Chemistry and health of olive oil phenolics

Cardiovascular and Metabolic Benefits of Extra Virgin Olive Oil Phenolic Compounds: Mechanistic Insights from In Vivo Studies

Extra virgin olive oil (EVOO) represents a significant source of monounsaturated fatty acids (MUFA) and vitamin E, but it is also considered a functional food, due to the content of peculiar bioactive molecules, such as phenolic compounds, being able to modulate various processes related to aging and the most common metabolic and degenerative diseases. A lot of experimental research has focused on some of these components, but in most cases, the studies were performed in vitro testing compounds at non-physiological concentrations and achieving results that cannot easily be translated in vivo. Recent clinical studies demonstrated that in vivo these compounds are able to regulate physiological functions and prevent several pathological events including metabolic and cardiovascular diseases (CVDs), which represent the main causes of death worldwide. This review aims to sum up the major evidence on the beneficial effects of EVOO phenolic compounds in vivo on these pathologies, describing and evaluating the efficacy in relation to the mechanisms of diseases of the whole phenolic fraction and some of its specific components.

Evaluation of the protective and therapeutic effects of extra virgin olive oil rich in phenol in experimental model of neonatal necrotizing enterocolitis by clinical disease score, ınflammation, apoptosis, and oxidative stress markers

BACKGROUND AND AIM

Necrotizing Enterocolitis (NEC) is an inflammation-associated ischemic necrosis of the intestine. To investigate the effects of extra virgin olive oil (EVOO) on inflammation, oxidative stress, apoptosis, and histological changes in NEC-induced newborn rats.

MATERIALS AND METHODS

24 rats were randomly divided into three groups: control, NEC and NEC + EVOO. NEC induction was performed using hypoxia-hyperoxia, formula feeding, and cold stress. The NEC + EVOO group received 2 ml/kg EVOO with high phenolic content by gavage twice a day for 3 days. 3 cm of bowel including terminal ileum, cecum, and proximal colon was excised.

RESULTS

Weight gain and clinical disease scores were significantly higher in the NEC + EVOO group than in the NEC group (p < 0.001). EVOO treatment caused significant decreases in IL1β, IL6 levels (p = 0.016, p = 0.029 respectively) and EGF, MDA levels (p = 0.032, p = 0.013 respectively) compared to NEC group. Significant decreases were observed in IL6 gene expression in the NEC + EVOO group compared to the NEC group (p = 0.002). In the group NEC + EVOO, the number of Caspase-3 positive cells was found to be significantly reduced (p < 0.001) and histopathological examination revealed minimal changes and significantly lower histopathological scores (p < 0.001).

CONCLUSION

Phenol-rich EVOO prevents intestinal damage caused by NEC by inhibiting inflammation, oxidative stress, apoptosis.

Alternative Assisted Extraction Methods of Phenolic Compounds Using NaDESs

A renewed understanding of eco-friendly principles is moving the industrial sector toward a shift in the utilization of less harmful solvents as a main strategy to improve manufacturing. Green analytical chemistry (GAC) has definitely paved the way for this transition by presenting green solvents to a larger audience. Among the most promising, surely DESs (deep eutectic solvents), NaDESs (natural deep eutectic solvents), HDESs (hydrophobic deep eutectic solvents), and HNaDESs (hydrophobic natural deep eutectic solvents), with their unique features, manifest a wide-range of applications, including their use as a means for the extraction of small bioactive compounds. In examining recent advancements, in this review, we want to focus our attention on some of the most interesting and novel 'solvent-free' extraction techniques, such as microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) in relation to the possibility of better exploiting DESs and NaDESs as plausible extracting solvents of the phenolic compounds (PCs) present in different matrices from olive oil components, such as virgin olive pomace, olive leaves and twigs, virgin and extra virgin olive oil (VOO and EVOO, respectively), and olive cake and olive mill wastewaters (OMWW). Therefore, the status of DESs and NaDESs is shown in terms of their nature, efficacy and selectivity in the extraction of bioactive phytochemicals such as secoiridoids, lignans, phenolic acids and alcohols. Related studies on experimental design and processes' optimization of the most promising DESs/NaDESs are also reviewed. In this framework, an extensive list of relevant works found in the literature is described to consider DESs/NaDESs as a suitable alternative to petrochemicals in cosmetics, pharmaceutical, or food applications.

Applications of Plant Bioactive Compounds as Replacers of Synthetic Additives in the Food Industry

According to the Codex Alimentarius, a food additive is any substance that is incorporated into a food solely for technological or organoleptic purposes during the production of that food. Food additives can be of synthetic or natural origin. Several scientific evidence (in vitro studies and epidemiological studies like the controversial Southampton study published in 2007) have pointed out that several synthetic additives may lead to health issues for consumers. In that sense, the actual consumer searches for "Clean Label" foods with ingredient lists clean of coded additives, which are rejected by the actual consumer, highlighting the need to distinguish synthetic and natural codded additives from the ingredient lists. However, this natural approach must focus on an integrated vision of the replacement of chemical substances from the food ingredients, food contact materials (packaging), and their application on the final product. Hence, natural plant alternatives are hereby presented, analyzing their potential success in replacing common synthetic emulsifiers, colorants, flavorings, inhibitors of quality-degrading enzymes, antimicrobials, and antioxidants. In addition, the need for a complete absence of chemical additive migration to the food is approached through the use of plant-origin bioactive compounds (e.g., plant essential oils) incorporated in active packaging.

Chemical composition and antimicrobial activity of essential oils of two wild olive subspecies Olea europaea L.var. sylvestris and the endemic olive Olea europaea subsp. lapperinie from Algeria

Two wild olive subspecies are fixed in this research: Olea europaea L.var. sylvestris and Olea europaea subsp. laperrinei despite its ecological value, the chemical composition of subsp. laperrinei oil remains unknown. The samples were harvested from the different geographical area. Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-flame-ionization detection (GC-FID) analysis of Olea europaea L. var. sylvestris allowed the identification of 29 compounds oil with Nonanal (11.82%), theaspiranea A (9.81%), 3-hexen-1-ol,benzoate(9.31%) as a major constituents, while in the subspecies of the Saharan region 31 compounds were separated, where α-pinene (16%), β-Ocimene (12.82%), dl-Limonene (8.20%) were the main components. The results of the disc diffusion method showed that the two volatile oils have efficient antibacterial activity but, subsp. laperrinei essential oil has a higher range of inhibition, in which P. aeruginosa and B. subtilis showed an extreme sensitivity, while the K. pneumoniae bacterium shows a great resistance to the two essential oils.

The Chemical Composition and Health-Promoting Benefits of Vegetable Oils-A Review

With population and economic development increasing worldwide, the public is increasingly concerned with the health benefits and nutritional properties of vegetable oils (VOs). In this review, the chemical composition and health-promoting benefits of 39 kinds of VOs were selected and summarized using Web of Science TM as the main bibliographic databases. The characteristic chemical compositions were analyzed from fatty acid composition, tocols, phytosterols, squalene, carotenoids, phenolics, and phospholipids. Health benefits including antioxidant activity, prevention of cardiovascular disease (CVD), anti-inflammatory, anti-obesity, anti-cancer, diabetes treatment, and kidney and liver protection were examined according to the key components in representative VOs. Every type of vegetable oil has shown its own unique chemical composition with significant variation in each key component and thereby illustrated their own specific advantages and health effects. Therefore, different types of VOs can be selected to meet individual needs accordingly. For example, to prevent CVD, more unsaturated fatty acids and phytosterols should be supplied by consuming pomegranate seed oil, flaxseed oil, or rice bran oil, while coconut oil or perilla seed oil have higher contents of total phenolics and might be better choices for diabetics. Several oils such as olive oil, corn oil, cress oil, and rice bran oil were recommended for their abundant nutritional ingredients, but the intake of only one type of vegetable oil might have drawbacks. This review increases the comprehensive understanding of the correlation between health effects and the characteristic composition of VOs, and provides future trends towards their utilization for the general public's nutrition, balanced diet, and as a reference for disease prevention. Nevertheless, some VOs are in the early stages of research and lack enough reliable data and long-term or large consumption information of the effect on the human body, therefore further investigations will be needed for their health benefits.

Oil Pulling and Polyphenols: Treatment of Gingivitis Patients with 'Itri Extra-Virgin Olive Oil'

OBJECTIVES

The aim of the study was to evaluate the effectiveness of extra virgin olive (EVO) oil and fruity oil for the treatment of gingivitis.

MATERIALS AND METHODS

A sample of 75 patients over 18 years of age with gingivitis induced by plaque bacteria was divided into three groups: study group A, with extra virgin olive oil; study group B, with fruity oil; and control group C. In the two study groups, EVO oil was administered as a mouthwash to patients with gingival inflammation. The protocol included a daily application of the product for 30 days, with three recalls 15 days apart. Clinical parameters of plaque formation and gingivitis, including plaque index (PI) and bleeding index (BI), were assessed at each recall and scored on a specific periodontal chart. The control group received no mouthwash treatment in addition to normal daily oral hygiene procedures, and the same clinical parameters as the study group were evaluated. Data were evaluated using SPSS 27.0 software for Windows (SPSS Inc., Chicago, IL, USA). Then, the pre- and post-treatment values of the groups were compared using Student's t-test, setting p < 0.05 as the significance level.

RESULTS

Comparison of the three groups showed that extra-virgin olive oil was an adjuvant in the treatment of gingival inflammation, improving PI and BI. In group A, the mean plaque index showed a 48% reduction, and the bleeding index showed a 64% reduction after 30 days. In group B, the mean plaque index showed a 35% reduction and a bleeding index reduction of 43% after 30 days.

CONCLUSIONS

The collected data showed significant improvements in the formation of bacterial plaque and gingivitis. The exact mechanism of such treatment is still to be elucidated. As a result of this, further studies with a different sample of patients than those used and a comparison with other products need to be addressed to verify and demonstrate the antibacterial and anti-inflammatory effects of the components of this natural product.

Fatty Acid and Phenolic Profiles of Virgin Olive Oils from Local and European Varieties Planted in Lebanon

In Lebanon, olive oil is an integral part of its history and culinary traditions. However, the quality of this product, originating from different growing regions of the country, is rarely addressed. The objectives of this study were to compare the fatty acids and phenolic profiles of virgin olive oils produced from two local and eight European varieties, and to use these profiles as a tool for their characterization. Seventy-six samples were collected from two olive-growing regions of Lebanon and at two harvesting times. Fatty acid composition was determined by gas chromatography with a flame ionization detector, total phenols was determined by spectrophotometry and individual phenols by high performance liquid chromatography with diode array detector. All samples were also analyzed using near infrared spectroscopy. The experimental data were collected in numerical matrices and treated by chemometric methods. The results showed the significant effect of the geographical origin, the olive variety and the harvesting time on the ripening and industrial yield of the olives and on the major fatty acids and phenols of olive oil. Moreover, the used chemometric methods allowed the discrimination of European olive varieties based on their high contents of oleic acid, oleacein and oleocanthal.

Unveiling How Hydroxytyrosol Destabilizes α-Syn Oligomers Using Molecular Simulations

The etiology of Parkinson's disease (PD) is mainly linked to the α-synuclein (α-Syn) fibrillogenesis. Hydroxytyrosol (HT), also known as 3,4-dihydroxyphenylethanol, is a naturally occurring polyphenol, found in extra virgin olive oil, and has been shown to have cardioprotective, anticancer, antiobesity, and antidiabetic properties. HT has neuroprotective benefits in neurodegenerative diseases and lessens the severity of PD by reducing the aggregation of α-Syn and destabilizing the preformed toxic α-Syn oligomers. However, the molecular mechanism by which HT destabilizes α-Syn oligomers and alleviates the accompanying cytotoxicity remains unexplored. The impact of HT on the α-Syn oligomer structure and its potential binding mechanism was examined in this work by employing molecular dynamics (MD) simulations. The secondary structure analysis depicted that HT significantly reduces the β-sheet and concomitantly increases the coil content of α-Syn trimer. Visualization of representative conformations from the clustering analysis depicted the hydrogen bond interactions of the hydroxyl groups in HT with the N-terminal and nonamyloid-β component (NAC) region residues of α-Syn trimer, which, in turn, leads to the weakening of interchain interactions in α-Syn trimer and resulted in the disruption of the α-Syn oligomer. The binding free energy calculations depict that HT binds favorably to α-Syn trimer (ΔG_binding = -23.25 ± 7.86 kcal/mol) and a notable reduction in the interchain binding affinity of α-Syn trimer on the incorporation of HT, which, in turn, highlights its potential to disrupt α-Syn oligomers. The current research provided mechanistic insights into the destabilization of α-Syn trimer by HT, which, in turn, will provide new clues for developing therapeutics against PD.

Oleuropein: Chemistry, extraction techniques and nutraceutical perspectives-An update

Olive family (Oleaceae) contains several species among which Olea europaea L. is mostly used for production of olive oils. Various parts of olive tree are rich source of diverse bioactive compounds such as Apigenin, elenolic acid, Hydroxytyrosol, Ligstroside, Oleoside, Oleuropein, Oleuropein aglycone, Tyrosol, etc. Among these, oleuropein, a secoiridoid is predominantly found in olive leaves and young olive fruits of different species of Oleaceae family. Scientists have adopted numerous extraction methods (conventional & latest) to increase the yield of oleuropein. Among these techniques, maceration, soxhlet, microwave-assisted, ultrasonication, and supercritical fluid methods are most commonly employed for extraction of oleuropein. Evidently, this review emphasizes on various in-vitro and in-vivo studies focusing on nutraceutical properties of oleuropein. Available literature highlights the pharmaceutical potential of oleuropein against various diseases such as obesity, diabetes, cardiovascular complications, neurodegenerative diseases, cancer, inflammation, microbial infections, and oxidation. This review will benefit the scientific community as it narrates comprehensive literature regarding absorption, metabolism, bioavailability, extraction techniques, and nutraceutical perspectives associated with oleuropein.

A Systematic Ex-Vivo Study of the Anti-Proliferative/Cytotoxic Bioactivity of Major Olive Secoiridoids' Double Combinations and of Total Olive Oil Phenolic Extracts on Multiple Cell-Culture Based Cancer Models Highlights Synergistic Effects

Several individual olive oil phenols (OOPs) and their secoiridoid derivatives have been shown to exert anti-proliferative and pro-apoptotic activity in treatments of human cancer cell lines originating from several tissues. This study evaluated the synergistic anti-proliferative/cytotoxic effects of five olive secoiridoid derivatives (oleocanthal, oleacein, oleuropein aglycone, ligstroside aglycone and oleomissional) in all possible double combinations and of total phenolic extracts (TPEs) on eleven human cancer cell lines representing eight cell-culture-based cancer models. Individual OOPs were used to treat cells for 72 h in half of their EC₅₀ values for each cell line and their synergistic, additive or antagonistic interactions were evaluated by calculating the coefficient for drug interactions (CDI) for each double combination of OOPs. Olive oil TPEs of determined OOPs' content, originating from three different harvests of autochthonous olive cultivars in Greece, were evaluated as an attempt to investigate the efficacy of OOPs to reduce cancer cell numbers as part of olive oil consumption. Most combinations of OOPs showed strong synergistic effect (CDIs < 0.9) in their efficacy, whereas TPEs strongly impaired cancer cell viability, better than most individual OOPs tested herein, including the most resistant cancer cell lines evaluated.

Human serum albumin nanoparticles as a versatile vehicle for targeted delivery of antibiotics to combat bacterial infections

Urinary tract infections (UTIs) are among the most common bacterial infections. Despite a wide range of therapeutic options, treatment success is compromised by the efficient mechanism of tissue colonization of uropathogenic Escherichia coli. In advanced drug delivery systems, a similar, glycan-mediated targeting mechanism may be realized by conjugating the drug to a plant lectin, like wheat germ agglutinin (WGA). We introduce a drug delivery vehicle consisting of human serum albumin as nanoparticle shell, olive oil as core component, the active pharmaceutical ingredients (API) trimethoprim and rifampicin as well as WGA to facilitate cellular internalization. When WGA was embedded into the proteinaceous particle shell, cell binding studies revealed up to 60 % higher cell binding potential. Additionally, nanoparticles showed a good efficacy against gram-negative just as against gram-positive bacteria. The combination of the promising cell-associative properties and the proven antimicrobial potential might lead to an improved efficacy of advanced treatment of UTIs.

Application of Doehlert Experimental Design for Optimization of a New-Based Hydrophilic Interaction Solid-Phase Extraction of Phenolic Acids from Olive Oils

In this work, a rapid, precise, and cost-valuable method has been established to quantify phenolic compounds in olive oil using new-based hydrophilic interaction solid-phase extraction (SPE). Boehlert's experimental design applied the determination of the optimal operating conditions. An investigation into the effects of the methanol composition (50-100%), the volume of eluent (1-12 mL), and pH (1-3) on the extraction of phenols acids and total phenols from Tunisian olive oils was performed. The results showed that the extraction conditions had a significant effect on the extraction efficiency. The experiment showed that the greatest conditions for the SPE of phenolic acids were the methanol composition at 90.3%, pH at 2.9, and volume at 7.5 mL, respectively. The optimal conditions were applied to different types of olive oils, and it could be concluded that larger concentrations of polyphenols were found in extra virgin olive oil (89.15-218), whereas the lowest levels of these compounds (66.8 and 5.1) were found in cold-pressed crude olive oil and olive pomace oil, respectively.

Phenolic Extract from Extra Virgin Olive Oil Induces Different Anti-Proliferative Pathways in Human Bladder Cancer Cell Lines

Regular consumption of olive oil is associated with protection against chronic-degenerative diseases, such as cancer. Epidemiological evidence indicates an inverse association between olive oil intake and bladder cancer risk. Bladder cancer is among the most common forms of cancer; in particular, the transitional cell carcinoma histotype shows aggressive behavior. We investigated the anti-proliferative effects of a phenolic extract prepared from an extra virgin olive oil (EVOOE) on two human bladder cancer cell lines, namely RT112 and J82, representing the progression from low-grade to high-grade tumors, respectively. In RT112, the EVOOE reduced cell viability (IC50 = 240 μg/mL at 24 h), triggering a non-protective form of autophagy, evidenced by the autophagosome formation and the increase in LC-3 lipidation. In J82, EVOOE induced a strong decrease in cell viability after 24 h of treatment (IC50 = 65.8 μg/mL) through rapid and massive apoptosis, assessed by Annexin V positivity and caspase-3 and -9 activation. Moreover, in both bladder cancer cell lines, EVOOE reduced intracellular reactive oxygen species, but this antioxidant effect was not correlated with its anti-proliferative outcomes. Data obtained suggest that the mixture of phenolic compounds in extra virgin olive oil activates different anti-proliferative pathways.

New Affordable Methods for Large-Scale Isolation of Major Olive Secoiridoids and Systematic Comparative Study of Their Antiproliferative/Cytotoxic Effect on Multiple Cancer Cell Lines of Different Cancer Origins

Olive oil phenols (OOPs) are associated with the prevention of many human cancers. Some of these have been shown to inhibit cell proliferation and induce apoptosis. However, no systematic comparative study exists for all the investigated compounds under the same conditions, due to difficulties in their isolation or synthesis. Herein are presented innovative methods for large-scale selective extraction of six major secoiridoids from olive oil or leaves enabling their detailed investigation. The cytotoxic/antiproliferative bioactivity of these six compounds was evaluated on sixteen human cancer cell lines originating from eight different tissues. Cell viability with half-maximal effective concentrations (EC50) was evaluated after 72 h treatments. Antiproliferative and pro-apoptotic effects were also assessed for the most bioactive compounds (EC50 ≤ 50 μM). Oleocanthal (1) showed the strongest antiproliferative/cytotoxic activity in most cancer cell lines (EC50: 9−20 μM). The relative effectiveness of the six OOPs was: oleocanthal (1) > oleuropein aglycone (3a,b) > ligstroside aglycone (4a,b) > oleacein (2) > oleomissional (6a,b,c) > oleocanthalic acid (7). This is the first detailed study comparing the bioactivity of six OOPs in such a wide array of cancer cell lines, providing a reference for their relative antiproliferative/cytotoxic effect in the investigated cancers.

Studies on the Detection of Oleuropein from Extra Virgin Olive Oils Using Enzymatic Biosensors

Oleuropein (OLEU) is an important indicator of the quality and authenticity of extra virgin olive oils (EVOO). Electrochemical sensors and biosensors for the detection of oleuropein can be used to test the adulteration of extra virgin olive oils. The present study aimed at the qualitative and quantitative determination of oleuropein in commercial EVOO samples by applying electrochemical techniques, cyclic voltammetry (CV) and square wave voltammetry (SWV). The sensing devices used were two newly constructed enzyme biosensors, supported on single-layer carbon-nanotube-modified carbon screen-printed electrode (SPE/SWCNT) on whose surface tyrosinase (SPE/SWCNT/Tyr) and laccase (SPE/SWCNT/Lac) were immobilized, respectively. The active surfaces of the two biosensors were analyzed and characterized by different methods, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FTIR) and the results confirmed the efficient immobilization of the enzymes. SPE/SWCNT/Tyr was characterized by a low detection limit (LOD = 9.53 × 10⁻⁸ M) and a very good sensitivity (0.0718 μA·μM⁻¹·cm⁻²) over a wide linearity range from 0.49 to 11.22 μM. The process occurring at the biosensor surface corresponds to kinetics (h = 0.90), and tyrosinase showed a high affinity towards OLEU. The tyrosinase-based biosensor was shown to have superior sensitive properties to the laccase-based one. Quantitative determination of OLEU in EVOOs was performed using SPE/SWCNT/Tyr and the results confirmed the presence of the compound in close amounts in the EVOOs analysed, proving that they have very good sensory properties.

The role of Mediterranean diet and gut microbiota in type-2 diabetes mellitus associated with obesity (diabesity)

The human body is made up of 10¹⁴ human cells and 10¹⁵ bacterial cells, forming a combined structure that is described as a "superorganism". Commensal, symbiotic, and pathogenic microorganisms in the human body, many of which are located inside the intestine, affect health conditions and diseases. An important factor contributing to the development of chronic diseases is dysbiosis, which occurs when the number of pathogenic microorganisms increases. Dysbiosis is associated with increased intestinal permeability, endotoxemia (increased LPS), pro-inflammatory cytokine release, energy harvest, and adiposity, thus being involved in the pathogenesis of disorders like diabetes and obesity. Nutritional habits are the most important environmental factor that affects intestinal microbial composition. A dietary pattern that was proven successful in regulating gut microbiota is the renowned Mediterranean diet, which is characterized by high plant-based foods consumption, moderate fish and dairy products consumption, and low red meat consumption. There is an inverse relationship between adherence to the Mediterranean diet and chronic diseases like obesity and diabetes. In addition to the direct effects of the Mediterranean diet on the pathogenesis of these diseases, it can also be effective in preventing these diseases due to its effects on the intestinal microbiota. It is noted that the number of Bifidobacterium and Bacteroides increases the longer one's eating habit adhere to the Mediterranean diet, and the number of Firmicutes decreases, accordingly, thus supporting the symbiotic distribution in the intestinal microbiota.

Recent Advances in Analytical Methods for the Detection of Olive Oil Oxidation Status during Storage along with Chemometrics, Authenticity and Fraud Studies

Olive oil is considered to be a food of utmost importance, especially in the Mediterranean countries. The quality of olive oil must remain stable regarding authenticity and storage. This review paper emphasizes the detection of olive oil oxidation status or rancidity, the analytical techniques that are usually used, as well as the application and significance of chemometrics in the research of olive oil. The first part presents the effect of the oxidation of olive oil during storage. Then, lipid stability measurements are described in parallel with instrumentation and different analytical techniques that are used for this particular purpose. The next part presents some research publications that combine chemometrics and the study of lipid changes due to storage published in 2005-2021. Parameters such as exposure to light, air and various temperatures as well as different packaging materials were investigated to test olive oil stability during storage. The benefits of each chemometric method are provided as well as the overall significance of combining analytical techniques and chemometrics. Furthermore, the last part reflects on fraud in olive oil, and the most popular analytical techniques in the authenticity field are stated to highlight the importance of the authenticity of olive oil.

Characterization and Quantification of Capsaicinoids and Phenolic Compounds in Two Types of Chili Olive Oils, Using HPLC/MS

Chili olive oil is a popular addition to various foods in many countries. In a detailed study, the content of phenols and capsaicinoids in chili olive oil was determined using chili flakes and whole chilies. A total of 99.8% of the phenols in chili olive oil were secoiridoids, with elenolic acid, oleuropein aglycones, and ligostride aglycones being the most abundant. Chili olive oil with chili flakes contained higher levels of capsaicinoids (+21.6%) compared to whole chili olive oil. Capsaicin and dihydrocapsaicin accounted for about 95% of all capsaicinoids in the chili olive oil. The extraction rate of dry “Cayenne” chili was 7.1% in whole chili olive oil and 9% in chili olive oil with flakes, confirming that chili flakes are better extracted in olive oil. With the determination of 29 individual phenols and five individual capsaicinoids, the study provided a detailed insight into the secondary metabolites of chili olive oil and confirmed that it is a health source.

Biochemical Characterization of Six Traditional Olive Cultivars: A Comparative Study

Olives are an essential ingredient in Turkish food culture. Turkey has grown to become one of the top five producers of olives and olive oils in the world. Olive trees in general are found in the coastal parts of the country. The fruits of six traditional cultivars of olive (Gemlik, Domat, Memecik, Ayvalik, Cilli, and Adana Topagi), grown in Adana, were characterized based on their fruit skin color, the amount of chlorophylls, fatty acids, antioxidant activity, and total phenolic compounds, as well as volatile compounds. The international cultivar Manzanilla, grown in the same orchards as the traditional cultivars, was also included in the study to make a comparison. Compared to the Manzanilla cultivar, Memecik showed the highest amount of total phenolic content and antioxidant activity with the highest level of lightness, blueness/yellowness, and color intensity. Ayvalik presented the highest level of greenness/redness. Although the highest fruit lightness and darkness were found in the Cilli cultivar, with the highest amount of chlorophyll a (2.63 mgL−1), there was more chlorophyll b in Adana Topagi fruits (3.34 mgL−1). The highest percentage of fatty acids was found in the Gemlik cultivar of 66.81%, among which oleic acid was the major component. The total aldehydes ranged between 33.43% and 50.60%. Compared to Manzanilla and the traditional cultivars, the Domat cultivar had the highest amount of hexanal of 44.42%. Adana Topagi had the highest amount of alcohols (61.34%) and acids (1.31%). Memecik registered the highest amount of ketones (17.86%) and terpenes (20.34%). Among all cultivars, Manzanilla displayed the highest amount of esters (2.30%). In this study, traditional cultivars were found to be the richest in health-promoting chemicals. Furthermore, a significant variability among the cultivars was revealed, implying that metabolic fingerprinting approaches could be used to differentiate cultivars once more research into the effects of the growing conditions and environmental factors on the chemical profiles of each cultivar is carried out.

Consumers' Attitudes and Purchase Intention for a Vitamin-Enriched Extra Virgin Olive Oil

This study aims to examine Italian consumer preferences for extra virgin olive oil (EVOO) enriched with vitamins and to analyze the key drivers that affect consumer choices for this product. Specifically, we assessed consumers' intention to purchase the enriched product compared to the conventional one. The methodology adopted inferential and multivariate statistical techniques: (1) exploratory factor analysis (EFA), (2) ordinary least squares regression (OLS) and (3) non-hierarchical clustering. This study appears to be the first research project related to exploring consumers' interest in an extra virgin olive oil enhanced with vitamins, thereby providing preliminary indications. The main results represent a significant starting point for the development of new marketing strategies for the food industry.

The olive constituent oleuropein exerts nephritic protective effects on diabetic nephropathy in db/db mice

BACKGROUND

Oleuropein, the most prevalent polyphenol in olives, exerts many positive impacts on human health, including counteracting cancer. However, the effect of oleuropein on diabetic nephropathy (DN) progression remains elusive.

METHODS

A total of three groups of mice were used in our study. Two groups of db/db mice fed with or without oleuropein. A group of wide-type mice fed with normal diet was used as normal control. After ten weeks of treatment, the body weight, biochemical parameters, oxidative stress markers, inflammatory cytokines levels, and kidney injury status were measured.

RESULTS

Our results demonstrated that oral administration of oleuropein reduced body weight, alleviated kidney injury, and decreased oxidative stress and inflammatory response in db/db mice. The oleuropein inhibited cell apoptosis via regulation of MAPK signalling pathways and its downstream targets Bax, caspase-3, and Bcl-2 expression.

CONCLUSION

Oleuropein may server as a favourable additional agent for the treatment of patients with DN.

Biological effects of olive oil phenolic compounds on mitochondria

Phenolic compounds derived from olive oil have beneficial health properties against cancer, neurodegenerative, and metabolic diseases. Therefore, there are discrepancies in their impact on mitochondrial function that result in changes in oxidative capacity, mitochondrial respiration, and energetic demands. This review focuses on the versatile role of oleuropein, a potent antioxidant that regulates the AMPK/SIRT1/mTOR pathway to modulate autophagy/mitophagy and maintain metabolic homeostasis.

Treated Unconventional Waters Combined with Different Irrigation Strategies Affect 1H NMR Metabolic Profile of a Monovarietal Extra Virgin Olive Oil

The agricultural sector is facing a decrease in water supply and water quality at a global level and this is a problem that strictly affects all the Mediterranean olive growing areas. The aim of this work was to evaluate, for the first time, by NMR Spectroscopy and multivariate data analysis the metabolic profiling of the oils produced under different irrigation schemes. Arbosana olive oils were obtained from the use of saline reclaimed water (RW) and treated municipal wastewater (DW), combined with: full irrigation (FI) and regulated deficit irrigation (RDI). The results show a higher relative content of saturated fatty acids in EVOOs obtained from RDI strategy, regardless of the water source. Moreover, an increase in unsaturated fatty acids, a ω6/ω3 ratio content was observed in EVOOs obtained from RW when compared with DW water. Furthermore, the RW–RDI showed an increase in secoiridoid derivatives and hydroperoxides with respect to DW–RDI. A sustainable irrigation management, by combining a deficit irrigation strategy and saline reclaimed water source, could be crucial in order to overcome the problem of water scarcity and to guarantee the olive oil nutraceutical properties. The 1H NMR-based metabolomic approach proved a powerful and versatile tool for this specific investigation.

Olive oil intake and cancer risk: A systematic review and meta-analysis

BACKGROUND

Research evidence has established the beneficial effects of diet in cancer prevention; various epidemiological studies have suggested that olive oil component could play a role in decreasing cancer risk. This systematic review and meta-analysis aims to investigate the association between olive oil consumption, cancer risk and prognosis.

METHODS

A systematic search was conducted in PubMed, EMBASE and Google Scholar databases (end-of-search: May 10, 2020). Pooled relative risk (RR) and 95% confidence intervals (95% CIs) were estimated with random-effects (DerSimonian-Laird) models. Subgroup analyses, sensitivity analyses and meta-regression analysis were also performed.

RESULTS

45 studies were included in the meta-analysis; 37 were case-control (17,369 cases and 28,294 controls) and 8 were cohort studies (12,461 incident cases in a total cohort of 929,771 subjects). Highest olive oil consumption was associated with 31% lower likelihood of any cancer (pooled RR = 0.69, 95%CI: 0.62-0.77), breast (RR = 0.67, 95%CI: 0.52-0.86), gastrointestinal (RR = 0.77, 95%CI: 0.66-0.89), upper aerodigestive (RR = 0.74, 95%CI: 0.60-0.91) and urinary tract cancer (RR = 0.46, 95%CI: 0.29-0.72). Significant overall effects spanned both Mediterranean and non-Mediterranean participants, studies presenting a multivariate and a univariate analysis and all subgroups by study quality.

CONCLUSIONS

Olive oil consumption seems to exert beneficial actions in terms of cancer prevention. Additional prospective cohort studies on various cancer types and survivors, as well as large randomized trials, seem desirable.

Synergistic Effect of Squalene and Hydroxytyrosol on Highly Invasive MDA-MB-231 Breast Cancer Cells

Several studies relate Mediterranean diet and virgin olive oil (VOO) intake with lower risk of several chronic diseases, including breast cancer. Many of them described antitumor properties of isolated minor compounds present in VOO, but beneficial properties of VOO arise from the effects of all its compounds acting together. The aim of the present study was to test the antitumor effects of two minor compounds from VOO (hydroxytyrosol (HT) and squalene (SQ)) on highly metastatic human breast tumor cells (MDA-MB-231) when acting in combination. Both isolated compounds were previously analyzed without showing any antitumoral effect on highly invasive MDA-MB-231 breast cancer cells, but the present results show that HT at 100 µM, combined with different concentrations of SQ, could exert antitumor effects. When they are combined, HT and SQ are able to inhibit cell proliferation, promoting apoptosis and DNA damage in metastatic breast cancer cells. Therefore, our results suggest that the health-promoting properties of VOO may be due, at least in part, to the combined action of these two minor compounds.

Olive Tree Derivatives and Hydroxytyrosol: Their Potential Effects on Human Health and Its Use as Functional Ingredient in Meat

Olive (Olea europaea) is one of the most extensive crops in the Mediterranean countries, and an important source of extra distinctive compounds that has been widely tested due to its known health benefits. Olive derivatives, such as extra virgin olive oil (EVOO) and olive leaves are rich in antioxidant compounds such as hydroxytyrosol (HXT) and oleuropein and oleic acid, as main monounsaturated fatty acid. Because of HXT molecular structure, its regular consumption reports important beneficial properties such as anti-inflammatory, antimicrobial, antioxidant, and anticancer. As a matter of fact, its antioxidant and antimicrobial effects made this compound a good preservative agent against meat deterioration and spoilage, capable of replacing some synthetic additives whose continued and regular consumption may negatively affect the human health. On the contrary side, this extract has an unpleasant odor and flavor, so a synthetic source of HXT could also be used to improve the sensory quality of the meat products. In this sense, this review exposes the health benefits provided by the consumption of EVOO and HXT, and the newest research about its application on meat, together new trends about its use as functional ingredient in meat and meat products.

Polyphenols, the Healthy Brand of Olive Oil: Insights and Perspectives

Given their beneficial potential on human health, plant food bioactive molecules are important components influencing nutrition. Polyphenols have been widely acknowledged for their potentially protective role against several complex diseases. In particular, the polyphenols of olive oil (OOPs) emerge as the key components of many healthy diets and have been widely studied for their beneficial properties. The qualitative and quantitative profile defining the composition of olive oil phenolic molecules as well as their absorbance and metabolism once ingested are key aspects that need to be considered to fully understand the health potential of these molecules. In this review, we provide an overview of the key aspects influencing these variations by focusing on the factors influencing the biosynthesis of OOPs and the findings about their absorption and metabolism. Despite the encouraging evidence, the health potential of OOPs is still debated due to limitations in current studies. Clinical trials are necessary to fully understand and validate the beneficial effects of olive oil and OOPs on human health. We provide an update of the clinical trials based on olive oil and/or OOPs that aim to understand their beneficial effects. Tailored studies are needed to standardize the polyphenolic distribution and understand the variables associated with phenol-enriched OO. An in-depth knowledge of the steps that occur following polyphenol ingestion may reveal useful insights to be used in clinical settings for the prevention and treatment of many diseases.

Potential of olive oil and its phenolic compounds as therapeutic intervention against colorectal cancer: a comprehensive review

Colorectal cancer (CRC) is one of the major causes of death across the world and incidence rate of CRC increasing alarmingly each passing year. Diet, genomic anomalies, inflammation and deregulated signalling pathways are among the major causes of CRC. Because of numerous side effects of CRC therapies available now, researchers all over the world looking for alternative treatment/preventive strategy with lesser/no side effects. Olive oil which is part of Mediterranean diet contains numerous phenolic compounds that fight against free radicals and inflammation and also well-known for protective role against CRC. The current review focused on the recent evidences where olive oil and its phenolic compounds such as hydroxytyrosol, oleuropein and oleocanthal showed activities against CRC as well to analyse the cellular and molecular signalling mechanism through which these compounds act on. These compounds shown to combat CRC by reducing proliferation, migration, invasion and angiogenesis through regulation of numerous signalling pathways including MAPK pathway, PI3K-Akt pathway and Wnt/β-catenin pathway and at the same time, induce apoptosis in different CRC model. However, further research is an absolute necessity to establish these compounds as nutritional supplements and develop therapeutic strategy in CRC.

Identification of Tyrosyl Oleate as a Novel Olive Oil Lipophenol with Proliferative and Antioxidant Properties in Human Keratinocytes

Lipophenols are an emerging subclass of phenolic compounds characterized by the presence of a lipid moiety. Recently, hydroxytyrosyl oleate (HtyOle), a derivative of hydroxytyrosol, has been identified in olive oil and by-products. Furthermore, HtyOle possesses anti-inflammatory, antioxidant, and tissue regenerating properties. In this work, the potential occurrence of tyrosyl oleate (TyOle) in olive oil was investigated based on the hypothesis that its precursors tyrosol and oleic acid, both present in relatively high amount can be coupled together. Moreover, TyOle effects have been investigated in human keratinocytes to verify its proliferative and antioxidant properties. The quantitative determination of TyOle was carried out by the external standard method in liquid chromatography coupled with mass spectrometry (LC/MS), in negative mode using multiple reaction monitoring (MRM). The proliferative properties of TyOle on immortalized human keratinocytes (HaCat) were evaluated by 3-(4,5-dimethylthiasol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes were observed by fluorescent staining with phalloidin (for F-actin) or 4,6-diamidino-2-phenylindole (DAPI, for chromatin) dye. The antioxidant activity was assessed at the level of production of mitochondrial reactive oxygen species (ROS) induced with UV exposure. TyOle was identified in all the oil samples investigated. Interestingly, TyOle concentration was higher in defective or low-quality oils than in extra virgin oils. The formation of TyOle likely occurs during the crushing and kneading processes and its concentration is related to the increase of rancidity and of the concentration of free precursors. Herein we show that TyOle induced an increase in the viability of HaCat cells and cytoskeletal remodeling.

Phenols, Flavors, and the Mediterranean Diet

Phenols or phenolics are a class of compounds that have one or more hydroxyl groups attached to a 6-carbon aromatic ring, they occur as plant secondary metabolites, having in common the antioxidant activity. Their average daily intake varies widely around the world. Many researchers consider coffee, tea, wine, cocoa products, fruits and vegetables as the main sources of polyphenols in different diets. However, spices and culinary herbs have been referred to as the foods richest in polyphenols. Despite spices and culinary herbs are used in small amounts as seasonings, their contribution to the dietary supply of phytonutrients should not be disregarded. A diet rich in a variety of polyphenols (and other phytonutrients) has potential health benefits, namely in the prevention of chronic diseases and cancer. In addition, flavor and color are the most important factors for the selection of food by consumers. A multitude of endogenous food compounds, including phenolics, are involved in food flavor. The presence of phenolic compounds in the food matrix has been mainly associated with the perception of bitter taste and tactile sensation of astringency. However, these compounds can also impact the color and aroma notes of fruits and vegetables. Thus, understanding the sensory impact of these substances and relationships with consumers' approaches towards phenolic-rich fruits and vegetables may help find strategies to increase the consumption of such foods. A well-known example of a tasty, healthy and sustainable dietary model is the Mediterranean Diet. In this study, we summarize the dietary intake of some polyphenols from different dietary patterns around the world and the contribution of natural phenolic compounds to the flavor of food and beverages, in particularly those associated to the Mediterranean Diet.

Natural Compound from Olive Oil Inhibits S100A9 Amyloid Formation and Cytotoxicity: Implications for Preventing Alzheimer's Disease

Polyphenolic compounds in the Mediterranean diet have received increasing attention due to their protective properties in amyloid neurodegenerative and many other diseases. Here, we have demonstrated for the first time that polyphenol oleuropein aglycone (OleA), which is the most abundant compound in olive oil, has multiple potencies for the inhibition of amyloid self-assembly of pro-inflammatory protein S100A9 and the mitigation of the damaging effect of its amyloids on neuroblastoma SH-SY5Y cells. OleA directly interacts with both native and fibrillar S100A9 as shown by intrinsic fluorescence and molecular dynamic simulation. OleA prevents S100A9 amyloid oligomerization as shown using amyloid oligomer-specific antibodies and cross-β-sheet formation detected by circular dichroism. It decreases the length of amyloid fibrils measured by atomic force microscopy (AFM) as well as reduces the effective rate of amyloid growth and the overall amyloid load as derived from the kinetic analysis of amyloid formation. OleA disintegrates already preformed fibrils of S100A9, converting them into nonfibrillar and nontoxic aggregates as revealed by amyloid thioflavin-T dye binding, AFM, and cytotoxicity assays. At the cellular level, OleA targets S100A9 amyloids already at the membranes as shown by immunofluorescence and fluorescence resonance energy transfer, significantly reducing the amyloid accumulation in GM1 ganglioside containing membrane rafts. OleA increases overall cell viability when neuroblastoma cells are subjected to the amyloid load and alleviates amyloid-induced intracellular rise of reactive oxidative species and free Ca²⁺. Since S100A9 is both a pro-inflammatory and amyloidogenic protein, OleA may effectively mitigate the pathological consequences of the S100A9-dependent amyloid-neuroinflammatory cascade as well as provide protection from neurodegeneration, if used within the Mediterranean diet as a potential preventive measure.

Olive oil consumption can prevent non-communicable diseases and COVID-19 : Review

The Mediterranean diet is appraised as the premier dietary regimen and its espousal is correlated with the prevention of degenerative diseases and extended longevity. The consumption of olive oil stands out as the most peculiar feature of the Mediterranean diet. Olive oil rich in various bioactive compounds like oleanolic acid, oleuropein, oleocanthal, and hydroxytyrosol is known for its anti-inflammatory as well as cardioprotective property. Recently in silico studies have indicated that phytochemicals present in olive oil are a potential candidate to act against SARS-CoV-2. Although extensive studies on olive oil and its phytochemical composition; still, some lacunas persist in understanding how the phytochemical composition of olive oil is dependent on upstream processing. The signaling pathways regulated by olive oil in the restriction of various diseases is also not clear. To answer these queries, a detailed search of research and review articles published between 1990 to 2019 were reviewed in this effect. Olive oil consumption was found to be advantageous for various chronic non-communicable diseases. Olive oil's constituents are having potent anti-inflammatory activities and thus restrict the progression of various inflammation-linked diseases ranging from arthritis to cancer. But it is also notable that the amount and nature of phytochemical composition of household olive oil are regulated by its upstream processing and the physicochemical properties of this oil can give a hint regarding the manufacturing method as well as its therapeutic. Moreover, daily uptake of olive oil should be monitored as excessive intake can cause body weight gain and change in the basal metabolic index. So, it can be concluded that olive oil consumption is beneficial for human health, and particularly for the prevention of cardiovascular diseases, breast cancer, and inflammation. The simple way of processing olive oil maintains the polyphenol constituents and provides more protection against non-communicable diseases and SARS-CoV-2.

A comprehensive review on different classes of polyphenolic compounds present in edible oils

Edible oils are used as a frying medium and in the preparation of several food products. They are mainly constituting triacylglycerols as major components, while other compounds are classified as minor constituents, which include polyphenols. This class of compounds plays an important role in the thermal stability and quality attributes of the finished industrial food products. In addition to other antioxidants, the desired thermal stability of edible is achieved by either fortification or mixing of edible oils. This comprehensive review was therefore aimed to review the different classes of polyphenolic compounds present in commonly consumed edible oils. The edible oils reviewed include soybean, olive, rapeseed, canola, sunflower, flaxseed, sesame, cottonseed, palm, almond, peanut, chestnut, coconut, and hazelnut oils. The identified classes of polyphenolic compounds such as simple phenols, hydroxybenzoic acids, phenylethanoids, hydroxycinnamic acid, esters of hydroxycinnamic acids, coumarins & chromans, stilbenes, flavonoids, anthocyanins, and lignans were discussed. It was observed that a single edible from different origins showed the varied composition of the different classes of phenolic compounds. Among the oils, soybean, sunflower, olive, and brassica oils received higher attention in terms of polyphenol composition. Some classes of phenolic compounds were either not reported or absent in one edible oil, while present in others. Among the different classes of phenolics, hydroxybenzoic acids, hydroxycinnamic acid and flavonoids were the most widely present compounds. Phenolic compounds in edible oils possess several health benefits such as antioxidant, antibacterial, anti-viral, anti-inflammatory, anti-tumour, antioxidants, cardioprotective, neuroprotective, anti-diabetic properties and anti-obesity.

Antioxidant and Neuroprotective Activity of Extra Virgin Olive Oil Extracts Obtained from Quercetano Cultivar Trees Grown in Different Areas of the Tuscany Region (Italy)

Neurodegenerative diseases are driven by several mechanisms such as inflammation, abnormal protein aggregation, excitotoxicity, mitochondrial dysfunction and oxidative stress. So far, no therapeutic strategies are available for neurodegenerative diseases and in recent years the research is focusing on bioactive molecules present in food. In particular, extra-virgin olive oil (EVOO) phenols have been associated to neuroprotection. In this study, we investigated the potential antioxidant and neuroprotective activity of two different EVOO extracts obtained from Quercetano cultivar trees grown in two different areas (plain and hill) of the Tuscany region (Italy). The different geographical origin of the orchards influenced phenol composition. Plain extract presented a higher content of phenyl ethyl alcohols, cinnammic acids, oleacein, oleocanthal and flavones; meanwhile, hill extract was richer in lignans. Hill extract was more effective in protecting differentiated SH-SY5Y cells from peroxide stress thanks to a marked upregulation of the antioxidant enzymes heme oxygenase 1, NADPH quinone oxidoreductase 1, thioredoxin Reductase 1 and glutathione reductase. Proteomic analysis revealed that hill extract plays a role in the regulation of proteins involved in neuronal plasticity and activation of neurotrophic factors such as BDNF. In conclusion, these data demonstrate that EVOOs can have important neuroprotective activities, but these effects are strictly related to their specific phenol composition.

Chemical and volatile characteristics of olive oils extracted from four varieties grown in southwest of China

The present study was conducted to determine the quality parameters, fatty acid profile, minor compounds (pigments, tocopherols, phenolic compounds, squalene and total sterols) and volatile compounds of olive oils from four common olive cultivars (cv. 'Koroneiki', 'Coratina', 'Frantoio' and 'Arbequina') planted in China. The effect of maturation stage on the characteristics of the oils was also evaluated. All samples were classified as extra virgin according to the standards established by IOC. Statistically significant differences (p < 0.05) were observed in the most analytical indicators of the oils among the cultivar and ripening. Coratina oils contained the highest contents of carotenoids, chlorophylls, tocopherols, phenolic compounds and high level of volatiles, demonstrating their excellent nutritional qualities and pleasant flavors. Whereas, Koroneiki oils contained the highest contents of oleic acid and squalene. Further, high levels of total sterols were found in Frantoio and Arbequina oils. Phenolic compounds and volatiles decreased with increase of ripe degree, which indicated the oils from green olive fruits possess better quality and flavor.

Effect of olive ripening degree on the antidiabetic potential of biophenols-rich extracts of Brava Gallega virgin olive oils

The diet management is imperative to anticipate risk factors that favour the development of diseases; indeed, the intake of virgin olive oil could be an alternative natural source of α-glucosidase enzyme inhibitors, which delay the digestion rate of carbohydrates. Consequently, the impact of diabetes mellitus (DM) could be diminished. Extra Virgin Olive Oils (EVOO) were elaborated from Galician autochthonous variety 'Brava Gallega' with olives selected at three different degree of ripeness (ripening index, RI: 1.4, 3.0, 5.5) in order to assess the effect of maturation on overall chemical composition, sensory quality, and enzyme inhibition. The phenolic profile of the EVOOs determined by LC-ESI-IT-MS exhibited quantitative differences as ripening advanced; for example oleocanthal, tyrosol, luteolin and apigenin concentrations were higher in the overripe olive oil (RI 5.5). Anyway, the phenolic extracts (from every tested RI) were more active than acarbose. In particular, those obtained from the most mature olives displayed the most powerful inhibitory activity (IC₅₀ value of 143 µg of dry extract/mL). In addition, the significant effect of these compounds (i.e. luteolin, apigenin, tyrosol and oleocanthal) on the inhibitory activity of the olive oil extracts was demonstrated. Our results suggest that, regardless of RI, the inhibitory activity of 'Brava Gallega' olive oils could represent a valuable strategy for reinforcing the health claim of olive oil for phenolic compounds.

Phenolic Compounds Obtained from Olea europaea By-Products and their Use to Improve the Quality and Shelf Life of Meat and Meat Products-A Review

Consumers are interested in consuming clean label foods. Replacing synthetic additives with natural alternatives (especially sources rich in polyphenols) is a valid solution to produce and also preserve foods, especially meat and meat products. Olea europaea leaves and olive pomace and wastewater contain polyphenols that can be explored in this context. In this review, we summarize the main aspects related to the phenolic composition, extraction conditions, antimicrobial potential, and antioxidant activity (in vitro and in vivo) of Olea europaea leaves, olive pomace and wastewater as well as their applications in the production of meat and meat products. This review found evidence that extracts and isolated polyphenols from the Olea europaea tree and olive processing by-products can be explored as natural antioxidant and antimicrobial additives to improve the preservation of meat and meat products. The polyphenols found in these residues (especially oleuropein, hydroxytyrosol and tyrosol) increased the redox state in the main meat-producing animals and, consequently, the oxidative stability of fresh meat obtained from these animals. Moreover, the extracts and isolated polyphenols also improved the shelf life of fresh meat and meat products (as additive and as active component in film) by delaying the growth of microorganisms and the progression of oxidative reactions during storage. The accumulated evidence supports further investigation as a natural additive to improve the preservation of reformulated muscle products and in the production of edible and sustainable films and coatings for fresh meat and meat products.

Improving the quality of vegetable oils treated with phytochemicals: a comparative study

In this study, sunflower, corn, peanut and hazelnut oils were investigated according to their oxidative stability and antioxidant activity parameters. The related vegetable oils were treated with gallic acid, rutin and carotenoid. Olive leaf extract having a large variety of phytochemical was also valorized. After the leaf samples were extracted through a homogenizer, they were added into the vegetable oils, respectively. Moreover, synthetic antioxidants were also dissolved into the oils for control reasons. Stability of the vegetable oils against the oxidation was evaluated via Rancimat by measuring induction time. The quality parameters of treated and untreated oil samples were compared depending on phenolic and carotenoid contents, antioxidant activity and induction time.

Special designed deep eutectic solvents for the recovery of high added-value products from olive leaf: a sustainable environment for bioactive materials

Deep Eutectic Solvents have been specially designed, and used for the extraction of phenolics from olive tree (Olea europea) leaves. 11 deep eutectic solvents containing a hydrogen bond donor (glycerol, ethylene glycol, lactic acid, urea, dimethyl urea and D-sorbitol) and a hydrogen bond acceptor (L-proline, citric acid, glycerol, ethylimidazole and methylimidazole) with several molar ratios have been designed. Addition of water into the solvent system increased the extraction efficiency by a remarkable difference (45%). After the best combination has been decided to extract the primary phenolic (oleuropein), operation conditions (water content in the deep eutectic solvent, speed of the homogenizer and time for the extraction) of the homogenizer-aided extraction (HAEX) for olive leaf extract has been optimized through Box-Behnken design of Response Surface Approach. The experimental yields of oleuropein, verbascoside and rutin were 15.50, 5.51 and 0.98 mg per gram dried leaf under the optimal conditions (48.9% of water in DES for 60 sec at 13310 rpm). Our best DES (citric acid/lactic acid) has yielded the most efficient extract rich in oleuropein, even with an ≈8% higher performance than that of a most commonly used solvent (75% ethanol).

New insights in the in vitro release of phenolic antioxidants: The case study of the release behavior of tyrosol from tyrosol-loaded ethylcellulose microparticles during the in vitro gastrointestinal digestion

In this study, tyrosol - a phenolic antioxidant that present in olive oil and olive mill wastes - was embedded in ethylcellulose microparticles by double emulsion solvent evaporation technique. The effect of loading content (5 % w/w and 10 % w/w) on the release behavior and bioaccessibility of tyrosol was evaluated. The polymer endowed efficient protection to tyrosol during the in vitro gastrointestinal digestion of loaded microparticles as the maximum release of tyrosol was observed during the simulated intestinal digestion, and the releases were kept outstanding low during the simulated salivary and gastric digestions. The bioaccessibility of tyrosol was improved when encapsulated. The best-fitting models of the release profiles of tyrosol were the first, and the zero-order models for formulations considering a loading of 5% w/w and 10 % w/w, respectively. The results of this study bring new perspectives for the design of loaded microparticles that will be further submitted to gastrointestinal digestion.

Hydroxytyrosol as a Promising Ally in the Treatment of Fibromyalgia

Fibromyalgia (FM) is a chronic and highly disabling syndrome, which is still underdiagnosed, with controversial treatment. Although its aetiology is unknown, a number of studies have pointed to the involvement of altered mitochondrial metabolism, increased oxidative stress and inflammation. The intake of extra virgin olive oil, and particularly of one of its phenolic compounds, hydroxytyrosol (HT), has proven to be protective in terms of redox homeostatic balance and the reduction of inflammation. In this context, using a proteomic approach with nanoscale liquid chromatography coupled to tandem mass spectrometry, the present study analysed: (i) Changes in the proteome of dermal fibroblasts from a patient with FM versus a healthy control, and (ii) the effect of the treatment with a nutritional relevant dose of HT. Our results unveiled that fibroblast from FM show a differential expression in proteins involved in the turnover of extracellular matrix and oxidative metabolism that could explain the inflammatory status of these patients. Moreover, a number of these proteins results normalized by the treatment with HT. In conclusion, our results support that an HT-enriched diet could be highly beneficial in the management of FM.