Ligstroside Aglycone Research Articles

Single and Multiple Inoculum of Lactiplantibacillus plantarum Strains in Table Olive Lab-Scale Fermentations

In order to improve the olives’ quality, and to reduce the de-bittering time during the table olive fermentation process, it is necessary to pilot the fermentation by inoculating the brine with selected cultures of microorganisms. Some probiotic tests, such as resistance/sensitivity to antibiotics, bile salt hydrolase (BSH) activity, growth at acidic pH, an auto-aggregation assay, and a test of the production of exopolysaccharides, were carried out in order to screen 35 oleuropeinolytic Lactiplantibacillus plantarum subsp. plantarum strains to be used in guided fermentations of table olives. On the basis of the technological and probiotic screening, we analyzed the progress of three different lab-scale fermentations of Olea europaea L. Itrana cv. olives inoculated with spontaneous, single, and multiple starters: jar A was left to ferment spontaneously; jar B was inoculated with a strongly oleuropeinolytic strain (L. plantarum B1); jar C was inoculated with a multiple inoculum (L. plantarum B1 + L. plantarum B51 + L. plantarum B124). The following parameters were monitored during the fermentation: pH, titratable acidity, NaCl concentration, the degradation of bio-phenols, and the enrichment rate of hydroxytyrosol and tyrosol in the olive’s flesh, oil and brine. The degradation of secoiridoid glucosides appeared to be faster in the inoculated jars than in the spontaneously-fermented jar. The production of hydroxytyrosol and ligstroside aglycons was high. This indicated a complete degradation of the oleuropein and a partial degradation of the ligstroside. The multiple inoculum ensured a complete debittering, and could give probiotic traits. The presence of L. plantarum B1 and B124 as a fermentation starter guarantees an optimal trend of de-bittering and fermentation variables, thus ensuring the production of a better final product. L. plantarum B51 could be considered to be a promising probiotic candidate for obtaining probiotic food of completely vegetable origin.

Characterization of Phenolic Compounds, Vitamin E and Fatty Acids from Monovarietal Virgin Olive Oils of "Picholine marocaine" Cultivar.

Olive oil is an important product in the Mediterranean diet, due to its health benefits and sensorial characteristics. Picholine marocaine is the most cultivated variety in Morocco. The present research aims to evaluate the phenolic compounds, vitamin E and fatty acids of commercial Picholine marocaine virgin olive oils (VOOs) from five different North Moroccan provinces (Chefchaouen, Taounate, Errachidia, Beni Mellal and Taza), using HPLC-photodiode array (PDA)/electrospray ionization (ESI)-MS, normal phase (NP)-HPLC/ fluorescence detector (FLD) and GC-flame ionization detector (FID)/MS, respectively. The obtained results showed an average content of 130.0 mg kg−1 of secoiridoids (oleuropein aglycone, 10-hydroxy-oleuropein aglycone and ligstroside aglycone, oleocanthal and oleacein), 108.1 mg kg−1 of phenolic alcohols (tyrosol and hydroxytyrosol), 34.7 mg kg−1 of phenolic acids (caffeic acid, ferulic acid and elenolic acid), and 8.24 mg kg−1 of flavonoids (luteolin, luteolin glucoside, apigenin). With regard to vitamin E, α-tocopherol was the most abundant vitamin E (57.9 mg kg−1), followed by α-tocotrienol (2.5 mg kg−1), γ-tocopherol (4.5 mg kg−1) and β-tocopherol (1.9 mg kg−1), while δ-tocopherol was not detected. Moreover, 14 fatty acids were found and, among them, oleic acid (76.1%), linoleic acid (8.1%) palmitic acid (8.7%) and stearic acid (2.5%) were the major fatty acids detected. Finally, heat map and principal component analysis allowed us to classify the studied provinces in terms of VOO chemical composition: Chefchaouen (tyrosol and hydroxytyrosol), Taounate (oleuropein aglycone), Errachidia (ferulic acid, w-3 and w-6), Beni Mellal (oleocanthal) and Taza (luteolin and oleic acid).

Insight into the Storage-Related Oxidative/Hydrolytic Degradation of Olive Oil Secoiridoids by Liquid Chromatography and High-Resolution Fourier Transform Mass Spectrometry.

The study of negative effects potentially exerted by the exposure to oxygen and/or light and, thus, also by the type of container on the quality of extra virgin olive oil (EVOO) during its prolonged storage requires an appropriate choice of analytical methods and components to be monitored. Here, reverse-phase liquid chromatography coupled to high-resolution/accuracy Fourier transform mass spectrometry with electrospray ionization was exploited to study oxidative/hydrolytic degradation processes occurring on the important bioactive components of EVOO known as secoiridoids, i.e., oleuropein and ligstroside aglycones, oleacin, and oleocanthal, during storage up to 6 months under controlled conditions. Specifically, isomeric oxidative byproducts resulting from the transformation of a carbonylic group of the original secoiridoids into a carboxylic group and compounds resulting from hydrolysis of the ester linkage of secoiridoids, i.e., elenolic and decarboxymethyl elenolic acids and tyrosol and 3-hydroxytyrosol, were monitored, along with their precursors. Data obtained from EVOO storage at room temperature in glass bottles with/without exposure to light and/or oxygen indicated that, although it was more relevant if a periodical exposure to oxygen was performed, a non-negligible oxidative degradation occurred on secoiridoids also when nitrogen was used to saturate the container headspace. In a parallel experiment, the effects of storage of the same EVOO (250 mL) for up to 6 months in containers manufactured with different materials/shapes were considered. In particular, a square dark glass bottle, a stainless-steel can, and a ceramic jar, typically used for EVOO commercialization, and a clear polyethylene terephthalate bottle, purposely chosen to prompt secoiridoid degradation through exposure to light and oxygen, were compared. Dark glass was found to provide the best combined protection of major secoiridoids from oxidative and hydrolytic degradation, yet the lowest levels of oxidized byproducts were observed when the stainless-steel can was used.

Pilot continuous centrifugal liquid-liquid extraction of extra virgin olive oil biophenols and gram-scale recovery of pure oleocanthal, oleacein, MFOA, MFLA and hydroxytyrosol

This study provides an efficient pilot-scale liquid-liquid extraction process for the recovery of total phenolic fraction (TPF) from extra virgin olive oil (EVOO) and the further purification of the major TPF constituents (oleocanthal, oleacein, monoaldehydic form of oleuropein aglycone, monoaldehydic form of ligstroside aglycone and hydroxytyrosol) using successively centrifugal partition chromatography and reversed phase high performance liquid chromatography. Special attention was paid for the selection of the appropriate raw material, which should be rich in the targeted high-value compounds. For the extraction of the selected EVOOs, a green technique based on liquid-liquid partitioning using the biphasic system n-Hept/EVOO/EtOH/H2O 3:2:3:2 v/v was carried out, first on pioneering laboratory-scale annular centrifugal extractor (ACE) and then on pilot device. 240 L from three different EVOOs (3x80 L of each EVOO) were extracted yielding 285 g of TPF in approximately 2 h. The second step of this procedure was the purification of the target compounds. A preparative centrifugal partition chromatography (CPC) process was firstly applied for the initial TPF fractionation using a step gradient elution-extrusion method with a series of 4 biphasic systems composed of n-Hept/EtOAc/EtOH/H2O in ratios 4:1:3:2, 3:2:3:2, 2:3:3:2 and 1:4:3:2 (v/v/v/v). Preparative reversed phase high performance liquid chromatography (prep-RP-HPLC) was then carried out to polish the target compounds from the enriched CPC fractions resulting in purity higher than 97%. In parallel, the above purification analysis led to the isolation of four minor TPF constituents of which three are new natural products (EDA lactone, (1R, 8E)-1-ethoxy-ligstroside aglycon and (1S, 8E)-1-ethoxy-ligstroside aglycon) and one ((9E, 11E)-13-oxotrideca-9,11-diencoic acid) is described for the first time as EVOO constituent.

Evaluation of Italian extra virgin olive oils based on the phenolic compounds composition using multivariate statistical methods

The content of 40 phenolic compounds was determined in 68 samples of extra virgin olive oils (EVOOs) coming from 9 Italian regions using high-performance liquid chromatography coupled to diode array detector and mass spectrometry. Oleuropein isomers (M = 540 g/mol) and derivatives (M = 378 g/mol) together with ligstroside aglycone isomers (M = 362 g/mol) and derivatives (M = 394 g/mol) were the major EVOOs compounds (median of 44–228 mg/kg). On the other hand, verbascoside isomers (M = 624 g/mol) and apigenin (M = 270 g/mol) were the minor compounds (median < 2 mg/kg). Different techniques of multivariate data analysis were applied to find important parameters for discrimination of EVOOs. Principal component analysis and factor analysis distributed the samples into two groups according to the total amount of phenols and quantity of elenolic acid giving information about ripeness of olives. Linear discriminant analysis successfully classified the samples according to their geographical origin into three groups (Northern Italy, Southern Italy, and Sicily).

Ligstroside aglycone as a novel nutraceutical in treatment of osteoarthritis

Purpose: Osteoarthritis (OA) is a degenerative disease of the joints characterised by the imbalance of anabolic and catabolic processes in articular cartilage. It is one of the most significant causes of disability in the world affecting over 60% of people over the age of 60, causing joint stiffness, pain and a decrease in the quality of life. Currently no successful disease-modifying agent has been found to prevent or treat the condition. To address this unmet need, alternative approaches, including the use of nutraceuticals as a novel therapeutic intervention are under examination.

Purified oleocanthal and ligstroside protect against mitochondrial dysfunction in models of early Alzheimer's disease and brain ageing

As components of the Mediterranean diet (MedDiet) olive polyphenols may play a crucial role for the prevention of Alzheimer's disease (AD). Since mitochondrial dysfunction is involved in both, brain ageing and early AD, effects of 10 different purified phenolic secoiridoids (hydroxytyrosol, tyrosol, oleacein, oleuroside, oleuroside aglycon, oleuropein, oleocanthal, ligstroside, ligstroside aglycone and ligustaloside B) and two metabolites (the plant metabolite elenolic acid and the mammalian metabolite homovanillic acid) were tested in very low doses on mitochondrial function in SH-SY5Y-APP695 cells - a cellular model of early AD. All tested secoiridoids significantly increased basal adenosine triphosphate (ATP) levels in SY5Y-APP695 cells. Oleacein, oleuroside, oleocanthal and ligstroside showed the highest effect on ATP levels and were additionally tested on mitochondrial respiration. Only oleocanthal and ligstroside were able to enhance the capacity of respiratory chain complexes. To investigate their underlying molecular mechanisms, the expression of genes associated with mitochondrial biogenesis, respiration and antioxidative capacity (PGC-1α, SIRT1, CREB1, NRF1, TFAM, complex I, IV and V, GPx1, SOD2, CAT) were determined using qRT-PCR. Exclusively ligstroside increased mRNA expression of SIRT1, CREB1, complex I, and GPx1. Furthermore, oleocanthal but not ligstroside decreased Aβ 1–40 levels in SH-SY5Y-APP695 cells. To investigate the in vivo effects of purified secoiridoids, the two most promising compounds (oleocanthal and ligstroside) were tested in a mouse model of ageing. Female NMRI mice, aged 12 months, received a diet supplemented with 50 mg/kg oleocanthal or ligstroside for 6 months (equivalent to 6.25 mg/kg b.w.). Young (3 months) and aged (18 months) mice served as controls. Ligstroside fed mice showed improved spatial working memory. Furthermore, ligstroside restored brain ATP levels in aged mice and led to a significant life extension compared to aged control animals. Our findings indicate that purified ligstroside has outstanding performance on mitochondrial bioenergetics in models of early AD and brain ageing by mechanisms that may not interfere with Aβ production. Additionally, ligstroside expanded the lifespan in aged mice and enhanced cognitive function.

Characterization of Extra Virgin Olive Oil from Southern Brazil

AbstractSix olive oils extracted from the cultivars Arbequina, Arbosana, Coratina, Frantoio, Koroneiki, and Picual from 2017 and 2018 harvests, cultivated in Pinheiro Machado, Rio Grande do Sul, Brazil, are evaluated for standard oil composition parameters and bioactive constituents (pigments, tocopherols, and phenolic compounds). Multivariate principal component analysis (PCA) and univariate ANOVA and Fisher's LSD test are used to verify the effect of cultivar and harvest year on oil composition. Olive oil composition met extra virgin olive oil (EVOO) standard parameters and is influenced by both cultivar and harvest year. EVOO produced in 2018 has greater chlorophyll, caffeic acid, ligstroside aglycone, hydroxyoleuropein aglycone, syringic acid, and hydroxytyrosol acetate contents than the EVOOs from 2017. Linoleic acid, ferulic acid, ligstroside aglycone, and hydroxytyrosol acetate are the variables whose contents most contributed to the differentiation of oils by cultivar in both harvest years. Chemical characterization analyses allow for the differentiation of oil composition based on harvest year and cultivar. Metabolic quality data obtained here support the establishment of a local EVOO profile and the compounds that most contributed to treatment differentiation may serve as markers that can be utilized in determining origin, cultivar, and harvest year.Practical Applications: Olive production in Brazil is recent and is based on European cultivars which have not been bred for the local environmental conditions. Therefore, the measurement of olive oil metabolic quality will determine cultivar adaptability to local edaphoclimatic conditions as well as assist in the establishment of a standard of identity for the product and promote the development of its market. Olive oil produced in Southern Brazil shows high quality, and is especially rich in phenolic compounds. Although harvest year influences oil composition, oil from both harvests meet EVOO standards and cultivar specific metabolic markers are observed. This study provides the foundation for olive producers in Southern Brazil to seek authentication of the geographical origin of olive oil.

Osteoarthritis treatment with a novel nutraceutical acetylated ligstroside aglycone, a chemically modified extra-virgin olive oil polyphenol

Recent studies have shown that dietary patterns confer protection from certain chronic diseases related to oxidative stress, the immune system and chronic low-grade inflammatory diseases. The aim of this study was to evaluate the anti-inflammatory potential and the capacity to attenuate cartilage degradation using extra-virgin olive oil–derived polyphenols for the treatment of osteoarthritis. Results show that both nutraceuticals ligstroside aglycone and acetylated ligstroside aglycone showed an anti-inflammatory profile. Acetylated ligstroside aglycone significantly reduced the expression of pro-inflammatory genes including NOS2 and MMP13 at both RNA and protein levels; decreased nitric oxide release; and, importantly, reduced proteoglycan loss in human osteoarthritis cartilage explants. Our study demonstrated that a new synthetic acetylated ligstroside aglycone derivative offers enhanced anti-inflammatory profile than the natural nutraceutical compound in osteoarthritis. These results substantiate the role of nutraceuticals in osteoarthritis with implications for therapeutic intervention and our understanding of osteoarthritis pathophysiology.

Direct determination of phenolic secoiridoids in olive oil by ultra-high performance liquid chromatography-triple quadruple mass spectrometry analysis

In recent years, a large number of biological properties and an important role in the organoleptic characteristics of olive oil have been attributed to phenolic secoiridoids, such as oleacein, oleocanthal, oleuropein aglycone and ligstroside aglycone. Consequently, quantifying them is of great interest for the olive oil sector. Currently, there is no consensus in which analytical method must be use to accurately determine these compounds in olive oil, mainly owing to the lack of reference standards for calibration. In this work, analytical standards of phenolic secoiridoids have been used to develop a quantitative and rapid analytical method by UHPLC-MS/MS, in which sample extraction is not carried out. Simple dilutions of the sample with dry tetrahydrofuran and dry acetonitrile were performed before analysing them. It is worth noting that under these conditions the generation of artefacts such as acetals and hemiacetals of the aldehydic forms is highly reduced. The detection and quantification was performed with a Xevo TQS tandem quadrupole mass spectrometer. The method was validated at four concentration levels and finally applied to six samples of extra virgin olive oil.

Anti-Proliferative Effects of an Extra-Virgin Olive Oil Extract Enriched in Ligstroside Aglycone and Oleocanthal on Human Liver Cancer Cell Lines.

Oleocanthal and ligstroside aglycone are olive oil-derived polyphenols. The former interferes with tumor growth with minor or no cytotoxicity on non-tumorigenic primary cell lines. The information about the bioactivity of ligstroside aglycone are scanty, with the exception of a known antioxidant power. Hepatocellular carcinoma is a malignant tumor with high mortality rates. Systemic chemotherapy is only marginally effective and is frequently complicated by toxicity. Previous observations have shown that hepatocellular carcinoma cell lines become more sensitive to taxol when it is combined with Tumor Necrosis Factor α (TNFα). The present work aimed to assess the effects of a polyphenolic extract containing both oleocanthal and ligstroside aglycone on proliferation and/or death in three liver cancer cell lines (HepG2, Huh7 and Hep3B). The possibility to enhance such effect by the addition of TNFα was also investigated. Both cell proliferation and death were enhanced by the exposure to the polyphenolic extract. Such effect was associated with induction of autophagy and could be potentiated by TNFα. The presence of ligstroside aglycone in the extract lowered the oleocanthal concentration required for cytotoxicity. These results show for the first time that the effects of a polyphenol extract can be potentiated by TNFα and that modulation of autophagy likely account for these effects.

Structural characterization of the ligstroside aglycone isoforms in virgin olive oils by liquid chromatography-high-resolution Fourier-transform mass spectrometry and H/Dexchange.

A systematic structural characterization of the isomeric forms related to ligstroside aglycone (LA), one of the most relevant secoiridoids contained in virgin olive oils, was performed using reverse phase liquid chromatography with electrospray ionization Fourier-transform single and tandem mass spectrometry, operated in negative ion mode (RPLC-ESI(-)-FTMS and FTMS/MS). The high mass resolution and accuracy provided by the adopted orbital trap mass analyzer enabled the recognition of more than 10 different isomeric forms of LA in virgin olive oil extracts. They were related to four different types of molecular structure, two of which including a dihydropyranic ring bearing one or two aldehydic groups, whereas the others corresponded to dialdehydic open-structure forms, differing just for the position of a C═C bond. The contemporary presence of enolic or dienolic tautomers associated to most of these compounds, stable at room temperature (23°C), was also assessed through RPLC-ESI-FTMS analyses operated under H/D exchange conditions, ie, by using D2 O instead of H2 O as co-solvent of acetonitrile in the RPLC mobile phase. As discussed in the paper, the results obtained for LA indicated a remarkable structural similarity with oleuropein aglycone (OA), the most abundant secoiridoid of olive oil, whose isoforms had been previously characterized using the same analytical approach.

Multivariate approach to assess the chemical composition of Italian virgin olive oils as a function of variety and harvest period

Fatty acids, phenolic compounds, and tocopherols of Coratina, Bosana, Semidana, and Tonda di Cagliari virgin olive oils, were measured over a 45-day harvest period. Phenolic composition was the primary factor distinguishing Bosana, Tonda di Cagliari, and Semidana, whereas fatty acids differentiated Coratina and the other cultivars. Harvest period principally influenced oleacein, oleocanthal, oleuropein and ligstroside aglycones, and flavonoids. High phenolic content was observed for Coratina (1039–688 mg/kg) and Bosana (788–592 mg/kg). A drastic decrease in phenolic content was observed in Semidana (529–134 mg/kg) and Tonda di Cagliari (507–142 mg/kg) during the harvest period. These two cultivars also had low MUFA/PUFA (6.0–4.0 and 4.9–3.2 respectively), suggesting that these varieties should be harvested earlier in the season. These results provide information to producers for improved management of the harvesting process, which is strongly affected by varietal factors.

Modification of Phenolic Compounds and Volatile Profiles of Chemlali Variety Olive Oil in Response to Foliar Biofertilization

AbstractThe main objective of this work was to study the effects of foliar biofertilizers on individual volatile profiles and phenolic compounds of olive oil (Olea europaea L. cv. Chemlali). Three foliar biofertilizers were used in two successive application seasons: T1 (rich in nitrogen, phosphorus and potassium); T2 (rich in calcium); and T3 (application of both T1 and T2). Results showed that foliar fertilization with T2 increased the phenolic compound contents (e.g., oleuropein aglycone and decarboxymethyl ligstroside aglycone) of Chemlali olive oil. It also enhanced the levels of many volatile compounds responsible for the good flavor of olive oil such as hexanal. However, T1‐tested fertilizer led to a significant decrease in the content of phenolic compounds, although they seemed to improve significantly the levels of the majority of volatile compounds, especially hexanal. Based on these results, a significant relationship between plant nutrition and quality of oil was observed. Our results demonstrated a potential positive influence on the concentration of sensory quality compounds under T2 (Ca2+‐based fertilizer). This result should be considered in the design of foliar nutrient application management strategies for olive trees.

Quality and chemical profiles of virgin olive oils of three European cultivars suitable for super-high-density planting conditions in eastern Morocco

This study aims to evaluate the quality and chemical composition of virgin olive oils of Greek (Koroneiki) and Spanish (Arbequina and Arbosana) varieties grown in north-eastern Morocco under irrigated super-high-density planting system, via the study of their minor compounds, fatty acid and triacylglycerol compositions, and oxidative stability. The majority of the evaluated parameters are influenced by varietal and environmental factors. The studied varieties produced good quality oils with a chemical composition that meets the requirements of the International Olive Council. Koroneiki oil has the highest levels of total phenols (530 mg kg-1) and C18:1 (76.70%) as well as the better stability to oxidation (98.64h). Arbosana oil is distinguished by the abundance of tocopherols (449.27 mg kg-1) and an intermediate oxidative stability (74.49 h). The highest phytosterol content was recorded in Arbequina oil (1971 mg kg-1). Eleven phenolic compounds were identified and quantified. Decarboxymethylated forms of oleuropein aglycone and ligstroside aglycone were the main components in all the analyzed oils (95-165 mg kg-1 and 115-181 mg kg-1, respectively).The results of principal component analysis show a clear discrimination between the studied varieties according to antioxidant parameters, triacylglycerol and phytosterol data.

Fatty Acids and Phenolic Profiles of Extravirgin Olive Oils from Selected Italian Cultivars Introduced in Southwestern Province of Pakistan.

Mediterranean olive trees have been cultivated in Pakistan for decades to promote olive cultivation and use of olive oil. The qualitative characteristics of seven mono and one multi-varietal extra virgin olive oils (EVOOs) extracted from Italian cultivars grown in different areas of Balochistan a southwestern province of Pakistan were evaluated. Present study aims to assess the impact of bioclimatological change on biochemical profile of exotic cultivars. The dominating fatty acids found in analyzed EVOOs were oleic (65-72%), linoleic (10.61-18.33%) and palmitic acids (12-16%). The tocopherols α, (β+γ) and δ contents showed a great diversity which ranged from (60-408) mg/kg while, total phenol concentration ranged from (200-370) mg/kg. The analyses of phenolic compounds revealed the presence of phenolic acids, phenolic alcohols, secoiridoids, flavonoids, oleuropein and verbascosides. One-way ANOVA revealed significant differences (p < 0.05) regarding studied parameters. Principal component analysis (PCA) was applied to identify the main components and to classify samples into groups in terms of fatty acids and phenolic profiles. The first group (Frantoio, Moraiolo, Pendolino, Multi-varietal mixture) characterized by high amount of oleic acid and MUFAs/PUFAs ratio. The second group (Maurino and Leccino) correlates with SFAs and third (Ottobrattica, Coratina) with PUFAs. Based on the PCA of phenolic profile the studied cultivars were divided into two main groups. Morialo, Pendolino and Maurino correlated with (phenolic acids, hydroxytyrosol, flavonoids and secoiridoids). Frantoio, Ottobrattica, Coratina, multi-varietal and Leccino were correlated with oleuropein, tyrosol and ligstroside aglycon. The obtained data was compared with those obtained from same cultivars in their original and/or different growing area. Marked differences were observed in the composition of oleic, linoleic, palmitic acids, secoiridoids and total phenolic contents. These differences could be due to change in geographical location and climatical condition of Balochistan. The cultivar Moraiolo has shown best adaptation and preserved its biochemical composition among all studied cultivars.

Monitoring the volatile and hydrophilic bioactive compounds status of fresh and oxidized Chemlali virgin olive oils over olive storage times

The virgin olive oils (VOOs) under examination were from the main Tunisian cultivar ‘Chemlali’. Olive fruits used for oil production were stored in plastic containers for four weeks at ambient temperature. Hydrophilic bioactive compounds and volatile profiles of the corresponding oils were analyzed. Chemometric analysis showed that VOO obtained from fruits stored during one week is similar to that of freshly harvested fruits. They preserved their bioactive and volatile molecular markers of freshness with the predominance of the secoiridoid aldehydic form of oleuropeine aglycon, and the C6 lipoxygenase products. However, VOO obtained from fruits stored for a long time, showed degradation of the derivatives of oleuropeine and ligstroside aglycons, a decrease in the lignan, and flavonoid groups, whereas phenolic acids showed a remarkable increase. The volatile profile was characterized by a decrease in the LOX products, and biosynthesis of the volatile molecular markers of oxidation C7-C10 aldehydes (nonanal, decanal, (Z) and (E)-2-heptenal, (E)-2-octenal, and (E,E)-2,4-heptadienal), and hydrocarbons (n-dodecane, and n-tetradecane). Mono and sesquiterpenes showed also an increase over storage time. Consequently, and in order to avoid deterioration of VOO composition, chemometric analysis showed that the olive fruits should be processed as soon as possible after being harvested, with a maximum storage time of one week.

Oleocanthalic Acid, a Chemical Marker of Olive Oil Aging and Exposure to a High Storage Temperature with Potential Neuroprotective Activity.

The investigation of olive oils stored for a period of 24 months under appropriate conditions (25 °C, dark place, and airtight container) led to the identification of a new major phenolic ingredient, which was named oleocanthalic acid. The structure of the new compound was elucidated using one- and two-dimensional nuclear magnetic resonance in combination with tandem mass spectrometry. The new compound is an oxidation product of oleocanthal and is found in fresh oils in very low concentrations. The concentration of oleocanthalic acid increased with storage time, while the oleocanthal concentration decreased. A similar increase of the oleocanthalic acid/oleocanthal ratio was achieved after exposure of olive oil to 60 °C for 14 days. Although the presence of an oxidized derivative of decarboxymethylated ligstroside aglycon had been reported, it is the first time that its structure is characterized. The isolated compound could induce the expression of amyloid-β major transport proteins as well as tight junctions expressed at the blood-brain barrier, suggesting that oleocanthalic acid could be beneficial against Alzheimer's disease.

Characterization of phenolic extracts from Brava extra virgin olive oils and their cytotoxic effects on MCF-7 breast cancer cells

The aim of the present work was to evaluate the phenolic profile of the ‘Brava’ extra virgin olive oil and assess its potential as a “natural adjuvant” in combination with chemotherapy treatment. The total phenol content of the phenolic extracts was 764 mg gallic acid equivalents/kg and the total antioxidant capacity was 2309, 1881 and 2088 μM trolox equivalents/kg determined by Diphenyl-1-picrylhydrazyl free radical method, Ferric Reducing Antioxidant Power and Trolox Equivalent Antioxidant Capacity assay, respectively. Secoiridoids comprised 83% of the total phenolic compounds. The main secoiridoid from oleuropein was the main isomer of oleuropein aglycone (74 mg/kg). The main secoiridoid from ligstroside was the main isomer of ligstroside aglycone (214 mg/kg). These phenolic extracts showed a significant decrease in cell viability on MCF-7 breast cancer cells in a dose and time dependent manner. 48 h-treatments with different concentrations of the extracts induced intracellular ROS generation and cell death.

Bioactive compounds from extra virgin olive oils: Correlation between phenolic content and oxidative stress cell protection

When compared with other edible vegetable oils, the extra virgin olive oil (EVOO) exhibits excellent nutritional properties due to the presence of biophenolic compounds. Although they constitute only a very small amount of the unsaponifiable fraction of EVOO, biophenols strongly contribute to the sensorial properties of this precious food conferring it, for example, the bitter or pungent taste. Furthermore, it has been found that biophenols possess beneficial effects against many human pathologies such as oxidative stress, inflammation, cardiovascular diseases, cancer and aging-related illness. In the present work, the biophenolic content of 51 Italian and Spanish EVOOs was qualitatively and quantitatively identified and their antioxidant ability analyzed by oxygen radical absorbance capacity (ORAC) assay. Results indicated that the maximum relationship can be found if the ORAC value is correlated with the concentration of the large family composed by ligstroside and oleuropein derivatives together with their degradation products, hydroxytyrosol and tyrosol. Then, selected biophenolic extracts were tested in NIH-3T3 cell line to verify their ability in the recovery of the oxidative stress revealed by DCFH-DA assay. Results were linearly correlated with the concentration of ligstroside aglycone (aldehyde and hydroxyl form).