Lorenzo Cerretani

Abstract:

Abstract: the use of differential scanning calorimetry (DSC) for assessing the deterioration effect of microwave heating on vegetable oils, and on olive oils in particular, has been partially explored in literature. The aim of this work was to evaluate the potential of DSC to discriminate among microwaved extra virgin olive oils (EvOo from different olive cultivar and origin), according to changes on thermal properties (upon cooling and heating) and traditional oxidative stability indices (peroxide, p-anisidine and TOTOX values).

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Abstract: A useful procedure for the qualitative and quantitative determination of vegetable oils (canola, hazelnut, pomace and high linoleic/oleic sunflower) as adulterants in commercial samples of extra virgin olive oil, has been developed. Partial least squares (PLS) was employed for the analysis of Fourier transform infrared spectroscopy (FTIR) spectral data of the blend oil samples. Calibration models were constructed for extra virgin olive oil purity, with wavelength selection in the infrared region, according to their predictive ability, with first derivative and mean centering used as data pretreatment. PLS models were internally validated by the leave-one-out procedure. The method developed was very suitable for the determination of modeled adulterants but it may also reveal an adulteration even if it does not derive from the adulterants employed in this study.

Abstract: The separation and determination of tocopherols (Ts) in vegetable oils by nano-LC chromatography with UV-vis detection using lauryl methacrylate ester-based monolithic columns has been developed. The separation of Ts was optimized in terms of mobile phase composition on the basis of the best compromise among efficiency, resolution and analysis time. Using a mobile phase composed of ACN/methanol/water, an excellent resolution between Ts was achieved within 18 min. The LODs were lower than 0.26 mug/mL, being repeatability values of retention time and peak area below 0.15 and 3.1%, respectively. The method was applied to the quantification of Ts and tocotrienols present in several vegetable oils from different botanical origins.

Abstract: In this work 31 virgin olive oil samples produced during 2006-2007 oil season from an industrial olive oil plant in abruzzo region were analyzed. In particu-lar, the study focused on the evaluation of microcomponents, such as chlorophyll and carotenoids, responsible for the color of the oil and its modification in dependence on the frying treatments to which the samples were undergoing (till 60 min of heating treatment). For this purpose colorimetric (cielab), spectrophotometry and chromatographic analysis were carried out and the correlations between color and pigment amounts were studied. The color of the oils were strongly conneqed with the amount of pigments that depended on the olive varieties and the carotenoids fraction showed a lower thermal stability than the chlorophylls.

Abstract: The purpose of this study was to determine the total trans fat content from the Fourier transform infrared (FT-IR) spectra of neat fats extracted from cereal-based foods using a single-bounce horizontal attenuated total reflectance (SB-HATR) sampling accessory. Partial least squares (PLS) regression was employed for the development of calibration models. A trans fat calibration curve was prepared by adding trielaidine gravimetrically to trans free canola oil. Regression of the FT-IR/PLS-predicted trans contents was 0.999 with a root-mean-square error of calibration (RMSEC) and root-mean-square error of prediction (RMSEP) 0.07% and 0.07%, respectively. Amongst the samples examined, the fat content was in the range of 8.2-27.2%, whilst most samples contained more than 10% trans fat; the highest trans fat content was 16.3%. The FT-IR results were comparable with gas chromatography (GC).

Abstract: An electronic nose based on an array of 6 metal oxide semiconductor sensors was used, jointly with linear discriminant analysis (LDA) and artificial neural network (ANN) method, to classify oils containing the five typical virgin olive oil (VOO) sensory defects (fusty, mouldy, muddy, rancid and winey). For this purpose, these defects, available as single standards of the International Olive Council, were added to refined sunflower oil. According to the LDA models and the ANN method, the defected samples were correctly classified. On the other hand, the electronic nose data was used to predict the defect percentage added to sunflower oil using multiple linear regression models. All the models were able to predict the defect percentage with average prediction errors below 0.90%. Then, the develop is a useful tool to work in parallel to panellists, for realizing a rapid screening of large set of samples with the aim of discriminating defective oils.

Abstract: The present study focused on the development of a sensory evaluation system, using a quantitative descriptive analysis (QDA) scheme, to define the sensory attributes of boiled potato slices. A HS-SPME-GC-MS technique for a rapid determination of volatile components in boiled potatoes was also investigated. In addition to the mechanism of generation of off-odours and off-flavours in boiled potatoes (POF), the effects of the use of food additives after cooking were examined. POF formation, analysed by both sensory evaluation and HS-SPME, demonstrated an oscillating mechanism of formation of volatile compounds, probably related to enzymatic lipid oxidation and hydroperoxide generation. In particular, POF were strongly correlated with the presence of 2-pentenal, 2-hexenal, 2-heptenal, 2-pentylfuran and 2-decenal. In all, about 50 compounds were detected by HS-SPME technique. Treatment with ascorbate or citrate, after cooking and before storage, did not prevent the formation of off-flavours, in contrast to sodium pyrophosphate. Potassium meta-bisulphite prevented POF formation, but caused the creation of other off-flavours detected by a trained panel.

Abstract: A sensory analysis of 112 virgin olive oils was performed by a fully trained taste panel. The samples were divided in "defective" and "not defective" on the basis of their olfactory attributes. Then, the "not defective" samples were classified into "low", "medium" and "high" according to the fruity aroma intensity perceived by assessors. All samples were also analysed by FT-NIR and FT-IR spectroscopy and processed by classification methods (LDA and SIMCA). The results showed that NIR and MIR spectroscopy coupled with statistical methods are an interesting technique compared with traditional sensory assessment in classifying olive oil samples on the basis of the fruity attribute. The prediction rate varied between 71.6% and 100%, as average value. The spectroscopic methods, combined with chemometric strategies, could represent a reliable, cheap and fast classification tool, able to draw a complete fingerprint of a food product, describing its intrinsic quality attributes, that include its sensory attributes.

Abstract: The aim of this review is to describe different filtration systems of extra virgin olive oil (EVOO): a) to remove suspended solids, b) to eliminate humidity and making the oil brilliant, c) cross-flow filtration and d) new filtration systems based on filter bag and the flow of an inert gas. During filtering operations quantitative and qualitative changes take place, especially on minor components, which are of great value in establishing of the quality of EVOO. The present review focuses on the effect of these different filtration systems in the minor fraction of EVOO with particular emphasis on waxes, carbonyl compounds, pigments, lipophilic and hydrophilic phenols, phospholipids and proteins.

Abstract: A method for the determination of tocopherols and tocotrienols in vegetable oils by nanoliquid chromatography with UV-vis detection has been developed. The separation of tocopherols was optimized in terms of mobile phase composition on the basis of the best compromise between efficiency, resolution, and analysis time. The optimal conditions were achieved using a C18 silica monolithic column (150 mm x 0.1 mm) with an isocratic elution of acetonitrile/methanol/water (acidified with 0.2% acetic acid) at a flow rate of 0.5 microL min(-1), giving a total analysis time below 18 min. The method has been applied to the quantification of tocopherols and tocotrienols present in several vegetable oils with different botanical origins.

Abstract: The phenolic profiles of two different virgin olive oils and their admixtures in different percentages have been analyzed after heating treatments by microwave or conventional oven. Changes in the phenolic profile upon heating were evaluated by chromatographic and spectroscopic methods, also monitoring the antioxidant activity by ABTS(*+) test. 3,4-DHPEA-EA, p-HPEA-EA, and EA showed the highest decreases after thermal treatments. The only compounds that showed a clear increase with heating, in particular by conventional oven, were the dialdehydic form of elenolic acid (EDA) and p-hydroxyphenylethanol linked to the dialdehydic form of elenolic acid (p-HPEA-EDA). A comparison between the variations after heating of the sum of monoaldehydic and dialdehydic forms of phenolic compounds obtained by using different analytical approaches (HPLC-DAD/MSD and 1D and 2D NMR spectroscopy) was made. The results showed a good agreement of these two high-resolution techniques.

Abstract: Thirteen monovarietal extra virgin olive oils (EVOos) from two Italian regions were evaluated by means of differential scanning calorimetry (DSC) to study statistical correlations among major and minor chemical components and thermal properties obtained by cooling transitions and their deconvoluted peaks. The application of DSC for the discrimination of EVOos according to the cultivar and geographical origin was also considered. Thermal properties of the cooling transitions (except for the crystallization enthalpy) were almost all influenced by triolein content and fatty acid composition. Thermal properties (area, onset and offset temperatures of transition, transition range, and peak temperature) of the three deconvoluted peaks were found to be significantly correlated not only to major but also to minor components (diacylglycerols, free fatty acids) and oxidative stability indices. The analysis of thermal properties obtained by cooling transition did not lead to sample discrimination according to geographical provenience. However, T_on, T_off, and peak areas of the two deconvoluted transitions that peaked at the lowest temperatures, as well as T_off of deconvoluted peak at the highest temperature, significantly differentiated oil samples according to their geographical origin. These findings may be confirmed by the appliance of multivariate statistical analysis to a larger set of samples to select thermal parameters able to discriminate among EVOos of different geographical provenience. Practical applications: DSC application exhibits some advantages upon the classical analytical methods as it does not require sample preparation and use of solvents, thus resulting in a reduced environmental impact. The results of this study suggest that DSC can be used to test quality and to determine geographical origin of EVOo.

Abstract: The aim of this work was to develop a rapid resolution liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (RRLC-ESI-TOF-MS) method followed by tetrazolium salt (MTT)-based cell viability assays for qualitative and quantitative classification of extra virgin olive oil (EVOO) varieties by phenolic and other polar compound contents as well as for rapid characterization of putative cytotoxic activities against human cancer cells. Five different Spanish EVOO varieties were analyzed, and RRLC-ESI-TOF-MS method was applied for qualitative and quantitative identification of most important phenolic compounds. We finally employed MTT-based cell viability protocol to assess the effects of crude EVOO phenolic extracts (PEs) on the metabolic status of cultured SKBR3 human breast cancer cells. MTT-based cell viability assays revealed a wide range of breast cancer cytotoxic potencies among individual crude PE obtained from EVOO monovarietals. Remarkably, breast cancer cell sensitivity to crude EVOO-PEs was up to 12 times higher in secoiridoids enriched-PE than in secoiridoids-low/null EVOO-PE.

Abstract: Fourier-transform infrared spectroscopy, followed by linear discriminant analysis of the spectral data, was used to classify Italian Pecorino cheeses according to their ripening time and manufacturing technique. The Fourier transform infrared spectra of the cheeses were divided into 18 regions and the normalized absorbance peak areas within these regions were used as predictors. Linear discriminant analysis models were constructed to classify Pecorino cheeses according to different ripening stages (hard and semi-hard) or according to their manufacturing technique (fossa and nonfossa cheeses). An excellent resolution was achieved according to both ripening time and manufacturing technique. Also, a final linear discriminant analysis model considering the 3 categories (hard nonfossa, hard fossa, and semi-hard nonfossa) was constructed. A good resolution among the 3 categories was obtained.

Abstract: A simple and reliable method for the evaluation of the phenolic fraction of extra virgin olive oils (EVOO) by capillary electrochromatography (CEC) with UV-Vis detection, using lauryl acrylate (LA) ester-based monolithic columns, has been developed. The percentages of the porogenic solvents in the polymerization mixture, and the mobile phase composition, were optimized. The optimum monolith was obtained with a monomers/porogens ratio of 40:60% (wt/wt) using a LA/1,3-butanediol diacrylate ratio of 70:30% (wt/wt) and a 1,4-butanediol/1-propanol ratio of 25:75% (wt/wt). A satisfactory resolution between the phenolic compounds was achieved in less than 25 min with a 15:85 (v/v) ACN-water buffer containing 5 mM formic acid at pH 3.0. The method was applied to the analysis of the phenolic fraction of EVOO samples. Using linear discriminant analysis of the CEC phenolic profiles, the EVOO samples belonging to three different geographical origins (Croatia, Italy and Spain) were correctly classified with an excellent resolution among all the categories.

Abstract: The storage conditions of bottled or tank-stored virgin olive oil, as well as all the agronomical and technological variables of the processing stages, are particularly relevant for preserving the highly valued organoleptic quality of this product. All the efforts made in the olive grove and in the oil mill to produce virgin olive oil with good sensory characteristics can be undermined if improper storage conditions are used. In particular, it is necessary to protect the oil against lipid oxidation which can have many deleterious effects on the quality of virgin olive oil, including the formation of unpleasant organoleptic characteristics, the drastic reduction of the bouquet and taste notes as well as the reduction of naturally-occurring antioxidant compounds and therefore shortening of its the shelf life. The oxidation process during storage is known and involves changes to both the major and minor components of virgin olive oil. To slow down the oxidation rate during storage, certain factors such as the presence of oxygen and traces of metals, exposure to light and the binomial storage time/temperature, must be kept under control. This overview will present the importance of reducing these pro-oxidizing effects, as well as the main changes which may occur during the storage of virgin olive oil at the expense of the minor constituents that are more relevant for the olfactive and gustative characteristics and its impact on the aroma and taste of the oil, particularly the phenolic and volatile compounds.

Abstract: An electronic nose based on an array of six metal oxide semiconductor sensors was used to monitor the oxidative status of virgin olive oils (VOO) during storage. VOO samples, with and without phenolic compounds, were stored at 60 °C for 7 weeks. Once a week, absorbance at 232 and 270 nm, oxidized stability index, electronic nose, and sensory analysis were evaluated. Linear discriminant analysis models were constructed in order to classify samples according to oxidative levels. Based on these models, VOO samples with and without phenolic compounds at different storage times, divided in eight categories, were correctly classified also achieving a good correlation for sensory analysis. The method is a fast and economical tool for on-line monitoring of VOO oxidation status.

Abstract: The effect of microwave heating of extra virgin olive oil (EVOo), olive oil (Oo) and pomace olive oil (Po) in domestic appliances, was investigated in terms of chemical oxidative indices (peroxide, p-anisidine and Totox values), free acidity, water content, total phenol content and different classes of phenolic compounds. Water content of unheated EVOo was higher as compared to the other two oils and it was found to decrease with increasing treatment time in all oils, especially in EVOo. Lipolysis was noticeable in EVOo only at highest treatment times. p-Anisidine values showed a sinusoidal trend in EVOo and Oo with a maximum at 6 and 15 min, respectively, while they gradually increased in Po. Significant amounts of phenols were detected only in unheated EVOo, even though about 30% were lost after 6 min. Among the different classes of phenolic compounds, o-diphenols and lignans displayed the highest microwave heating resistance in the whole time range of microwave application, which is of great importance from a nutritional standpoint. The utilisation of Po may be encouraged especially at short microwave treatment times for both domestic and food catering applications.

Abstract: A rapid Fourier transformed infrared (FTIR) attenuated total reflectance (ATR) spectroscopic method was applied to the determination of fatty acid (FA) profile and peroxide value (PV) of virgin olive oil. Calibration models were constructed using partial least squares (PLS) regression. A FA calibration model was constructed in the spectral range from 3033 to 700 cm-1. Oleic acid (62.0-80.0%), linoleic acid (5.3-15.0%), saturated fatty acids (SFA, 12.6-19.7%), mono-unsaturated fatty acids (MUFA, 64.4-81.0%) and poly-unsaturated fatty acids (PUFA, 6.0-15.9%) were considered for chemometric analysis. PV (5.7-15.7 meq O2 kg-1) was calibrated using the signal of the full spectral range 4000-700 cm-1 with first derivative pre-treatment. The LODs of the FTIR-chemometric methods were: 3.0% for oleic acid, 0.5% for linoleic acid, 1.3% for SFA, 3.0% for MUFA, 0.3% for PUFA and 1.0 meq O2 kg-1 for PV. Analytical methods were evaluated by use of validation samples (n = 25 for all the FA related parameters and n = 10 for PV) with nearly quantitative recovery rates (98-103%). The proposed method provided results comparable to official procedures, with the advantages of being less expensive and more rapid.

Abstract: Rapid analytical techniques were used to analyze the lipid fraction and to characterize phenolic compounds in Italian walnuts (Chandler cv.) grown in the same experimental orchard under different agronomical conditions. Lipid components such as fatty acids, sterols and tocopherols were determined by capillary gas chromatography using a flame ionization detector. Linoleic and linolenic acids were the most representative ω-6 and ω-3 essential dietary fatty acids present. A total lipid chromatogram was used to simultaneously determine free sterols and tocopherols. Walnuts contained substantial amounts of γ- and δ-tocopherol, which explains their antioxidant properties. Sitosterol, Δ⁵-avenasterol and campesterol were the major free sterols found. Micellar electrokinetic chromatography was used to analyze simple and complex phenols (tannin profile), while the total phenol amount and the antioxidant activity of phenolic extracts were assessed by spectrophotometric assays with Folin-Ciocalteu and ABTS ^•+ reagents, respectively. The total phenol content was higher than most foodstuffs. Moreover, more than 96% of the phenolic fraction belonged to the tannin class. Statistical analysis of the data showed that higher levels of nitrogen fertilization led to a significant increase in linoleic acid. This effect can induce a faster oxidation of lipid fraction of walnuts. Nevertheless, major nitrogen fertilization and irrigation were able to enrich walnuts in phenolic compounds. PRACTICAL APPLICATIONS Walnuts (Juglans regia L.) are a good source of essential fatty acids, tocopherols and phenolic compounds that contribute to reducing the risk of coronary heart disease, and also inhibit the oxidation of human plasma and low density lipoproteins. In this work, the applicability of fast analytical determinations was utilized to discriminate different walnut samples. Total lipid chromatogram was used for the simultaneous determination of the profile of sterols and tocopherols; micellar electrokinetic chromatography was used for the phenolic separation, which takes less than 10 min. The proposed methods are ideal for routine analysis of the lipidic and phenolic fractions in order to control the quality of walnuts. © 2009 Wiley Periodicals, Inc.

Abstract: Application of differential scanning calorimetry (DSC) to discriminate among extra virgin olive oils on the basis of cultivar-environment interaction was preliminary evaluated on Tunisian samples from two varieties (Chetoui and Chemlali) and different geographical origin relating thermal properties obtained by cooling and heating thermograms to chemical composition. Higher content of triunsaturated triacylglycerols and oleic acid and lower amount of palmitic acid were detected in Chetoui samples in comparison with Chemlali oils. Cooling thermograms exhibited two well distinguishable exothermic peaks in all samples; the major event at lowest temperature was taller and sharper in Chetoui samples whereas the other peaking at highest temperature was more evident for Chemlali oils. Crystallization enthalpy did not account for the differences observed in chemical composition between the two cultivars. On the contrary, T _on and T _off of crystallization were found to significantly differ according to the compositional differences due to cultivars and geographical provenience interaction. Heating profiles exhibited a minor exothermic peak followed by multiple endothermic events and appeared also distinctive of oil samples from two cultivars. All thermal properties obtained by the analysis of heating thermograms significantly differed among oil samples from different geographical provenience. The application of DSC appeared useful to differentiate samples of different cultivars and/or geographical proveniences. © 2008 Springer-Verlag.

Abstract: We evaluated dehydrofreezing in strawberries in terms of retention of healthy compounds (i.e. polyphenolics) and sensory qualities for direct consumption in substitution of fresh fruit. Different osmodehydration (OD at 30 °C and 5 °C), vacuum osmodehydration (VOD at 30 °C) and immersion chilling freezing (ICF) processes were applied in sucrose syrup. Samples were analyzed for dry matter, soluble solids, pH, titratable acidity, mass transfers, polyphenolic content by HPLC-DAD/MSD, volatile profile by SPME-GC/MSD and consumer acceptance. The results of sensory evaluation, in particular, confirmed the cryoprotective effects of osmotic processes of fruits with respect to untreated frozen control samples. The OD samples at 5 °C presented a water loss to solid gain ratio comparable to OD at 30 °C and VOD samples. Moreover, while osmo-dehydrofreezing at relatively high temperatures caused a slight depletion of phenolic compounds, the samples osmodehydrated at 5 °C showed higher polyphenolic retention. Data on aromatic compounds showed that some compounds increased (e.g. ethanol and acetaldehyde), while others did not appear to be affected by the pre-treatments.

Abstract: The effect of microwave heating of commercial categories of olive oil for human consumption (extra virgin olive oil [EVOo], olive-pomace oil [Po] and olive oil [Oo]) on DSC thermal properties was evaluated at different times of microwave treatment. Marked changes of DSC cooling profiles were found for EVOo and Po subjected to microwaving, with the major exotherm that shifted towards lower temperature and decreased height with increasing treatment time. Thermal properties (during DSC cooling analysis) changed in all samples: crystallisation enthalpy significantly decreased and the phase transition developed over a larger temperature range, due to more heterogeneous chemical composition of all oils that resulted from triacylglycerol lysis to the formation of lipid oxidation products. Heating profiles of EVOo and Po were also modified by microwave treatment, as the minor endotherm progressively disappeared, significantly shifting offset temperature of transition towards lower temperature. Oo did not exhibit such changes of thermal properties and phase transition profiles as described for EVOo and Po. This may be mainly related to its lower water content although the simultaneous presence of small amounts of antioxidant molecules (polyphenols) may have contributed to partially prevent thermal degradation of this oil in comparison with the others. These preliminary results suggest that DSC can be useful, not only for monitoring modifications of chemical composition with increasing microwave treatment time, but also to discriminate amongst olive oils according to their response to microwave exposure.

Abstract: BACKGROUND: There is much interest in foods that belong to Protected Designations of Origin (PDO) because the quality and other essential and exclusive characteristics are guaranteed because of a particular geographical environment. We have used a capillary electrophoretic method for the simple, rapid and simultaneous characterization and quantification of the polyphenolic fraction of extra-virgin olive oil from different PDOs (18 compounds in less than 7 min). To demonstrate the usefulness of this method, we have analyzed 16 samples of a Spanish PDO and nine other samples belonging to an Italian PDO (n = 5). RESULTS: In this way, it was possible to compare the phenolic profiles of the oils of different zones of the same PDO, as well as the phenolic profiles of Spanish and Italian extra-virgin olive oils. Uni variate statistics were used for differentiating the oils produced in each PDO. Furthermore, the correlations among several of the phenolic compounds present in the extracts of olive oil and its sensorial properties were checked. decarboxylated oleuropein aglycon (DOA) (b) (peak 6) was the compound more related to the bitterness of the oils, Ac Pin (peak number 4) and the unidentified peak with t_mig 4.025 min played an important role in the pungent taste of the oils, and these two latter compounds and the peak 13 seemed to be related to the fruitiness of the oils. CONCLUSIONS: The electrophoretic method described in the current work has the ability to detect and quantify simultaneously 18 phenolic compounds(belonging to five different families)inlessthan7 min. This technique could improve the characterization of this polar fraction and determine the geographical origin of olive oils or detect possible 'PDO markers'. In fact, capillary electrophoresis coupled to statistical analysis enabled discrimination among olive oils belonging to two different PDOs considering eight phenolic compounds present in the extracts, and also identification of the phenolic compounds which could have more influence on several sensory attributes such as bitterness, pungency and fruitiness. © 2009 Society of Chemical Industry.

Abstract: In this study, 15 virgin olive oils from an industrial oil plant in the Abruzzo region were analyzed in terms of the volatile compounds responsible for the characteristic odor and olfactory perception of virgin olive oils and its modification upon frying (up to 60 min of heat treatment). Dynamic headspace-gas chromatography-mass spectrometry analysis was used to evaluate the volatile profile before and after each frying step and examine correlations with qualitative characteristic of oil (fatty acid composition, total phenolic compound content, tocopherols and pigments). The chemometric approach (genetic algorithms-partial least squares/multiple linear regression) developed for this study is a novel model for data treatment to select important variables in olive oil composition and understand their influence on spoilage during frying. An inverse correlation between oleic acid content and formation of toxic volatiles such as acrolein and crotonal during frying was demonstrated. Moreover, it was also observed that pigments such as chlorophylls, pheophytins, and carotenoids may prevent the formation of some aldehydes during frying. © Springer-Verlag 2009.

Abstract: During storage and distribution of extra virgin olive oil alterations in product quality can occur that depend on environmental temperatures. The effect of the storage at different temperatures of virgin olive oil was monitored by peroxide value, fatty acid activity, OSI test and sensory analysis. Samples stored at controlled temperature (12°C) showed a higher oxidative stability than oils kept at room temperature. Adequate control of temperature after production until consumption may represent an important parameter for the future in order to preserve the original quality of virgin olive oil.

Abstract: This work refers to the qualitative and sensory characteristics of a Tunisian minor olive variety (cv. marsaline) with regards to the irrigation regime and the cultivation site. marsaline fruits were collected from two different regions in the North West of Tunisia. Samples were also tested in both a rain-fed control and an irrigation regime. the morphological characteristics were analyzed and on the obtained oils quality indices, major and minor compounds, oxidative stability and organoleptic attributes were all carried out. preliminary results confirmed that marsaline is a good pickling olive variety, and the oils of this minor cultivar had an interesting olive oil composition. the irrigation regime had a positive influence on antioxidant compounds and consequently on the oxidative stability, while the geographic area modified the marsaline fatty acid composition.

Abstract: The deodorization of low quality virgin olive oils applying a "mild" technology, is a current fraud: the olive oils obtained from this illegal treatment, under vacuum and at low temperatures, may be mixed with extra virgin olive oils (EV). This adulterated product is characterized by a chemical composition very similar to a genuine EV. In this work, to confirm the presence of mildly deodorized olive oils in oils sold as EV, an analytical method recently proposed by some Italian and Spanish researchers was applied to several commercial samples. This not official method (but temporarily recommended by IOC) is based on the gas-chromatographic determination of methyl and ethyl esters of fatty acids (alkyl esters). Aioreover, analysis of water content and volatile compounds were carried out on samples. In fact, according to previous experimental observations, both the water amount and the volatile profile changed as a consequence of mild deodorization.

Abstract: Differential scanning calorimetry (DSC) was employed to detect high oleic sunflower oil (HOSo) as an adulterant in extra-virgin olive oil (EVOo) by means of cooling and heating thermograms. Addition of HOSo did not significantly alter cooling profiles of EVOo except for onset temperature of crystallization, which was significantly shifted toward lower temperature at 40% of adulterant addition. At the same percentage of adulteration, the heating profile of EVOo was significantly changed as the major endotherm broadened and the minor event became smaller and less evident. Cooling thermograms of pure oils and their admixtures were deconvoluted into three constituent exothermic peaks in an attempt to detect addition of HOSo at levels lower than 40%. Thermal properties of the two lower-temperature exotherms (area percentage, offset temperature and range of transition) were significantly changed at ≥20% of HOSo substitution, suggesting that DSC can be employed to detect this oil as an EVOo adulterant. PRACTICAL APPLICATIONS Adulteration of extra-virgin olive oil (EVOo) with cheaper oils from other vegetable sources or seeds, as well as with lower quality olive oils, is a serious concern for oil suppliers and consumers and requires the use of new analytical techniques for their detection. Differential scanning calorimetry (DSC) exhibits some advantages over the classical analytical methods as it does not require sample preparation and use of solvents, thus resulting in a reduced environmental impact. Results suggested that its application to the detection of EVOo adulteration with high oleic sunflower oil, a vegetable oil largely employed for this type of fraud, is promising with the support of the deconvolution analysis of cooling thermograms. © 2009 Wiley Periodicals, Inc.

Abstract: Chemical changes produced in an extra virgin olive oil sample in the presence (EVOO) and absence (EVOOP) of its phenolic fraction during an accelerated storage treatment at 60 degrees C up to 7 weeks were studied. Modifications in phenol content, as well as changes in several quality parameters (free acidity, peroxide value, UV absorbance, fatty acid composition, oxidative stability index, and tocopherol content) were also evaluated under the same storage conditions and compared to those of the same sample deprived of phenolic compounds. When the phenolic extract of the EVOO was studied, a decrease of the antioxidants first present in the sample and an increase of the oxidized products were observed. In addition, oxidation seemed to produce the transformation of such phenolic compounds as secoiridoids and the appearance of oxidized forms of them. These latter compounds could be used as molecular markers of the lack of extra virgin olive oil freshness.

Abstract: Atmospheric pressure chemical ionization mass spectrometry was used to predict the oxidative status of virgin olive oils (VOO) during their storage. VOO samples, with and without phenolic compounds, were stored in the dark at 60 degrees C up to 7 weeks. The VOO samples were diluted in an alkaline propanol/methanol mixture and directly infused into an ion-trap mass spectrometer. The abundances of the [M-H](-) peaks of free fatty acids, oxidized fatty acids, tocopherols and phenolic compounds, jointly with their oxidized forms, were measured and used as predictors. Two linear discriminant analysis (LDA) models were constructed in order to classify samples according to their oxidative levels. The first model was constructed using both VOO samples (with and without phenols), considering as predictors only fatty acids and their oxidized products. The second LDA model was constructed with the VOO sample with phenolic compounds considering as predictors all the peaks measured. In both models, the samples divided in the eight different storage times were correctly classified (100%) by leave-one-out cross-validation with an excellent resolution among all the category pairs (for the first model Wilks' lambda, lambda(w) = 0.229 and for the second lambda(w) = 0.928). This method is a very fast tool for on-line monitoring of VOO oxidation status.

Abstract: Thermal decomposition of 12 monovarietal extra virgin olive oils from different geographical origins (eight from Italy, two from Spain, and the others from Tunisia) was evaluated by simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC) analyses. All extra virgin olive oils showed a complex multistep decomposition pattern with the first step that exhibited a quite different profile among samples. Thermal properties of the two peaks obtained by the deconvolution of the first step of decomposition by DSC were related to the chemical composition of the samples (triacylglycerols, fatty acids, total phenols and antioxidant activity). Onset temperatures of the thermal decomposition transition and T(p) values of both deconvoluted peaks as well as the sum of enthalpy were found to exhibit statistically significant correlations with chemical components of the samples, in particular palmitic and oleic acids and related triacylglycerols. Activation energy values of the second deconvoluted peak obtained by the application of kinetic procedure to the first step of decomposition were also found to be highly statistically correlated to the chemical composition, and a stability scale among samples was proposed on the basis of its values.

Abstract: This works aims to set up a rapid and nondestructive method to evaluate the advanced oxidation of virgin olive oils (VOOs). An electronic nose based on an array of six metal oxide semiconductor sensors was used, jointly with multiple linear regression (MLR), to predict the oxidized fatty acid (OFA) concentration in VOO samples characterized by different oxidative status. An MLR model constructed using five predictors was able to predict OFA concentration with an average validation error of 9%.

Abstract: In this study, mildly deodorized olive oil (DEO) and its admixtures with extra virgin olive oil (EVOO) have been analyzed after heating treatments by microwave and conventional oven. Different patterns in oxidative and hydrolytic degradation of lipids in genuine and sophisticated olive oils have been evaluated by chromatographic and spectroscopic methods and related to heating treatments. The experimental plan focused on the assessment of the (a) hydrolytic degree of the samples by the free acidity and the 1,2- and 1,3-diacylglycerols (DAG) determinations; (b) oxidative status of the samples by the assessment of the peroxide value (POV) and oxidized fatty acid (OFA), the specific absorption at 270 nm (k(270)), the accelerated aging test (OSI) and volatile compounds. In general, the thermal treatment by conventional oven led to a higher content of 1,3-DAG and secondary oxidation products than microwave heating. A duo-trio sensory test was also performed: tasters were not able to discriminate between EVOO and DEO heated by conventional oven whereas they were when oils were microwaved.

Abstract: The phenolic fraction modification was evaluated in untreated vacuum impregnated frozen apple slices from two varieties (Granny Smith and Stark Delicious) a few days after freezing and after 12 months of frozen storage. After 12 months the phenolic content of both fresh and vacuum impregnated apple slices varied greatly. The most important change was the increase of many polymeric flavan-3-ols, which may be due to hydrolysis of polymeric procyanidins. Furthermore, there was significant correlation (r ² = 0.52, P < 0.05) between the increase in flavan-3-ols and the decrease in pH. In fact, control Stark slices presented the highest pH, and had no statistically significant increase in flavan-3-ols. Other classes of phenolic compounds were decreased in apple slices following frozen storage. © 2007 Springer-Verlag.

Abstract: The wholeness and healthiness of milled fruits are very important conditions for the final quality of virgin olive oil for example, the action of pests as Bactrocera Oleae during the olives growth is one of the main causes of undesirable metabolic processes that lead to the deterioration of the virgin olive oil quality. in this work, the evaluation of the main indices of virgin olive oil quality (free acidity, peroxide number, sensory analysis) was firstly achieved; secondly, the effect of different degrees of Bactrocera Oleae infestation on qualiquantitative composition in volatile compounds of 32 virgin olive oils was evaluated. the SPME/GC analytical technique, coupled with the use of mass spectrometry detector (GC-MSD) and flame ionization detector (GC-FID) was applied to extract, to identify and to quantify the volatile fraction. statistical elaboration of data evidenced good correlations between percentages of attack and free acidity (R=0.77), peroxide number (R=0.58) and some of the volatile molecules. in particular, the 6-methyl-5-hepten-2-one was the most positively correlated (R=0,78) compound with Bactrocera Oleae attack. the results of NIPALS-PLS elaboration have shown higher similarity between the aromatic profiles of oils produced from damaged olives and those of winey and fusty official defects (supplied by 100C).

Abstract: This article investigated the relationship between the phenol contents, the antioxidant activity and the organoleptic characteristics of the two main tunisian virgin olive oils (cvv. chétoui and chemlali). the chétoui oils presented the highest values of total phenols, radical scavenging activity and bitter index. results elaborated statistically put in evidence interesting correlations between the phenol mainly secoiridoid contents with antioxidant activity and the intensity of bitterness of the tested monovarietal virgin olive oils.

Abstract: The potential application of differential scanning calorimetry (DSC) to verify adulteration of extra virgin olive oil with refined hazelnut oil was evaluated. Extra virgin olive oil and hazelnut oil were characterised by significantly different cooling and heating DSC thermal profiles. Addition of hazelnut oil significantly enhanced crystallisation enthalpy (at hazelnut oil [greater-or-equal, slanted]20%) and shifted the transition towards lower temperatures (at hazelnut oil [greater-or-equal, slanted]5%). Lineshape of heating thermograms of extra virgin olive oil was significantly altered by hazelnut oil addition: a characteristic exothermic event originated at -27 °C in extra virgin olive oil and progressively disappeared with increasing hazelnut oil content, while the major endothermic peak at -3.5 °C broadened (at hazelnut oil [greater-or-equal, slanted]40%) and the minor endothermic peak at 8 °C shifted toward lower temperatures (at hazelnut oil [greater-or-equal, slanted]5%). The preliminary results presented in this study suggest that DSC analysis may be a useful tool for detecting adulteration of extra virgin olive oil with refined hazelnut oil.

Abstract: The antioxidant fraction was evaluated following several experimental methods for olive fruit processing. Two extra virgin olive oils (EVOO) extracted by a low scale mill (with and without the de-stoning phase) were compared to samples obtained with a continuous three phase industrial plant. The EVOO produced by the industrial plant with a three phase decanter showed lower oxidative stability than the oils obtained by the low scale mill; in this last case, this work reports the effects of the technological procedure relative to stone removal.

Abstract: The oxidative stability of oil-in-water emulsions, containing bovine serum albumin (BSA) and virgin olive oil phenolic compounds, was studied by the determination of the formation of volatile oxidation products. Four oil-in-water emulsions with and without phenols isolated from virgin olive oil and BSA were prepared. These model systems were stored at 60 °C to accelerate lipid oxidation. Volatile oxidation products were monitored every three days by headspace solid-phase microextraction coupled with gas chromatography. Although individually olive oil phenolic compounds and BSA showed a significant antioxidant activity, the combination of these components showed a very good synergy, quantified as 127%. In fact, the emulsion containing both phenolic compounds and BSA showed a very low level of oxidative deterioration after 45 days storage.

Abstract: The chemical composition of virgin olive oil may be influenced by genotype and different agronomic (i.e. fruit ripeness degree, water supply) and technological factors. This article reports the evaluation of the influence of the olive ripening stage on the quality indices, the major and the minor components and the oxidative stability of the two main monovarietal Tunisian cultivars (cvv. Chétoui and Chemlali) virgin olive oils. Moreover, the olives cv. Chétoui were tested in a rain-fed control and an irrigation regime. The oils sampled at five different ripeness stages were submitted to liquid chromatographic determination (HPLC-DAD/MSD) of their quali-quantitative phenolic and tocopherolic profiles. Moreover, the triacylglycerol and fatty acid compositions, and minor components such as squalene, pigments and their relation with the oil oxidative stability were evaluated. The tested oils showed very good correlation between the oxidative stability and the concentrations of total phenols, practically secoiridoids and [alpha]-tocopherol.

Abstract: Several studies have suggested that the phenolic fraction plays an important role during storage and therefore in the shelf life of virgin olive oil. This investigation examines the effect of freezing olives (-18°C) before processing into oil on the transfer of the phenolic compounds into the subsequent oil, and the consequential changes in oxidative stability. Oil samples obtained from frozen olives (24 h at -18°C), crushed with and without preliminary thawing, were compared to a control sample; both oils were obtained using a two-phase low-scale mill. The oxidative stability in different samples was assessed in terms of primary and secondary oxidation products as measured by peroxide values and oxidative stability index times, respectively. The quality of the oil samples was also checked through the percentage of free acidity and the phenolic content. Phenols were determined by both spectrophotometric assays (total phenols and o-diphenols) and HPLC-DAD/MSD. The antiradical capacity of the phenolic fraction was determined by DPPH and ABTS spectrophotometric tests. These analyses showed that thawing of olives before oil extraction led to a significant loss of oxidative stability and phenols; in contrast, samples obtained from frozen olives that were not thawed before crushing showed qualitative characteristics similar to control samples. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.

Abstract: ABTS•+ test, o-diphenols (spectrophotometric) and HPLC-DAD phenolic content in vacuum impregnated apple slices from Stark Delicious and Granny Smith cvv. were studied. Vacuum impregnation (VI) was carried out in a pilot plant using an aqueous solution containing 37.9% dextrose, 15.2% sucrose, 1.0% ascorbic acid, 0.25% calcium chloride and 0.25% sodium chloride. The impregnation time was 30 min and the vacuum pressure was 100 mbar; the temperature was 25 °C during all processing steps and the solution/fruit ratio was 11:1. At the end of VI, samples were left 5 min in syrup. They were then rinsed with water, drained in a vibrating screen and quickly frozen. A significant decrease (p < 0.05) of the o-diphenol content was seen (17.84 and 12.32% of the initial content in Stark and Granny varieties, respectively). The same trend was confirmed by HPLC-DAD where reductions in total phenols were 21.57 and 26.86% in Stark and Granny, respectively. Individual phenolic compounds showed different rates of depletion, although in some cases there was no reduction. The ABTS•+ test was strongly affected by the presence of ascorbic acid (AA), which was much higher in treated samples. Sensory evaluation showed higher values of hardness, crispness, juiciness and sourness in VI Granny Smith than VI Stark delicious, with a higher retention of texture parameters in the former. Finally, sweetness was slightly higher in VI Stark. © 2007 Springer-Verlag.

Abstract: Differential scanning calorimetry thermograms of five commercial categories of olive oils (extra virgin olive oil, olive oil, refined olive oil, olive-pomace oil and refined olive-pomace oil) were performed in both cooling and heating regimes. Overlapping transitions were resolved by deconvolution analysis and all thermal properties were related to major (triacylglycerols, total fatty acids) and minor (diacylglycerols, lipid oxidation products) chemical components. All oils showed two well distinguishable exothermic events upon cooling. Crystallization enthalpies were significantly lower in olive oils due to a more ordered crystal structure, which may be related to the higher triolein content. Pomace oils exhibited a significantly higher crystallization onset temperature and a larger transition range, possibly associated to the higher amount of diacylglycerols. Heating thermograms were more complex: all oils exhibited complex exo- and endothermic transitions that could differentiate samples especially with respect to the highest temperature endotherm. These preliminary results suggest that both cooling and heating thermograms obtained by means of differential scanning calorimetry may be useful for discriminating among olive oils of different commercial categories.

Abstract: Adulteration of virgin and extra-virgin olive oils is an on going issue that is of particular interest to the regulating bodies investigating fraud. Unfortunately mass control of olive oils on the commercial market is impossible therefore adulteration is rife and unnoticeable. Nowadays the most problematic type of fraud is by way of reducing or eliminating unpleasant odours which are a real defect, or unwanted odour compounds originating from the geographical origin of the olive cultivar. If an adulterated oil is put on the market as a virgin oil, or if it is mixed with other oils and sold as virgin oil, it is difficult to identify the fraud when the adulteration is carried out under bland conditions "soft deodorization". Soft deodorization seems to be carried out in different ways: A sort of molecular distillation under vacuum or in a stream of nitrogen at low temperatures, or using absorbent powders, or using filtering membranes. In all these cases the composition of the volatile or polar compounds would be unbalanced (adsorbed more than the oil thanks to the use of high polarity powders), or there would be a selective loss of compounds of a certain dimension (through the use of the filtering membranes). In our opinion the analyses that could reveal such fraudulent treatments are: the determination of volatile compounds by means of SPME/GC that can show the reduced amount of volatile molecules: The decrease of the amount of water present in the micro-emulsion of the oil, following the "stripping" or by adsorption mechanisms.

Abstract: While frying is a widespread and popular way to prepare foods, it is well known that over time it subjects both the oil and the cooked food to oxidation, with undesirable organoleptic and nutritional consequences. In the Americas, soya oil is one of the most commonly used varieties for frying applications, yet is one of the most unstable oils due to Its peculiar combination of fatty acids. To address the unmet need for stable non hydrogenated soya oil in the popular frying industry, we undertook an experimental work designed to explore the effectiveness of a new antioxidant (EPT-Enhanced Citric Acid) in Soya oil in a high temperature industrial-like frying setting. To do so, a rapid and easily reproducible high temperature frying investigational model was applied. Measurement of both primary (PV) and secondary oxidative products (OFAs) was undertaken in up to 20 sequential French fries frying cycles. We found that the tested product was an effective antioxidant with heat resistant properties able to reduce both primary and secondary oxidation products (PV and OFAs).

Abstract: The aim of this study was to characterise the pigment profile (chlorophylls and carotenoids) of monovarietal virgin olive oils from six Italian olive cultivars (Ghiacciolo, Giarraffa, Sant'Agatese, Biancolilla, Nocellara del Belice and Gentile di Larino), from three Italian olive-growing regions (Emilia-Romagna, Sicily and Molise). The results show that the qualitative study of the pigment chlorophyll and carotenoid fractions of virgin olive oils demonstrated a common pattern that did not depend on the olive cultivar or growing region. Besides these, mutatoxanthin was only detected in oils from the Nocellara del Belice and Gentile di Larino cultivars, and pheophorbide a was only detected in oils from the Ghiacciolo and Sant'Agatese cultivars. However, significant quantitative differences were observed in the composition of the pigment fractions. The principal component discriminate analysis showed that the first two discriminate functions of the statistical analysis explained 78.9% of the total variance. The plot of discriminate functions showed an effect of the olive cultivar and growing area on the chlorophyll and carotenoid contents of the virgin olive oils. The results of this study are a contribution to the pigment characterization of the Italian monovarietal olive oils, which should be completed with more samples obtained from different crop seasons and different growing areas. © 2007 Springer-Verlag.

Abstract: Nectarines (Prunus persica L. cv. Maria Laura) were manually selected, cut in slices and divided into four groups: fresh, untreated frozen, soaked in osmotic solution and subsequently frozen, and vacuum impregnated (VI) and subsequently frozen. This investigation was focused on evaluation of consumer acceptance with respect to treated versus untreated frozen nectarine slices. In a preliminary acceptance test of untreated frozen nectarine slices, fruits were generally rejected on the basis of a darkened appearance and "oxidized" taste. These negative attributes were probably linked to the activity of polyphenol oxidase (PPO) and depletion of phenols due to cell rupture during freeze-thaw procedures. For these reasons, in order to evaluate the tendency of fruit to oxidation, several analyses were performed: the antioxidant capacity of phenolic fraction and the o-diphenol content were estimated by spectrophotometric assays, whereas the hydroxycinnamic acid (chlorogenic and neochlorogenic acids) composition was evaluated by high performance liquid chromatography (HPLC). Phenolic content and antioxidant capacity were found to correlate well with the acceptance level of frozen nectarine slices. In this regard a higher phenolic content associated with a higher acceptance level of nectarine samples. © 2007 Springer-Verlag.

Abstract: Changes in the oxidative stability of olive oil have been evaluated following several experimental trials for olive fruit processing. Oil samples were produced by a low scale mill under three different conditions: addition of saturated citric acid solution as a co-adjuvant addition of whole fruits of lemon or bergamot. Citric acid solution added to the samples during malaxation significantly increased oxidative stability of oils. While olive paste milled with bergamots showed significantly higher antioxidant activity than the control sample, the addition of lemon fruits did not exert the same effect.

Abstract: The phenolic fraction of virgin olive oil influences both its quality and oxidative stability. One of the principal threats of the quality of olive fruit is the olive fly ( Bactrocera oleae) as it alters the chemical composition. The attack of this olive pest has been studied in order to evaluate its influence on the quality of virgin olive oil (free acidity, peroxide value, fatty acid composition, water content, oxidative stability, phenols, and antioxidant power of phenolic fraction). The study was performed using several virgin olive oils obtained from olives with different degrees of fly infestation. They were acquired in different Italian industrial mills from the Abruzzo region. Qualitative and quantitative analyses of phenolic profiles were performed by capillary electrophoresis-diode array detection, and electrochemical evaluation of the antioxidant power of the phenolic fraction was also carried out. These analyses demonstrated that the degree of fly attack was positively correlated with free acidity ( r = 0.77, p < 0.05) and oxidized products ( r = 0.58, p < 0.05), and negatively related to the oxidative stability index ( r = -0.54, p < 0.05) and phenolic content ( r = -0.50, p < 0.05), mainly with secoiridoid compounds. However, it has been confirmed that the phenolic fraction of olive oil depends on several parameters and that a clear correlation does not exist between the percentages of fly attack and phenolic content.

Abstract: The effects of ripening degree of olives on volatile profile of monovarietal virgin olive oils (VOO) from Tunisian and Sicilian cultivars were investigated. Fruits obtained from Tunisia (Chétoui and Chemlali) and Italy (Nocellara del Belice, Biancolilla and Cerasuola) were picked at three different stages of ripeness and then immediately processed. Moreover, the changes in volatile composition were evaluated in Chétoui variety as a function of the irrigation regime versus the rain-fed control. Using headspace-solid-phase microextraction (HS-SPME) technique coupled to GC-MS and GC-FID, the volatile compounds of the monovarietal virgin olive oils were identified and quantitatively analyzed. The proportions of different classes of volatiles of oils showed significant differences throughout the maturity process. The results suggest that adding to the genetic factor; agronomic conditions affect the volatile formation and therefore the organoleptic properties of VOO.

Abstract: Virgin olive oil is valued for its flavor, but unacceptable off-flavors may develop on storage in food products containing this oil due to oxidation. The oxidative stability of oil-in-water emulsions containing bovine serum albumin (BSA) and virgin olive oil phenolic compounds was studied. Four oil-in-water emulsions with and without BSA and phenols isolated from virgin olive oil were prepared. These model systems were stored at 60 degrees C to speed up lipid oxidation. Primary and secondary oxidation products were monitored every three days. Peroxide values and conjugated diene contents were determined as measures of the primary oxidation products. p-Anisidine values and volatile compounds were determined as measures of the secondary oxidation products. This latter determination was carried out by headspace solid-phase microextraction coupled with gas chromatography. Although olive oil phenolic compounds and BSA contributed some antioxidant activity when present as individual additives, the combination of BSA with phenols in an emulsion showed 58-127% synergy, depending on which analytical method was used in the calculation. The emulsion containing phenolic compounds and BSA showed a low level of deterioration after 45 days of storage at 60 degrees C.

Abstract: Extra virgin olive oils from drupes of three Sicilian varieties (Biancolilla, Cerasuola, and Nocellara del Belice) collected at three different harvesting periods were analyzed upon heating by means of DSC, and thermal properties were related to the chemical composition of the samples. All thermograms exhibited multiple transitions with a minor exothermic peak, followed by a major endothermic event. Cerasuola samples showed higher overall enthalpy and narrower range of transition at all harvesting periods, as compared to the other oils. A more ordered crystal structure originating from a more uniform chemical composition, with higher triolein content, in Cerasuola may be hypothesized. At different harvesting periods, thermal transitions started at lower temperatures and developed over a narrower range in all cultivars, probably due to the insertion of molecules derived from triacylglycerol lysis (diacylglycerols and free fatty acids) and lipid oxidation products into the triacylglycerol crystal lattice. All heating thermograms were deconvoluted into one exothermic and five endothermic constituent peaks, and the effect of chemical components on thermal properties of the peaks was evaluated. DSC application upon heating appears to be very promising in discriminating among oil samples from olives of different cultivars and/or harvesting periods.

Abstract: Over last years consumers are paying more and more attention to a diet rich in fruits and vegetables that assure a proportionate intake of antioxidant compounds such as carotenoids, tocopherols, ascorbic acid, flavonoids and other phenolic compounds. Several scientific studies proved the efficacy of these minor compounds of foods in contrasting or slowing down degenerative and cardiovascular diseases. Freezing is a useful technology for preservation of nutritional compounds of food over long periods; but thawing causes a dramatic decrement of organoleptic and nutritional characteristic due to the high content of water in fruits. Several technologies, based upon osmotic processes (OD, PVOD, VI, ICF, etc.) could be used as pre-treatment, in order to improve fruit performance in freezing/thawing processes. This work reports results on the preservation of antioxidant capacity (based on ABTS radical cation test) and phenolic content (determined by HPLC) of some fruits (apples, nectarines and strawberries) osmotically pre-treated and subsequently frozen. Results show that these technologies could preserve phenolic content of fruits along with the storage period and during thawing for direct consumption.

Abstract: We have developed a liquid-chromatographic method using atmospheric pressure chemical ionization (APCI)-mass spectrometry (MS) detection in positive mode. This method was used to separate and identify 15 sterols and 2 dihydroxy triterpenes in saponified oils, enabling the analysis of these compounds directly from saponified samples without recourse to thin-layer chromatography; this fact thus significantly simplifies the process. The analyses were made using a Waters Atlantis 5 μm dC₁₈ 15 x 62.1 mm column with a gradient of acetonitrile/water (0.01% acetic acid) at a flow rate of 0.5 mL/min and a column temperature of 30 °C. The quantification of several of these compounds in soybean oil, palm oil, seed oil, sunflower oil, olive-pomace oil and virgin olive oil was carried out using their commercial standards, and the results were compared satisfactorily with the official method. © 2008 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

Abstract: Anthocyanins, the major colourants of strawberries, are polar pigments that are positively charged at low pH. Herein, we have assessed a new analytical method for the separation of anthocyanins using CZE. Acidic buffer solutions (pH <2) were employed in order to maintain pigments in the cation flavylium form and achieve high molar absorptivity at 510 nm. These spectral properties enabled us to identify strawberry anthocyanins in a preliminary stage by detection in the visible range, although the method was optimised at 280 nm to obtain the best S/N. The effects of buffer composition highlighted the necessity of adding an organic modifier to the running buffer to obtain a suitable separation. The electrophoretic method permitted the separation of the three main anthocyanins of strawberry extracts, namely pelargonidin 3-glucoside (Pg-glu), pelargonidin 3-rutinoside and cyanidin 3-glucoside. The electrophoretic results, expressed as retention time and separation efficiency of the major anthocyanin (Pg-glu), were compared to those achieved in HPLC, the analytical technique traditionally used for the investigation of anthocyanins in vegetable matrix. The content of Pg-glu in strawberries (cv. Camarosa), calculated with HPCE and HPLC methods, resulted respectively in 11.41 mg/L and 11.37 mg/L.

Abstract: Work was carried out on the characterization of monovarietal virgin olive oils (VOO) from Tunisia and Sicily (Italy). The two main Tunisian VOO (cvv. Chétoui of the North and cv. Chemlali grown in the Center and some regions of the South) and three principal Sicilian VOO (cvv. Nocellara del Belice, Biancolilla and Cerasuola) were studied. Moreover, the Chétoui oils were tested in a rain-fed control and an irrigation regime. All olive samples were picked at three different stages of ripeness. Analyses of major components (fatty acids and triacylglycerols) and minor ones (squalene, tocopherols and phenolic compounds) were carried out. Chétoui oils had a higher level of phenolic compounds followed by Chemlali. Generally, in the Sicilian oils these natural anti-oxidant contents were lower. These preliminary results indicate that it was possible to classify the Tunisian and Sicilian oils tested in their original growing area based on their chemical composition. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Abstract: This research has been carried out to determine the filtration effect on the phenolic content and on the visual characteristics of olive oil. The influence of the filtration system on the phenolic and water content of virgin olive oil that differed in the year of production, production system and the olive variety was measured. Samples were filtered in the laboratory using two different systems (cotton or filter paper plus sodium sulphate anhydrous). Qualitative and quantitative variation of the phenolic fraction of virgin olive oils was evaluated by HPLC-DAD-MS and correlated with their water content (by Karl Fischer titration) and oxidative stability under forced conditions (by OSI). Colorimetric assays were also carried out in order to calculate the effect of filtration on the visual characteristics of virgin olive oil. After filtration the oxidative stability index decreased and in particular, filtration with cotton showed a significant loss of hydroxytyrosol, a phenol endowed with high antioxidant activity. One interesting behaviour was highlighted: Filtration with either cotton or paper plus anhydrous sodium sulphate led to an apparent increase in the phenolic content. These apparently contradictory data can be explained by considering that the reduction of the water content permits a higher availability of phenolic compounds that remain in oil and are extracted with the methanol-water mixture. Lastly, the filtration of virgin olive oil produced a loss in the intensity of green color and an increase in its lightness. © 2007 Academic Journals Inc.

Abstract: The high oxidative stability of extra virgin olive oil is mainly due to its fatty acid composition, in particular to the high monounsaturated-to-polyunsaturated ratio, and to the presence of minor compounds having phenolic structure, that also have a major role in preventing oxidation. Several classes of phenolic compounds have been identified in extra virgin olive oil (phenolic acids, phenyl ethyl alcohols, flavonoids, lignans and secoiridoids) and among them the secoiridoids (aglyconic derivatives of oleuropein and ligstroside) are the most abundant constituents. Phenolic compounds belonging to o-diphenolic category, such as oleuropein aglycon (OA), decarboxymethyl-oleuropein aglycon (DOA), and hydroxytyrosol (HYTY), are mainly responsible for the oxidative resistance of extra virgin olive oil. In this work, results dealing with oxidative stability (OSI) of several samples (n=32) obtained from olives with a different degree of Bactrocera oleae attack (0-85%), are shown. Moreover an electrochemical evaluation of the antioxidant power (AOP) of the phenolic fraction has been carried out. This method enables the recognition of the phenols that may be easily oxidised. Data demonstrate an increase of products coming from hydrolytic and oxidative degradations of fatty acids as a function of the degree of olive fly attack. Moreover, their negative contribution to oil stability has been established. Olives soundness influenced mainly the phenolic content of samples, which as a result, affected the OSI values. Fatty acid composition was involved to a lesser extent.

Abstract: A rapid Fourier transform infrared (FTIR) attenuated total reflectance spectroscopic method was applied to determine qualitative parameters such as free fatty acid (FFA) content and the peroxide value (POV) in virgin olive oils. Calibration models were constructed using partial least squares regression on a large number of virgin olive oil samples. The best results (R² = 0.955, root mean square error in cross validation [RMSECV] = 0.15) to evaluate FFA content expressed in oleic acid % (w/w) were obtained considering a calibration range from 0.2 to 9.2% of FFA relative to 190 samples. For POV determination, the result obtained, built on 80 olive oil samples with a calibration range from 11.1 to 49.7 meq O₂/kg of oil, was not satisfactory (R² = 0.855, RMSECV = 3.96). We also investigated the capability of FTIR spectroscopy, in combination with multivariate analysis, to distinguish virgin olive oils based on geographic origin. The spectra of 84 monovarietal virgin olive oil samples from eight Italian regions were collected and elaborated by principal component analysis (PCA), considering the fingerprint region. The results were satisfactory and could successfully discriminate the majority of samples coming from the Emilia Romagna, Sardinian and Sicilian regions. Moreover, the explained variance from this PCA was higher than 96%. PRACTICAL APPLICATIONS The verification of the declared origin or the determination of the origin of an unidentified virgin olive oil is a challenging problem. In this work, we have studied the applicability of Fourier transform infrared coupled with multivariate statistical analysis to discriminate the geographic origin of virgin olive oil samples from different Italian regions. © 2007, Blackwell Publishing.

Abstract: The olives are the raw material for olive oil production. The olive oil is a typical product of Mediterranean area and it is one of the basic component of the famous "Mediterranean diet· It's well-known that, in relation to the production of olives, every cultivar has its own peculiarity. Moreover, the characteristics of a same cultivar, are strongly influenced by agricultural methods and seasonal trend. Recently, several studies proved that the choice of the optimal maturation of the olives for the collection, play a role of primary importance. Instead, the influence of the storage of the olives before the production process, and the parameters that can negatively affect the final product, are well-known from long time. The presence of a small amount of micro-emulsified water in the filtered and very clear olive oils, recently discovered, brought new inputs for the interpretation of several behaviours that seemed contradictory in the past.

Abstract: A total of 287 olive lots and 161 olive oil samples were analyzed for fat content, moisture and free acidity, using a Fourier transform near-infrared (FT-NIR) instalment located in an industrial mill. Samples having a wide range of both reference values and olive lot sizes (from &lt;0.5 to &gt;4 t) were collected at three industrial mill plants, located in the same Italian region, which utilize different technological equipment for virgin olive oil production. Olive paste spectra were acquired in diffuse reflectance, while oil samples were measured in transmission. Calibration models for oil content and moisture of olives as well as free acidity of virgin olive oils were developed using partial least squares (PLS) regression, first derivative and straight line subtraction. Results of calibration and validation of the PLS models selected were good. The PLS results indicate good similarity between data obtained from FT-NIR and reference laboratory methods, allowing a rapid and less expensive screening analysis. Unfortunately, the correlation between the oil yield values recorded for all olive lots at the industrial mills and the oil content predicted by FT-NIR was not satisfactory (R² = 0.605). © 2007 WILEY-VCH Verlag GmbH &amp; Co. KGaA.

Abstract: Although Emiua-Romagna region is only fifteenth, regard to the production of olive oil in Italy, in the last years its trend is turning towards the production of oils with high quality. The recent acquisition of designation of protected origin (PDO) "Colune di Romagna" (EC Reg. N. 1491/03) that follows the more historical PDO "Brisighella" (EC Reg. 1263/96), validates this tendency. The spreading of the care for healthy and natural food might be an explanation for this increasing ahention of consumers. Therefore, it is particularly important to improve the positive effects of the consumption of virgin olive oils for human health, due to both balanced ratio among fatty acids and the precious amount of antioxidants, vitamins and sensorial attributes. The productive area is concentrated in Romadna, among Ravenna, forlì-Cesena and Rimini provinces: In particular, the last one, has higher distribution of olive mills if compared to the others. The aim of this experimentation is to realize a piqure of the real situation representative of the mean production of Romagna. The chemical and organoleptic characteristics of a large group of samples have been studied. In particular, SPME/GC and HPLC-DAD/MSD has been carried out respectively for the study of volatile and phenolic profiles, and a study of correlation of these chemical composition with the main sensory notes perceived by a panel of assessors, has been realized.

Abstract: The growing interest in sensory analysis of olive oil, as required by European Union (EU) law 2568/91 (EEC Reg.) and following revisions (EC Reg. 796/02), calls for the need to define an analytical method to properly describe the sensory attributes for harmonic pairing of virgin olive oil to a specific food. To accomplish that, in February 2006, the sensory analysis panel of the Department of Food Sciences of the University of Bologna (Italy) carried out systematic sensory analyses of extra virgin olive oils and foods to evaluate the harmony of the pairing. Specific scorecards for olive oil, food and pairing harmony were defined; the resulting harmony was visualized graphically. Some examples of virgin olive oil and food pairing were also presented. PRACTICAL APPLICATIONS The key finding in this study is its use in the development of a method and relative harmony scorecard for virgin olive oil and food pairing. The results of the study suggest a disharmonic index to evaluate the harmony of pairing. © 2007, Blackwell Publishing.

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.

Abstract: The hydrophilic extract of virgin olive oil contains several phenolic compounds such as simple phenols, lignans, and secoiridoids that have been widely studied in recent years. Interest in the hydrophilic extract has also been extended to the fraction of oxidized phenols that form during storage as a consequence of oxidative stress. The present investigation compares the two most commonly used extraction methods, namely liquid-liquid extraction and SPE, on fresh virgin olive oil and that kept at different temperatures in the presence of oxygen to promote the formation of oxidative products. The selective retention of these natural and oxidized phenolic compounds in relation to the extraction method was assessed. Quantification of eight identified phenolic molecules and 11 unknown peaks was performed by HPLC-DAD/MSD.

Abstract: A comparison between the results obtained by using HPLC-UV, HPLC-MS, and CE-UV for characterizing the deterioration of extra-virgin olive oil during heating (180 degrees C) was investigated, taking into account phenolic compounds. The concentration of several compounds belonging to four families of phenols (simple phenols, lignans, complex phenols, and phenolic acids) was determined in the samples after the thermal treatment by all three techniques. Hydroxytyrosol, elenolic acid, decarboxymethyl oleuropein aglycon, and oleuropein aglycon reduced their concentration with the thermal treatment more quickly than other phenolic compounds present in olive oil. HYTY-Ac and Lig Agl were demonstrated to be quite resistant to this kind of treatment, and the behavior of lignans could be outstanding, as they belong to the family most resistant to thermal treatment. Several "unknown" compounds were determined in the phenolic profiles of the oils after the thermal treatment, and their presence was confirmed in refined olive oils. The oxidative stability index (OSI time) was reduced from 25 to 5 h after 3 h of heating, whereas the peroxide value showed a minimum after 1 h of heating.

Abstract: Thermal properties of monovarietal extra virgin olive oils were evaluated by means of differential scanning calorimetry (upon cooling) and related to their chemical composition (triacylglycerols, diacylglycerols, total and free fatty acids, oxidation status). The overall crystallization enthalpy did not significantly differ among samples and did not account for the differences observed in chemical compositions. On the contrary, a higher degree of unsaturation in the lipid profile induced a shift of the crystallization onset towards lower temperatures and narrowing of the crystallization temperature range. The presence of triacylglycerol lysis and lipid oxidation products shifted the crystallization towards higher temperatures and the phase transition developed over a larger temperature range. Differential scanning calorimetry thermograms were deconvoluted into three constituent exothermic peaks for all samples. The area of the two lower-temperature exotherms was found to be statistically correlated with the amount of triunsaturated and monosaturated triacylglycerols present in the oil. Thermal properties of extra virgin olive oil were found to be affected by oil chemical composition.

Abstract: Methanolic extracts were prepared from different organs of plants from five Passiflora species obtained by zygotic embryo culture and evaluated for their capacity to quench DPPH and ABTS^•+ radicals in comparison to that of Trolox, a water soluble vitamin-E analogue. Moreover their antimicrobial activity against E. coli was tested by agar diffusion and turbidity assays. P. nitida, P. foetida, and P. palmeri showed antimicrobial activity. P. nitida and P. palmeri also showed high antioxidant activity. P. tenuifila and P. coriacea demonstrated antioxidant power but not antimicrobial activity. The phenolic content of the different extracts was studied and quantified by spectrophotometric methods, HPLC, and mass spectrometry. High antioxidant activity correlated with high amounts of o-diphenol and catechin. An unknown component, tentatively identified as structural isomer of isoschaftoside, appeared to correlate with antimicrobial activity.

Abstract: The performances of two different extraction systems, the most widespread in Italy for virgin olive oil production, have been compared. With this aim, virgin olive oil was obtained from diseased olives by both traditional and continuous industrial plants; in particular, the crushing time and the malaxation temperature, considering the two process typologies respectively, were evalued. The analytical data related to the main quality parameters (free acidity, peroxide number, UV spectrophotometric indices and organoleptic analysis), to quali-quantitative phenolic fraction (total phenols and ο-diphenols by both spectrophotometric and HPLC-DAD/MSD analyses), to the antiradical power of the latter (DPPH assay) and to the oxidative stability index by forced conditions (OSI time), were compared. This comparison highlighted that the application of the two technological processes is able to affect the commodity marketing and sensorial quality of olive oils obtained from diseased olives.

Abstract: A rapid and reliable capillary zone electrophoresis method was used as a tool to obtain both qualitative and quantitative information about simple phenols, lignans, complex phenols (isomeric forms of secoiridoids), phenolic acids, and flavonoids in the solid-phase separation extracts from different Spanish extra-virgin olive oil in a short time (less than 6 min). Peak identification was done by using commercial and HPLC-isolated standards, studying the information of the electropherograms obtained at several wavelengths and also using the information previously reported. For the quantification of lignans and complex phenols (secoiridoid derivatives), we used a reference compound (oleuropein glucoside) at two different wavelengths (200 and 240 nm) and for the quantification of tyrosol and flavonoids, we used their commercially available standards.

Abstract: The antioxidant activity of the phenolic fraction of extra virgin olive oil was assessed in samples that had a decreasing content of antioxidants in the presence and absence of copper ions as a catalyst of autoxidation. The oxidation process was evaluated by measuring primary and secondary oxidation products. Changes in phenols and tocopherols were investigated by high-performance liquid chromatography. Both the total phenol content and their antioxidant activity were monitored by spectrophotometric assays (with Folin-Ciocalteu and ABTS*+ reagents). The important role of phenolic compounds (particularly the o-diphenols) in protection from autoxidation was confirmed. However, the tocopherols were more quickly consumed in oils that had the lowest content of o-diphenols, which also showed evidence of an ability to chelate copper. In particular, a dramatic decrease was observed in the isomeric form of decarboxymethyl-oleuropein aglycone after addition of the metal, despite its significant increase in samples stored in the absence of copper.

Abstract: The aim of this work was to evaluate the effects of Colombaia monocultivar extra virgin olive oil storage for one year at room temperature, on its principal qualitative parameters, such as free acidity and peroxide values and, in particular, on phenolic fraction compounds, the main contributors to the oxidative stability of virgin olive oils. The samples used for the trials were taken from the same storage containers, with progressive increase of headspace and oxygen against the oil, in order to recreate like home consumption conditions.

Abstract: Chemical characterisation was carried out on 12 virgin olive oil samples obtained from seven olive cultivars (Bosana, Carolea, Nocellara del Belice, Pizz'e Carroga, Semidana, Tonda and Zinzala cvs.). The olives came from different groves in Sardinia (Italy) and Corsica (France) that were processed by different types of continuous mills. Several qualitative parameters were evaluated (free acidity, peroxide value, and UV spectrophotometric indices) and analyses of major (fatty acids and triacylglycerol compositions) and minor components (chlorophylls, carotenoids, tocopherols and phenolic compounds) was also carried out. The oxidative stability index (OSI) and ABTS^•- test values were determined to evaluate the oxidative stability and antioxidant activity of the phenolic fraction, respectively. The results were subjected to a discriminative study by principal component analysis (PCA) to characterise the different oils. A first PCA using only the triglyceride compounds and a second using the minor polar compounds and their antioxidant activity was performed. The triglyceride composition was found to be particularly useful in discriminating the oil samples.

Abstract: We have devised a simple and rapid capillary electrophoretic method which provides the analyst with a useful tool for the characterization of the polyphenolic fraction of extra-virgin olive oil. This method that uses a capillary with 50 microm id and a total length of 47 cm (40 cm to the detector) with a detection window of 100 x 200 microm, and a buffer solution containing 45 mM of sodium tetraborate pH 9.3 offers valuable information about all the families of compounds present in the polar fraction of the olive oil. The detection was carried out by UV absorption at 200, 240, 280, and 330 nm in order to facilitate the identification of the compounds. Concretely, the method permits the identification of simple phenols, lignans, complex phenols (isomeric forms of secoiridoids), phenolic acids, and flavonoids in the SPE-Diol extracts from extra-virgin olive oil in a short time (less than 10 min) and provides a satisfactory resolution. Peak identification was done by comparing both migration time and spectral data obtained from olive oil samples and standards (commercial or isolated (by HPLC-MS) standards), with spiked methanol-water extracts of olive oil with HPLC-collected compounds and commercially available standards at several concentration levels, studying the information of the electropherograms obtained at several wavelengths and also using the information previously reported.

Abstract: Virgin olive oil has a high resistance to oxidative deterioration due to both a tryacylglycerol composition low in polyunsaturated fatty acids and a group of phenolic antioxidants composed mainly by polyphenols and tocopherols. Several phenolic compounds of extra-virgin olive oil (phenyl-ethyl alcohols, lignans and secoiridoids) were isolated by semi-preparative high-performance liquid chromatography and identified using ultraviolet, atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) detection. The purity of these extracts was confirmed by analytical HPLC using two different gradients. Finally, the antioxidant activity of the isolated compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and by accelerated oxidation in a lipid model system (OSI=Oxidative Stability Instrument).

Abstract: The relationship between oxidative stability and phenolic content of virgin olive oils (VOOs) produced by organic, integrated or conventional agricultural methods was investigated. The oil samples were obtained from olive orchards located in different Italian regions (Sicily, Umbria and Puglia) during the years 2003 and 2004. The oxidative stability was studied by measuring the primary oxidative products through the peroxide value and the OSI (Oxidative Stability Instrument) time value; the measure of the OSI time value determines indirectly also the secondary oxidative products, extrapolating in hours (h) the end of the first period of oxidation. The phenolic content was determined by a spectrophotometric assay (Total Phenols, TP) and a high-performance liquid chromatographic method, employing a mass spectrometry detector (HPLC-DAD-MSD). That allows identification and quantifications of many single phenolic compound. Belongin to phenyl ethyl alcohol, lignan and secoiridoid classes, are present the main o-diphenolic components, which are molecules provided with the highest antiradical power. To test the scavenging activity of the VOO phenolic extracts the widely known 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^-) method was used and the results were expressed as Trolox equivalents (an hydrophilic standard analogue of vitamin E). Moreover the research of some metals was carried out by inductively-coupled plasma optical emission spectroscopy analysis (ICP-OES) with CCD (charge coupled device) detector. In fact, metals, such as copper, are able to catalyse lipid oxidation, causing a deleterious influence for to VOO shelf-life. The difference in terms of trace metals is mainly linked to the use of fertilizers and the olive treatment processes; these practices may differentiate VOOs produced by organic, integrated and conventional agricultural methods. All the data were statistically elaborated to find possible correlations among the oxidative stability of VOOs, the quali-quantitative composition of their phenolic fraction, the presence of metal traces and the agricultural methods applied.

Abstract: The increasing popularity of olive oil is mainly attributed to its high content of oleic acid, which may affect the plasma lipid/lipoprotein profiles, and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of human disease. An overview of analytical methods for the measurement of polyphenols in olive oil is presented. In principle, the analytical procedure for the determination of individual phenolic compounds in virgin olive oil involves three basic steps: extraction from the oil sample, analytical separation, and quantification. A great number of procedures for the isolation of the polar phenolic fraction of virgin olive oil, utilizing two basic extraction techniques, LLE or SPE, have been included. The reviewed techniques are those based on spectrophotometric methods, as well as analytical separation (gas chromatography (GC), high-performance liquid chromatography (HPLC), and capillary electrophoresis (CE)). Many reports in the literature determine the total amount of phenolic compounds in olive oils by spectrophometric analysis and characterize their phenolic patterns by capillary gas chromatography (CGC) and, mainly, by reverse phase high-performance liquid chromatography (RP-HPLC); however, CE has recently been applied to the analysis of phenolic compound of olive oil and has opened up great expectations, especially because of the higher resolution, reduced sample volume, and analysis duration. CE might represent a good compromise between analysis time and satisfactory characterization for some classes of phenolic compounds of virgin olive oils.

Abstract: Virgin olive oil has a high resistance to oxidative deterioration due to its tryacylglycerol composition low in polyunsaturated fatty acids and due to the presence of a group of phenolic antioxidants composed mainly of polyphenols and tocopherols. We isolated several phenolic compounds of extra virgin olive oil (phenyl-ethyl alcohols, lignans, and secoiridoids) by semipreparative high-performance liquid chromatography (HPLC) and identified them using ultraviolet, atmospheric pressure chemical ionization, and electrospray ionization MS detection. The purity of these extracts was confirmed by analytical HPLC using two different gradients. Finally, the antioxidant capacity of the isolated compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical, by accelerated oxidation in a lipid model system (OSI, oxidative stability instrument), and by an electrochemical method.

Abstract: Acidity, measured in oleic acid, is an important qualitative parameter in oil industry, given that the contents of free fatty acid (FFA) have a direct effect on the vegetable oil stability to the thermo-oxidative degeneration. In this work it has been evaluated the effect of fatty acids with reference to the oxidative stability; it was employed a common peanut oil, devoid of fenolic components thank to the industrial rectification. Furthermore the peanut oil, with very low acidity (lower than 0.1%), was also submitted to an appropriate method of neutralization. Then growing percentages of oleic acid (solution at 10% of acidity) were added and finally the Oxidative Stability Index (OSI) was carried out. The pro-oxidant effect of FFA was confirmed by experimental values of OSI time; already at concentrations lower than 0.5% of oleic acid there was a substantial reduction of oil oxidative stability, while the pro-oxidant, effect gradually decreased at concentrations higher than 1%. Regression analysis of the experimental data did not show a general correlation law between FFA concentration and OSI time, but the breaking down of the pro-oxidant effect in groups was possible.

Abstract: The aim of this work is evaluating the effect of the monovarietal olive oil storage at different temperatures as regards phenolic fraction and oxidative stability of samples. In a previous research work, the AA demonstrated that the amount of olive oil phenolic compounds significantly decreased after a storage at -43°C for one month. It has been highlighted a positive correlation between the phenolic fraction decrease and the oxidative stability of the olive oils. However, in this experimental work the olive oil samples are stacked at 4° and -18°C and compared with reference samples stored at room temperature. As a matter of fact these temperatures can be compared to storage conditions during winter.

Abstract: In this paper, two monovarietal extravirgin olive oils, obtained from Ghiacciolo and Nostrana di Brisighella cvv. olives, were produced by two different extraction plants, a low-scale mill equipped with a two-phase decanter and a continuous water-saving industrial plant. The olive ripening index, the fatty acid analysis by capillary gas chromatography, the spectrophotometric determinations of total phenols and o-diphenols, the phenolic profile by HPLC-DAD/MSD and the oxidative stability by OSI, together with the sensory analysis on the oil produced, were evaluated. Independently of the olive processing plant, the oils originating from two cultivars of olive fruit showed different fatty acid compositions (particularly the C18:1/C18:2 ratio), phenol compositions and oxidative stabilities. Concerning the extraction system, for both cultivars, the oxidative resistance and the content of phenols and o-diphenols were higher for the oils produced by the low-scale mill. The quantitative descriptive analysis sensory analysis was not able to discriminate the oil samples from both cultivars obtained from the two plants, even if it underlined a higher bitter attribute for the Ghiacciolo cv. oil when it was obtained from the low-scale mill. The data of the sensory analysis were correlated with simple phenol and the secoiridoid contents, both determined by HPLC-DAD-MSD. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Abstract: The characteristic resistance to oxidation of virgin olive oil is related to its unique fatty acid composition in addition to several minor components that have antioxidant properties. Among the latter, phenols are the most important. Several factors can influence the chemical or enzymatic oxidative processes that extend or shorten the shelf-life of olive oil. Furthermore, the amount of phenolic compounds extracted during production is fundamental for the oxidative and nutritional quality of the oil. In fact, it is well known that different steps used for preparation of virgin olive oil may determine differences in the quantities of phenol. At present, various analytical methods are available to analyze the hydrophilic components, including spectrophotometric assays (traditional) and high resolution chromatographic techniques (HRGC, HPLC, HPCE). In this review we summarize these different methodologies and demonstrate that the amount of phenolic compounds in virgin olive oil as determined by both traditional and high resolution techniques can be influenced by different factors including the olive cultivar and degree of ripeness, as well as by production and extraction technologies.

Abstract: The evaluation of the influence of olive ripening degree on the stability of extra virgin olive oils by the determination of the oxidative stability index, the DPPH(*) radical test, and the quali-quantitative analysis of phenolic compounds, as well as the study of the variation of their sensory profiles, plays a key role in the assessment of the overall olive oil quality. Olives of the cv. Nostrana di Brisighella grown in the north-central Italian region of Emilia-Romagna were picked at four different stages of ripeness and immediately processed in an experimental mill. The polar extracts of oil samples were submitted to spectrophotometric analysis of total phenols and o-diphenols and to liquid chromatographic determination of their quali-quantitative profile (HPLC-DAD/MSD). To attain a complete description of oil samples, fatty acid composition, ultraviolet indices (K(232), K(270), and deltaK), free acidity degree, and peroxide value were also determined according to the European Union methods stated in Regulation 2568/91 (1, Off. J. Eur. Communities 1991, L248, 1-82). Sensory quantitative descriptive analysis (QDA) and triangular tests were performed to establish the influence of olive ripening degree on the resulting oil's organoleptic properties. The evolution of the analytical parameters studied shows that the ripeness stage of Nostrana di Brisighella olives that yields the best oil corresponds to a Jaén index value between 2.5 and 3.5. Oils produced from olives harvested within this time frame present a superior sensory profile accompanied by the highest possible chemical and nutritional properties.

Abstract: Capillary electrophoresis (CE) can be effectively used as a fast screening tool to obtain qualitative and semiquantitative information about simple and complex phenolic compounds of extra virgin olive oil. Three simple phenols (tyrosol, hydroxytyrosol, and vanillic acid), a secoiridoid derivative (deacetoxy oleuropein aglycon), and two lignans (pinoresinol and acetoxypinoresinol) were detected as the main compounds in extra virgin olive oils by high-performance liquid chromatography (HPLC) and capillary zone electrophoresis (CZE). Spectrophotometric indices, radical scavenging activity, and oxidative stability of extra virgin olive oil samples obtained from olives hand-picked at different ripening degrees were statistically correlated with the CZE and HPLC quantification. The concentration of phenols in extra virgin olive oil decreased with ripeness of olive fruits. The high correlations found between CZE and the other analytical results indicate that CE can be applied as a rapid and reliable tool to routinely determine phenolic compounds in extra virgin olive oils.

Abstract: The aim of this paper was the evaluation of the influence of the olive ripening degree on the oxidative stability of monovarietal extra-virgin olive oils, determined by OSI (Oxidative Stability Instrument) index and on the variation of their sensory score. Two cultivar of olives (cvv. Ghiaccolo e Nostrana di Brisighella, both from the Brisighella area) were picked at four different stages of ripeness and immediately processed by an experimental mill. In order to comprehend the relationship between olive ripening degree and oil's content of protective compounds, the oil samples were submitted to spectrophotometric analysis of polyhenols and o-diphenols and to liquid chromatographic determination of their quali-quantitative profile (HPLC-DAD/MSD). Moreover, it was evaluated the fatty acid composition (as oleic acid/linoleic acid ratio) and its relation with the oil oxidative stability. Finally, the samples were sensory analysed to establish the influence of the olive ripening degree on the oil quality. All the data were elaborated to emphasize eventual significant differences, due to the olive ripening degree.

Abstract: The main purpose of the present work was to evaluate the effects of some technological parameters on the oxidative stability of an extra-virgin olive oil (cv. Peranzana), obtained by two different extraction plants (pressure and continuous, by three phases decanter). The measure of the oil resistance to oxidation was carried out by OSI (Oxidative Stability Instrument). The estimation of phenols and polyphenols was realized by spectrophotometric and HPLC-DAD/MSD analyses. Ultraviolet indices (K₂₃₂ K₂₇₀ and ΔK), free acidity degree, peroxide value (POV) and discrimination sensory analysis (triangular test) were carried out to give a complete qualitative picture of the oil. All the data were statistically elaborated to emphasize eventual significant differences, related to the variation of the two technological parameters considered.

Abstract: The high oxidative stability of virgin olive oil is related to its high monounsaturated/polyunsaturated ratio and to the presence of antioxidant compounds, such as tocopherols and phenols. In this paper, the isolation of phenolic compounds from virgin olive oil, by different methods, was tested and discussed. Particularly liquid-liquid and solid-phase extraction methods were compared, assaying, for the latter, three stationary phases (C8, C18 and Diol) and several elution mixtures. Quantification of phenolic and o-diphenolic substances in the extracts was performed by the traditional Folin-Ciocalteau method and the sodium molybdate reaction, respectively. Furthermore, the quantification of phenolic compounds in the extracts and in a standard mixture was carried out both with diode array and mass spectrometric detection and capillary zone electrophoresis.

Abstract: In this work the AA evaluated some qualitative analytical parameters of extra-virgin olive oils from five industrial plants employing different extraction technologies; two cold pression, two centrifugation by three-phases-decanter, and a centrifugation plant, modified to recycle the mill waste waters, commonly named "eco". The samples were "Aprutino Pescarese" PDO (Protected Designation of Origin) extra-virgin olive oils collected in October and in November, corresponding respectively to the beginning and the end of 2001 2002 olive oil season. A decreasing content of total phenols, odiphenols and a reduction of the Oxidative Stability Index were observed from October to November, while no significative differences between the samples obtained in the two months were evidenced in the content of some single antioxidant compounds analysed by HPLC (hydroxytyrosol, tyrosol, and tocopherols). Regarding the qualitative differences of the oils produced by the different plants, the "eco" system showed, for both the harvest times, significative higher values of total phenols, o-diphenols and a longer oxidative stability.