State of the Art on Functional Virgin Olive Oils Enriched with Bioactive Compounds and Their Properties

Importance of malaxation conditions to virgin olive oil polar phenolic compounds content

Virgin olive oil (VOO), the "golden liquid" of the Mediterranean diet (MD), has experienced rising global consumption due to its health-related properties and remarkable sensory attributes. VOO's health benefits are linked mainly to its fatty acid and phenolic profiles. Polar phenolic compounds (PPCs) contribute to the VOO quality and sensory-nutritional aspects, being responsible for the only health claim regarding its protective influence on the oxidation of blood lipids. VOO's phenols are influenced by the rate of their solubilisation and the chemical/enzymatic reactions during processing, significantly affected by technological factors. Malaxation plays a significant role in VOO's PPCs content. This review highlights recent technological advances in VOO extraction, particularly the impact of malaxation on PPCs. Non-thermal methods, such as pulsed electric field and ultrasound show promise in improving PPCs content, especially secoiridoids. Future research efforts should focus on industrial-level studies and optimising extraction per olive genotype to standardise high-quality VOO production.

FoodAtlas: Automated knowledge extraction of food and chemicals from literature

Automated generation of knowledge graphs that accurately capture published information can help with knowledge organization and access, which have the potential to accelerate discovery and innovation. Here, we present an integrated pipeline to construct a large-scale knowledge graph using large language models in an active learning setting. We apply our pipeline to the association of raw food, ingredients, and chemicals, a domain that lacks such knowledge resources. By using an iterative active learning approach of 4120 manually curated premise-hypothesis pairs as training data for ten consecutive cycles, the entailment model extracted 230,848 food-chemical composition relationships from 155,260 scientific papers, with 106,082 (46.0 %) of them never been reported in any published database. To augment the knowledge incorporated in the knowledge graph, we further incorporated information from 5 external databases and ontology sources. We then applied a link prediction model to identify putative food-chemical relationships that were not part of the constructed knowledge graph. Validation of the 443 hypotheses generated by the link prediction model resulted in 355 new food-chemical relationships, while results show that the model score correlates well (R2 = 0.70) with the probability of a novel finding. This work demonstrates how automated learning from literature at scale can accelerate discovery and support practical applications through reproducible, evidence-based capture of latent interactions of diverse entities, such as food and chemicals.

Enhancing antioxidant and antibacterial properties of olive oil through garlic enrichment: a comprehensive study

The amalgamation of garlic's antibacterial potency with olive oil's nutritional benefits provides a natural, effective way to boost health and counters microbial threats. This study explored the antioxidant and antibacterial traits of garlic-enriched virgin olive oil (VOO) samples, focusing on various garlic forms (fresh, oven-dried, freeze-dried). Comparative analysis revealed fresh garlic's highest total phenolic content, flavonoid content, and strongest DPPH scavenging activity. GC/MS analysis unveiled distinct volatile profiles. Fresh garlic oil contained elevated allyl-methy-sulfide, diallyl-trisulfide, methyl-propyl-disulfide levels. Antibacterial evaluation displayed substantial inhibition zones, especially fresh garlic oil against E. coli, and oven-dried/freeze-dried garlic oils against P. aeruginosa. Lower Minimal Inhibitory Concentration (MIC) values for fresh garlic oil and freeze-dried garlic oil against both Gram-negative and Gram-positive bacteria signify potent antibacterial activity of garlic-enriched VOO. These findings underscore garlic-enriched VOO's potential as natural antibacterial agents, fortified with antioxidant traits, while emphasizing drying methods' role in shaping volatile compounds.

Enrichment of Olive Oils with Natural Bioactive Compounds from Aromatic and Medicinal Herbs: Phytochemical Analysis and Antioxidant Potential

Olive oil and herbs, two key components of the Mediterranean diet, are known for their beneficial effects on humans. In our study, we incorporated aromatic and medicinal herbs into local monovarietal olive oils via maceration procedures for enrichment. We identified the herbal-derived ingredients that migrate to olive oils and contribute positively to their total phenolic content and functional properties, such as radical scavenging activity. Thus, we characterized the essential oil composition of the aromatic herbs (GC-MS), and we determined the phenolic content and antioxidant capacity of the additives and the virgin olive oils before and after enrichment. The herbal phenolic compounds were analyzed by LC-LTQ/Orbitrap HRMS. We found that olive oils infused with Origanum vulgare ssp. hirtum, Rosmarinus officinalis and Salvia triloba obtained an increased phenolic content, by approximately 1.3 to 3.4 times, in comparison with the untreated ones. Infusion with S. triloba led to a significantly higher antioxidant capacity. Rosmarinic acid, as well as phenolic glucosides, identified in the aromatic herbs, were not incorporated into olive oils due to their high polarity. In contrast, phenolic aglycones and diterpenes from R. officinalis and S. triloba migrated to the enriched olive oils, leading to a significant increase in their phenolic content and to an improvement in their free radical scavenging capacity.

Improving the functionality of virgin and cold-pressed edible vegetable oils: Oxidative stability, sensory acceptability and safety challenges

In recent years, there has been a growing demand for minimally processed foods that offer health benefits and premium sensory characteristics. This trend has led to increased consumption of virgin (VOs) and cold-pressed (CPOs) oils, which are rich sources of bioactive substances. To meet consumer needs for new oil products conferring multi-functional properties over a longer storage period, the scientific community has been revisiting traditional enrichment practices while exploring novel fortification technologies. In the last four years, the interest has been growing faster; an ascending number of annually published studies are about the addition of different plant materials, agri-food by-products, or wastes (intact or extracts) to VOs and CPOs using traditional or innovative fortification processes. Considering this trend, the present review aims to provide an overview and summarize the key findings from relevant papers that were retrieved from extensively searched databases. Our meta-analysis focuses on exposing the most recent trends regarding the exploitation of VOs and CPOs as substrates, the fortification agents and their form of use, as well as the fortification technologies employed. The review critically discusses possible health claim and labeling issues and highlights some chemical and microbial safety concerns along with authenticity issues and gaps in quality specifications that manufacturers have yet to address. All these aspects are examined from the perspective of developing new oil products with well-balanced techno-, senso- and bio-functional characteristics.

How storage time affects sensory, chemical, and physical characteristics of flavored olive oil

The objectives of this study were to evaluate sensory, chemical, and physical characteristics of olive oil prepared by three flavoring methods and analyze changes during storage (0, 3, and 6 months). Favored olive oil was prepared by three flavoring methods (fresh, dried, and essential oil). Selected sensory, chemical, and color parameters were monitored based on international standards. The color was determined by spectrophotometer. The results confirmed that storage time and flavoring method affect sensory characteristics of the oil. Fresh garlic oil had significantly lower (p < .05) fruity smell. The level of pungent taste significantly increased (p < .05) in the dried rosemary oil, rosemary essential oil, and fresh and dried garlic flavored oils. The intensity of rosemary smell in the sample flavored with essential oil significantly decreased (p < .05) during storage. Opposite effect was observed in the sample flavored with dried rosemary, where the smell significantly increased (p < .05) during storage. The intensity of taste significantly increased (p < .05) in samples flavored by dried rosemary during storage. The peroxide value of all flavored oils samples increased (p < .05) during storage compared to unflavored oil where peroxide value did not change. Color indicators L*, a*, and b* show that addition of fresh rosemary causes the greatest change in olive oil color. The color change, especially the turbidity, was not perceived positive by tasters.

Co-Extraction Technique Improves Functional Capacity and Health-Related Benefits of Olive Oils: A Mini Review

Olive oil, a fundamental component of the Mediterranean diet, is recognized as a functional food due to its health-promoting composition. The concentration of phenolic compounds in olive oil is influenced by various factors such as genetics, agro-climatic conditions, and technological processes. Therefore, to ensure an ideal intake of phenolics through the diet, it is recommended to produce functional enriched olive oil that contains a high concentration of bioactive compounds. The co-extraction technique is used to create innovative and differentiated products that promote the sensory and health-related composition of oils. To enrich olive oil, various natural sources of bioactive compounds can be used, including raw materials derived from the same olive tree such as olive leaves, as well as other compounds from plants and vegetables, such as herbs and spices (garlic, lemon, hot pepper, rosemary, thyme, and oregano). The development of functional enriched olive oils can contribute to the prevention of chronic diseases and improve consumers' quality of life. This mini-review compiles and discusses relevant scientific information related to the development of enriched olive oil using the co-extraction technique and its positive effects on the health-related composition of oils.

Characterization of Flavoured Olive Oils of ‘Madural’ Variety

Flavoured oils arouse great interest among consumers in many countries due to their variety of flavours and versatility, especially in the culinary field. The aromatization of oils seeks to improve their sensory and nutritional properties, and extend their useful life due to the added substances can be beneficial as antioxidant and antimicrobial agent. In this research, olive oils of the ‘Madural’ variety from Trasos Montes region of Portugal have been obtained and flavoured with different aromatics herbs and condiments (flower of salt and bay leaf, garlic, rosemary and dehydrated lemon peel). The objective is to study the influence of the aromatic herbs and condiments on the physicochemical parameters of the oils: quality, purity, oxidative stability and microbiological analysis. It can be noted that the flavourings do not significantly alter the quality of the monovarietal oil, although, for some parameters, the excessive contact times can affect the category of the oil. On the other hand, the high content of antioxidants provided by flavouring agents can favour its stability and prolong its expiration. In this sense, the flavouring agent that contributes to stop the oxidation of the oil over time is salt + bay leaves, as higher oxidative stability values were detected than those obtained in monovarietal oil. However, oils flavoured with rosemary or lemon show a decrease over time for this parameter, which could indicate that this flavouring accelerates oxidation. In the case of oxidative stability referred to those flavoured with garlic, they present similar values to the monovarietal. The effect exerted by flavourings on the different parameters of the oils is complex, since it is influenced by the method followed and the operating variables established for flavouring.

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.

Singular Olive Oils from a Recently Discovered Spanish North-Western Cultivar: An Exhaustive 3-Year Study of Their Chemical Composition and In-Vitro Antidiabetic Potential

In this work, the quality and physicochemical parameters, phenolic composition, and antidiabetic potential of olive oils obtained from olives belonging to centenarian olive trees of the so-called ‘Mansa de Figueiredo’ cultivar were evaluated during three consecutive crop seasons (2017–2019). The oils produced during the three crop years were classified as extra virgin based on the quality-related indices, sensory analysis, and the genuineness-related parameters. In addition, LC-ESI-TOF MS was used to get a comprehensive characterisation of the phenolic fraction while LC-ESI-IT MS was applied for quantitation purposes. The content of phenolic compounds (ranging from 1837 to 2434 mg/kg) was significantly affected by the harvest year due to the environmental conditions and ripening index. Furthermore, although significant differences in the inhibitory effects against the α-glucosidase enzyme for the EVOOs extracted throughout the three successive years were detected, all the studied EVOOs exhibited a stronger inhibitor effect than that found for acarbose.

Emulsion and Microemulsion Systems to Improve Functional Edible Oils Enriched with Walnut and Pistachio Phenolic Extracts

The purpose of this research was to improve the properties of functional edible oils with potential health promoting effects, enriched with phenolic-rich extracts obtained from pistachio and walnut (5.1 and 27.4% phenolic contents respectively), by means of emulsion and micro emulsion systems. Stable water-in-oil (W/O) emulsions were obtained employing polyglycerol polyrhizinoleate (PGPR) as emulsifier (0.5, 2% H₂O in oil), despite having a whitish and opaque appearance; transparent and stable microemulsions were prepared using proper proportion (e.g., 97:3) between the oily phase and the mixture of aqueous phase and emulsifiers (3:2 lecithin-distilled monoglycerides (DMG). Total polar phenolics contents ranging between 257 and 835 mg/kg were obtained in the novel functional edible oils' formulations, reaching higher content using walnut as compared to pistachio extracts. Antioxidant capacity determined by the 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH) method increased approx. 7.5 and 1.5 times using walnut and pistachio extracts respectively. An emulsion using gallic acid and a microemulsion employing hydroxytyrosol, two well-known antioxidants, were also studied to compare antioxidant capacity of the proposed enriched oils. Furthermore, the oxidative stability of these products-very relevant to establish their commercial value-was measured under accelerated testing conditions employing the Rancimat equipment (100 °C) and performing an oven test (at 40 °C for walnut oils and 60 °C for pistachio and refined olive oils). Rancimat oxidative stability greatly increased and better results were obtained with walnut (2-3 times higher) as compared to pistachio extract enriched oils (1.5-2 times higher). On the contrary, under the oven test conditions, both the initial oxidation rate constant and the time required to reach a value of peroxide value equal to 15 (upper commercial category limit), indicated that under these assay conditions the protection against oxidation is higher using pistachio extract (2-4 times higher) than walnut's (1.5-2 times higher). Stable emulsions and transparent microemulsions phenolic-rich nut oils (250-800 mg/kg) were therefore developed, possessing a higher oxidative stability (1.5-4 times) and DPPH antioxidant capacity (1.5-7.5 times).

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.

Sustainable Use of Greek Herbs By-Products, as an Alternative Source of Biologically Active Ingredients for Innovative Products

The processing of medicinal and aromatic plants (MAPs) results in the production of a significant amount of plant by-products; herbal material of inferior quality and/or unusable plant parts that are not commercially exploitable. An extensive study of Greek native species was performed toward the production of innovative bioactive products using as raw materials the by-products obtained from the processing of cultivated MAPs. Origanum vulgare subsp. hirtum (oregano), Sideritis scardica (Greek mountain tea), Thymus vulgaris (thyme), and Matricaria recutita (chamomile) were selected due to their wide use for the preparation of beverages and culinary purposes. The determination of the percentage of the post-harvest processing by-products was performed for a 3 years period (2018–2020). Results showed that by-products derived from the above-mentioned species' processing constitute 64% (thyme), 54% (oregano), 37% (Greek mountain tea), and 24% (chamomile) of the total processed mass. To value the by-products as a potent source of bioactive ingredients, superior and inferior quality herbal material of the aforementioned plant species were extracted by an ultrasonic assisted extraction method. Hydroalcoholic extracts were chemically investigated using high-performance thin layer chromatography (HPTLC) and liquid chromatography-mass spectrometry (LC-MS) techniques. In addition, their free radical scavenging activity and total phenolic content (TPC) were estimated. Based on the results, herbs by-products revealed similar chemical content to the superior herbal material by the means of HPTLC and LC-MS analysis. In addition, strong free radical scavenging related to a high phenolic content was detected in the case of thyme, oregano, and Greek mountain tea. Moreover, the gas chromatography-mass spectrometry (GC-MS) analyses of the essential oils (EOs) of oregano and thyme by-products revealed the presence of carvacrol, thymol, γ-terpinene, and p-cymene among the major constituents. Finally, the LC-MS analyses of aqueous extracts of Greek mountain tea and chamomile by-products led to the identification of several bioactive compounds, such as flavonoids and phenylpropanoids. Overall, the presence of bioactive constituents in by-products, such as terpenes, phenolic compounds, and flavonoids underly their potent use as food antimicrobial and antioxidant additives, in the preparation of high added-value products, such as enriched aromatic edible oils, and innovative herbal teas, such as instant beverages.

Oxidative stability of soybean and corn oils enriched with Pluchea quitoc hydroalcoholic extract

Soybean and corn oils are among the most popular vegetable oils, and are ingredients which are widely used in cooking and in the food industry. These oils contain many unsaturated fatty acids such as oleic, linoleic and linolenic acids, which makes them easily oxidized by oxygen. Extensive efforts are being made to prevent or minimize vegetable oil oxidation through the development of antioxidants. Phenolic antioxidants which are present in some extracts can be used as food additives to prevent lipid oxidation. In this study chromatographic analyses (HPLC and GC) of the Pluchea quitoc hydroalcoholic extract were performed. The content of phenolic compounds by the Folin-Ciocalteau method and the antioxidant properties against radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) were also evaluated. The effect of samples prepared with soybean and corn oils enriched with Pluchea quitoc hydroalcoholic extract was determined and compared with samples of these oils which were free of antioxidants and with samples containing the synthetic antioxidant BHT. The results showed potential for application of the extract. A high content of phenolic compounds (314 milligrams of gallic acid equivalents (GAE)/g of extract) and good IC50 values were detected for the inhibition of the radicals DPPH and ABTS (13.2 µg·mL-1 and 5.6 µg·mL-1). In the evaluation of the oxidative stability of the oils enriched with this extract, it was found that at 1% concentration it was possible to obtain values of induction period (IP) close to the samples with added BHT.

Chemical characterization and nutritional quality investigations of healthy extra virgin olive oil flavored with chili pepper

The production of extra virgin olive oil (EVOO) flavored with diverse spices, herbs, fruits, and vegetables or natural aromas is believed to provide advantageous properties considering either the high nutritional value or biological activity in addition to the flavoring and industrial aspects. The biological activities including antioxidant and antimicrobial properties of Tunisian EVOO obtained from "Chemlali" variety and mixed with chili pepper were investigated. Molecular analyses, including the detection of twelve olive-infecting viruses and Pseudomonas savastanoi pv savastanoi, were performed to ensure that the samples were obtained from healthy olive trees and EVOO quality was not affected. Quality parameters like free acidity, peroxide number, oxidative stability, and specific absorption at K232 nm and K270 nm were also investigated and no significant variation was revealed. The content of minor compounds such as chlorophylls, carotenoids, and total phenols showed minor changes. However, the profiles of the volatile compounds showed remarkable differences, which appeared to be the main factor for the observed variability in consumer acceptance. The results showed for the first time high quantities of polyphenols and ortho-diphenols. Four colorimetric methods were used for the determination of the antioxidant activity, namely DPPH, ABTS, FRAP, and β-carotene test. Compared to the control, a higher level of antioxidant activity was observed for the flavored EVOO. Furthermore, significant results were obtained in the antimicrobial tests. The quality parameters of the mixture showed no alteration compared to the control. Finally, all the measurements and the chemical characterization gave a scientific basis for food technology innovation of new food products.

Effect of processing technology on chemical, sensory, and consumers' hedonic rating of seven olive oil varieties

This study established physicochemical and sensory characteristics of virgin olive oils (VOOs) and linked them to consumers' liking using external preference mapping. We used five Tunisian and two foreign VOO varieties produced by two processing systems: discontinuous (sp) and continuous three-phase decanter (3p). The samples were analyzed and evaluated by a panel of 274 consumers. The external preference mapping revealed five VOO clusters with a consumer preference scores rating from 40% to 65%. Consumers highly appreciated the foreign Coratina cultivar's olive oil; the main drivers being richness in polyphenols (markers of bitterness and pungency), mainly the oleuropein aglycone, and volatile compounds (markers of green fruity, green leaves, green apple, cut grassy almond, and bitterness), particularly the trans-2-hexenol. The Tunisian Chemlali (3p) oil was second highly preferred (scoring 55%). The positive drivers for olive oil preference (a profile of almond fruity green and low bitterness and pungency) are the richness in hexanal compounds. Arbequina (sp and 3p) and Chemlali (sp) were the least appreciated due to the fact that Arbequina VOO is not in the tradition of Tunisian consumers, whereas Chemchali VOO is a minor variety representing only 2% of olive oil production in Tunisia and consumed mostly in blends. The differentiation between the two processing systems depends on the variety of cultivar; consumers are able to identify the two processing system in the case of Chetoui, Leguim, and Chemchali.

Enhancement of the Green Extraction of Bioactive Molecules from Olea europaea Leaves

Olive leaves are a rich source of polyphenols that have beneficial antihypertensive, hypocholesterolemic, cardioprotective, and anti-inflammatory effects. The aim of this study was to compare the efficiency of conventional extraction (CE), microwave-assisted extraction (MWE), and microwave–ultrasound-assisted extraction (MWUE) for the extraction of bioactive molecules from olive leaves using water as a solvent and to define the optimal extraction conditions for all three methods used. CE conditions (temperature, time, magnetic stirrer rotational rate and particle diameter) and MWE extraction and MWUE conditions (microwave power, time, particle diameter, and temperature) were optimized using response surface methodology (RSM) based on the Box–Behnken experimental design. The total polyphenol content and antioxidant activity of all prepared extracts was analyzed and compared. The results showed that MWUE provided the highest amount of total polyphenols (Total Polyphenolic Content (TPC) = 273.779 ± 4.968 mgGAE gd.m.−1) and the highest antioxidant activity, which was about 3.1 times higher than CE. Optimal extraction conditions were determined to be 80 °C, 15 min, 200 μm, and 750 min-1 for CE, 700 W, 7.5 min, 300 μm, and 80 °C for MWE, and 800 W, 5 min, 100 μm, and 60 °C for MWUE. Considering the maximum amount of total polyphenols extracted, the results suggest that MWUE is the most effective green extraction process that extracted the highest amount of polyphenols and could be used by the food industry for commercial exploitation of currently unprofitable plant bioactive sources.

Qualitative and Quantitative Analysis of Phenolic Compounds in Spray-Dried Olive Mill Wastewater

The processing of olives for oil production generates the most abundant agro-industrial by-products in the Mediterranean area. The three-phase olive oil extraction process requires the addition of a large amount of water to the system, which is difficult to dispose of for its load of toxic pollutants. On the other hand, olive mill wastewater is a rich source of bioactive substances with various biological properties that can be used as ingredients in the food industry for obtaining functional and nutraceutical foods as well as in the pharmaceutical industry. In this study, we present the results relative to the phenolic compounds detected in dried olive mill wastewaters obtained using a spray dryer. Qualitative and quantitative analyses were obtained by high-pressure liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). In particular, the compounds here discussed are: apigenin (9.55 mg/kg dry weight), caffeic acid (2.89 mg/kg dry weight), catecol (6.12 mg/kg dry weight), p-cumaric acid (5.01 mg/kg dry weight), diosmetin (3.58 mg/kg dry weight), hydroxytyrosol (1.481 mg/kg dry weight), hydroxytyrosyl oleate (564 mg/kg dry weight), luteolin (62.38 mg/kg dry weight), luteolin-7-O-glucoside (88.55 mg/kg dry weight), luteolin-4-O-glucoside (11.48 mg/kg dry weight), oleuropein (103 mg/kg dry weight), rutin (48.52 mg/kg dry weight), tyrosol (2043 mg/kg dry weight), vanillin (27.70 mg/kg dry weight), and verbascoside (700 mg/kg dry weight). The results obtained highlighted that the use of dehumidified air as a drying medium, with the addition of maltodextrin, appears to be an effective way to produce a phenol-rich powder to be included in food formulations as well as in pharmaceutical preparations having different biological properties.

Antioxidant and protective effects of extra virgin olive oil incorporated with diallyl sulfide against CCl4-induced acute liver injury in mice

The present study delineates the effects of incorporation of 1% diallyl sulfide (DAS) into extra virgin olive oil (EVOO) on the physico-chemical characteristics, in vitro antioxidant, and in vivo hepatoprotective properties in CCl4-induced acute liver injury in mice. Results showed that the DAS-rich EVOO exhibited good oxidative stability over one-month storage and preserved its original quality-related parameters including major components (oleic acid, linoleic acid, and palmitic acid), and minor components (tocopherols, chlorophylls and carotenoids, tyrosol, hydroxytyrosol, elenolic acid, oleuropein and its aglycone, pinoresinol, vanilic acid, cinnamic acid, ferulic acid, luteolin, apigenin, and sterols). Compared with EVOO or DAS, the DAS-rich EVOO displayed the highest DPPH and ABTS-radical scavenging activities and showed the strongest cellular antioxidant activity (CAA). In connection with its free radical scavenging activity and CAA, DAS-rich EVOO significantly normalized the serum ALT and AST levels and prevented the increase in interleukin-6 in CCl4-intoxicated mice. The manifest anti-inflammatory and hepatoprotective effects of DAS-rich EVOO were further supported by liver histopathological examinations. Overall, the EVOO enrichment with DAS could open up opportunities for the development of novel functional food with improved antioxidant and hepatoprotective properties.

The Use of Electronic Nose as Alternative Non-Destructive Technique to Discriminate Flavored and Unflavored Olive Oils

Cv. Arbequina extra virgin olive oils (EVOO) were flavored with cinnamon, garlic, and rosemary and characterized. Although flavoring significantly affected the physicochemical quality parameters, all oils fulfilled the legal thresholds for EVOO classification. Flavoring increased (20 to 40%) the total phenolic contents, whereas oxidative stability was dependent on the flavoring agent (a slight increase for rosemary and a decrease for cinnamon and garlic). Flavoring also had a significant impact on the sensory profiles. Unflavored oils, cinnamon, and garlic flavored oils had a fruity-ripe sensation while rosemary flavored oils were fruity-green oils. Fruit-related sensations, perceived in unflavored oils, disappeared with flavoring. Flavoring decreased the sweetness, enhanced the bitterness, and did not influence the pungency of the oils. According to the EU regulations, flavored oils cannot be commercialized as EVOO. Thus, to guarantee the legal labelling requirement and to meet the expectations of the market-specific consumers for differentiated olive oils, a lab-made electronic nose was applied. The device successfully discriminated unflavored from flavored oils and identified the type of flavoring agent (90 ± 10% of correct classifications for the repeated K-fold cross-validation method). Thus, the electronic nose could be used as a practical non-destructive preliminary classification tool for recognizing olive oils’ flavoring practice.

Applicability of an In-Vitro Digestion Model to Assess the Bioaccessibility of Phenolic Compounds from Olive-Related Products

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

Co-Processed Olive Oils with Thymus mastichina L.-New Product Optimization

Olive co-processing consists of the addition of ingredients either in the mill or in the malaxator. This technique allows selecting the type of olives, the ingredients with the greatest flavoring and bioactive potential, and the technological extraction conditions. A new product-a gourmet flavored oil-was developed by co-processing olives with Thymus mastichina L. The trials were performed using overripe fruits with low aroma potential (cv. 'Galega Vulgar'; ripening index 6.4). Experimental conditions were dictated by a central composite rotatable design (CCRD) as a function of thyme (0.4-4.6%, w/w) and water (8.3-19.7%, w/w) contents used in malaxation. A flavored oil was also obtained by adding 2.5% thyme during milling, followed by 14% water addition in the malaxator (central point conditions of CCRD). The chemical characterization of the raw materials, as well as the analysis of the flavored and unflavored oils, were performed (chemical quality criteria, sensory analysis, major fatty acid composition, and phenolic compounds). Considering chemical quality criteria, the flavored oils have the characteristics of "Virgin Olive Oil" (VOO), but they cannot have this classification due to legislation issues. Flavored oils obtained under optimized co-processing conditions (thyme concentrations > 3.5-4.0% and water contents varying from 14 to 18%) presented higher phenolic contents and biologic value than the non-flavored VOO. In flavored oils, thyme flavor was detected with high intensity, while the defect of "wet wood", perceived in VOO, was not detected. The flavored oil, obtained by T. mastichina addition in the mill, showed higher oxidative stability (19.03 h) than the VOO and the co-processed oil with thyme addition in the malaxator (14.07 h), even after six-month storage in the dark (16.6 vs. 10.3 h).

Targeting Wnt signaling pathway by polyphenols: implication for aging and age-related diseases

Age is an important risk factor for different diseases. The same mechanisms that promote aging are involved in the development and progression of age-associated diseases. Polyphenols are organic compounds found in fruits and vegetables. Due to their beneficial properties (e.g. antioxidant and anti-inflammatory), polyphenols have been extensively used for treating chronic diseases. To exert their functions, polyphenols target various molecular mechanisms and signaling pathways, such as mTOR, NF-κB, and Wnt/β-catenin. Wnt signaling is a critical pathway for developmental processes. Besides, dysregulation of this signaling pathway has been observed in various diseases. Several investigations have been conducted on Wnt inhibitors at pre-clinical stages, showing promising results. Herein, we review the studies dealing with the role of polyphenols in targeting the Wnt signaling pathways in aging processes and age-associated diseases, including cancer, diabetes, Alzheimer's disease, osteoporosis, and Parkinson's disease.

Olive oil-derived nitro-fatty acids: protection of mitochondrial function in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive liver fat deposition in the absence of significant alcohol intake. Since extra virgin olive oil (EVOO) reduces fat accumulation, we analyzed the involvement of nitro-fatty acids (NO2-FA) on the beneficial effects of EVOO consumption on NAFLD. Nitro-fatty acids formation was observed during digestion in mice supplemented with EVOO and nitrite. Mice fed with a high-fat diet (HF) presented lower plasma NO2-FA levels than normal chow, and circulating concentrations recovered when the HF diet was supplemented with 10% EVOO plus nitrite. Under NO2-FA formation conditions, liver hemoxygenase-1 expression significantly increased while decreased body weight and fat liver accumulation. Mitochondrial dysfunction plays a central role in the pathogenesis of NAFLD while NO2-FA has been shown to protect from mitochondrial oxidative damage. Accordingly, an improvement of respiratory indexes was observed when mice were supplemented with both EVOO plus nitrite. Liver mitochondrial complexes II and V activities were greater in mice with EVOO supplementation and further improved in the presence of nitrite. Overall, our results strongly suggest a positive correlation between NO2-OA formation from EVOO and the observed improvement of mitochondrial function in NAFLD. The formation of NO2-FA can account for the health benefits associated with EVOO consumption.

Dried Destoned Virgin Olive Pomace: A Promising New By-Product from Pomace Extraction Process

At present the olive oil industry produces large amounts of secondary products once considered waste or by-products. In this paper, we present, for the first time, a new interesting olive by-product named “dried destoned virgin olive pomace” (DDVOP), produced by the pomace oil industry. The production of DDVOP is possible thanks to the use of a new system that differs from the traditional ones by having the dryer set at a lower temperature value, 350 °C instead of 550 °C, and by avoiding the solvent extraction phase. In order to evaluate if DDVOP may be suitable as a new innovative feeding integrator for animal feed, its chemical characteristics were investigated. Results demonstrated that DDVOP is a good source of raw protein and precious fiber; that it is consistent in total phenols (6156 mg/kg); rich in oleic (72.29%), linoleic (8.37%) acids and tocopherols (8.80 mg/kg). A feeding trial was, therefore, carried out on sheep with the scope of investigating the influence of the diet on the quality of milk obtained from sheep fed with DDVOP-enriched feed. The resulting milk was enriched in polyunsaturated (0.21%) and unsaturated (2.42%) fatty acids; and had increased levels of phenols (10.35 mg/kg) and tocopherols (1.03 mg/kg).

The effects of olive oil and cholesterol enriched diets on aortic fatty streak development and lipid peroxidation in rabbits

BACKGROUND AND AIM

High plasma cholesterol levels, mainly low-density lipoprotein-cholesterol (LDL) is a widely recognized major risk factor for coronary heart disease (CHD). According to epidemiologic studies' findings, people from the Mediterranean countries have lower CHD rates than other countries; in these countries the usual diet is high in olive oil. The present study compares the effects of a cholesterol-enriched diet with or without adding olive oil on serum lipoproteins, lipid peroxidation, and atherosclerosis development.

METHODS

Twenty Dutch male rabbits were categorized into four groups (one group as control, and others as experimental). They received one of control (CON), olive oil-rich (OIL), cholesterol-rich (CHOL), and cholesterol + olive oil (COIL) diet for 12 weeks. Fasting blood samples from the heart were collected at the beginning and the end of the experimental period.

RESULTS

Means of serum lipids were not significantly different at the beginning of the experimental period. After the intervention, significant differences were shown in total cholesterol (TC) (CON: 27.75 ± 4.83, OIL: 19.75 ± 2.62, CHOL: 1757.20 ± 149.62, COIL: 2906.40 ± 421.01; P < 0.001), high-density lipoprotein-cholesterol (HDL-C) (CON: 16 ± 1.47, OIL: 10.25 ± 1.70, CHOL: 22.2 ± 3.83, COIL: 28.60 ± 6.27; P = 0.04), triglyceride (CON: 65 ± 12.21, OIL: 71.75 ± 6.23, CHOL: 244.2 ± 44.45, COIL: 775.6 ± 105.07; P < 0.001), and MDA between groups (CON: 0.57 ± 0.10, OIL: 0.63 ± 0.15, CHOL: 5.62 ± 0.18, COIL: 2.06 ± 0.64; P < 0.001). The comparison of CHOL and the COIL groups showed a higher mean of malondialdehyde (MDA) in group CHOL (4.47 ± 0.28 vs 1.1 ± 0.6; P < 0.001). Aortic lesion was not observed in CON and OIL groups. Aortic lesion degree was significantly lower in the COIL group compared to the CHOL (2.4 ± 0.6 vs 3.66 ± 0.33; P = 0.02).

CONCLUSIONS

These findings showed the preventive effect of olive oil on atherosclerosis development. However, it is independent of the plasma lipoprotein effect, and olive oil probably acts on arteries directly.

Determination of theoretical calculations by DFT method and investigation of antioxidant, antimicrobial properties of olive leaf extracts from different regions

In this study, we studied samples of mature olive leaves from the districts of Incirli Ova within the province of Aydın and the district of Fethiye in Mugla/Turkey. Several processes were carried out on the olive leaves to use them in this study, including drying under different conditions, determination of moisture, extract output, overall determination of phenols, antioxidant activity determination and anti-microbial assays. The chemicals that were used in the study were Folin's reagent and gallic acid for total phenolic assays, DPPH (1,1-diphenyl-2-picrylhydrazyl) and Trolox for antioxidant activity assays and nutrient broth and nutrient agar for antimicrobial testing. In the theoretical part of the study, the structures of oleuropein and Trolox molecules were examined, and their oxidation properties were aimed to be determined and compared to experimental results. According to the results of total phenolic assays, the phenol contents in the olive leaves from Aydın and Mugla were observed to be very close to each other. In the anti-microbial assay, it was observed that the samples of olive leaves from Mugla were more antioxidant than those from Aydın.

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.

Evolution of Flavors in Extra Virgin Olive Oil Shelf-Life

Extra virgin olive oil (EVOO) is one of the most distinctive ingredients of the Mediterranean diet. There are many properties related to this golden ingredient, from supreme organoleptic characteristics to benefits for human health. EVOO contains in its composition molecules capable of exerting bioactivities such as cardio protection, antioxidant, anti-inflammatory, antidiabetic, and anticancer activity, among others, mainly caused by unsaturated fatty acids and certain minor compounds such as tocopherols or phenolic compounds. EVOO is considered the highest quality vegetable oil, which also implies a high sensory quality. The organoleptic properties related to the flavor of this valued product are also due to the presence of a series of compounds in its composition, mainly some carbonyl compounds found in the volatile fraction, although some minor compounds such as phenolic compounds also contribute. However, these properties are greatly affected by the incidence of certain factors, both intrinsic, such as the olive variety, and extrinsic, such as the growing conditions, so that each EVOO has a particular flavor. Furthermore, these flavors are susceptible to change under the influence of other factors throughout the oil's shelf-life, such as oxidation or temperature. This work offers a description of some of the most remarkable compounds responsible for EVOO's unique flavor and aroma, the factors affecting them, the mechanism that lead to the degradation of EVOO, and how flavors can be altered during the shelf-life of the oil, as well as several strategies suggested for the preservation of this flavor, on which the quality of the product also depends.

By-Products from Winemaking and Olive Mill Value Chains for the Enrichment of Refined Olive Oil: Technological Challenges and Nutraceutical Features

A growing body of literature is available about the valorization of food by-products to produce functional foods that combine the basic nutritional impact with the improvement of the health status of consumers. In this context, this study had two main objectives: (i) An innovative multistep extraction process for the production of a refined olive oil enriched with phenolic compounds (PE-ROO) extracted from olive pomace, olive leaves, or grape marc was presented and discussed. (ii) The most promising PE-ROOs were selected and utilized in in vitro and in vivo trials in order to determine their effectiveness in the management of high fat diet-induced-metabolic syndrome and oxidative stress in rats. The best results were obtained when olive leaves were used as source of phenols, regardless of the chemical composition of the solvent utilized for the extraction. Furthermore, while ethanol/hexane mixture was confirmed as a good solvent for the extraction of phenols compounds soluble in oil, the mix ROO/ethanol also showed a good extracting power from olive leaves. Besides, the ROO enriched with phenols extracted from olive leaves revealed an interesting beneficial effect to counteract high fat diet-induced-metabolic disorder and oxidative stress in rats, closely followed by ROO enriched by utilizing grape marc.

Structure-Biological Activity Relationships of Extra-Virgin Olive Oil Phenolic Compounds: Health Properties and Bioavailability

Extra-virgin olive oil is regarded as functional food since epidemiological studies and multidisciplinary research have reported convincing evidence that its intake affects beneficially one or more target functions in the body, improves health, and reduces the risk of disease. Its health properties have been related to the major and minor fractions of extra-virgin olive oil. Among olive oil chemical composition, the phenolic fraction has received considerable attention due to its bioactivity in different chronic diseases. The bioactivity of the phenolic compounds could be related to different properties such as antioxidant and anti-inflammatory, although the molecular mechanism of these compounds in relation to many diseases could have different cellular targets. The aim of this review is focused on the extra-virgin olive oil phenolic fraction with particular emphasis on (a) biosynthesis, chemical structure, and influence factors on the final extra-virgin olive oil phenolic composition; (b) structure-antioxidant activity relationships and other molecular mechanisms in relation to many diseases; (c) bioavailability and controlled delivery strategies; (d) alternative sources of olive biophenols. To achieve this goal, a comprehensive review was developed, with particular emphasis on in vitro and in vivo assays as well as clinical trials. This report provides an overview of extra-virgin olive oil phenolic compounds as a tool for functional food, nutraceutical, and pharmaceutical applications.

Virgin Olive Oil Quality Is Affected by the Microbiota that Comprise the Biotic Fraction of the Oil

This review summarizes the current knowledge on the effects of oil-borne yeasts on the physicochemical, sensorial, and health-related characteristics of virgin olive oil (VOO) during storage. Bacteria, yeasts, and molds constitute the biotic fraction of freshly produced VOO. During storage, the bacteria and molds often die after a short period, while the yeasts survive and condition the quality of VOO. To date, approximately twenty-four yeast species have been isolated from different types of olive oil and its by-products, and seven of these species have been identified as new species. The activity of some yeasts of the biotic fraction of olive oil improves the sensorial characteristics of VOO. Some yeasts can also worsen the quality of the product by allowing the appearance of defects, oxidation of polar phenols, and triacylglycerol hydrolysis. Some yeast species of VOO show in vitro beneficial health effects, such as probiotic and antioxidant activities.

The Fluid Aspect of the Mediterranean Diet in the Prevention and Management of Cardiovascular Disease and Diabetes: The Role of Polyphenol Content in Moderate Consumption of Wine and Olive Oil

A growing interest has emerged in the beneficial effects of plant-based diets for the prevention of cardiovascular disease, diabetes and obesity. The Mediterranean diet, one of the most widely evaluated dietary patterns in scientific literature, includes in its nutrients two fluid foods: olive oil, as the main source of fats, and a low-to-moderate consumption of wine, mainly red, particularly during meals. Current mechanisms underlying the beneficial effects of the Mediterranean diet include a reduction in inflammatory and oxidative stress markers, improvement in lipid profile, insulin sensitivity and endothelial function, as well as antithrombotic properties. Most of these effects are attributable to bioactive ingredients including polyphenols, mono- and poly-unsaturated fatty acids. Polyphenols are a heterogeneous group of phytochemicals containing phenol rings. The principal classes of red wine polyphenols include flavonols (quercetin and myricetin), flavanols (catechin and epicatechin), anthocyanin and stilbenes (resveratrol). Olive oil has at least 30 phenolic compounds. Among them, the main are simple phenols (tyrosol and hydroxytyrosol), secoroids and lignans. The present narrative review focuses on phenols, part of red wine and virgin olive oil, discussing the evidence of their effects on lipids, blood pressure, atheromatous plaque and glucose metabolism.

Expanding the DOPA Universe with Genetically Encoded, Mussel-Inspired Bioadhesives for Material Sciences and Medicine

Catechols are a biologically relevant group of aromatic diols that have attracted much attention as mediators of adhesion of "bio-glue" proteins in mussels of the genus Mytilus. These organisms use catechols in the form of the noncanonical amino acid l-3,4-dihydroxyphenylalanine (DOPA) as a building block for adhesion proteins. The DOPA is generated post-translationally from tyrosine. Herein, we review the properties, natural occurrence, and reactivity of catechols in the design of bioinspired materials. We also provide a basic description of the mussel's attachment apparatus, the interplay between its different molecules that play a crucial role in adhesion, and the role of post-translational modifications (PTMs) of these proteins. Our focus is on the microbial production of mussel foot proteins with the aid of orthogonal translation systems (OTSs) and the use of genetic code engineering to solve some fundamental problems in the bioproduction of these bioadhesives and to expand their chemical space. The major limitation of bacterial expression systems is their intrinsic inability to introduce PTMs. OTSs have the potential to overcome these challenges by replacing canonical amino acids with noncanonical ones. In this way, PTM steps are circumvented while the genetically programmed precision of protein sequences is preserved. In addition, OTSs should enable spatiotemporal control over the complex adhesion process, because the catechol function can be masked by suitable chemical protection. Such caged residues can then be noninvasively unmasked by, for example, UV irradiation or thermal treatment. All of these features make OTSs based on genetic code engineering in reprogrammed microbial strains new and promising tools in bioinspired materials science.

Characterization of New Olive Fruit Derived Products Obtained by Means of a Novel Processing Method Involving Stone Removal and Dehydration with Zero Waste Generation

As a result of an innovative olive fruit processing method involving stone removal and dehydration, a new kind of olive oil and olive flour are generated. The main objective of this work was to accomplish the comprehensive characterization of the minor compounds of both products and to evaluate the effect of the dehydration temperature on their composition. To this end, olive oil and flour samples obtained through the novel processing method were analyzed and compared with "conventional" virgin olive oils (VOO). The applied LC-MS methodology allowed the determination of 57 metabolites belonging to different chemical classes (phenolic compounds, pentacyclic trirterpenes, and tocopherols). Both the new oils and flours presented considerable amounts of olive fruit metabolites that are usually absent from VOO. Quantitative differences were found among VOOs and the new oils, probably due to the inhibition of some enzymes caused by the temperature increase or the absence of water during the processing.

Effectiveness of five flavored Tunisian olive oils on Anisakis larvae type 1: application of cinnamon and rosemary oil in industrial anchovy marinating process

BACKGROUND

Anisakidosis is caused by the ingestion of raw or undercooked fish or cephalopods containing viable Anisakis larvae. Several natural extracts, oils, essential oils, and their compounds have been tested against Anisakis. In this study the effectiveness of Tunisian olive oil with different spices or plants (cardamom, cinnamon, ginger, laurel, and rosemary) was tested against Anisakis larvae type 1.

RESULTS

For the in vitro test, larvae were submerged separately in the oils mentioned above and observed to check viability. Cinnamon oil was the most effective against parasites with lethal time (LT) scores being LT50  = 1.5 days and LT100  = 3 days, followed by rosemary. Laurel, cardamom, and ginger oils were less effective. For the ex vivo experiment, cinnamon, and rosemary oils were tested in anchovy fillets, previously artificially parasitized. Cinnamon was the most effective against parasites (dead after 4 days) as compared to rosemary (7 days).

CONCLUSION

The use of cinnamon and rosemary-flavored olive oil in the industrial marinating process can be considered as an efficient alternative to the freezing process required by European Regulation EC No 853/2004 to devitalize Anisakis. © 2019 Society of Chemical Industry.

Untargeted Metabolomics to Evaluate the Stability of Extra-Virgin Olive Oil with Added Lycium barbarum Carotenoids during Storage

A carotenoid-rich extract from Lycium barbarum L. was added to extra virgin olive oil (EVOO), obtaining a carotenoid-enriched oil (EVOOCar). The oxidative stability of EVOO and EVOOCar was evaluated during long-term storage of 28 weeks at room temperature, by measuring some classical parameters (acidity and peroxide values, spectrophotometric coefficients, fatty acid composition) and the content of minor compounds (i.e., α-tocopherol and lutein). At the end of the storage, higher content (p < 0.01) of α-tocopherol in EVOOCar in respect to EVOO were observed. Zeaxanthin dipalmitate, the most abundant carotenoid compound of Goji berries, decreased slightly (p < 0.05) in EVOOCar until the end of the storage. In regard to polyphenols, an ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS) using untargeted metabolomics was carried out. This latter approach discriminated the two oil samples during long-term storage, allowing to identify also the phenolic classes most exposed to significant variations during storage (i.e., mainly lignans and flavones). Besides, the addition of Goji carotenoids preserved the stability of tyrosol equivalents in EVOOCar during long-term storage. These results highlighted that the enrichment of EVOO with a carotenoid-rich extract can improve the shelf-life and nutritional value of added-oil, protecting EVOO natural antioxidants during long-term storage.

Metabolic syndrome, Mediterranean diet, and polyphenols: Evidence and perspectives

Metabolic syndrome (MetS) is defined as the co-occurrence of metabolic risk factors that includes insulin resistance, hyperinsulinemia, impaired glucose tolerance, type 2 diabetes mellitus, dyslipidemia, and visceral obesity. The clinical significance of MetS consists of identifying a subgroup of patients sharing a common physiopathological state predisposing to chronic diseases. Clinical and scientific studies pinpoint lifestyle modification as an effective strategy aiming to reduce several features accountable for the risk of MetS onset. Among the healthy dietary patterns, the Mediterranean diet (MedDiet) emerges in terms of beneficial properties associated with longevity. Current evidence highlights the protective effect exerted by MedDiet on the different components of MetS. Interestingly, the effect exerted by polyphenols contained within the representative MedDiet components (i.e., olive oil, red wine, and nuts) seems to be accountable for the beneficial properties associated to this dietary pattern. In this review, we aim to summarize the principal evidence regarding the effectiveness of MedDiet-polyphenols in preventing or delaying the physiopathological components accountable for MetS onset. These findings may provide useful insights concerning the health properties of MedDiet-polyphenols as well as the novel targets destined to a tailored approach to MetS.