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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.

'Brava' and 'Mansa de Figueiredo' extra-virgin olive oils (EVOOs) are two varieties identified from north-western Spain. A systematic phenolic characterization of the studied oils was undertaken by LC-ESI-IT-MS. In addition, the role of dietary polyphenols from these EVOOs has been evaluated against the inhibition of key enzymes (α-glucosidase and α-amylase) in the management of diabetes mellitus (DM). Oleuropein and ligstroside derivatives comprised 83% and 67% of the total phenolic compounds in 'Brava' and 'Mansa de Figueiredo' EVOOs, respectively. The main secoiridoids from oleuropein were DOA (3,4-DHPEA-EDA, 59 and 22 mg kg -1 , respectively) and the main isomer of OlAgl (3,4-DHPEA-EA, 74 and 23 mg kg -1 ). The main secoiridoids from ligstroside were D-LigAgl (p-HPEA-EDA or oleocanthal, 23 and 167 mg kg -1 ) and the main isomer of LigAgl (p-HPEA-EA, 214 and 114 mg kg -1 ). For α-glucosidase, both EVOO extracts displayed stronger inhibitory activity (IC 50 values of 60 ± 8 and 118 ± 9 μg mL -1 , respectively) than the commercial inhibitor acarbose (IC 50  = 356 ± 21 μg mL -1 ). Nevertheless, for α-amylase, only 'Brava' extracts showed anti-α-amylase capacity. A daily VOO intake lower than the requirements of EFSA seem to be enough to reach both 50% for α-glucosidase and 25% for α-amylase inhibition. These findings support the potential health benefits derived from Galician EVOOs that might be probably linked to the outstanding high concentration levels of phenolic acids and flavonoids., (Copyright © 2018. Published by Elsevier Ltd.)

The aim of the present work was to evaluate the phenolic profile of the 'Brava' extra virgin olive oil and assess its potential as a "natural adjuvant" in combination with chemotherapy treatment. The total phenol content of the phenolic extracts was 764 mg gallic acid equivalents/kg and the total antioxidant capacity was 2309, 1881 and 2088 μM trolox equivalents/kg determined by Diphenyl-1-picrylhydrazyl free radical method, Ferric Reducing Antioxidant Power and Trolox Equivalent Antioxidant Capacity assay, respectively. Secoiridoids comprised 83% of the total phenolic compounds. The main secoiridoid from oleuropein was the main isomer of oleuropein aglycone (74 mg/kg). The main secoiridoid from ligstroside was the main isomer of ligstroside aglycone (214 mg/kg). These phenolic extracts showed a significant decrease in cell viability on MCF-7 breast cancer cells in a dose and time dependent manner. 48 h-treatments with different concentrations of the extracts induced intracellular ROS generation and cell death., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this work, phenol-rich extracts from 'Cornicabra' and 'Picual' virgin-olive oils (EVOOs) were examined, for the first time, to establish their capacity to inhibit key enzymes involved in Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and 5-lipoxygenase (LOX)), major depressive disorder (MDD) and Parkinson's disease (PD) (monoamine oxidases: hMAO-A and hMAO-B respectively), and diabetes mellitus (DM) (α-glucosidase and α-amylase). 'Cornicabra' displayed the best inhibitory activity against all enzymes, when compared to 'Picual': BuChE (IC 50  = 156 ± 4 and 308 ± 33 mg mL -1 ), LOX (IC 50  = 26 ± 0.5 and 37 ± 3 mg mL -1 ), hMAO-A (IC 50  = 20 ± 2 and 37 ± 0.2 mg mL -1 ), hMAO-B (IC 50  = 131 ± 7 and 215 ± 13 mg mL -1 ) and α-glucosidase (IC 50  = 154 ± 17 and 251 ± 31 mg mL -1 ), respectively. The behaviour observed can be associated with the higher content of secoiridoids, lignans and phenolic acids in 'Cornicabra' EVOO., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The increasing interest in the Mediterranean diet is based on the protective effects against several diseases, including neurodegenerative disorders. Polyphenol-rich functional foods have been proposed to be unique supplementary and nutraceutical treatments for these disorders. Extra-virgin olive oils (EVOOs) obtained from 'Brava' and 'Mansa', varieties recently identified from Galicia (northwestern Spain), were selected for in vitro screening to evaluate their capacity to inhibit key enzymes involved in Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and 5-lipoxygenase (5-LOX)), major depressive disorder (MDD) and Parkinson's disease (PD) (monoamine oxidases: h MAO-A and h MAO-B respectively). 'Brava' oil exhibited the best inhibitory activity against all enzymes, when they are compared to 'Mansa' oil: BuChE (IC 50 = 245 ± 5 and 591 ± 23 mg·mL -1 ), 5-LOX (IC 50 = 45 ± 7 and 106 ± 14 mg·mL -1 ), h MAO-A (IC 50 = 30 ± 1 and 72 ± 10 mg·mL -1 ) and h MAO-B (IC 50 = 191 ± 8 and 208 ± 14 mg·mL -1 ), respectively. The inhibitory capacity of the phenolic extracts could be associated with the content of secoiridoids, lignans and phenolic acids., Competing Interests: The authors declare no conflicts of interest.

Virgin olive oil, the main fat of the Mediterranean diet, is per se considered as a functional food-as stated by the European Food Safety Authority (EFSA)-due to its content in healthy compounds. The daily intake of endogenous bioactive phenolics from virgin olive oil is variable due to the influence of multiple agronomic and technological factors. Thus, a good strategy to ensure an optimal intake of polyphenols through habitual diet would be to produce enriched virgin olive oil with well-known bioactive polyphenols. Different sources of natural biological active substances can be potentially used to enrich virgin olive oil (e.g., raw materials derived from the same olive tree, mainly olive leaves and pomaces, and/or other compounds from plants and vegetables, mainly herbs and spices). The development of these functional olive oils may help in prevention of chronic diseases (such as cardiovascular diseases, immune frailty, ageing disorders and degenerative diseases) and improving the quality of life for many consumers reducing health care costs. In the present review, the most relevant scientific information related to the development of enriched virgin olive oil and their positive human health effects has been collected and discussed.

The interest of Galician oil producers (NW Spain) in recovering the ancient autochthonous olive varieties Brava and Mansa has increased substantially in recent years. Virgin olive oils produced by co-crushing both varieties in two different proportions, reflecting the usual and most common practice adopted in this region, have gradually emerged for the production of virgin olive oils. Herein, the sensory and chemical characteristics of such oils were characterized by quality and genuineness-related parameters. The results of chemical analysis are discussed in terms of their effective contribution to the sensory profile, which suggests useful recommendations for olive oil producers to improve the quality of oils. Antioxidant compounds, together with aromas and coloured pigments were determined, and their contribution in determining the functional value and the sensory properties of oils was investigated. In general, given the high levels of phenolic compounds (ranging between 254 and 375mg/kg oil), tocopherols (about 165mg/kg oil) and carotenoids (10-12mg/kg oil); these are oils with long stability, especially under dark storage conditions, because stability is reinforced with the contribution of chlorophylls (15-22mg/kg oil). A major content of phenolic compounds, as well as a predominance of trans-2-hexen-1-al within odor-active compounds (from 897 to 1645μg/kg oil), responsible for bitter sensory notes. This characterization allows to developing new antioxidant-rich and flavour-rich VOOs, when co-crushing with a higher proportion of Brava olives, satisfying the consumers' demand in having access to more healthy dishes and peculiar sensory attributes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The current trend of the olive oil market is the production of high quality extra from traditional minor olive varieties with peculiar and differentiated characteristics (especially with respect to the aromatic and phenolic composition). In this way, the interest of Galician oil producers (NW Spain) in recovering old autochthonous Local olive fruits has increased substantially in recent years. In order to investigate the potential of the Local olives by either producing high quality monovarietal oils or mixing with the most widespread olives in Galicia (Arbequina and Picual cv.), quality indices, and fatty acid composition as well as volatile and phenolic profiles were determined and compared. All EVOOs studied in this work can be considered as “extra virgin olive oil” due to quality indices fell within the ranges established in legislation. Picual and Local olive oils as well as those resulting from their co-crushing reach values which are required by EU legislation to add the specific health claim on the oil label. Co-crushing Picual: Local (80:20) provided a significant enhancement of grass and apple nuances and a decrease of banana notes with respect to Picual oils. The co-crushing process improved sensory and health properties of Picual extra virgin olive oils. The effect of co-crushing on phenolics, ester volatiles and banana nuances cannot be easily modulated, contrary to quality indices and fatty acid composition, both changing linearly in strict correlation with the fruit mass ratio. [ABSTRACT FROM AUTHOR]

Systematic studies of physico-chemical and stability-related properties, and chemical composition, of extra virgin olive oils (EVOOs) obtained from drupes cropped in specific regions are of special agricultural interest. This is particularly so with new production areas, where careful selection of the most suitable olive varieties for EVOO production is required. This paper reports the first comprehensive chemical characterisation of EVOOs obtained from three different olive varieties (viz., Picual, Morisca and Manzanilla de Sevilla) grown in a new cultivation area in Galicia (NW Spain). The Morisca variety was that providing the highest industrial oil yield (21%). However, the three types of EVOO exhibited no statistically significant differences in standard quality-related indices other than acidity. Morisca EVOO was that with the lowest content in oleic acid (mean = 68%) and highest content in linoleic acid (mean = 13%). Also, Morisca EVOO exhibited the highest sterol levels (mean = 1616 mg/kg) and Picual EVOO the lowest (mean = 1160 mg/kg). Picual EVOO contained greater amounts of the phenolic compounds luteolin and pinoresinol than both Morisca and Manzanilla de Sevilla EVOOs. Finally, Manzanilla de Sevilla EVOO exhibited differential attributes, with banana and olive fruit aromatic series prevailing predominantly over bitter-like, pungent-like and leaf series. [ABSTRACT FROM AUTHOR]

Highlights: [•] Aroma differences can be attributed to different enzymes distribution in pulp vs. seed. [•] Decrease in trans-2-hexen-1-al and increase in 1-hexanol with ripeness. [•] trans-2-Hexen-1-al>> cis-3-hexenyl acetate>>hexyl acetate were dominant in pulp. [•] Cultivars can be mainly characterised by specific nuances. [•] Aroma trends based on ripening and pungency distinguish among the cultivars. [Copyright &y& Elsevier]

Dynamic headspace-thermal desorption/gas chromatography-mass spectrometry was employed to characterize the volatile profile of extra virgin olive oils before and after the process of sedimentation plus racking. Several oils produced in the provinces of Ourense (San Cibrao das Viñas) and Lugo (Quiroga) (northwestern Spain) and in that of Córdoba (southwestern Spain) were selected for such a purpose. There are no data on the effect of racking on the headspace composition of EVOOs. The volatile components were identified, and the differences found were highlighted in terms of the process but also in terms of different varieties and origins. The results suggest that besides the genetic factor, environmental conditions and process treatments influence the volatile formation. After racking, there is an increase of fruity vs. green notes (C6 alcohols vs. C6 aldehydes) and an apple-like character vs. a banana-like nuance (C6 linoleic acid route vs. C6 linolenic acid route) but also a more bitter character (C5 vs. C6 volatiles), with whiskey, spicy and malty nuances (by the slight increase of minor alcohols and aldehydes). [ABSTRACT FROM AUTHOR]

Abstract: A reliable, sensitive and effective automated method based on dynamic headspace–thermal desorption (DHS–TD) combined to gas chromatography–mass spectrometry (GC–MS) was developed to identify and quantify simultaneously 51 characteristic volatile compounds from extra-virgin olive oils (EVOOs). The most important parameters affecting the DHS extraction were evaluated by two chemometric approaches: a screening 23 factorial design and a Box–Behnken response surface design. The method was validated to ensure the quality of the results. The precision was satisfactory with relative standard deviations (RSD %) less than 10% and 13% for repeatability and reproducibility, respectively. The method showed good linearity and limits of detection were in the range 4.2–110.2ng/g. The accuracy of the method was also evaluated by means of recovery tests undertaken on EVOO samples fortified at two concentration levels. The recoveries obtained ranged from 50.9 to 113.9%. Finally, the proposed method was applied to control for the first time the flavour profile of EVOOs from an emerging production area in north-western Spain (Galicia), with the aim of detecting quantitative differences in two cases: (a) small differences among oils from different trademarks based on the same olive variety or coupage, and (b) larger differences among oils based on different olive varieties or coupages. To achieve the identification of the major potential impact odorants, the odour activity value (OAV) was also calculated. [Copyright &y& Elsevier]

• VOO phenolic compounds act as natural regulators of hyperglycemia. • Secoiridoids are the most abundant phenolic compounds in Brava Gallega VOO extracts. • VOO extracts are stronger inhibitors of α-glucosidase than commercial acarbose. • Extracts from oils from mature olives display the highest inhibitory activity. 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 (IC 50 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. [ABSTRACT FROM AUTHOR]