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Journal ArticleDOI

Phenolic profiles of Portuguese olive fruits (Olea europaea L.): Influences of cultivar and geographical origin

TL;DR: In this paper, the phenolic compounds present in 29 samples of olive fruits were analysed by reversed-phase HPLC/DAD and/or HPLC-DAD/ESI-MS/MS.
About: This article is published in Food Chemistry.The article was published on 2005-03-01 and is currently open access. It has received 313 citations till now. The article focuses on the topics: Hydroxytyrosol & Oleuropein.

Summary (3 min read)

1. Introduction

  • Phenolic compounds are secondary plant metabolites, with a great structural diversity and a wide phylogenetic distribution (Harborne, 1989).
  • The most frequently described flavonoids include luteolin 7-Oglucoside, rutin and apigenin 7-O-glucoside, and the anthocyanins, cyanidin 3-O-glucoside and cyanidin 3-Orutinoside (Amiot, Fleuriet, &Macheix, 1986, 1989; Esti, Cinquanta, & La Notte, 1998; Romani, Mulinacci, Pinelli, Vincieri, & Cimato, 1999; Ryan & Robards, 1998).

2.1. Samples

  • Olive fruits (Tables 1–3) were collected from different locations in north (Macedo de Cavaleiros, Mirandela, Valpac os, Mogadouro and Figueira de Castelo Rodrigo) and central Portugal (Fund~ao and Castelo Branco), yielding a total of 29 samples from 18 different cultivars.
  • In each region, the chosen cultivars were those predominating in the respective area.
  • The fruits were stored at )20 C and the cores were removed before lyophilisation.
  • The lyophilisations were carried out using a Labconco 4.5 apparatus (Kansas City, USA).
  • Olive fruits, 100 for each sample, were randomly taken, classified into the categories below, and homogenized prior to storage.

2.2. Standards

  • The standards used were from Sigma (St. Louis, MO, USA) or Extrasynth ese (Genay, France) and cyanidin 3- O-glucoside and cyanidin 3-O-rutinoside were from Polyphenols (Sandnes, Norway).
  • Methanol, formic and hydrochloric acids and n-hexane were obtained from Merck (Darmstadt, Germany).
  • The water was treated in a Milli-Q water purification system (Millipore, Bedford, MA, USA) before use.

2.4. Extraction of phenolic compounds

  • The extraction was achieved as previously reported (Vinha et al., 2002): each sample (ca. 1.5 g) was thor- oughly mixed with methanol until complete extraction of these compounds (negative reaction to NaOH 20%).
  • The methanolic extract was filtered, evaporated to dryness under reduced pressure (40 C) and redissolved in methanol (4 ml) of which 20 ll were injected for HPLC analysis.

2.5. Purification of phenolic extract by SPE column

  • The methanolic extract obtained was taken to dryness under reduced pressure (40 C), and redissolved in 50 ml of acidified water (pH 2 with HCl) to avoid the ionisation of the phenolic compounds.
  • The aqueous solution was then passed through an ISOLUTE C18 (NEC) column, previously conditioned with 60 ml of methanol and 140 ml of acidified water (pH 2 with HCl).
  • The loaded cartridge was washed with 60 ml of n-hexane to eliminate the lipid fraction (Pirisi, Cabras, Cao, Migliorini, & Muggelli, 2000) and the retained phenolic compounds were then eluted with methanol (60 ml).
  • Tr, traces; nd, not detected; P , sum of the determined phenolics; Cy-3-glucoside, cyanidin 3-O-glucoside; Cy-3-rutinoside, cyanidin 3-O-rutinoside; Lut 7-gluc, luteolin 7-O-glucoside; Api 7-gluc, apigenin 7-O-glucoside; Quer 3-rham, quercetin 3-O-rhamnoside; RT – retention time.
  • The injection volume for HPLC analysis was 20 ll.

2.6. HPLC-DAD system for qualitative and quantitative analysis of phenolic compounds

  • Phenolic compounds quantification was achieved by the absorbance recorded in the chromatograms relative to external standards.
  • Spectral data from all peaks were accumulated in the 240–600 nm range and chromatograms were recorded at 500 nm.
  • The mass detector was an Agilent G2445A ion-trap mass spectrometer (Agilent Technologies, Waldbronn, Germany) equipped with an electrospray ionisation (ESI) system and controlled by Agilent Software v. 4.0.25.

3.1. Identification of the compounds

  • The peaks on the chromatogram at 500 nm (Fig. 1, peaks 4 and 5) showed identical spectra, with two maxima at 280 and 516–518 nm, which suggested the presence of anthocyanins or anthocyanin derivatives.
  • Upon HPLC–MS analysis, peak 4 showed a pseudomolecular ion [M+H]þ at m=z 449 and the MS2 event yielded a fragment ion at m=z at 287, typical mass in the positive mode of the cyanidin aglycone, corresponding to the loss of glucose (m=z 162).
  • An authentic standard of cyanidin 3-O-glucoside was injected and the retention time, UV and MS spectra matched those of peak 4.
  • The non-coloured phenolic compounds were identified by comparison of their retention times and UV–Vis spectra in the 200–600 nm range with those obtained from standards.
  • Verbascoside was identified by comparison with the compound already described by us from Lippia citriodora (Valent~ao, Andrade, Areias, Ferreres, & Seabra, 1999).

3.2. Quantitative results

  • As a general rule, when the cleaning step was used the amount of each phenolic compound extracted was higher.
  • This observation could not be confirmed in this study: in fact, samples with higher M.I. did not show high values for the ratio hydroxytyrosol/oleuropein and no correlation was found between M.I. and hydroxytyrosol contents, even for the same cultivar.
  • In 25, out of the 29 analysed samples, luteolin 7-O-glucoside and rutin were the predominant flavonoids and, in general, rutin was present in higher amounts than the luteolin derivative.
  • This seems to be a fact common to other olive cultivars, since these two compounds are always reported to occur in olive fruits, even when other compounds are not present (Esti et al., 1998; Servili et al., 1999).
  • With a M.I. of 3.3, presented higher amounts of anthocyanins than many other samples with higher M.I., leading to the assumption that factors other than ripeness influence the anthocyanin content.

3.3. Factors influencing the phenolic profile

  • Several factors are known to affect the quantitative phenolic profiles of olive fruits.
  • Some clear conclusions can be drawn from the results herein obtained.
  • On comparing samples A2, E4, and Q1, three samples from the same geographical origin and with similar M.I. (2.5, 2.4 and 2.7, respectively), but collected from different cultivars, there are very similar phenolic profiles, denoting a strong influence of geographical origin.
  • The same can be observed for the samples N1 and H1, that exhibit similar profiles, even with very different M.I.s.

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Citations
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Journal ArticleDOI
TL;DR: A survey on phenolic compounds of virgin olive oils bearing in mind their chemical-analytical, healthy and sensory aspects is realized, starting from the basic studies, the results of researches developed in the last ten years will be focused.
Abstract: Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet. The importance of VOO is mainly attributed both to its high content of oleic acid a balanced contribution quantity of polyunsaturated fatty acids and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of several human diseases. The polar phenolic compounds of VOO belong to different classes: phenolic acids, phenyl ethyl alcohols, hydroxy-isochromans, flavonoids, lignans and secoiridoids. This latter family of compounds is characteristic of Oleaceae plants and secoiridoids are the main compounds of the phenolic fraction. Many agronomical and technological factors can affect the presence of phenols in VOO. Its shelf life is higher than other vegetable oils, mainly due to the presence of phenolic molecules having a catechol group, such as hydroxytyrosol and its secoiridoid derivatives. Several assays have been used to establish the antioxidant activity of these isolated phenolic compounds. Typical sensory gustative properties of VOO, such as bitterness and pungency, have been attributed to secoiridoid molecules. Considering the importance of the phenolic fraction of VOO, high performance analytical methods have been developed to characterize its complex phenolic pattern. The aim of this review is to realize a survey on phenolic compounds of virgin olive oils bearing in mind their chemical-analytical, healthy and sensory aspects. In particular, starting from the basic studies, the results of researches developed in the last ten years will be focused.

728 citations

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TL;DR: Special attention will be devoted to the use of tandem-mass spectrometric (MS/MS) techniques for the characterization of several important sub-classes of flavonoids, and to the potential of combined diode-array UV (DAD UV), tandem-MS and nuclear magnetic resonance (NMR) detection for unambiguous identification.

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TL;DR: In this article, the authors highlight on the treatment approaches and valorization options for dealing with olive mill waste residues, predominantly those allowing for the recovery of valuable natural components such as phenolic compounds, dietary fibers, animal feed, biofuel, biogaz, enzymes, polymers and other.

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TL;DR: This review focuses comprehensively on the nutrients and high-value bioactives profile as well as medicinal and functional aspects of different parts of olives and its byproducts.
Abstract: The Olive tree (Olea europaea L), a native of the Mediterranean basin and parts of Asia, is now widely cultivated in many other parts of the world for production of olive oil and table olives Olive is a rich source of valuable nutrients and bioactives of medicinal and therapeutic interest Olive fruit contains appreciable concentration, 1–3% of fresh pulp weight, of hydrophilic (phenolic acids, phenolic alchohols, flavonoids and secoiridoids) and lipophilic (cresols) phenolic compounds that are known to possess multiple biological activities such as antioxidant, anticarcinogenic, antiinflammatory, antimicrobial, antihypertensive, antidyslipidemic, cardiotonic, laxative, and antiplatelet Other important compounds present in olive fruit are pectin, organic acids, and pigments Virgin olive oil (VOO), extracted mechanically from the fruit, is also very popular for its nutritive and health-promoting potential, especially against cardiovascular disorders due to the presence of high levels of monounsaturates and other valuable minor components such as phenolics, phytosterols, tocopherols, carotenoids, chlorophyll and squalene The cultivar, area of production, harvest time, and the processing techniques employed are some of the factors shown to influence the composition of olive fruit and olive oil This review focuses comprehensively on the nutrients and high-value bioactives profile as well as medicinal and functional aspects of different parts of olives and its byproducts Various factors affecting the composition of this food commodity of medicinal value are also discussed

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TL;DR: Current knowledge on the bioavailability and biological activities of olive oil phenolic compounds is summarized to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet.
Abstract: The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet. Studies (human, animal, in vivo and in vitro) have demonstrated that olive oil phenolic compounds have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, antimicrobial activity and bone health. This paper summarizes current knowledge on the bioavailability and biological activities of olive oil phenolic compounds.

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Cites background from "Phenolic profiles of Portuguese oli..."

  • ...Variation in the phenolic concentration exists between differing virgin olive oils due to numerous factors including: variety of the olive fruit [34–42], region in which the olive fruit is grown [37], agricultural techniques used to cultivate the olive fruit [34,43,44], maturity of the olive fruit at harvest [35,39,44–48], and olive oil extraction, processing, storage methods and time...

    [...]

References
More filters
Book
29 Nov 2017
TL;DR: This text is a comprehensive reference covering the chemistry, physiology, chemotaxonomy, biotechnology and food technology aspects of the anthocyanins.
Abstract: This text is a comprehensive reference covering the chemistry, physiology, chemotaxonomy, biotechnology and food technology aspects of the anthocyanins. Topics discussed include types of anthocyanins, structural transformations, colour stabilization and intensification factors, biosynthesis and intensification factors, biosynthesis, analysis and functions of anthocyanins. An in-depth review of the literature discussing anthocyanins of fruits, cereals, legumes, roots, tubers, bulbs, cole crops, oilseeds, herbs, spices, and minor crops is included as well.

922 citations

Journal ArticleDOI
TL;DR: Oleuropein and some other related phenolic compounds are reviewed in this article, their occurrence, distribution, biosynthesis and transformation during maturation and during industrial processing (preparation of table olives and oil production) are described.
Abstract: In this paper, oleuropein and some other related phenolic compounds are reviewed. Their occurrence, distribution, biosynthesis and transformation during maturation and during industrial processing (preparation of table olives and oil production) are described. Their role in human health is proposed based on current human, animal and in vitro studies as molecules with antioxidant and antimicrobial properties.

391 citations

Journal ArticleDOI
TL;DR: Mise en evidence de 2 groupses parmi 11 varietes : les varietés a petits fruits ont une forte teneur en oleuropeine and une faible Teneur in verbacoside, les variants a gros fruits ont des caracteristiques inverses as discussed by the authors.
Abstract: Mise en evidence de 2 groupes parmi 11 varietes : les varietes a petits fruits ont une forte teneur en oleuropeine et une faible teneur en verbacoside, les varietes a gros fruits ont des caracteristiques inverses. La maturation puis l'apparition d'anthocyanes se traduisent par des variations des phenols

374 citations


"Phenolic profiles of Portuguese oli..." refers background or result in this paper

  • ...This observation corroborates the correlation already noticed by Amiot et al. (1986) and later reasonably confirmed by Esti et al. (1998), that the cultivars with the highest oleuropein content were those with the least verbascoside....

    [...]

  • ...Quantitative and even qualitative changes in the phenolic composition occur during ripening and considerable differences can be observed according to the stage of development of the fruit (Amiot et al., 1986, 1989; Esti et al., 1998; Romani et al., 1999)....

    [...]

  • ...These values are higher than those reported by Romani et al. (1999) and Esti et al. (1998) for Italian cultivars but lower than some values reported by Amiot et al. (1986) for French cultivars....

    [...]

  • ...%) when compared with those from other studied cultivars, namely the Italian ones studied by Romani et al. (1999) and the French ones studied by Amiot et al. (1986) who found values around 0.5%....

    [...]

  • ...Some studies are already published concerning the influence of these factors on some French (Amiot et al., 1986) Spanish (Bot ıa et al....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the total polar fraction and individual phenols present in virgin olive oil were tested for their antioxidant effect in refined olive oil, and the results showed that the phenols had little or no effect on the stability of the oil.
Abstract: The total polar fraction and individual phenols present in virgin olive oil were tested for their antioxidant effect in refined olive oil. Hydroxytyrosol and caffeic acid showed protection factors greater than BHT. Protocatechuic and syringic acid were also found to have antioxidant activity. Tyrosol, p-hydroxyphenylacetic acid, o-coumaric acid, p-coumaric acid, p-hydroxybenzoic acid and vanillic acid had very little or no effect, and their contribution to the stability of the oil is negligible.

347 citations


"Phenolic profiles of Portuguese oli..." refers background in this paper

  • ...…two Portuguese cultivars may produce excellent olive oils in terms of oxidative resistance, given their very high levels of hydroxytyrosol and oleuropein, two compounds that are considered to give strong protection against autoxidation and thermoxidation of olive oil (Papadopoulos & Boskou, 1999)....

    [...]

  • ...In virgin olive oils, they are the main agents responsible for the resistance against autoxidation and photoxidation (Bot ıa et al., 2001; Papadopoulos & Boskou, 1999; Romani et al., 1999)....

    [...]

Journal ArticleDOI
01 Jan 1998-Analyst
TL;DR: In this article, the structure of plant phenolics or more hydroxy substituents or more than one substitution substitutions was investigated in olives, and the role of phenolics in the development and maturation of olives.
Abstract: Introduction Structure of plant phenolics or more hydroxy substituents Role of phenolics in olives Properties and function Phenolics as antioxidants Phenolics and fruit quality Factors affecting the phenolic profile of olives Varietal influences Other factors Olive development and maturation Processing and storage Oil production Table olives Analysis Sample preparation Quantification Chromatographic methods Liquid chromatography Detection

248 citations

Frequently Asked Questions (12)
Q1. What have the authors contributed in "Phenolic profiles of portuguese olive fruits (olea europaea l.): influences of cultivar and geographical origin" ?

The influences of maturation index, nature of the cultivar and geographical origin are discussed. 

HPLC-DAD/MS system for anthocyanins identificationChromatographic separation was carried out on a LiChroCART column (250 · 4 mm, RP-18, 5 lm particle size, Merck, Darmstadt, Germany), using the solventsystem water–formic acid (19:1) (A) and methanol (B), starting with 5% methanol and installing a gradient to obtain at 3 min – 15% B, 13 min – 25% B, 25 min – 30% B, 35 min – 35% B, 39 min – 40% B, 42 min – 45% B, 45 min – 45% B, 50 min – 47% B, 60 min – 48% B, 64 min – 50% B and 66 min – 100% B. 

In 25, out of the 29 analysed samples, luteolin 7-O-glucoside and rutin were the predominant flavonoids and, in general, rutin was present in higher amounts than the luteolin derivative. 

The most important classes of phenolic compounds in olive fruit include phenolic acids, phenolic alcohols, flavonoids and secoiridoids (Macheix, Fleuriet, & Billot, 1990; Ryan & Robards, 1998; Soler-Rivas, Esp ın, & Wichers, 2000). 

If future analysis confirms the results now obtained, the authors can conclude that at least two Portuguese cultivars may produce excellent olive oils in terms of oxidative resistance, given their very high levels of hydroxytyrosol and oleuropein, two compounds that are considered to give strong protection against autoxidation and thermoxidation of olive oil (Papadopoulos & Boskou, 1999). 

Upon HPLC–MS analysis, peak 4 showed a pseudomolecular ion [M+H]þ at m=z 449 and the MS2 event yielded a fragment ion at m=z at 287, typical mass in the positive mode of the cyanidin aglycone, corresponding to the loss of glucose (m=z 162). 

The phenolic alcohols of olives are 3,4-dihydroxyphenylethanol (hydroxytyrosol) and p-hydroxyphenylethanol (tyrosol) (Macheix et al., 1990;* Corresponding author. 

Olive fruits (Tables 1–3) were collected from different locations in north (Macedo de Cavaleiros, Mirandela, Valpac os, Mogadouro and Figueira de Castelo Rodrigo) and central Portugal (Fund~ao and Castelo Branco), yielding a total of 29 samples from 18 different cultivars. 

The high levels of anthocyanins in Negrinha do Freixo (sample N1) and Picual (sample O1) can be explained by the fact that the fruits of these cultivars are usually consumed as naturally black table olives, which means that they are collected when almost black (the other cultivars are usually used for oil production and are collected before they reach complete maturation). 

For instance sample B1, with a M.I. of 3.3, presented higher amounts of anthocyanins than many other samples with higher M.I., leading to the assumption that factors other than ripeness influence the anthocyanin content. 

Although it is generally accepted that free flavonoids appear at the end of the maturation stage as a consequence of hydrolytic processes, no correlation was found between maturation index and the levels of free luteolin. 

Chromatographic separation was carried out as reported previously (Vinha et al., 2002), with an analytical HPLC unit (Gilson), using a Spherisorb ODS2 column (250 · 4.6 mm, RP-18, 5 lm particle size, Merck, Darmstadt, Germany) with the solvent system water– formic acid (19:1) (A) and methanol (B), starting with 5% methanol and installing a gradient to obtain 15% B at 3 min, 25% B at 13 min, 30% B at 25 min, 35% B at 35 min, 40% B at 39 min, 45% B at 42 min, 45% B at 45 min, 47% B at 50 min, 48% B at 60 min, 50% B at 64 min and 100% B at 66 min.