and on the rate of macronutrients. The emission rate of the new synthesized volatiles during heating processes was mainly attributed to enzymatic oxidation of some fatty acids. Hexanal, (Z)-2-heptenal, (E)-2-octenal, (E)-2-nonenal, (E,E) and (E,Z)-2,4-decadienal, and (E,E)-2,4-nonadienal, derived from linoleic acid, and heptanol, octanal, nonanal, decanal, (E) and (Z)-2-decenal, (E)-2-undecenal, and (E,E)-2,4-nonadienal, are emitted after degradation of oleic acid. During thermo-oxidation, the ECN 44 (LLO, and OLnO), and the ECN 46 (OLO, and PLO + SLL) compounds decreased, whereas, the ECN 48 (OOO, and PPO), and the ECN 50 (SOO) compounds increased when temperature and heating time increased. The several variations of the studied biochemical compounds depend to the heating processes. Ripening stage of olive fruits can be used as a tool to monitor the emission rate of the aldehydic volatiles, but cannot be used for a chemometric discrimination., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background/aim: The aim of the present study was to investigate the antioxidant effects of a feed supplemented with polyphenolic additives from olive mill wastewater (OMW) on lambs., Materials and Methods: Lambs received breast milk until the postnatal period, and then they were divided into two groups and received control and OMW feed for 55 days. Redox biomarkers were measured in blood and tissues at days 15, 42 and 70 after feeding., Results: Feed supplemented with OMW reduced thiobarbituric acid reactive species and protein carbonyls and increased total antioxidant capacity, glutathione and catalase activity in both blood and tissues., Conclusion: The administration of OMW-containing feed reinforced the antioxidant defense of lambs, which may improve their wellbeing and productivity. Additionally, this exploitation of OMW may solve problems of environmental pollution in areas with olive oil industries., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Olive oil displays remarkable organoleptic and nutritional features, which turn it into a foodstuff appreciated by consumers, and a basic component of the Mediterranean diet. Indeed, the noticed benefits of including olive oil in the diet have been assigned to the presence of diverse bioactive compounds with different molecular structures. These compounds confer a wide range of biological properties to this food matrix, including the prevention of distinct human diseases as well as the modulation of their severity. The most relevant bioactive compounds present in olive oil correspond to benzoic and cinnamic acids, phenolic alcohols and secoiridoids, and also flavonoids. Over the last decades, several studies, devoted to gaining a further insight into the relative contribution of the separate groups and individual compounds for their biological activities, have been conducted, providing relevant information on structure-activity relationships. Therefore, this paper critically reviews the health benefits evidenced by distinct phenolic compounds found in olive oils, thus contributing to clarify the relationship between their chemical structures and biological functions, further supporting their interest as essential ingredients of wholesome foods.

After the sustained consumption of virgin olive oil (VOO), the unabsorbed native phenols (mainly hydroxytyrosol (HT)) are transformed into its catabolites in the intestine by microbials. The role of these catabolites in preventing colon cancer has not been sufficiently investigated. This work aims to study the antiproliferative and apoptotic activities in colon (Caco-2; HT-29) cancer cell lines of the main catabolites detected in human feces (phenylacetic, phenylpropionic, hydroxyphenylpropionic, and dihydroxyphenylpropionic acids and catechol), after the sustained VOO intake. Additionally, an assessment of the ability of these colonic cells to metabolize the studied compounds was performed. The results showed that HT and phenylacetic and hydroxyphenylpropionic acids produce cell cycle arrest and promote apoptosis. HT-29 cells were more sensitive to phenol treatments than Caco-2. In synthesis, the results of the present study represent a good starting point for understanding the potential apoptotic and antiproliferative effects of VOO phenolic compounds and their colonic metabolites.

The production of olive oil is considered to be one of the largest agricultural business sectors in the Mediterranean area. Apart from its significant impact on the economies of countries in Southern Europe, Northern Africa and Middle East, olive oil production also involves considerable social and environmental considerations. However, despite such importance, the environmental effects of olive oil production have not been studied as much other agricultural productions and farming systems, which are more characteristic of central and northern Europe. We present a thorough and systematic literature review of scientific publications with respect to the use of environmental tools in the life cycle of olive oil. The analysis takes into consideration the farming of olive trees, the manufacture of olive oil, packaging, transportation and reverse logistics. To that end, journal publications up to 2015 in this specific field are recorded and, at the same time, the most important environmental impacts are revealed and a gap analysis is carried out. The analysis conducted reveals that farming of olive trees (with pesticide use and waste/by-product production being the 'hottest' topics) and the manufacturing of olive oil (concentrating mostly on waste/by-product production and management) are the phases with the highest environmental focus from the scientific community. Moreover, gaps in the literature are detected mostly with respect to fuel consumption and the use and promotion of renewable energy sources in olive oil production. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)

This study explored the effects of supplemental dietary extra virgin olive oil (EVOO), gallic acid (GA), or lemongrass essential oil (LGEO) on growth performance, nutrient digestibility, carcass traits, lipid peroxidation, hematological, and antioxidative status in growing rabbits under heat stress conditions. A total of 48 male growing New Zealand White rabbits were randomly divided into four equal groups, which received a basal diet without any supplementation or supplemented with 15 g EVOO, 500 mg GA, or 400 mg LGEO/kg of diet, for eight consecutive weeks. Results revealed that the overall mean of temperature humidity index was 84.67 ± 0.35, reflecting a state of severe heat stress. Moreover, dietary supplementation with EVOO, GA, or LGEO significantly increased live body weight and daily body weight gain but decreased both feed conversion ratio and daily water consumption. Additionally, a significant increase in both organic matter and crude protein digestibility besides a remarkable elevation in the nutritive values of digestible crude protein, total digestible nutrients, and digestible energy, as well as an increase in the numbers of WBCs, lymphocytes, and heterophils was significant in EVOO-supplemented rabbits. Supplementation with EVOO, GA, or LGEO in the heat-stressed growing rabbit's diet enhanced catalase activity and reduced glutathione content, whereas EVOO-treated rabbits had the highest values. Also, malondialdehyde activity was reduced in response to all tested additives. In conclusion, these findings suggested that addition of EVOO, GA, or LGEO in growing rabbit's diet could be used effectively to alleviate negative impacts of heat stress load on performance, nutrient digestibility, oxidative status, and hemato-biochemical features. Furthermore, among these additives, EVOO achieved the best effects.

This study was carried out in two olive orchards (Olea europaea L., cv. Chemlali) located in a polluted area near a fertilizers factory and in a control unpolluted site, managed with similar cultivation techniques. The aim was to investigate the physiological and biochemical responses of polluted plants (PP), exposed to atmospheric metal contamination (Cd, Cu, Fe, Mn, Ni and Pb) as compared to control plants (CP). Leaves, roots and fruits of PP showed a depression of their non-enzymatic and enzymatic antioxidant defences and a disruption of their hormonal homeostasis. The anomalous physiological status of PP was also demonstrated by the lower values of pigments in leaves and fruits, as compared to CP. Atmospheric metals negatively affected olive oil chemical and sensory quality. However, despite metal deposition on fruit surfaces, the accumulation of potentially toxic metals in olive oil was negligible. Considering that olive oil is an important food product worldwide and that many productive olive orchards are exposed to several sources of pollution, this work could contribute to clarify the effects of atmospheric metal pollution on olive oil quality and its potential toxicity for humans., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Regulated deficit irrigation (RDI) is used in hedgerow olive orchards to achieve a sustainable balance between water savings, tree vigor and oil production. Its effects on the presence of compounds responsible for the taste of the oil and its nutritional value are controversial. The present 3-year study was conducted in an 'Arbequina' orchard (1667 trees ha -1 ) under a full irrigation (FI) treatment (470.1 mm year -1 of water) and two RDI treatments scaled to replace 60% and 30%, respectively, of FI. The quality parameters, antioxidant contents and volatiles of the extracted virgin olive oil (VOO) were analyzed., Results: In general, oils from the 30% RDI treatment had higher contents of pigments and phenolic compounds, a higher oleic/linoleic ratio and the highest oxidative stability, despite their lower tocopherol content. FI oils showed higher (E)-2-hexenal, 1-penten-3-one, ocimene, E-2-pentenal and pentene dimer contents than 30RDI oils, but lower contents of (E)-2-pentenol and volatile esters., Conclusion: The results of the present study suggest that a RDI strategy supplying 30% of the total irrigation needs induces an increase in natural antioxidants in VOO. Neither yield, nor the rest of the quality parameters were affected by the reduced irrigation. However, abundant autumn precipitation can over-ride these effects of 30% RDI treatment on oil quality. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)

The aim of this study was to discriminate the extra virgin olive oils (EVOO) based on quality characteristics, chemical composition and antioxidant activity according to ripening stages of olives. Two different olive varieties (Memecik and Gemlik) were obtained at different stages of ripening based on skin color (green, purple and black). Quality properties of olive oils; free fatty acidity, peroxide value, K232 and K270, purity properties; fatty acid and triacylglycerol (TAG) composition and antioxidant compounds like total phenol, carotenoid and chlorophyll content and antioxidant activity (oxidative stability, ABTS radical scavenging activity) analyses were performed. Higher amount of oleic, linoleic and palmitic acids were observed in olive oils. Oleic acid amount of olive oils decreased, linoleic acid increased with ripening. The most abundant TAG of olive oils were ECN 48, OOO, SLO+POO, ECN 46 and LOO/PLO. Olive oils were clearly classified by principal component analysis based on fatty acid and TAG composition., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The main purpose of this study is to investigate the direct hydrothermal liquefaction of oil mill wastewater (OMWW). Experiments were carried out at different temperatures (240-300°C), water contents (58-88wt.%) and reaction times (15-45min). Results show that the highest bio-oil yield was about 58wt.%, resulting in a higher heating value of 38MJ/kg. This was conducted at the following optimal conditions: water content 88wt.%, a temperature of 280°C, and 30min as reaction time. To put bio-oil into wide application, the various physical and chemical characteristics were determined. A detailed chemical composition analysis of bio-oil was performed by gas chromatography-mass spectrometry (GC-MS) coupled with a flame ionization detector (FID). The dominant compounds were identified by using NIST library. Analyses show that the bio-oil contains mainly oleic acid, hexadecanoic acid, fatty acid methyl ester, fatty acid ethyl ester, amino acid derived compounds and phenolic compounds., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Olive oil contains compounds with interesting biological activities which are influenced by the cultivar, the geographic origin and other factors. The aims of this work were to (1) investigate these factors in Neb Jmel olive oil from various Tunisian origins; (2) determine the influence of geographic conditions on phenolic composition of Neb Jmel olive oil and consequently on the antioxidant compounds; and (3) verify whether oils could be discriminated based on geographical origin., Results: The characterisation of extra-virgin Neb Jmel olive oil produced in its original location has been conducted. Owing to the effect of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all studied olives were collected at the same season, and their oil obtained under the same processing technique. Many analyses were carried out to characterise the different olive oils: free acidity, peroxide value, fatty acid composition, Rancimat assay, pigments content and phenolic compounds by (1) H NMR. A recently developed method for the direct measurement of the oleocanthal and oleacein levels in olive oil by quantitative (1) H NMR was applied. The method was applied to the study of four Neb Jmel olive oils samples, and a broad variation of concentrations of all four secoiridoids was recorded. The concentration of each ranged from 55 to 529 mg kg(-1) and the sum of the four major secoiridoids (known as D3) ranged from 436 to 1063 mg kg(-1) ., Conclusion: The quantification of major phenolic compounds of olive oil by NMR indicated that environmental conditions influence the production of qualitative phenolic fractions. All these compounds can be used as base 'markers' to characterise and differentiate these olive oil on geographic origin. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)

Background: Olives dropped on the ground naturally sometimes are not separated from those fresh and healthy collected from the tree for harvest and processing. In this work we compared the quality, ethanol content and bioactive components of virgin olive oils from ground-picked olives, tree-picked fruits and their mixture., Results: Ground-picked olives produced 'Lampante' virgin olive oils; these are of a lower quality category, because of important alterations in chemical and sensory characteristics. Ethyl esters showed the highest values, although under the regulated limit. The mixture of ground and tree-picked olives gave oils classified as 'virgin' because of sensory defects, although the quality parameters did not exceed the limits for the 'extra' category. Ethanol content showed a significant increase in the oils from ground- picked olives and their mixture with respect to those from tree-picked fruits. Furthermore, bioactive compounds showed a significant decrease as fruit quality was poorer., Conclusion: Ground-picked olives must be harvested and processed separately since they produce low-quality virgin olive oils with sensory defects and lower concentrations of bioactive compounds. The higher acidity and ethanol concentration observed in oils from ground-picked fruits or their mixture may help ethyl ester synthesis during storage. © 2015 Society of Chemical Industry., (© 2015 Society of Chemical Industry.)

In the present paper, two irrigation treatments were applied to olive trees cv. Chemlali: irrigation with treated wastewater (TWW) and with olive mill wastewater (OMW), which was spread at three levels (50, 100, and 200 m(3)/ha). This work is interested in two topics: (1) the influence of different irrigation treatments on olive oil composition and quality and (2) the comparison between OMW and TWW application using different statistical analyses. The obtained variance analysis (ANOVA) has confirmed that there are no significant differences in oil quality indices and flavonoids between the control and treatments amended by OMW or TWW (p > 0.05). However, the irrigation affected some aspects of olive oil composition such as the reduction in palmitic acid (16.32%) and increase in linoleic acid (19.55%). Furthermore, the total phenols and α-tocopherol contents increased significantly following OMW and TWW treatments. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) defined three irrigation groups: OMW 50 and 100 m(3)/ha, OMW 200 m(3)/ha and control, and TWW treatment. The full factorial design revealed that OMW amendment by 100 m(3)/ha is the best irrigation treatment. Thus, the optimal performances in terms of olive oil quality and composition were shown by olive oil extracted from olives grown under irrigation with 100 m(3)/ha of OMW.

Oxidative stress generated by an excessive production of free radicals has been linked to the development of several health problems such as cardiovascular diseases. We investigated the protective efficacy of Extra Virgin Olive Oil (EVOO) and its lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) against the cardiotoxicity and DNA damage induced by co-exposure to aluminum (AlCl3) and acrylamide (ACR). Rats were divided into eight groups of six each: controls, AlCl3 (50 mg per kg body weight) administered via drinking water and ACR (20 mg per kg body weight) given by gavage, combined group plus EVOO (300 μl); combined group plus the hydrophilic fraction (1 ml); combined group plus the lipophilic fraction (300 μl); extra virgin olive oil (EVOO) and its fractions were administered daily by gavage for 21 days. Three other groups, considered as positive controls, received either EVOO, OOLF or OOLH. Exposure of rats to both AlCl3 and ACR provoked oxidative stress objectified by an increase in MDA, AOPP and a decrease in GSH, NPSH and vitamin C levels. The activities of CAT, GPx and SOD were also decreased. EVOO and its OOLF fraction exhibited a pronounced enhancement of antioxidant status while a partial recovery in the antioxidant status was obtained with the OOHF fraction. Plasma LDH and CK activities, TC, LDL-C levels, TC/HDL-C and LDL-C/HDL-C ratios were increased, while HDL-C and TG decreased in rats treated with both AlCl3 and ACR. Co-administration of EVOO, OOLF or OOHF to treated rats restored cardiac biomarkers and lipid profile to near-normal values. Histological studies and DNA damage confirmed the biochemical parameters and the beneficial role of EVOO and its two fractions. Our results suggest that extra virgin olive oil and its two fractions can decrease the frequency of cardiac complications and genotoxicity.

The neuroprotective effect of virgin olive oil (VOO) polyphenols has been related to their antioxidant effect. The main objective was to analyze how tyrosol and hydroxytyrosol contribute to the antioxidant and neuroprotective effects of VOO in a model of hypoxia-reoxygenation in rat brain slices. Rats were treated per os (po) (10 or 20 mg/kg/day) with hydroxytyrosol ethyl ether (HTEE), tyrosol ethyl ether (TEE), or 3,4-di-o-methylidene-hydroxytyrosol ethyl ether (MHTEE), used as a negative control for antioxidant effects. Lipid peroxidation was inhibited with HTEE, TEE, and MHTEE (from 5.0 ± 1.5 to 2.6 ± 1.5, 4.5 ± 1.5, and 4.8 ± 1.5 nmol/mg protein, respectively). However, all three compounds had similar neuroprotective effects: from 2.8 ± 0.07 to 1.8 ± 0.02 arbitrary units for HTEE, 1.4 ± 0.09 arbitrary units for TEE, and 1.3 ± 0.2 arbitrary units for MHTEE. All three compounds inhibited 3-nitrotyrosine production (from 3.7 ± 0.3 to 1.2 ± 0.03 nmol/0.1 g tissue for HTEE, 1.0 ± 0.2 nmol/0.1 g tissue for TEE, and 1.3 ± 0.1 nmol/0.1 g tissue for MHTEE), prostaglandin E2 production (from 55.7 ± 2.2 to 46.4 ± 1.9 pg/0.1 g tissue for HTEE, 24.7 ± 1.3 pg/0.1 g tissue for TEE, and 27.6 ± 2.6 pg/0.1 g tissue for MHTEE), whereas only HTEE inhibited IL1β production (from 35.7 ± 1.5 to 21.6 ± 0.8 pg/0.1 g tissue). Pearson correlation coefficients related neuroprotective effect with an antioxidant effect for HTEE (R = 0.72, p < 0.001), and inhibition of nitrosative stress (R = 0.78, 0.67, and 0.66 for HTEE, TEE, and MHTEE, respectively, p < 0.001) and inflammatory mediators (R = 0.72, 0.79, and 0.64 for HTEE, TEE, and MHTEE, respectively, p < 0.001) with all three compounds.

To investigate the variability of 4-monomethylsterols and 4,4'-dimethylsterols in olive oil as a result of variety, ripening, and storage temperature, 36 samples were subjected to gas chromatography with flame ionization detection (GC-FID) and with mass spectrometric detection (GC-MS), and results were processed by univariate and multivariate statistics. Relative amounts (percent) of β-amyrin, cycloartenol, and 24-methylenecycloartanol accounted for the most variation due to variety, while citrostadienol (percent) and 24-methylenecycloartanol (milligrams per 100 g) were strongly affected by ripening. Multivariate statistics differentiated olive oils regardless of storage conditions, which implied the possibility to use 4-monomethyl- and 4,4'-dimethylsterols as indicators of variety and ripening degree for fresh and stored oils. Absolute changes in 4-monomethyl- and 4,4'-dimethylsterols after storage were of a much smaller magnitude, meaning the investigated olive oils essentially retained health-beneficial features that derive from these compounds. Relative changes caused by storage were specific for each storage temperature and were useful in discriminating oils by linear discriminant analysis.

No previous information exists on the effects of water deficit on the phytoprostanes (PhytoPs) content in extra virgin olive oil from fruits of mature olive (Olea europaea L. cv. Cornicabra) trees during pit hardening. PhytoPs profile in extra virgin olive oil was characterized by the presence of 9-F1t-PhytoP, 9-epi-9-F1t-PhytoP, 9-epi-9-D1t-PhytoP, 9-D1t-PhytoP, 16-B1-PhytoP + ent-16-B1-PhytoP, and 9-L1-PhytoP + ent-9-L1-PhytoP. The qualitative and quantitative differences in PhytoPs content with respect to those reported by other authors indicate a decisive effect of cultivar, oil extraction technology, and/or storage conditions prone to autoxidation. The pit hardening period was critical for extra virgin olive oil composition because water deficit enhanced the PhytoPs content, with the concomitant potential beneficial aspects on human health. From a physiological and agronomical point of view, 9-F1t-PhytoP, 9-epi-9-F1t-PhytoP, and 16-B1-PhytoP + ent-16-B1-PhytoP could be considered as early candidate biomarkers of water stress in olive tree.

The purpose of this research was to characterize an olive core collection using some agronomic characters and simple sequence repeat (SSR) markers and to determine SSR markers associated with the content of fatty acids in olive oil. SSR marker analysis demonstrated the presence of a high amount of genetic variation between the olive cultivars analyzed. A UPGMA dendrogram demonstrated that olive cultivars did not cluster on the basis of their geographic origin. Fatty acid components of olive oil in these cultivars were determined. The results also showed that there was a great amount of variation between the olive cultivars in terms of fatty acid composition. For example, oleic acid content ranged from 57.76 to 76.9% with standard deviation of 5.10%. Significant correlations between fatty acids of olive oil were observed. For instance, a very high negative correlation (-0.812) between oleic and linoleic acids was detected. A structured association analysis between the content of fatty acids in olive oil and SSR markers was performed. STRUCTURE analysis assigned olive cultivars to two gene pools (K = 2). Assignment of olive cultivars to these gene pools was not based on geographical origin. Association between fatty acid traits and SSR markers was evaluated using the general linear model of TASSEL. Significant associations were determined between five SSR markers and stearic, oleic, linoleic, and linolenic acids of olive oil. Very high associations (P < 0.001) between ssrOeUA-DCA14 and stearic acid and between GAPU71B and oleic acid indicated that these markers could be used for marker-assisted selection in olive.

The effect of modifying polyphenol oxidase (PPO) and peroxidase (POX) activity during the extraction of virgin olive oil has been assessed in terms of its influence on the phenolic profile of the oil produced. These enzymes were modified by adding exogenous enzyme or specific inhibitors during the milling and subsequent kneading step, studying the effect on specific phenolic compounds in the oils. PPO is the main enzyme involved in phenolic oxidation at the milling step whereas POX activity seems to be the main influence during the kneading step. The data obtained suggest it is possible to increase the nutritional and organoleptic quality of virgin olive oil by inhibiting these enzymes during olive fruit processing. Treatment with the PPO inhibitor tropolone produced a twofold increase in the phenolic fraction, which would therefore seem to be an interesting strategy to improve the nutritional and organoleptic properties of virgin olive oil., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Olive processing wastewaters account for highly pollutant agro-industrial effluents. Their phenolic compounds are responsible for their toxicity. Those natural compounds have to be degraded or recovered before any discharge into the environment. This investigation deals with the extraction and concentration of the phenolic compounds into an aqueous phase using a mixture of nonionic/anionic surfactants. A synergistic effect for the extraction of the natural phenolic compounds was observed when Genapol X-80 was combined with sodium dodecyl sulphate (SDS). For the tested Genapol X-80 concentration (1-5%), a minimum concentration of 2.5 mM SDS was demonstrated to be necessary to reach maximum extraction rates. The extraction efficiencies were only slightly affected by temperatures between 20 and 50 °C. However, the recovery rate of the phenolic compounds increased with the augmentation of the contact time. The pH has also been found to greatly influence the extraction of the phenolic compounds and the coacervate volume fraction. At optimal conditions, the coacervate phase was enriched up to four times whereas the maximum reduction of the phenolic content in the diluted phase reached more than 40% in one step extraction.