Key odorants of french fries

Twenty-one compounds, which had been screened in preceding experiments as potent odorants of french fries prepared in palm oil (PO), were quantified by stable isotope dilution assays. Nineteen odorants were dissolved in sun-flower oil in concentrations equal to those in PO. The flavor profile of the model obtained was close to that of a real sample of PO. A comparison of the complete model with models lacking one or more compounds indicated the following key odorants of PO: 2-ethyl-3,5-dimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 3-isobutyl-2-methoxypyrazine, (E,Z)- and (E,E)-2,4-decadienal, trans-4,5-epoxy-(E)-2-decenal, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, methylpropanal, 2- and 3-methylbutanal, and methanethiol. Replacement of palm oil by coconut fat led to a coconut note in the profile of french fries. γ-Octalactone was identified as a major contributor to this note.     

Characterization of the Volatile, Phenolic and Antioxidant Properties of Monovarietal Olive Oil Obtained from cv. Halhali

Volatile and phenolic compositions of olive oil obtained from the cv. Halhali were investigated in the present study. Fruits were harvested at the optimum maturity stage of ripeness and immediately processed with cold press. Simultaneous distillation/extraction (SDE) with dichloromethane was applied to the analysis of volatile compounds of olive oil. Sensory analysis showed that the aromatic extract obtained by SDE was representative of olive oil odour. In the olive oil, 40 and 44 volatile components were identified and quantified in 2010 and 2012 year, respectively. The total amount of volatile compounds was 18,007 and 19,178 μg kg^?1 for 2010 and 2012, respectively. Of these, 11 compounds in the 2010 and 12 in the 2012 harvest presented odour activity values (OAVs) greater than 1, with 1‐octen‐3‐ol, ethyl‐3‐methyl butanoate, (E)‐2‐heptenal and (E,Z)‐2,4‐decadienal being those with the highest OAVs in olive oil. The high‐performance liquid chromatographic method coupled with diode‐array detection was used to identify and quantify phenolic compounds of the olive oil. A total of 14 phenolic compounds in both years were identified and quantified in olive oil. The major phenolic compounds that were identified in both years were hydroxytyrosol, tyrosol, elenolic acid, luteolin, and apigenin. Antioxidant activity of olive oil was measured using the DPPH and ABTS methods.     

A Comparative Study of the Potent Odorants of Different Virgin Olive Oils

The flavour of virgin olive oil was investigated by means of an aroma extract dilution analysis. A comparative study of four oil samples differing in the flavour, indicated that the following odorants were mainly responsible for the odour notes given in brackets: (Z)-3-hexenol, hexanal, (E)-2-hexenal and (Z)-3-hexenal (green), ethyl 2-methylbutyrate, (Z)-3-hexenyl acetate and ethyl cyclohexanoate (fruity), (E,E)-2,4-decadienal, (E)- and (Z)-2-nonenal (fatty) and 4-methoxy-2-methyl-2-butanethiol (black currant-like).     

Oxidation-derived flavor compounds as quality indicators for packaged olive oil

Aroma compounds in packaged extra virgin olive oil can be present naturally or be derived through oxidative degradation under favorable conditions of temperature, light, and oxygen availability. In this study, the identity and quantity of flavor compounds were determined for extra virgin olive oil packaged in 0.5-L glass, poly(ethylene terephthalate), and poly(vinyl chloride) bottles and stored at 15,30, and 40°C under fluorescent light or in the dark for 1 yr. A set of mathematical equations concerning the rates of the most fundamental oxidation reactions in the oil was prepared and numerically solved, and the reaction constants were estimated for specific temperature values. Mainly, the presence of fluorescent light, followed by elevated temperature, stimulated oxidative alterations in the olive oil. Separated and identified flavor compounds were recorded for all the olive oil samples. Based on their abundance and evolution in the oil samples, those most clearly describing oxidation were hexanal, nonanal, (E)-2-decenal, (E)-2-heptenal, and 2-pentyl furan. These compounds could be used as markers of the oxidation process to monitor and describe the quality of packaged olive oil quantitatively.     

Primary odorants of laundry soiled with sweat/sebum: Influence of lipase on the odor profile

Odorants still attached to laundry soiled with human axillary sweat and sebum after a mild washing procedure [European full-scale, short-cycle wash (20 min wash, 15 min rinse) at 30°C, using color detergent, at 3.5 g/L] were extracted and analyzed by aroma extract dilution analysis. Esters (ethyl-2-methylpropanoate and ethylbutanoate), ketones (1-hexen-3-one and 1-octen-3-one) and, in particular, aldehydes [(Z)-4-heptenal, octanal, (E)-2-octenal, methional, (Z)-2-nonenal, (E,Z)-2,6-nonadienal, (E,Z)-2,4-nonadienal, (E,E)-2,4-decadienal, and 4-methoxybenzaldehyde] were identified as primary odorants. Organic acids, which are dominant characteristic odorants in human axillary sweat, were, on the other hand, effectively removed during the washing process. The influence of lipase activity on the odor profile was investigated by analyzing selected sets of textile swatches, sampled from the right/left axillary of male runners, washed in the presence or absence of lipase. The swatches were examined by a sensory ranking analysis prior to the analytical odor analysis. Swatches selected for the subsequent odor analysis possessed greater odor intensity when washed in the presence of lipase than the corresponding swatches washed in the absence of lipase. The aroma extract dilution analysis revealed that aldehydes were present in slightly greater concentrations in swatches washed in the presence of lipase. The aldehydes are believed to be formed through oxidative degradation of triglycerides present in human sebum, which may be facilitated by lipase. Based on sensory panel results and dilution analysis of odorants, the impact of lipase on the odor impression was, however, minor and thus believed to be inadequate as explanation for malodor generation in laundry as experienced by the consumer.     

Effect of extraction conditions on sensory quality of virgin olive oil

The extraction conditions of virgin olive oil have a great influence on its sensory quality. During the centrifugation process, temperature and time of malaxing can be altered to potentially affect quality. Malaxing times (15, 30, 45, 60, and 90 min) and temperatures (25 and 35°C) were studied in an experimental oil mill. Volatile compounds, produced through the lipoxygenase pathway (hexanal, Z-3-hexenal, E-2-hexenal, hexyl acetate, Z-3-hexenyl acetate, hexan-1-ol, E-3-hexen-1-ol, Z-3-hexen-1-ol, and E-2-hexen-1-ol), were analyzed by dynamic headspace gas chromatography, gas chromatographymass spectrometry, and gas chromatography-olfactometry. Different amounts of volatiles responsible for positive attributes of green aroma and negative attributes of astringent mouthfeel of virgin olive oil were determined. The results, after applying mathematical procedures, showed that a temperature of 25°C and a malaxing time between 30 and 45 min produced volatile compounds that contribute to the best sensory quality. High temperature (T≥35°C) with minimum values of time (t<30 min) could also be useful as an alternative way to obtain pleasant green virgin olive oils.     

Microbial survival and odor in laundry

The survival and distribution of microflora during laundering at 30 or 40°C in commercial U.S. and European Union (E.U.) detergents were determined in laboratory wash experiments. Four test strains—Staphylococcus epidermidis, S. aureus, Escherichia coli, and Pseudomonas aeruginosa—were evaluated on cotton textile. A significant survival and transfer between textiles were found for all four test strains washed in E.U. and U.S. color detergents (without bleach), whereas no survival was observed in bleach-containing detergents. Gram-negative strains generally survived in greater numbers than Gram-positive strains. A greater survival was observed in U.S. detergents at U.S. conditions (30°C, 12 min) than in E.U. detergents at E.U. conditions (40°C, 30 min). The adhesion of odorants to cotton and polyester textiles during washing and drying was studied using six previously identified odorants in laundry [ethylbutanoate, (Z)-4-heptenal, (E)-2-nonenal, 3-methylbutanoic acid, 2-methoxyphenol (guaiacol) and 4-methyloctanoic acid]. All odorants were effectively removed from cotton during wash, whereas the odorants were more strongly associated with polyester fibers. During wash, hydrophobic odorants [(Z)-4-heptenal, (E)-2-nonenal, and guaiacol] adhered more strongly to polyester than the acids. The odor formed by surviving skin microflora attached to textiles soiled with human sebum and sweat after laundering at 30°C was studied by sensory evaluation and aroma extract dilution analysis. Intensive odor was formed in both cotton and polyester textiles during prolonged drying. Generally, the odor formation in cotton swatches and the bacterial count of the wash liquor from cotton swatches were greater than the odor formation and bacterial count from polyester swatches. Odorants with animal notes (branched fatty acids) dominated the odor profile after prolonged drying. Polyester swatches possessed a more complex odor profile than cotton; in particular, aldehydes were more dominating in polyester than in cotton. A high-impact and malodorous component, 3-methylindole, was formed during prolonged drying in cotton. The study demonstrates that microbial odor formation is a dominating factor determining the odor impression of laundered cotton and polyester textiles dried under slow drying conditions. The initial soiling with aromatic components has an additional impact on the odor profile of polyester textiles after wash, due to strong adherence of odorants during the wash cycle.     

Modification of fish oil aroma using a macroalgal lipoxygenase

The odor of fish oil is the major factor limiting its application in food. In this study, the addition of butylated hydroxytoluene to fish oil did not significantly inhibit the generation of fishy and rancid odors. To reduce the undesirable odors, fish oil was treated with lipoxygenase (LOX) to produce volatile compounds via position-specific cleavage of hydroperoxides. An extract of a green marine macroalga, Ulva conglobata, showed a high level of 13-LOX activity and 9-LOX to a lesser extent, and produced strong green, melon-like, and fresh-fish-like flavor notes from fish oil. The LOX-modified fish oil contained 99% of the highly unsaturated fatty acids (HUFA; containing three or more double bonds) originally present, total volatile compounds increased from 3477 to 3787 ppb after LOX treatment. Compounds with strong odors accounted for about 40% of the total volatiles. Increasing the level of LOX activity used to treat fish oil produced higher concentrations of the desirable unsaturated aldehydes, ketones, and alcohols, with odors resembling fresh fish, apple, citrus, melon, fruit, and oyster. These compounds were tentatively identified as E,Z-2,6-nonadienal E-2-hexenal, E,E-2,4-octadienal, E,E-3-5-octadien-2-one, and alcohols E-2-pentenol and 2-butoxyethanol. The LOX treatment also slightly increased the content of the undesirable volatile components, including sour and rancid odors, tentatively identified as acetic acid and E,Z- and E,E-2,4-decadienals     

A comparative study of mayonnaise and italian dressing prepared with lipase-catalyzed transesterified olive oil and caprylic acid

Viscoelastic properties of mayonnaise and Italian salad dressing prepared with olive oil and enzymatically synthesized structured lipid (SL) from caprylic acid and olive oil were studied using an SR5000 dynamic stress rheometer. Storage modulus (G′) and loss modulus (G″) were determined as functions of frequency, temperature, and stress. Frequency sweeps did not show significant differences between dressings prepared with olive oil or SL. For all mechanical spectra, G′ values were consistently higher than G″ values. Both Italian dressing and mayonnaise samples displayed similar gel-like characteristics. Mayonnaise and Italian dressings made with olive oil separated when they were brought to room temperature from refrigeration temperatures. SL-based mayonnaise did not separate. Only minor separation was observed in SL-based Italian dressing. A change in the crystallization properties of the two oils was probably responsible for the differences observed after refrigeration. Both SL-based and unmodified olive oil-based mayonnaise and Italian dressing samples had similar viscoelastic character.     

Fatty acid profile and aroma compounds of lipoxygenase-modified chicken oil

Adipose fat tissue, which contributes 1.6–5.8% of total chicken carcass weight, has been underutilized by chicken processors because of its “chickenish odor.” The objective of this study was to prepare a chicken oil from which the undesirable odor notes were eliminated and in which the desirable volatile compounds were enhanced. Chicken adipose fat was dry-rendered at 140°C for 30 min and yielded 78.5% oil. Monoenoic FA constituted 55.8% of the chicken oil, and of that oleic acid constituted 92.8%. Treatment of chicken oil with an algal lipoxygenase extracted from Ulva spp. at 33°C for 30 min resulted in an increase of 0.40% in total monoenoic acids, a decrease of 33.3% in total polyenoic acids, and a decrease in total FA of 0.8%. A noticeable improvement in the odor of chicken oil after lipoxygenase treatment was observed by sensory evaluation and a GC-sniffing technique. The modified chicken oil contained more desirable volatile compounds—ethyl acetate, pentanal, 2-pentyl furan, E-2-heptenal, and nonanal—than the original chicken oil, provided fruity and tea-leaf aromas, and had reduced levels of the undesirable volatile compounds heptanal, 2,4-heptadienal, 2,4-nonadienal, and dodecanal. These modifications reduced the chickenish and oxidized odor notes.     

The triacylglycerol structure of olive oil determined by silver ion high-performance liquid chromatography in combination with stereospecific analysis

The compositions of positionssn-1,sn-2 andsn-3 of triacylglycerols from “extra-virgin” olive oil (Olea europaea) were determined. The procedure involved preparation of diacyl-rac-glycerols by partial hydrolysis with ethyl magnesium bromide; 1,3-, 1,2- and 2,3-diacyl-sn-glycerols as (S)-(+)-1-(1-naphthyl)ethyl urethanes were isolated by highperformance liquid chromatography (HPLC) on silica, and their fatty acid compositions were determined. The same procedure was also carried out on the five main triacylglycerol fractions of olive oil after separation according to the degree of unsaturation by HPLC in the silver ion mode. Although stereospecific analysis of the intact triacyl-sn-glycerols indicated that the compositions of positionssn-1 andsn-3 were similar, the analyses of the molecular species demonstrated marked asymmetry. The data indicate that the “1-random, 2-random, 3-random” distribution theory is not always applicable to vegetable oils.     

Quantification of key odorants formed by autoxidation of arachidonic acid using isotope dilution assay

Six odor-active compounds generated by autoxidation of arachidonic acid (AA) were quantified by isotope dilution assay (IDA), i.e., hexanal (1), 1-octen-3-one (2), (E,Z)-2,4-decadienal (3), (E,E)-2,4-decadienal (4), trans-4,5-epoxy-(E)-2-decenal (5), and (E,Z,Z)-2,4,7-tridecatrienal (6). Compound 1 was the most abundant odorant with about 700 mg/100 g autoxidized AA, which corresponds to 2.2 mol% yield. Based on the odor activity values (ratio of concentration to odor threshold), odorants 3 (fatty) and 5 (metallic) showed the highest sensory contribution followed by 1 (green), 2 (mushroom-like), 6 (egg white-like), and 4 (fatty). For the first time, reliable quantitative results are reported for odorants 1–6 in autoxidized AA, in particular odorant 6, which is a characteristic compound found in autoxidized AA. Synthesis of deuterated 6, required for IDA, is described in detail. The formation of odorants 1–6 by autoxidation of AA is discussed with respect to the quantitative data.     

Flavor components of olive oil—A review

The 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.     

Aroma volatile compounds from two fresh pineapple varieties in china

Volatile compounds from two pineapples varieties (Tainong No.4 and No.6) were isolated by headspace solid phase microextraction (HS-SPME) and identified and quantified by gas chromatography-mass spectrometry (GC/MS). In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile compounds were identified according to their retention time on capillary columns and their mass spectra, and quantified with total concentrations of 1080.44 μg·kg(-1) and 380.66 μg·kg(-1) in the Tainong No.4 and No. 6 pineapples, respectively. The odor active values (OAVs) of volatile compounds from pineapples were also calculated. According to the OAVs, four compounds were defined as the characteristic aroma compounds for the Tainong No. 4 pineapple, including furaneol, 3-(methylthio)propanoic acid methyl ester, 3-(methylthio)propanoic acid ethyl ester and δ-octalactone. The OAVs of five compounds including ethyl-2-methylbutyrate, methyl-2-methylbutyrate, 3-(methylthio)propanoic acid ethyl ester, ethyl hexanoate and decanal were considered to be the characteristic aroma compounds for the Tainong No. 6 pineapple.     

Characterization of Turkish Virgin Olive Oils Produced from Early Harvest Olives

Olives were collected from various districts of Turkey (North and South Aegean sub-region, Bursa-Akhisar, South East Anatolia region) harvested over seven (2001–2007) seasons. The aim of this study was to characterize the chemical profiles of the oils derived from single variety Turkish olives including Ayvalik, Memecik, Gemlik, Erkence, Nizip Yaglik and Uslu. The olive oils were extracted by super press and three phase centrifugation from early harvest olives. Chosen quality indices included free fatty acid content (FFA), peroxide value (PV) and spectrophotometric characteristics in the ultraviolet (UV) region. According to the FFA results, 46% (11 out of 24 samples) were classified as extra virgin olive oils; whereas using the results of PV and UV, over 83% (over 19 of the 24 samples) had the extra virgin olive oil classification. Other measured parameters included oil stability (oxidative stability, chlorophyll pigment, pheophytin-α), cis–trans fatty acid composition and color index. Oxidative stability among oils differed whereas the cis–trans fatty acid values were within the national and international averages. Through the application of two multivariate statistical methods, Principal component and hierarchical analyses, early harvest virgin olive oil samples were classified according to the geographical locations categorized in terms of fatty acid profiles. Such statistical clustering gave rise to defined groups. These data provide evidence of the variation in virgin olive oil quality, especially early harvest and cis–trans isomers of fatty acid profiles from the diverse agronomic conditions in the olive growing regions of Turkey.     

Effects of α-Tocopherol on Oxidative Stability and Phytosterol Oxidation During Heating in Some Regular and High-Oleic Vegetable Oils

The first part of this study evaluated oxidative stability in high-oleic rapeseed oil, palm olein, refined olive oil, low erucic acid rapeseed oil and sunflower oil. The results showed oxidative stability in the order: palm olein > high-oleic rapeseed oil > refined olive oil > low erucic acid rapeseed oil > sunflower oil, as determined by the Rancimat method. Addition of α-tocopherol at high levels of up to 0.2% increased the oxidative stability of refined olive oil, whereas the opposite effect was generally observed in the other oil samples. In the second part of the study, high-oleic rapeseed oil, palm olein, refined olive oil and refined olive oil containing 0.2% α-tocopherol were heated for 3, 6, 9 and 12 h at 180 °C. The peroxide and p-anisidine values generally increased over time in the samples, including olive oil containing 0.2% α-tocopherol. High-oleic rapeseed oil contained the highest amount of total sterols and total phytosterol oxidation products (POPs), but during heating the total POPs content increased moderately (~10%), in contrast to the threefold increase after 12 h of heating in palm olein and refined olive oil. Very high levels of 6-hydroxy derivatives of brassicastanol, campestanol and sitostanol and of 7-ketobrassicasterol were observed in high-oleic rapeseed oil samples. Addition of 0.2% α-tocopherol during heating significantly decreased POPs formation in refined olive oil (P < 0.05).     

Oxidative Evolution of Virgin and Flavored Olive Oils Under Thermo-oxidation Processes

Changes in the oxidative status of Chétoui olive oil were monitored to attest the efficiency of some bioactive compounds from aromatic plants to improve the stability of olive oils after a maceration process at different concentrations. Aromatized olive oils were prepared by addition of lemon and thyme extracts at four different concentrations (20–80 g kg⁻¹ of oils) to virgin olive oils. The following parameters were monitored: free fatty acids, peroxide value, ultra violet absorption characteristics at 232 and 270 nm, fatty acid composition and aromatic profiles. After thermo-oxidation processes, the oleic/linoleic acid ratio remained stable (4.5). Oxidative stability slightly decreased during thermo-oxidation processes. The heating of the oils changed their volatile profile and led to the formation of new volatile compounds, such as the two isomers of 2,4-heptadienal after heating at 100 °C or (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal after thermo-oxidation at 200 °C. The use of lemon and thyme extracts modified the aromatic and the nutritional value of the olive oil by the transfer of some bioactive compounds, such as limonene and carvacrol. In contrast, the oxidative stability of the product did not change. Furthermore, the aromatized oils may be employed in seasoning and cooking of some foods.     

Chemical Composition of Turkish Olive Oil––Ayvalik

Although large amounts of olive oil are produced in Turkey, not much information on its chemical composition is available in the literature to date. The aim of this study was to evaluate the chemical composition of commercial olive oils produced from the Ayvalik olive cultivar in Canakkale, Turkey. Five different samples corresponding to the olive oil categories of extra virgin (conventional, extra virgin olive oil (EVOO), and organic extra virgin olive oil (OGOO) production), virgin olive oil (OO-1), ordinary virgin olive oil (OO-2) and refined olive oil (RFOO) were evaluated. Olive oils were collected from two consecutive production years. According to the free fatty acids, the absorbance values (K₂₃₂ and K₂₇₀), and peroxide values of all the samples conformed to the European standards for olive oil. The level of oleic acid was in the range of 68–73%; while the linoleic acid content was significantly lower in the refined olive oils. The tocopherol and polyphenol content was in the lower range of some European olive oils. However, pinoresinol was a major phenolic compound (5–77 mg/kg depending on the oil category). Its content was markedly higher than in many other oils, which would be a useful finding for olive oil authentication purposes.     

Rapid Determination of Free Fatty Acid in Extra Virgin Olive Oil by Raman Spectroscopy and Multivariate Analysis

We introduce a visible Raman spectroscopic method for determining the free fatty acid (FFA) content of extra virgin olive oil with the aid of multivariate analysis. Oleic acid was used to increase the FFA content in extra virgin olive oil up to 0.80% in order to extend the calibration span. For calibration purposes, titration was carried out to determine the concentration of FFA for the investigated oil samples. As calibration model for the FFA content (FFA%), a partial least squares (PLS) regression was applied. The accuracy of the Raman calibration model was estimated using the root mean square error (RMSE) of calibration and validation and the correlation coefficient (R ²) between actual and predicted values. The calibration curve of actual FFA% obtained by titration versus predicted values based on Raman spectra was established for different spectral regions. The spectral window (945–1600 cm⁻¹), which includes carotenoid bands, was found to be a useful fingerprint region being statistically significant for the prediction of the FFA%. High R ² and small RMSE values for calibration and validation could be obtained, respectively.     

Evaluation of Authenticity of Iranian Olive Oil by Fatty Acid and Triacylglycerol Profiles

For evaluation of the authenticity of Iranian olive oil, samples from many Iranian olive oil producers especially north of Iran in the production year 2007 were collected. The fatty acid and triacylglycerol compositions were measured. The most recent calculation methods including ∆ECN the difference between the actual and theoretical ECN42 (equivalent carbon number), triglyceride content and R of olive oils according to IOOC methods were applied. On the basis of our results, we were able to classify the olive oils into the extra virgin, virgin olive and olive oil categories. The important fatty acids are oleic, palmitic and linoleic acids and their main triacylglycerols are OOO, POO, OOL, PLO, SOS plus POP, and OLL, respectively. On the basis of the triacylglycerol results, experimental ECN48, ECN46, ECN50, ECN44 and ECN42 were obtained. By using the fatty acids results and a computer program, the theoretical ECN42 and ECN44 were calculated. Then R values, being the ratio of r ECN42/r ECN44 for authenticity of all olive oils and ∆ECN for determining categories of olive oils, were defined. The results of olive oil samples were in the accepted limits of Codex and IOOC. Finally we suggest that the R and ∆ECN can be used in identification of adulteration of olive oils and also they are useful from the point of view of authenticity and classification.