The Experts below are selected from a list of 1263 Experts worldwide ranked by ideXlab platform
Marta Herraiz - One of the best experts on this subject based on the ideXlab platform.
-
Ultrasonically assisted solid-phase extraction and GC analysis of filbertone in Hazelnut Oil
Journal of the American Oil Chemists' Society, 2003Co-Authors: María Luisa Ruiz Castillo, Marta HerraizAbstract:Ultrasound was used to assist solid-phase extraction (SPE) of filbertone ( E -5-methylhept-2-en-4-one) from Hazelnut Oil. Interferences from TG were reduced for effective separation and detection during chromatographic analysis. The enantiomeric distribution of filbertone was determined. Different sorbent materials, sample volumes, and eluents were tested, and the effect on filbertone recovery by ultrasound during the elution step was evaluated. Experimentation performed on a 2-mL volume of Oil diluted with a 2-mL volume of n -hexane, using a silica modified with either a cyano or phenyl group during the extraction, and ultrasound-assisted elution with a 1-mL volume of chloroform allowed filbertone recoveries of up to 94.4% (relative SD 6.5%) vs. 11% obtained when ultrasound was not applied. This improvement is most likely due to a mechanism of cavitation. Ultrasonically assisted SPE is proposed as an accesible and simple alternative to multidimensional chromatographic techniques to accomplish the reliable determination of the enantiomeric excess of chiral compounds in complex matrices, such as Hazelnut Oil, since experimental conditions that can bring about racemization are not required.
-
Ultrasonically assisted solid‐phase extraction and GC analysis of filbertone in Hazelnut Oil
Journal of the American Oil Chemists' Society, 2003Co-Authors: Maria Luisa Ruiz Del Castillo, Marta HerraizAbstract:Ultrasound was used to assist solid-phase extraction (SPE) of filbertone (E-5-methylhept-2-en-4-one) from Hazelnut Oil. Interferences from TG were reduced for effective separation and detection during chromatographic analysis. The enantiomeric distribution of filbertone was determined. Different sorbent materials, sample volumes, and eluents were tested, and the effect on filbertone recovery by ultrasound during the elution step was evaluated. Experimentation performed on a 2-mL volume of Oil diluted with a 2-mL volume of n-hexane, using a silica modified with either a cyano or phenyl group during the extraction, and ultrasound-assisted elution with a 1-mL volume of chloroform allowed filbertone recoveries of up to 94.4% (relative SD 6.5%) vs. 11% obtained when ultrasound was not applied. This improvement is most likely due to a mechanism of cavitation. Ultrasonically assisted SPE is proposed as an accesible and simple alternative to multidimensional chromatographic techniques to accomplish the reliable determination of the enantiomeric excess of chiral compounds in complex matrices, such as Hazelnut Oil, since experimental conditions that can bring about racemization are not required.
-
Off-line coupling of high-performance liquid chromatography and 1H nuclear magnetic resonance for the identification of filbertone in Hazelnut Oil
Journal of the American Oil Chemists' Society, 2001Co-Authors: M. L. Ruiz Del Castillo, Marta Herraiz, M. D. Molero, Antonio HerreraAbstract:A new procedure is presented for off-line coupling of high-performance liquid chromatography and proton nuclear magnetic resonance spectroscopy (1H NMR) in Hazelnut Oil analysis. The optimization of some parameters affecting both the liquid chromatography preseparation step and the effective multiple-solvent suppression required for the NMR study enabled us to determine the presence in a Hazelnut Oil of (E)-5-methyl-hept-2-en-4-one (filbertone), a marker previously proposed to detect the adulteration of olive Oil with Hazelnut Oil. The described procedure requires the filtration of the Oil prior to its introduction into the chromatographic system and combines the advantages of providing sufficient sensitivity and selectivity with simple methodology and reduced sample handling.
-
Determination of (E)-5-methylhept-2-en-4-one in deodorised Hazelnut Oil. Application to the detection of adulterated olive Oils
Journal of the Science of Food and Agriculture, 2000Co-Authors: Gracia Patricia Blanch, M. Mar Caja, Manuel María Urrutia León, Marta HerraizAbstract:The presence of (E)-5-methylhept-2-en-4-one (filbertone) in a Hazelnut Oil, deodorised in a laboratory system using nitrogen as stripping gas, is studied regarding its usefulness as a chiral marker for detecting adulterations of olive Oil. The analytical method involves the use of both simultaneous distillation–solvent extraction as a sample concentration step and a chiral stationary phase in the subsequent gas chromatographic analysis. The procedure is simple, rapid, effective for detecting adulterations of olive Oil with Hazelnut Oil and can reduce falsely negative results obtained if conventional parameters included in current regulations are exclusively considered when establishing purity in olive Oils. © 2000 Society of Chemical Industry
-
A contribution to the study of the enantiomeric composition of a chiral constituent in Hazelnut Oil used in the detection of adulterated olive Oil
European Food Research and Technology, 1999Co-Authors: Gracia Patricia Blanch, M. Del Mar Caja, M. L. Ruiz Del Castillo, Marta HerraizAbstract:A method is proposed for the determination of the adulteration of olive Oil with Hazelnut Oil which is based on the study of the enantiomeric makeup of (E)-5-methylhept-2-en-4-one (filbertone). The possibilities of either using a sample preparation technique or performing direct injection of the samples (i.e., without any kind of sample pretreatment) are considered and both simultaneous distillation extraction followed by gas chromatographic analysis and direct injection in on-line coupled reverse-phase liquid chromatography to gas chromatography are used. In both cases, a chiral stationary phase is employed in the gas chromatography step and the determination of the enantiomeric composition of filbertone is recommended for an accurate evaluation and quick control for detecting the adulteration of olive Oil with Hazelnut Oil.
Meltem Serdaroglu - One of the best experts on this subject based on the ideXlab platform.
-
effect of replacing beef fat with Hazelnut Oil on quality characteristics of sucuk a turkish fermented sausage
Meat Science, 2008Co-Authors: Gulen Yildizturp, Meltem SerdarogluAbstract:Turkish fermented sausages (sucuk) were produced by replacing 15, 30 and 50% of beef fat with Hazelnut Oil incorporated as pre-emulsified with simplesse® 100 (whey protein powder) Each treatment was formulated to contain 20% total fat and beef fat was the only fat material used in the control (C) group. After 12 days of fermentation and ripening, all sucuk samples had TBA values within acceptable limits (<1.0). Increasing levels of Hazelnut Oil in sucuk formulation increased penetrometer values (softer texture) and moisture content. Hazelnut Oil replacement had a significant effect on redness values of the samples. Cholesterol content decreased progressively as the percentage of Hazelnut Oil increased in the formulation. Replacement of 50% beef fat with 50% Hazelnut Oil significantly increased MUFA, PUFA and MUFA + PUFA/SFA ratios. The use of Hazelnut Oil resulted in significant decreases in the slice appearance, texture and taste scores. However there was no significant difference in the overall acceptability score of samples, except those in which Hazelnut Oil replaced 15% beef fat, which had the highest score.
-
Effect of replacing beef fat with Hazelnut Oil on quality characteristics of sucuk - A Turkish fermented sausage.
Meat science, 2007Co-Authors: Gülen Yıldız-turp, Meltem SerdarogluAbstract:Turkish fermented sausages (sucuk) were produced by replacing 15, 30 and 50% of beef fat with Hazelnut Oil incorporated as pre-emulsified with simplesse® 100 (whey protein powder) Each treatment was formulated to contain 20% total fat and beef fat was the only fat material used in the control (C) group. After 12 days of fermentation and ripening, all sucuk samples had TBA values within acceptable limits (
M Rafecas - One of the best experts on this subject based on the ideXlab platform.
-
Analysis of olive and Hazelnut Oil mixtures by high-performance liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry of triacylglycerols and gas-liquid chromatography of non-saponifiable compounds (tocopherols and sterols)
Journal of chromatography. A, 2000Co-Authors: J Parcerisa, I Casals, J Boatella, R Codony, M RafecasAbstract:We analysed the triacylglycerol, tocopherol and sterol composition of Hazelnut Oil, olive Oil and their mixtures (90% olive Oil with 10% Hazelnut Oil, 70% olive with 30% Hazelnut Oil and 50% olive Oil with 50% Hazelnut Oil). The main triacylglycerols were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmitoylglycerol, 2,3-dioleyl-1-linoleylglycerol and 2,3-dioleyl-1-stearoylglycerol. Non-saponfiable compounds (tocopherols and sterols) were derivatised as O-trimethylsilyl ethers. Alpha-tocopherol was the main vitamin E isomer in all samples; however, small amounts of beta-tocopherol and gamma-tocopherol were also found. Beta-sitosterol and delta5-avenasterol were the principal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive Oil and Oil mixtures, was not found in Hazelnut Oil. The discriminant analysis showed that Hazelnut Oil, olive Oil and Oil mixtures were clearly separated according to their triacylglycerol composition.
-
analysis of olive and Hazelnut Oil mixtures by high performance liquid chromatography atmospheric pressure chemical ionisation mass spectrometry of triacylglycerols and gas liquid chromatography of non saponifiable compounds tocopherols and sterols
Journal of Chromatography A, 2000Co-Authors: J Parcerisa, I Casals, J Boatella, R Codony, M RafecasAbstract:Abstract We analysed the triacylglycerol, tocopherol and sterol composition of Hazelnut Oil, olive Oil and their mixtures (90% olive Oil with 10% Hazelnut Oil, 70% olive with 30% Hazelnut Oil and 50% olive Oil with 50% Hazelnut Oil). The main triacylglycerols were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmitoylglycerol, 2,3-dioleyl-1-linoleylglycerol and 2,3-dioleyl-1-stearoylglycerol. Non-saponfiable compounds (tocopherols and sterols) were derivatised as O -trimethylsilyl ethers. α-Tocopherol was the main vitamin E isomer in all samples; however, small amounts of β-tocopherol and γ-tocopherol were also found. β-Sitosterol and Δ 5 -avenasterol were the principal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive Oil and Oil mixtures, was not found in Hazelnut Oil. The discriminant analysis showed that Hazelnut Oil, olive Oil and Oil mixtures were clearly separated according to their triacylglycerol composition.
J Parcerisa - One of the best experts on this subject based on the ideXlab platform.
-
Analysis of olive and Hazelnut Oil mixtures by high-performance liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry of triacylglycerols and gas-liquid chromatography of non-saponifiable compounds (tocopherols and sterols)
Journal of chromatography. A, 2000Co-Authors: J Parcerisa, I Casals, J Boatella, R Codony, M RafecasAbstract:We analysed the triacylglycerol, tocopherol and sterol composition of Hazelnut Oil, olive Oil and their mixtures (90% olive Oil with 10% Hazelnut Oil, 70% olive with 30% Hazelnut Oil and 50% olive Oil with 50% Hazelnut Oil). The main triacylglycerols were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmitoylglycerol, 2,3-dioleyl-1-linoleylglycerol and 2,3-dioleyl-1-stearoylglycerol. Non-saponfiable compounds (tocopherols and sterols) were derivatised as O-trimethylsilyl ethers. Alpha-tocopherol was the main vitamin E isomer in all samples; however, small amounts of beta-tocopherol and gamma-tocopherol were also found. Beta-sitosterol and delta5-avenasterol were the principal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive Oil and Oil mixtures, was not found in Hazelnut Oil. The discriminant analysis showed that Hazelnut Oil, olive Oil and Oil mixtures were clearly separated according to their triacylglycerol composition.
-
analysis of olive and Hazelnut Oil mixtures by high performance liquid chromatography atmospheric pressure chemical ionisation mass spectrometry of triacylglycerols and gas liquid chromatography of non saponifiable compounds tocopherols and sterols
Journal of Chromatography A, 2000Co-Authors: J Parcerisa, I Casals, J Boatella, R Codony, M RafecasAbstract:Abstract We analysed the triacylglycerol, tocopherol and sterol composition of Hazelnut Oil, olive Oil and their mixtures (90% olive Oil with 10% Hazelnut Oil, 70% olive with 30% Hazelnut Oil and 50% olive Oil with 50% Hazelnut Oil). The main triacylglycerols were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmitoylglycerol, 2,3-dioleyl-1-linoleylglycerol and 2,3-dioleyl-1-stearoylglycerol. Non-saponfiable compounds (tocopherols and sterols) were derivatised as O -trimethylsilyl ethers. α-Tocopherol was the main vitamin E isomer in all samples; however, small amounts of β-tocopherol and γ-tocopherol were also found. β-Sitosterol and Δ 5 -avenasterol were the principal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive Oil and Oil mixtures, was not found in Hazelnut Oil. The discriminant analysis showed that Hazelnut Oil, olive Oil and Oil mixtures were clearly separated according to their triacylglycerol composition.
-
fatty acid distribution in polar and nonpolar lipid classes of Hazelnut Oil corylus avellana l
Journal of Agricultural and Food Chemistry, 1997Co-Authors: J Parcerisa, Daryl G Richardson, Magdalena Rafecas, Rafael Codony, Josep BoatellaAbstract:The lipid extract from Hazelnuts was classified as polar (glucolipids = 1.4% and phospholipids = <1%) or nonpolar (triacylglycerides = 98.4%) by column and thin-layer chromatography. Fatty acids derivatized as methyl esters were analyzed by gas chromatography with flame ionization detector and mass spectrometer. Oleic acid was predominant in all lipid classes, followed by linoleic, palmitic, and stearic. Myristic, palmitoleic, hexadecadienoic, linolenic, eicosanoic, and eicosenoic acids were also present in minor proportions. Monounsaturated fatty acids predominated in nonpolar lipids, whereas saturated and polyunsaturated acids were more prominent in polar lipids. Fatty acid contents were compared by ANOVA. Significant differences were found for fatty acid contents in the different lipid classes (p < 0.05). A negative correlation was found between monounsaturated−polyunsaturated and monounsaturated−saturated fatty acids. Keywords: Hazelnut Oil; nonpolar and polar lipids; fatty acid distribution
Ramón Aparicio - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of the methods based on triglycerides and sterols for the detection of Hazelnut Oil in olive Oil
Grasas y Aceites, 2007Co-Authors: Diego L. García-gonzález, María Viera, Noelia Tena, Ramón AparicioAbstract:Two analytical methods, based on the difference between theoretical and empirical triglycerides and the ratios between some free and esterified sterols have been checked to determine their usefulness in detecting the presence of low quantities of any kind of Hazelnut Oil in olive Oil. The methods were confirmed by means of internal and external validations, the latter carried out in 21 different laboratories in three inter-comparison trials. The resulting information suggests a cut-off at 8% for the method based on triglycerides and 10% for that based on the quantification of sterols. The former also shows better reliability measures in reproducibility; i.e., number of false positives, efficiency (90% vs. 82%) and Youden index (0.81 vs. 0.77).
-
Detection of the presence of refined Hazelnut Oil in refined olive Oil by fluorescence spectroscopy
Journal of agricultural and food chemistry, 2007Co-Authors: Ana Sayago, Maria T. Morales, Diego L. García-gonzález, Ramón AparicioAbstract:The fluorescence spectroscopy technique has been tested as regards its ability to differentiate between refined Hazelnut and olive Oils. Classification of these Oils based on their excitation−emission fluorescence spectra data (spectral range 300−500 nm of the excitation spectra at λem = 655 and spectral range 650−900 of the emission spectra at λex =350 nm) was performed using principal component analysis and artificial neural networks. Both methods provided good discrimination between the refined Hazelnut and olive Oils. The results have also pointed out the possibilities of a spectrofluorimetric method joined to multivariate analysis, to differentiate refined Oils, and even to detect the presence of refined Hazelnut Oils in refined olive Oils at percentages higher than 9%. Keywords: Fluorescence; refined olive Oil; refined Hazelnut Oil; multivariate analysis
-
The detection of the presence of Hazelnut Oil in olive Oil by free and esterified sterols
European Food Research and Technology, 2006Co-Authors: Carlo Mariani, Giorgio Bellan, Elena Lestini, Ramón AparicioAbstract:Genuine olive and Hazelnut Oils from diverse geographical origins, as single varieties and blends, were mixed at different percentages and analysed by the method based on the quantification of free and esterified sterols. Two formulas based on three sterols (Campesterol, Δ^7-stigmastenol and Δ^7-avenasterol) together with empirical decision rules were able to detect the presence of Hazelnut Oil in olive Oil when the percentage of the former was more than 6–8%, although this figure was much lower in the most of the adulterations. Results of univariate and multivariate statistical procedures based on the analysis of 116 samples are presented in support of the method efficiency.
-
Using 1H and 13C NMR techniques and artificial neural networks to detect the adulteration of olive Oil with Hazelnut Oil
European Food Research and Technology, 2004Co-Authors: Diego L. García-gonzález, Luisa Mannina, Marco D’imperio, Anna Laura Segre, Ramón AparicioAbstract:The lack of any official analytical method to detect the adulteration of olive Oil with a low percentage of Hazelnut Oil is explained by the similarities in the chemical compositions of both kinds of Oils. To counter this problem, an artificial neural network based on 1H-NMR and 13C-NMR data has been developed to detect olive Oil adulteration, and the results from this ANN are presented here. A training set consisting of Hazelnut Oils, pure olive Oils, and olive Oils blended with 2–20% Hazelnut Oils was used to design and train a multilayer perceptron with 100% correct classifications. This mathematical model was also validated using an external validation set of blend samples (3–15%) and genuine samples. The detection limit of the model was around 8%.
-
Detection of Hazelnut Oil in virgin olive Oil by a spectrofluorimetric method
European Food Research and Technology, 2004Co-Authors: Ana Sayago, Maria T. Morales, Ramón AparicioAbstract:The possibilities of a spectrofluorimetric method joined to multivariate analysis to assess the genuineness of olive Oil in admixtures with Hazelnut Oils were studied. Virgin olive, virgin Hazelnut and refined Hazelnut Oil samples and admixtures between them at 5, 10, 15, 20, 25 and 30% adulteration were analysed at λ ex=350 nm. The precision of the method, in terms of repeatability and internal reproducibility, was established by means of the analysis of a virgin olive Oil sample under different conditions, the RSD showing values less than 10%. Raw data of the spectra were subjected to mathematical treatment by calculation of the first derivative, selection of the maximum values and application of one-way ANOVA, to assess the most prominent variables in the discrimination process. The response to the addition of adulterant was linear, adjusted-R 2=0.99 for virgin olive and refined Hazelnut Oil mixtures, and 0.98 for virgin olive and virgin Hazelnut Oil mixtures. Stepwise linear discriminant analysis applied to each admixture separately and to the whole set of samples allowed 100% correct classifications.
