Components Of Olive Oil Research Articles

Antiatherogenic components of olive oil.

Olive oil is the principal source of fat in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Olive oil is characterized by a high proportion of monounsaturated oleic acid, but the main peculiarity of extra-virgin oil is the presence of remarkable quantities of phenolic compounds, notably hydroxytyrosol and oleuropein, that provide high stability and strong taste. Recently, several studies have demonstrated that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and exert additional potent biologic activities that could partially account for the observed cardioprotective effects of the Mediterranean diet.

Effect of minor components of virgin olive oil on topical antiinflammatory assays.

Interest in the health-promoting effects of virgin olive oil, an important part of the "Mediterranean diet", prompted us to determine the antiinflammatory effects of erythrodiol, beta-sitosterol and squalene, identified as major components of the so-called "unsaponifiable fraction" of virgin olive oil, as well as of the phenolic compounds from the "polar fraction": oleuropein, tyrosol, hydroxytyrosol and caffeic acid. Their activities were compared to those of both, total unsaponifiable and polar fractions. This study was designed to analyse the antiinflammatory effect of these specific compounds from virgin olive oil on edema in mice induced by either arachidonic acid (AA) or 12-O-tetradecanoylphorbol acetate (TPA). The inhibition of the myeloperoxidase (MPO), marker enzyme of the accumulation of neutrophils in the inflamed tissue, was also investigated by the TPA model. The topical application of the olive oil compounds (0.5 mg/ear) produced a variable degree of antiinflammatory effect with both assays. In the auricular edema induced by TPA, beta-sitosterol and erythrodiol from the unsaponifiable fraction of the oil showed a potent antiedematous effect with a 61.4% and 82.1% of inhibition respectively, values not very different to that of the reference indomethacin (85.6%) at 0.5 mg/ear. The four phenolics exerted a similar range of inhibition (33-45%). All compounds strongly inhibited the enzyme myeloperoxidase, indicating a reduction of the neutrophil influx in the inflamed tissues. The strongest inhibitor of AA edema was the total unsaponifiable fraction which inhibition was 34%, similar to that obtained by the reference drug dexamethasone at 0.05 mg/ear. Among the phenolics, oleuropein also produced an inhibition of about 30% with the same dose, but all the other components were found less active in this assay. The anti-inflammatory effects exerted by both unsaponifiable and polar compounds might contribute to the potential biological properties reported for virgin olive oil against different pathological processes.

Changes in the volatile components of virgin olive oil during fruit storage in aqueous media

Storage of olives in sea water is a traditional way of fruit storage in olive oil production in Croatia that is still in frequent use. The changes of volatile compounds of olive oil, responsible for positive and negative odor properties that occur during this kind of fruit storage, were investigated. The influence of sea water was compared to brine and drinking water and with storage in the open air. The composition and content of volatile compounds were determined by dynamic headspace analysis with direct connection to gas chromatography and mass spectrometry. No significant differences were found among aqueous media. The olive oils from aqueous media had an essentially different composition and content of positive as well of negative volatile compounds in comparison to the reference sample and the samples stored in the air. The analytical method can give useful information about fruit storage before olive oil extraction.

Contribution of chemical components of cornicabra virgin olive oils to oxidative stability. A study of three successive crop seasons

AbstractOxidation is the primary cause of virgin olive oil quality deterioration. This paper presents a correlation between oxidative stability, as determined by the Rancimat method, and some chemical components involved in the oxidation process of a set of 74 Cornicabra virgin olive oils obtained from three successive crop seasons (94/95 to 96/97). Results showed a clear influence of total polyphenols on virgin olive oil stability, with linear regression coefficients which were similar for the three seasons studied, and a much lower contribution of α‐tocopherol and unsaturated fatty acids, mainly linoleic acid. A significant effect dependent on the crop season was also observed.

Olive oil hydroxytyrosol protects human erythrocytes against oxidative damages

Hydroxytyrosol, the major representative phenolic compound of virgin olive oil, is a dietary component. Its possible protective effect on hydrogen peroxide (H 2O 2)-induced oxidative alterations was investigated in human erythrocytes. Cells were pretreated with micromolar hydroxytyrosol concentrations and then exposed to H 2O 2 over different time intervals. Subsequently, erythrocytes were analyzed for oxidative hemolysis and lipid peroxidation. Our data demonstrate that hydroxytyrosol prevents both oxidative alterations, therefore, providing protection against peroxide-induced cytotoxicity in erythrocytes. The effect of oxidative stress on erythrocyte membrane transport systems, as well as the protective role of hydroxytyrosol, also were investigated in conditions of nonhemolytic mild H 2O 2 treatment. Under these experimental conditions, a marked decrease in the energy-dependent methionine and leucine transport is observable; this alteration is quantitatively prevented by hydroxytyrosol pretreatment. On the other hand, the energy-independent glucose transport is not affected by the oxidative treatment. The reported data give new experimental support to the hypothesis of a protective role played by nonvitamin antioxidant components of virgin olive oil on oxidative stress in human systems.

Changes in olive oil components during deodorization and/or physical refining at the pilot plant scale using nitrogen as stripping gas

A detailed study has been performed of the changes made by the action of the independent variables (temperature, flow of stripping gas, thickness of oil layer in the deodorizer, and length of the process) on different quality parameters of olive oil deodorized and/or physically refined in a discontinuous process (in a pilot plant of 250 kg maximum capacity using nitrogen as stripping gas in place of steam). The changes caused in the contents of unsaturated fatty acids (elaidinization) in the contents of 3,5-stigmastadiene (dehydrated beta sitosterol), and of saturated fatty acids in the β-position have been studied. A bleached olive oil with 1.85% of ffa was analyzed in a design of experiments using a modified Yates factorial statistical analysis. The results obtained from similar assays carried out with bleached sunflower seed oil with 0.56°C of acidity (using a 4 × 4 latin square experimental scheme) were used as starting point to select the most important independent variables. It has been concluded that the content of trans fatty acids in the deodorized oils depends indirectly on the four variables, and although the elaidic acid content is correct in all cases, the content of trans 18:2 and trans 18:3 readily exceeds the permitted limit when the temperature is above 250°C and the residence times are long. The same occurs with the content of saturated fatty acids in β-position of triglycerides and the content of 3,5-stigmastadiene. This means that the oil must be deodorized at a lower temperature, with longer residence time and greater energy spending. As the different olive oils have different initial characteristics, it is of interest to establish criteria, which are able to forecast whether a particular oil could be refined under pre-set conditions. A similar study should be made to obtain refined oils in other plants. Veranderungen der Olivenolzusammensetzung wahrend des Desodorierprozesses und der physikalischen Raffination in einer Pilotanlage mit Stickstoff als Trenngas Eine detaillierte Studie uber den Einflus der unabhangigen Variablen (Temperatur, Trenngasflus, Dicke der Olschicht im Desodorisator und Prozeslange) auf verschiedene Qualitatsparameter von desodoriertem und/oder physikalisch raffiniertem Olivenol im diskontinuierlichen Verfahren wurde durchgefuhrt (in einer Pilotanlage mit einer maximalen Kapazitat von 250 kg unter Verwendung von Stickstoff als Trenngas). Die Auswirkungen auf ungesattigte Fettsauren (Elaidinisierung), auf den Gehalt an 3,5-Stigmastadien und auf gesattigte Fettsauren in β-Stellung wurden untersucht. Es wurde gebleichtes Olivenol mit 1,8°C Sauregehalt fur die Faktorenanalyse nach Yates eingesetzt. Die Ergebnisse aus vergleichbaren Ansatzen mit gebleichtem Sonnenblumenol mit 0,56°C Sauregehalt wurden als Ausgangspunkt fur die Selektion der wichtigsten unabhangigen Variablen verwendet. Es wurde angenommen, das der Gehalt an trans-Fettsauren in den desodorierten Olen indirekt von den vier Variablen abhangt, und obwohl der Elaidinsauregehalt in allen Fallen in Ordnung ist, ubersteigt der Gehalt an trans-18:2- und trans-18:3-Fettsauren den zugelassenen Grenzwert, sobald die Temperatur hoher als 250°C und die Verweilzeit zu lang ist. Das gleiche gilt fur den Gehalt an gesattigten Fettsauren in β-Stellung der Triglyceride und 3,5-Stigmastadien. Das bedeutet, das das Ol bei niedrigerer Temperatur, mit langeren Verweilzeiten und mit einem groseren Energieaufwand desodoriert werden mus. Da die verschiedenen Olivenole unterschiedliche Ausgangscharakteristika haben, ist es wichtig, Kriterien aufzustellen, anhand derer vorausgesagt werden kann, ob ein Ol unter den vorgegebenen Bedingungen raffiniert werden kann. Eine vergleichbare Studie sollte mit raffinierten Olen aus anderen Analysen durchgefuhrt werden.

Changes in olive oil components during deodorization and/or physical refining at the pilot plant scale using nitrogen as stripping gas

A detailed study has been performed of the changes made by the action of the independent variables (temperature, flow of stripping gas, thickness of oil layer in the deodorizer, and length of the process) on different quality parameters of olive oil deodorized and/or physically refined in a discontinuous process (in a pilot plant of 250 kg maximum capacity using nitrogen as stripping gas in place of steam). The changes caused in the contents of unsaturated fatty acids (elaidinization) in the contents of 3,5-stigmastadiene (dehydrated beta sitosterol), and of saturated fatty acids in the β-position have been studied. A bleached olive oil with 1.85% of ffa was analyzed in a design of experiments using a modified Yates factorial statistical analysis. The results obtained from similar assays carried out with bleached sunflower seed oil with 0.56°C of acidity (using a 4 × 4 latin square experimental scheme) were used as starting point to select the most important independent variables. It has been concluded that the content of trans fatty acids in the deodorized oils depends indirectly on the four variables, and although the elaidic acid content is correct in all cases, the content of trans 18:2 and trans 18:3 readily exceeds the permitted limit when the temperature is above 250°C and the residence times are long. The same occurs with the content of saturated fatty acids in β-position of triglycerides and the content of 3,5-stigmastadiene. This means that the oil must be deodorized at a lower temperature, with longer residence time and greater energy spending. As the different olive oils have different initial characteristics, it is of interest to establish criteria, which are able to forecast whether a particular oil could be refined under pre-set conditions. A similar study should be made to obtain refined oils in other plants. Veränderungen der Olivenölzusammensetzung während des Desodorierprozesses und der physikalischen Raffination in einer Pilotanlage mit Stickstoff als Trenngas Eine detaillierte Studie über den Einfluß der unabhängigen Variablen (Temperatur, Trenngasfluß, Dicke der Ölschicht im Desodorisator und Prozeßlänge) auf verschiedene Qualitätsparameter von desodoriertem und/oder physikalisch raffiniertem Olivenöl im diskontinuierlichen Verfahren wurde durchgeführt (in einer Pilotanlage mit einer maximalen Kapazität von 250 kg unter Verwendung von Stickstoff als Trenngas). Die Auswirkungen auf ungesättigte Fettsäuren (Elaidinisierung), auf den Gehalt an 3,5-Stigmastadien und auf gesättigte Fettsäuren in β-Stellung wurden untersucht. Es wurde gebleichtes Olivenöl mit 1,8°C Säuregehalt für die Faktorenanalyse nach Yates eingesetzt. Die Ergebnisse aus vergleichbaren Ansätzen mit gebleichtem Sonnenblumenöl mit 0,56°C Säuregehalt wurden als Ausgangspunkt für die Selektion der wichtigsten unabhängigen Variablen verwendet. Es wurde angenommen, daß der Gehalt an trans-Fettsäuren in den desodorierten Ölen indirekt von den vier Variablen abhängt, und obwohl der Elaidinsäuregehalt in allen Fällen in Ordnung ist, übersteigt der Gehalt an trans-18:2- und trans-18:3-Fettsäuren den zugelassenen Grenzwert, sobald die Temperatur höher als 250°C und die Verweilzeit zu lang ist. Das gleiche gilt für den Gehalt an gesättigten Fettsäuren in β-Stellung der Triglyceride und 3,5-Stigmastadien. Das bedeutet, daß das Öl bei niedrigerer Temperatur, mit längeren Verweilzeiten und mit einem größeren Energieaufwand desodoriert werden muß. Da die verschiedenen Olivenöle unterschiedliche Ausgangscharakteristika haben, ist es wichtig, Kriterien aufzustellen, anhand derer vorausgesagt werden kann, ob ein Öl unter den vorgegebenen Bedingungen raffiniert werden kann. Eine vergleichbare Studie sollte mit raffinierten Ölen aus anderen Analysen durchgeführt werden.

Comparison between Extra Virgin Olive Oil and Oleic Acid Rich Sunflower Oil: Effects on Postprandial Lipemia and LDL Susceptibility to Oxidation

The aim of our study was to determine whether the minor polar components of virgin olive oil could have favorable effects (1) on fasting and postprandial lipid profile and (2) on low-density lipoprotein (LDL) composition and susceptibility to oxidation in vitro. Ten normolipidic subjects were included in a crossover study (two diet periods of 3 weeks) and received either virgin olive oil (OO diet) or oleic acid rich sunflower oil. An oral fat load was performed at the end of each period. The plasma lipid levels were not significantly different after both diets in the fasting and postprandial states. A few minor variations of the LDL composition were observed only in the postprandial lipemia, and they were different after both diets. The LDL oxidation susceptibility was evaluated by the formation of conjugated dienes. With LDL isolated in the fasting state, the diene production decreased (p = 0.0573) only after the OO diet. The dienes determined at time 0 and the maximal dienes obtained during the oxidation reaction decreased (p = 0.0145 and p = 0.0184, respectively) only after the OO fat load. Nevertheless, the diene production decrease was not significant (p = 0.0848). Our results suggest a mild effect of minor components of virgin olive oil related to a decrease of LDL susceptibility to oxidation; further analyses are necessary to give clear conclusions about their role.

Flavor components of olive oil—A review

AbstractThe unique and delicate flavor of olive oil is attributed to a number of volatile components. Aldehydes, alcohols, esters, hydrocarbons, ketones, furans, and other compounds have been quantitated and identified by gas chromatography‐mass spectrometry in good‐quality olive oil. The presence of flavor compounds in olive oil is closely related to its sensory quality. Hexanal, trans‐2‐hexenal, 1‐hexanol, and 3‐methylbutan‐1‐ol are the major volatile compounds of olive oil. Volatile flavor compounds are formed in the olive fruit through an enzymatic process. Olive cultivar, origin, maturity stage of fruit, storage conditions of fruit, and olive fruit processing influence the flavor components of olive oil and therefore its taste and aroma. The components octanal, nonala, and 2‐hexenal, as well as the volatile alcohols propanol, amyl alcohols, 2‐hexenol, 2‐hexanol, and heptanol, characterize the olive cultivar. There are some slight changes in the flavor components in olive oil obtained from the same oil cultivar grown in different areas. The highest concentration of volatile components appears at the optimal maturity stage of fruit. During storage of olive fruit, volatile flavor components, such as aldehydes and esters, decrease. Phenolic compounds also have a significant effect on olive oil flavor. There is a good correlation between aroma and flavor of olive oil and its polyphenol content. Hydroxytyrosol, tyrosol, caffeic acid, coumaric acid, and p‐hydroxybenzoic acid influence mostly the sensory characteristics of olive oil. Hydroxytyrosol is present in good‐quality olive oil, while tyrosol and some phenolic acids are found in olive oil of poor quality. Various off‐flavor compounds are formed by oxidation, which may be initiated in the olive fruit. Pentanal, hexanal, octanal, and nonanal are the major compounds formed in oxidized olive oil, but 2‐pentenal and 2‐heptenal are mainly responsible for the off‐flavor.

Physiology of lipase formation inPenicillium candidum

Penicillium candidum grew and produced lipase in a culture medium supplemented with 0.2% olive oil. Significant enzyme production required the presence of olive, oil and was prevented by cycloheximide. Polyacrylamide gel electrophoresis of filtrates from olive oil fermentations gave a single band of lipase activity (MW 80 KDa). Among the olive oil components only oleate allowed significant lipase production. Other carboxylic and saturated fatty acids containing similar or lower numbers of carbon atoms, did not cause derepression of lipase formation.

The Effects of Olive Oil upon Rat Serum Lipid Levels and Lymphocyte Functions Appear to Be Due to Oleic Acid

In order to investigate whether previously reported effects of feeding olive oil (OO) upon rat serum lipid concentrations and immune cell functions are due to oleic acid, weanling rats were fed for 6 weeks on diets containing 20% by weight of OO, safflower oil (SO), or high oleic acid sunflower oil (HOSO); a low-fat (LF) diet containing 2.5% by weight of lipid was used as a control. Feeding the OO or HOSO diets resulted in an elevated serum triacylglycerol concentration as compared with feeding the LF or SO diets. The serum total cholesterol concentrations were raised in the animals fed the high-fat diets and were highest in animals fed the OO or the HOSO diet. The fatty acid composition of the serum and of spleen lymphocytes reflected that of the diet fed. The mitogen-stimulated spleen lymphocyte proliferation ex vivo was significantly lower following OO or HOSO feeding as compared with LF or SO feeding. Similarly, feeding the OO or the HOSO diet resulted in lower spleen natural killer cell activity as compared with LF or SO feeding. These observations indicate that the effects of OO feeding are most likely due to oleic acid rather than to other components of OO.

Determinación de algunos parámetros de pureza en aceites de oliva. Resultados de un estudio colaborativo

The results of a collaborative study with the participation of Governmental and Olive Oil Industry laboratories is presented. This study was carried out to determine the precision of the analytical methods used for quantifying certain components of olive oils. Samples of virgin olive oil, olive oil and residue olive oil were analysed for total sterols, sterolic composition, trans isomers from fatty acids, waxes and stigmastadienes, using the analytical methods included in the Commission Regulation EEC 2568/91 of the European Union and modifications therein, and in Document TC20/11 of the International Olive Oil Council (1993). The results have been statistically procesed according to the standard ISO 5725-1986 (E).

Inhibition of platelet aggregation and eicosanoid production by phenolic components of olive oil

This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B 2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B 2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC 50s (concentration resulting in 50% inhibition) of DHPE for ADP- or collagen-induced PRP aggregations were 23 and 67 μM, respectively. At 400 μM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB 2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB 2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects on PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavonoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.

Two types of functionally different GABA-A receptors mediating intestine contractility

Aging is a complex process. It is considered a risk factor for several diseases such as cancer, neurodegenerative diseases, cardiovascular diseases, and diabetes, most of which have an oxidative and inflammatory base. Given that life expectancy is increasing, there is a present interest in the search for anti-aging strategies that allow a healthy aging. Interestingly, in Spain, where the Mediterranean Diet (MD) is the reference food pattern, life expectancy will have the highest average by 2040. This diet is characterized, among other items, by virgin olive oil intake, which contains between 50–200 mg/kg of hydroxytyrosol, a major polyphenolic component of olive oil. Hydroxytyrosol is formed by the hydrolysis of oleuropein during the maturing of olives, storage of olive oil, and preparation of table olives. It is a yield of oleuropein by microbiota action in the organism after virgin olive oil consumption. The daily intake in context of the MD is estimated to be around 0.15 and 30 mg/day. In the last few years, hydroxytyrosol has received increasing attention due to its multiple pharmacological activities, such as antioxidant, anti-inflammatory and pro-apoptotic activities. It has also been the focus of extensive research regarding its bioactivity. In this sense, hydroxytyrosol is under consideration for the development of new anti-aging strategies. In this review we will summarize the potential anti-aging effects of hydroxytyrosol and its protective role in several age-related diseases.

Stable carbon isotope ratios (carbon-13/carbon-12) of olive oil components

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStable carbon isotope ratios (carbon-13/carbon-12) of olive oil componentsG. Bianchi, F. Angerosa, L. Camera, F. Reniero, and C. AnglaniCite this: J. Agric. Food Chem. 1993, 41, 11, 1936–1940Publication Date (Print):November 1, 1993Publication History Published online1 May 2002Published inissue 1 November 1993https://doi.org/10.1021/jf00035a024RIGHTS & PERMISSIONSArticle Views272Altmetric-Citations33LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (536 KB) Get e-Alerts Get e-Alerts

THE ROLE OF DIGLYCERIDES, MONOGLYCERIDES, AND FREE FATTY ACIDS IN OLIVE OIL MINOR SURFACE-ACTIVE LIPID INTERACTION WITH PROTEINS AT OIL-WATER INTERFACES

ABSTRACT Adsorbed film viscoelasticity experiments were conducted in order to study the contribution of diglycerides, monoglycerides and free fatty acids to the interaction between the surface-active fraction of olive oil with bovine serum albumin and sodium caseinate at olive oil-protein solution interfaces. Removal of the surface-active components of natural olive oil by column chromatography, followed by addition of diolein, monoolein or oleic acid to the resulting purified olive oil, brought about a marked decrease in the viscoelasticity parameters of adsorbed bovine serum albumin films, in all the three cases. Furthermore, adsorbed sodium caseinate films remained purely viscous. High viscoelasticity of adsorbed bovine serum albumin and sodium caseinate films at the natural olive oil-protein solution interfaces is attributed to the mixed nature of the films and to the various types of interactions occuring between the adsorbed high and low-molecular weight constituents of the films

The influence of minor surface-active components of olive oil on emulsification with bovine serum albumin

Minor surface-active lipids occurring in virgin olive oil enhance the interfacial area per millilitre of oil created during the emulsification by bovine serum albumin (BSA). These components adsorb at the newly formed oil—water interface, bring about a marked decrease in the interfacial tension value and aid, together with adsorbed protein molecules, in the formation and stabilization of emulsion oil droplets. Minor surface-active lipids do not appear to affect the amount of protein adsorbed at the oil—water interface. This could mean that the penetration of the interface by protein molecules arriving at the interface is not inhibited by the presence of already adsorbed surface-active lipid molecules.

Effect of dietary olive oil non-glyceride fraction on plasma cholesterol level and liver phospholipid fatty acid composition

Evidence has shown that dietary supplementation with virgin olive oil (OLO) lowers plasma cholesterol (CH) level. The present study demonstrated in animals that OLO supplementation also suppresses the conversion of 20:3n-6 to 20:4n-6 (Δ 5 desaturation, or D5D). Our results also indicated that the components in OLO responsible for suppressing both plasma CH and D5D activity are contained mainly in the non-glyceride fraction. Among various components examined, squalene or polyphenolic acids (caffeic, vanillic and protocatechuic acids) failed to affect either plasma CH level or D5D activity. Feeding of polyphenol-stripped OLO did not change plasma CH levels, but it enhanced the D5D activity suggesting that polyphenols might be responsible for suppressing the D5D activity. Previous reports by others have already shown that dietary phytosterols lower plasma CH level whereas they enhance the D5D activity. It is suggested that the hypocholesterolemic and the D5D suppressing effects are two independent functions modulated by different components in the virgin OLO.

Olive oil as a cause of contact allergy in patients with venous eczema, and occupationally

From 1985 to 1989, 13 cases of contact allergy to olive oil have been identified in the Departments of Dermatology of Kristianstad and Ostersund Hospitals. Known components of olive oil could not be proved to be the cause of the allergy. This high number of patients with contact allergy to olive oil and possible explanations are discussed.

Bitter Taste of Virgin Olive Oil: Correlation of Sensory Evaluation and Instrumental HPLC Analysis

ABSTRACTA method for the extraction by C18 columns and HPLC analysis of bitter components of virgin olive oils was developed. Factorial design showed the suitability of using two columns and three HPLC analyses per sample. An equation obtained by multiple regression analysis, related bitterness with the area of peaks, which explained 92% or variance.