bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital tribes in the university classrooms
Authors: Gutiérrez-Martín Alfonso , Palacios-Picos Andrés , Torrego-Egido Luis
Published: March 2010

The discourse stating that the profound changes in ICT of the last decade have also radically altered the way our students learn, and that they can all now be considered digital natives, is increasingly prevalent. However, this paper argues that these changes are not as immediate, automatic or beneficial as the dominant political and technological discourse on the benefits of ICT would have us believe, and that they give rise to many different situations that characterize university teaching and learning practice. Using the ratings of three Likert questionnaires on information processing and communication in three different environments (Moodle, Tuenti and the classroom itself), and applying multivariate techniques (factor analysis and cluster analysis), we have found four clusters: pro-ICT students, anti-ICT students, listless student and neutral student. The presence of such segments of students allows us to conclude that, although computers are nowadays taken for granted in Higher Education classrooms, we are perhaps overestimating both the real impact of ICT on teaching and students’ digital competencies, and that this false perception of reality benefits technology vendors but not methodological and pedagogic innovation, which can only be achieved through the necessary reflection on education matters from educational principles.

Se ha extendido el discurso que afirma que los profundos cambios en las TIC experimentados en la última década han modificado también radicalmente el aprendizaje de nuestros estudiantes universitarios, considerados todos ellos nativos digitales. En este artículo se sostiene, sin embargo, que dichos cambios no son tan inmediatos, automáticos o beneficiosos como el discurso dominante sobre la bondad de las TIC pretende hacernos creer, y que dan lugar a múltiples y variadas situaciones intermedias que caracterizan la actual enseñanza universitaria. Utilizando las valoraciones de tres cuestionarios tipo Likert sobre los procesos de información y comunicación en tres entornos diferenciados (una plataforma virtual de enseñanza aprendizaje, Moodle, Tuenti, como ejemplo de red social, y las aulas presenciales) y mediante técnicas multivariantes (análisis factorial y de conglomerados) se encuentran cuatro segmentos de estudiantes: alumnado optimista o pro-TIC, alumnado pesimista o anti-TIC, alumnado apático y alumnado neutral. La presencia de dichos segmentos de estudiantes nos permite concluir que, aunque la presencia del ordenador en las aulas universitarias forma ya parte del imaginario colectivo, tal vez se esté sobrevalorando tanto el impacto de las TIC en la educación superior como las competencias digitales de los alumnos, y que esta falsa percepción de la realidad puede beneficiar a los vendedores de tecnología, pero no a la innovación metodológica, que sólo se podrá conseguir mediante la necesaria reflexión desde postulados educativos.
I want to be a journalist: looking for motivation in journalism
Authors: Pastor-Alonso María-de-los-Ángeles
Published: March 2010

This paper has an approach to the different characteristics which make up the public’s image of journalists, analysing the motivations behind the decision of those who became and those who want to become journalists. In the case of professional journalists, there is a theoretical framework from which to analyze the essential influences on the decision to become a journalist: we can underline the development of personal talents, and the social influence of journalism and its existential possibilities. These reasons help explain some professional behaviour and attitudes, and point to why journalism is a questionable profession in Spain nowadays. The ideal profile of a journalist inevitably influences the value placed on the work of journalists, and also affects the decision of those who contemplate a career in journalism. Moreover, these youngsters who want to become journalists – whose motivations are contrasted in an investigation into students in the final year of High School and the first year of university - accept the usual stereotypes of journalists, even those which present a kind of mythical image, but these youngsters are also conscious of the need for personal criticism. They call for the return to the most important values and qualities of journalism to develop professional competence.

Se realiza en este artículo un acercamiento a las características que configuran la imagen del periodista ante el gran público, examinando los motivos que intervienen en la decisión de quienes se han dedicado a este oficio y de quienes desean hacerlo en el futuro. En el caso de los profesionales en ejercicio, se dispone ya de un marco teórico suficiente para analizar las influencias que en su momento fueron determinantes en la vocación de los informadores: destacan el desarrollo de ciertos talentos personales, el papel social atribuido al periodismo y sus posibilidades vitales. Estas razones explican ciertos comportamientos y actitudes profesionales y señalan las causas de que en la actualidad el periodismo sea una profesión socialmente cuestionada en España. El «perfil ideal» del periodista actúa de rasero inevitable para valorar el trabajo de los comunicadores, e influye, a su vez, en la elección de quienes se inclinan por el periodismo como profesión. Por su parte, estos jóvenes que quieren ser periodistas –cuyas motivaciones son contrastadas a través de un sondeo realizado a estudiantes del último curso de Bachillerato y primero de la licenciatura– aceptan los estereotipos que circulan sobre los informadores, incluso los que proyectan una estampa más mitificada, pero también son conscientes de la necesidad de una seria autocrítica. Ellos mismos reivindican, en suma, la vuelta a los valores más apreciados del oficio y las cualidades que desarrollen la competencia profesional.
Aplication of headspace techniques to the extraction of volatile organic compounds from paprika oleoresin
Authors: Guadayol J. M. , Baquero T. , Caixach J.
Published: March 2010

Static and dynamic headspace techniques have been applied to the extraction and concentration of volatile organic compounds (VOCs) from paprika oleoresin. In dynamic headspace, both purge and trap and sweeping techniques have been used. In order to show the influence of temperature on the extraction techniques, three differents temperatures have been applied to each technique. The separation and identification of the extracted VOCs has been carried out through HRGC/MS. The extraction techniques are simple and easily reproducible.
Flavour changes due to effect of different packaging materials on storing of cottonseed oil, hydrogenated oil and margarine.
Authors: El-Shattory Y. , Saadia M. A. , Said F. H.
Published: March 2010

Bleached cottonseed oil, partially hydrogenated palm oil and margarine were packed in metal cans and white plastic bottles and stored for seven months at room temperature on side bench. Assessment of the stability of the oils towards flavour deterioration was reported. The deterioration of flavour developed from bleached cottonseed oil, partially hydrogenated palm oil and margarine was observed due to increase amount of aldehydes and ketones which play an important role in deterioration of the oils. From the results we found metal can offered suitable and better protection against deterioration than plastic package for cottonseed oil, partially hydrogenated palm oil. While plastic container was better for storing margarine and this is due to the presence of water and salt in margarine where they compose about 16% and 2% respectively.
Use of the 2-thiobarbituric acid (TBA) test for evaluation of the autoxidative process in foods.
Authors: Vicario Romero I. M. , Guillén Sans R. , Guzmán Chozas M.
Published: March 2010

In this overview several aspects concerning the application of 2-thiobarbituric acid (TBA) test for measuring oxidative rancidity in foods are described and discussed. Different factors like food processing, sample induced oxidation and preparation, applied methodologies and interferences, are considered. The application of the TBA test to some foods like meats, fish, eggs, milk and dairy products, cereals, infant-foods, animal fats and vegetable oils are described. Correlation between TBA index or TBA number and other oxidation indices (i.e. peroxide value) as well as sensory evaluation are also considered.
Preparation of polyunsaturated fatty acid concentrates from the liver oil of dogfish (Squalus acanthias) from the Black Sea.
Authors: Stefanova K. , Seizova K. , Georgieva G. , Zlatanova L. , Kuleva L. , Popov S.
Published: March 2010

The fatty acid composition of the liver oil from the Black Sea dogfish Squalus acanthias, as well as its seasonal variations were determined. A scheme for concentration of polyunsaturated fatty acids from the dogfish liver oil by urea complexation was proposed. From 360g of free fatty acids a 48g concentrate was obtained, containing 7,8% C20:4, 16,4% C20:5. 9,2% C22:5 and 49,7% C22:6.
Variations on nutritive value of Jijona nougat in suprema, extra and popular qualities.
Authors: Blázquez Abellán G. , Orzáez Villanueva M. T. , Díaz Marquina A.
Published: March 2010

In this paper, the nutritive value of the three qualities of Jijona- Nougat has been analysed. These qualities are regulated by the Spanish Regulations for Nougat and Marzipan (Reglamentación Técnico-Sanitaria para Turrones y Mazapanes), (Real Decreto 1167/1990). Thirty-three samples of Jijona-Nougat have been studied: twenty-one samples belonging to «Suprema» quality (corresponding to three different batches of production of seven commercial brands). Nine samples belonging to «Extra» quality (three different batches of production of three commercial brands). Three «Popular» samples, corresponding to three different batches of production from the unique manufacturer found on the market. Moisture and macronutrients: protein, fat and carbohydrates, have been determined in all the samples. The results and their statistical study are shown in this paper.
Used of pesticides in cottonseed cultivars. Present trends.
Authors: Martínez M. J. , Crespi M.
Published: March 2010

The paper reviews the world production of cotton and the use of pesticides in its growth. The risks derived from their abuse, especially chlorinated ones, are commented. Organophosphorous pesticides and carbamates have a wider spectrum of activity and less environmental persistence, although their are more toxic for mammalian beings. Since the 70th, the «piretrinas» have solved some of the problems derived from pets with resistance to the above mentioned two pesticides. Nevertheless, utilization of pesticides in this culture should be diminished since their use is not efficient nowadays and even in some cases there is a production decrease. On the other hand, consumers are progressively demanding the so called «ecological products». Thus, EU countries should be more restrictive with respect to the pesticides tolerances in cotton to be able to use the «Ecological label» of the European Union.
Fatty acid, sterol and proximate compositions of peanut species (Arachis L.) seeds from Bolivia and Argentina
Authors: Grosso Nelson R. , Zygadlo Julio A. , Burroni Laura V. , Guzmán Carlos A.
Published: March 2010

The oil, protein, ash and carbohydrates contents, iodine value, fatty acid and sterol compositions were studied in seeds of Arachis correntina, A. durannensis, A. monticola, A. batizocoi, and A. cardenasii originating from Bolivia and Argentina. Oil content was greatest in A. batizocoi (mean value 53,35%). The protein level was higher in A. monticola (mean value 29,40%) and A. durannensis (29,13%). Mean value of oleic acid varied between 34,91% (A. durannensis and A. cardenasii) and 42,60% (Arachis correntina), and linoleic acid oscilated between 40,23% (A. correntina) and 45,86% (A. durannensis). The better oleic to linoleic ratio was exhibited by A. correntina (1,06). Iodine value was lower in A. batizocoi (106,0). The sterol composition in the different peanut species showed higher concentration of β-sitosterol (mean values oscilated between 55,70-58,70%) following by campesterol (15,18-16,47%), stigmasterol (10,67- 12,27%) and Δ5-avenasterol (10,80-12,13%).
Chemical and sensory characteristics of «Arbequina» olive oil obtained in different growing areas of Spain
Authors: Touss J. , Romero A. , Plana J. , Guerrero L. , Díaz I. , Hermoso J. F.
Published: March 2010

Within the quality virgin olive oils produced in Spain, Catalonia has two of the six currently existing Origin Denominations (Garrigues and Siurana). Their production of extra virgin oil proceeds of the «Arbequina» cultivar, approximately 8.000 tm, distributed between the CD «Garrigues», in Lleida (5.000 tm), and «Siurana» in Tarragona (3.000 tm). These oils are very appreciated at domestic as well as at international level because of their excellent taste. In the last years, this variety is being expanded in other regions of Spain (Andalusia, Aragon, etc.) and over the worid (Argentina, France, etc.). The physico-chemical and sensory characteristics of «Arbequina» virgin olive oils produced are studied, mainly in Catalonia, Andalusia and Aragon. The obtained preliminary results indicate that some quality parameters of the «Arbequina» oil are variable, being cultivated in different environments, mainly certain fatty acids, polyphenols, oxidative stability and some sensory attributes of the oil.
Non-steady rheological behavior of oil-in-water emulsions stabilized by a sucrose palmitate.
Authors: Partal P. , Guerrero A. , Bejarano M. , Gallegos C.
Published: March 2010

Non-steady flow properties of concentrated oil in water emulsions containing oil (60-80% wt.), water and sucrose palmitate (1-5% wt.) of high hydrophilic-lypophilic balance were investigated. Stress growth, steady flow and linear viscoelastic measurements were carried out for this study. The emulsions studied exhibited a thixotropic behavior showing a very rapid stress overshoot. The stress decay was fitted to a Figoni-Shoemaker model using two exponentials. An stress undershoot was also produced under certain conditions. Shear brought about strong structural changes, such as droplet size redistribution at high oil content and temperature. Thus, the steady state viscosity does not fit an Arrhenius type equation with temperature. A shear thinning behavior was found for the steady state viscosity and the peak viscosity.
Characterization of hydrogenated fats for margarine manufacturing purposes.
Authors: Grimaldi Renato , Nassu Renata Tieko , Guaraldo Gonçalves Lireny Aparecida , Nogueira Cavaletti Moreira Rosana
Published: March 2010

Eight samples of hydrogenated vegetable fats were characterized by their fatty acid composition, trans isomers content and thermal behaviour, using gas chromatography (GC), infrared spectroscopy (IR), pulsed Nuclear Magnetic Resonance (pNMR) and Differential Scanning Calorimetry (DSC) techniques, respectively. Fatty acid composition showed some variations In relation to the unsaturated fatty acids. Trans isomer content, values varied from 22.8% to 35.6%. Solid fat content values were measured using AOCS and lUPAC methods, which differ In the tempering procedures. Values obtained by IUPAC method were higher than the AOCS ones, only at lower temperatures (10 and 21,1°C). Samples were divided Into three groups according to their solids profile: superior (C/E/G/H) intermediate (F) and Inferior (A/B/D). Melting and crystallization curves were obtained by Differential Scanning Calorimetry. Melting enthalpies ranged from 51.3 to 76.5 J.g-1 and crystallization enthalpies varied from -34.2 to -18.9 J.g-1 Characteristic temperatures showed little differences between the samples and each of them showed a characteristic DSC curve. All samples showed a great melting range as expected for hydrogenated fats used for margarines manufacture.
Virgin olive oil and cardiovascular diseases. Plasma lipid profile and lipid composition of human erythrocyte membrane.
Authors: Ruiz Gutiérrez V. , Muriana F. J. G. , Villar J.
Published: March 2010

We studied the effect of virgin olive oil on plasma lipids and erythrocyte membrane lipids of healthy subjects and hypertensive patients (with or without hypercholesterolaemia). The effect of high-oleic sunflower oil was also tested. The study was conducted over two 4-week periods, with a washout (4-week) period between both monounsaturated diets. Olive oil and high-oleic sunflower oil signiflcantly increased the plasma HDL cholesterol concentration, but only decreased the plasma LDL cholesterol concentration in healthy subjects. There was a reduction in the ratio of cholesterol to phospholipids in the erythrocyte membrane of healthy subjects, while an increase in the erythrocyte of hypertensive patients after both MUFA periods. The content of membrane cholesteryl esters was fully decreased. Olive oil (but not high-oleic sunflower oil) increased the content of long-chain PUFAs (arachidonic acid, and docosapentaenoic and docosahexaenoic acids of n-3 family) in the erythrocyte membrane of hypertensive patients. The effects were more evident in hypercholesterolaemic patients. Our study indicates that olive oil and high-oleic sunflower oil improve the plasma atherogenic profile In humans, although olive oil (and not high-oleic sunflower oil) had favourable effect on membrane homeostasis processes.
Polluting potential of wastewater from fish meal and oil industries.
Authors: Mendiola Santiago , Achútegui Juan J. , Sánchez Francisco J. , San José Mª José
Published: March 2010

. In this study we addressed the polluting potential that constitutes the disposal of wastewater from the fish meal and oil Industries Into the sea. With this aim we have analysed some phisico-chemical and bacteriologic aspects of the effluents of these industries, including: weight percentage of organic matter, chemical oxygen load, fatty acids saturation, and presence of Salmonellas. The results suggest a low polluting potential for these effluents, although the acid pH and the high rate of saturation found In fatty acids of oil fishes could imply a certain toxicity for the marine environment.
Antioxidative activity of 3,4-dihydroxyplienylacetic acid and α-tocopherol on the triglyceride matrix of olive oil. Effect of acidity.
Authors: Blekas Georgios , Boskou Dimitrios
Published: March 2010

Minor constituents of virgin olive oil are important for the remarkable stability of the oil in autoxidation, but the exact role and the extent to which each antioxidant factor contributes to the total antioxidant effect has not been thoroughly Investigated. In this study the role of α-tocopherol is explored at various acidity levels and at low concentrations of ortho-diphenols. A substrate of olive oil triacylglycerols devoid of prooxidant or antioxidant constituents was prepared from refined olive oil by column chromatography To tills substrate, slightly oxidized, the additives (oleic acid, 3,4-dihydroxyphenylacetic acid and α-tocopherol) were added and the stability was assessed by periodical measurements of peroxide values. It was found that free fatty adds reduce mainly the protective activity of the ortho-diphenol. It is also concluded that α-tocopherol has a synergistic effect with the ortho-diphenols and contributes significantly to the retardation of peroxide formation. This is Important for oils poor in ortho-diphenols.
Effect of organic loading rate on anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process in a fluidized bed reactor
Authors: Borja Rafael , Alba José , Martín Antonio , Mancha Angela
Published: March 2010

A study of the anaerobic digestion process of wastewaters from the washing of olives prior to the oil production process was carried out in a fluidized bed reactor with sepiolite immobilised biomass at 35°G. The bioreactor worked satisfactorily using Influent COD concentrations of 4.5,3.5,2.5 and 1.5 g COD/I for a hydraulic retention time (HRT) range of 4.5 to 1,25 days. COD removal efficiencies in the range 50-90% were achieved in the reactor, when evaluated at organic loading rates of between 0.46 and 2.25 g COD/I day using the highest influent substrate concentration (So = 4.5 g COD/I). COD and volatile fatty acid (VFA) concentration were Increased In parallel with the increase of organic loading rate in the reactor, VFA concentration showing a maximum value of 1.55 g acetic acid/I at the most unfavourable case studied (So = 4,5 g COD/I and HRT = 1.25 days). The increase in effluent VFA concentrations was always counteracted by the high alkalinity values (3440-4670 mg CaCO3/l) which brought about the high stability of the process and values of the alkalinity/VFA ratio lower than 0.3-0.5, except for the above-mentioned case, limit value over which the anaerobic process is destabilized. The yield coefficient of methane production was 0.281 methane STP/g COD removed.
Using Uruguayan pillared clays for bleaching corn oil.
Authors: Pagano T. , Sergio M. , Montenegro A. , Diano W. , Grompone M. A.
Published: March 2010

In the present paper adsorptive capacity to remove carotenes from a com oil by an Uruguayan montmorillonite modified by different treatments: exchange with Na+ ions (M-Na), acid-activation (Act), exchange with Ca2+ and pillaring with Keggin ions (Pile-Act), acid-activation and pillaring (Act Pil-Ca), is studied. Bleaching action of the Uruguayan modified montmorillonites is compared with two commercial days: Tonsil Optimum (Süd-Chemie) and montmorillonite of type K 10 (Aldrich). Our results demonstrate that Act and Pilc-Ca samples are so efficient bleaching clays as commercials but M-Na sample Is lower. Also, mixtures of Pilc-Ca with commercial clays, added together in one step or consecutively in two steps, are studied. These procedures do not improved the bleaching action. As conclusion, the modified clay Pilc-Ca allows to bleach a neutralized and degummed corn oil, giving an end product similar to edible commercial oils. Such effect is improved with the simultaneous action with activated clays.
Influence of the enzymatic treatment on the quality of vegetable oils
Authors: Sineiro J. , Domínguez H. , Núñez M. J.
Published: March 2010

In this paper the effects of the enzymatic treatment on the quality and composition of vegetable edible oils are revised. Stability and refinability related aspects of oils from seeds, olive and other fruits are presented, so as an organoleptic valoration of the olive oil. Oils from enzyme aided processes show composition and characteristics similar to the ones from oils obtained from raw materials.
Correlation of maturity groups with seed composition in soybeans, as influenced by genotypic variation.
Authors: Maestri Damián M. , Meriles José M. , Guzmán Carlos A.
Published: March 2010

Seeds of 19 soybean cultivars (Glycine max (L.) Merrill) with maturity groups V, VI or VII were analyzed for proximate composition, fatty acids and sterols. Protein, oil, carbohydrate and ash contents varied between 344-463 g kg-1, 178-233 g kg-1, 234-338 g kg-1, and 40.0-49.3 g kg-1 of dry matter, respectively. Fatty acid profiles revealed that the major acids were palmitic (9.2-12.5%), oleic (17.7-22.1%) and linoleic (53.6-56.9%). Linolenic acid ranged from 8.6 to 10.4%. Sitosterol (48.1-56.8%) was the main component of the sterol fraction, followed by campesterol (18.4-21.7%) and stigmasterol (13.4-18.0%). Statistically significant differences between genotypes were found for the majority of parameters evaluated, but there are not significant variations among maturity groups.
Quality of virgin olive oil from territorial quality label «Les Garrigues» D.O. (Lleida. Spain) along the 1995/96 harvest
Authors: Motilva Mª José , Jaria Ismael , Bellart Ismael , Romero Mª Paz
Published: March 2010

The Garrigues territorial quality label (Les Garrigues D.O.) is located in the southern part of Lleida (Catalonian. Spain). The most oil produced in this D.O. corresponds to extra virgin classification and it has a distinctive sensorial quality, as a consecuence of olive cultivar («Arbequina» cv) and the careful elaboration of oil. The new cultural technologies applied to the olive tree cultivar and.the new technologies of olive oil extraction have made necessary the study of oil composition and quality during consecutive harvests, to know if the quality could be afected. The objective of this work is the characterization of virgin olive oils (67 samples from 13 olive mills) during the 1995/96 harvest. Analytical controls show that the mean acidity index is 0.17% in oleic acid, the mean peroxide value is 6.9 meq oxygene active/kg of oil and the mean K270 of 0.21; these quality parameters fulfill the policy values of «Les Garrigues» D.O. The mean polyphenol content is 152 ppm expressed as cafeic acid, with a great variability among olive mills. As harvesting time progresses, the concentration of pigments in olive oil decreases. The concentration of chlorophyl and that of carotenoid pigments at the begin of the harvest is 15 and 12.6 mg/kg of oil respectively and at the end of the period they are 6 and 4.6 mg/kg of oil respectively. The oil color, expressed as visual ABT index and the chromatic ordinates CIELAB, lies within the yellow zone and does not vary along the harvest season.
Studies on cocoa butter-replacer mixtures suitable for the local chocolate production.
Authors: El-Mallah M. Hassan , Megahed M. G.
Published: March 2010

Mixtures of cocoa butter with different replacers, added at different levels, were prepared. From their properties, and particularly solid fat index, helped much in selecting the more suitable mixture for local chocolate production. It was found that cocoa butter-Illexao mixtures, at levels 10% and 15% replacer, gave more satisfactory results with respect to mouthfeel, hardness and brittleness.
Correlation between seed size, protein and oil contents, and fatty acid composition in soybean genotypes
Authors: Maestri Damián M. , Guzmán Garios A. , Giorda Laura M.
Published: March 2010

Eighteen soybean genotypes (Glycine max (L.) Merrill) with maturity groups IV, V, VI or VII were grown in 1995/96 at the Estación Experimental Agropecuaria (EEA-INTA) of Manfredi and Marcos Juárez, Argentina. The aim of this research was to determine possible associations between seed size, protein and oil contents, and fatty composition. Seed size varied between 13.9-21.0 g/100 seeds. Protein and oil contents ranged from 331 to 448 and from 198 to 267 g kg-1, respectively, and showed no significant correlation with seed size. There were significant correlations between seed size and individual fatty adds: positive with stearic and oleic and negative with linoleic. The results obtained suggest that seed size and its relationship with individual fatty acids must be considered in soybean breeding programs.
Evolution of biométrie parameters and chemical composition of olives from the Moroccan Picholine variety during fruit ripeness
Authors: Ajana H. , El Antari A. , Hafidi A.
Published: March 2010

The evolution of the maturity index during the ripeness of olives from the Moroccan Picholine variety did not show any significant variation before the middle of September. After this date it began the growing and reached the maximum value (4.7) at the middle of January. The weight of olives increased continuously from June to November, and remained constant over two months beyond the maximal value of 3.95g (November and December). The weight of the olive kernels was constant during all the sampling period. The olive dimensions (length and width) showed similar trend as the olive weight. The polar lipid fraction of the oil predominated over the neutral one during June and July and after this date, the neutral fraction prevailed. The maximum value was reached in December. The protein content decreased from 4.6 to 2.3%. Ash content grow from 2.72 to 5.57%. The chlorophyll content in the oils decrease progressively and showed an inverse correlation with the maturity index. The phosphorus content diminished until September and then continued to be constant.
New trends in determining the authenticity of corn oil
Authors: El-Mallah M. Hassan , Mumi T. , El-Shami S.
Published: March 2010

HPLC analysis of triacylglycerols and minor components, such as free and acylated sterols, and sterylglycosides, tocopherols and ¡soprenoid alcohols, have been employed for establishing oil authenticity. GLC analysis of the whole sterols as their TMS - derivatives has been also conducted. Genuine oils, namely, rapeseed, sunflower and corn oil as well as corn oil admixtures with the two oils were analyzed. Triacylglycerols and tocopherols were directly determined in the oils whereas the four sterol in lipids (free and acylated sterols and sterylglycosides) and isoprenoid alcohols were isolated and derivatized into their anthroyi nitrile derivatives. It was concluded that the analysis of minor components in combination with triacylglycerols is more advantageous for authentication of corn oil. However, ¡soprenoid alcohols are more decisive in this respect. Natural variability of the components in the oils from different origins can modify the detection limits.
Spectrophotometric analysis of the lipid fraction of microwave heated and soaked soybeans.
Authors: Evangelista C. M. , Regitano-D'Arce M.A. B.
Published: March 2010

The flavor of soybean products, particularly soy milk, is one of the main problems to its acceptance by Western people. The objective of this work was to evaluate the effects of different microwave pre-heating times on soybean oxidative quality by monitoring the spectrophotometric absorptivity at 232 nm of its lipid fraction during soaking for soymilk production. A decrease in oxidation level was observed in microwave heated soybeans and the longer the exposure time was, the lower was the absorptivity. Absorptivity of non-heated soybeans was 5,36, while those heated for 150s, reached a temperature of 142,5°C and presented 2.93. Data could be represented by a polynomial equation of second order.
Dehydrated soup cubes fatty components characterization
Authors: Correa-Cabrera R. , Capote A. , Rodríguez-Ayán M. N. , Grompone M. A.
Published: March 2010

Fats represent a major part of the weight of dehydrated soup cubes. As these products are stored at room temperature, the fatty components should show no partial melting during the Summer months. Six fatty raw materials, mixtures of these fats already prepared by the manufacturer and lipidic extracts from the finished cubes (both hen and vegetables soups) are analyzed in this work, trying to relate origin (fatty acid composition) with stability against temperature changes (DSC thermogram). Some of the studied fats are found acceptable according to the expected shelf life of the product, although others should be modified before usage, either by fractioning or by hydrogenation.
Quality changes of Moringa oleífera, variety Mbololo of Kenya, seed oil during frying.
Authors: Tsaknis John , Spiliotis Vasilis , Lalas Stavros , Gergis Vlasis , Dourtoglou Vasilis
Published: March 2010

The frying performance of Moringa oleífera variety Mbololo of Kenya seed oil (produced by cold pressure, extraction with n-hexane and a mixture of chloroform-methanol) was studied especially as regards repeated frying operations. The oils were used for intermittent frying of potato slices and cod filets at a temperature of 175 ± 5°C for 5 consecutive days. Under such conditions thermal and oxidative decomposition of the oils takes place. The chemical changes occurring in the oils were evaluated. Free fatty acid content, peroxide value, specific extinction at 232 nm, polar compounds, colour and viscosity of the oils all increased, whereas the iodine values, smoke points, polyunsaturated fatty acid content, induction period and tocopherol concentration decreased. The effect of the oils on the organoleptic quality of these fried foods was also determined. The analytical and sensory data showed that the lowest deterioration occurred in cold pressure produced oil and the highest in n-hexane extracted oil.
Some compositional characteristics of capers (Capparis spp,) seed and oil
Authors: Akgül Attila , Özcan Musa
Published: March 2010

Capparis spinosa L. var. spinosa and Capparis ovata Desf. var. canescens seeds were evaluated for weight, sizes, moisture, ash, crude protein, crude oil, energy and crude fiber. The relative density, refractive index, free fatty acids, peroxide value, iodine value, saponification value, unsaponifiables and wax were determined in the seed oils. The main fatty acids identified by gas chromatography were palmitic, oleic and linolelc acids. The seeds were rich in protein, oil, and fiber and showed similar composition between then with a high content in unsaturated fatty acids, suggesting that they may be valuable for food uses.
Characterization, quantitation and evolution of monoepoxy compounds formed in model systems of fatty acid methyl esters and monoacid triglycerides heated at high temperature
Authors: Berdeaux O. , Márquez-Ruiz G. , Dobarganes M. C.
Published: March 2010

Monoepoxy compounds formed after heating methyl oleate and linoleate, triolein and trilinolein at 180°C for 5, 10 and 15 hours, were characterized and quantitated after derivatization to fatty acid methyl esters by using two base-catalyzed procedures. Structures were identified by GC-MS before and after hydrogénation. A complete recovery of the epoxy compounds was obtained by comparing results from methyl oleate and linoleate before and after transesterification, and good repeatability was also attained. Similar amounts of epoxides were found for methyl esters and triglycerides of the same degree of unsaturation, although formation was considerably greater for the less unsaturated substrates, methyl oleate and triolein, possibly due to the absence of remaining double bonds in the molecule which would involve a lower tendency to participate in further reactions. On other hand, independently of the degree of unsaturation of the model systems and of the period of heating, significantly higher amounts of trans isomers were formed. Finally from comparison between the amounts of epoxides and the level of polar fatty acids in samples, it was deduced that monoepoxy compounds were one of the major groups formed under the conditions used.
Study of the fat content, iodine index and index and degree of acidity in Alicante and Jijona nougats
Authors: Blázquez-Aballan G. , Díaz Marquina A. , Orzáez Villanueva Mª T.
Published: March 2010

In this paper, a study of the fat content, and the index and degree of acidity and iodine index has been carried out in twenty four samples belonging to Alicante nougat and Jijona nougat in the Supreme and Extra qualities, which are regulated by the Spanish Regulations for Nougat and Marzipan (Reglamentación Técnico- Sanitaria para Turrones y Mazapanes). Results indicate that these nougats present high and very similar fat contents in both. The iodine indexes are higher and more disperse in the Supreme and Extra qualities of Jijona nougat. The values of acidity index, obtained indicate the good quality of the fat used in these two types of nougat.
Preparation of sn-2 long-chain polyunsaturated monoacylglycerols from fish oil by hydrolysis with a stereospecific lipase from mucor miehei
Authors: Nieto Susana , Gutiérrez Jorge , Sanhueza Julio , Valenzuela Alfonso
Published: March 2010

The preparation of sn-2 eicosapentaenoyi glycerol and sn-2 docosahexaenoyi glycerol by the hydrolysis of fish oil by the sn-1, sn-3 stereo-specific immobilised lipase (Lipozyme IM-20) from mucor miehei is described. Monoacylglycerols obtained after the enzymatic hydrolysis were separated by silver nitrate-coated silicic acid column chromatography Both monoacylglycerols can be individually separated in almost pure form by elution from the column with a solvent mixture. The preparation of sn-2 substituted monoacylglycerols from marine origin allows their utilization as substrates for the synthesis of structured long-chain polyunsaturated fatty acid-containing triacylglycerols at specific positions.
Comparative study of the obtention of crude and semi-purified lipase extracts from rice bran.
Authors: Bella Cruz A. , Barrera-Arellano D.
Published: March 2010

Crude lipase extracts from defatted rice bran were obtained using three different extraction solutions: 1; CaCl2 0.01 M; 2; Sacarose 0.6M, KCI 10mM, MgCl2 1mM, Ditiotreitol 2mM and 3; Sacarose 0.4M, Ditiotreitol 2mM. Factors (variables) studied were pH (6.0, 7.0, 8.0) and extraction time (1h, 2h, 3h). Extraction temperature was 4 °C. The extracts obtained presented different lipase activities, and the crude extract obtained with CaCl2 0.01 M was the one with the highest specific activity (12.1mU/mg). Partial purification of this crude extract with acetone and ammonium sulfate resulted in fractions with specific activities of 50.7mU/mg and 63.5mU/mg, respectively.
Repercussion of the mill olive cool-storage on the production process of virgin olive oil.
Authors: Canet Miguel , García José Mª
Published: March 2010

During the 1993-94 season, a total of 1,003,351 Kg. of olive fruits (Olea europaea, cvs. Blanqueta y Villalonga) were stored in a cool room at 5 °C until a maximum time of 18 days. The virgin olive oil obtained from these fruits showed physical, chemical and sensorial indices inside the limits established for the «extra» virgin olive oil. The cool-storage of the olive fruits made possible a maximum yield in the processing machinery for 8 weeks without an appreciable lost of quality on the virgin olive oil obtained. It allows a better amortisation of the disposable equipments and, requiring the distribution of the fruit in boxes, contributes to the rationalisation of the olive fruit postharvest manipulation.
Quality criteria, expiration period and marketing loss estimations of pre-treated and cold stored mullet fish.
Authors: Hassan Ibrahim M. , Khallaf Mohamed F. , Abd-Al Fattah Laila E. , Yasin Nessrien M.
Published: March 2010

Monitoring of protein breakdown products and lipid autoxidation in farmed mullet fish as a function of a proposed treatments prior to chilling process at 3 °C ± 1 was carried out. Furthermore, sensory evaluation of three investigated treatments, whole mullet fish (RM)-eviscerated and soaked in distilled water (WSRM)-eviscerated and soaked in a solution containing 5% K-sorbate + 5% Na4P2O7 + 2% Na-citrate + 0.2% ascorbic acid (SSRM), were followed during chilling storage. Estimation of the predicted length of cold storage period as well as the marketing losses of the marketable mullet fish was also elucidated. The marketing losses of mullet fish at whole or retail market levels were also estimated by using a pre-tested questionnaire. Total volatile basic nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) increased concomitantly during cold storage of differently treated mullet fish. Moreover, lipid oxidation and hydrolysis products were followed by determining peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and ratio of absorbance (A400/A450) as well as acid value (AV) and free volatile fatty acids (FVFA). Mostly, these parameters show upward trend with different rates depending on the applied treatment. Soaking treatment greatly retarded fish spoilage during cold storage. As regards, SSRM samples withstand spoilage up to about 15 days compared to only 8 and 9 days for both RM and WSRM samples, respectively.
Effect of lipid damages on processed fish quality.
Authors: Augbourg Santiago P.
Published: March 2010

Marine species constitute a food group recognised as being easily damaged during the technological processing. Between the different damage pathways that can act on a marine food, a big attention has been given to the oxidation ability of lipids, as a result of supporting a high content on polyunsaturated fatty acids. In the present work, the role of lipid changes of a marine species on the quality degree is reviewed over the most employed technological processes (freezing and frozen storage, chilled storage, cooking, canning, drying, salting and smoking). The use of the main quality lipid indices for assessing the quality degree changes in each process is also analysed.
Quality of virgin olive oil as influenced by origin area.
Authors: Ranalli A. , De Mattia G. , Patumi M. , Proietti P.
Published: March 2010

To elucidate the weight and the influence of the origin area on the analytical and compositional variables of olive oil, an investigation was carried out. Five Italian geographical zones were chosen. They were in the neighbour of the: (i) Faculty of Agriculture of University of Perugia (UNI-PG); (ii) the Olive Growing Institute-National Research Council of Perugia (NRC-PG); (iii) the Experimental Olive Growing Institute of Spoleto (EOI-SPOL); (iv) the Agricultural Technical Institute of Pescia (ATI-PES); and (v) the Faculty of Agriculture of University of Florence (UNI-FL). From these areas, Frantoio, Leccino and Moraiolo olive variety samples were taken, which were processed by a mini oil-mill. The research results showed that the quality, typicality and shelf-life parameters and the flavour of the oils were largely influenced by the origin zone, i.e., by the climatic and pedologic factors of the production environment. The influence exerted on some oil constituent groups, as phenols, tocopherols, aromatic volatile compounds, and fatty acids, should be emphasized as these components are closely related to the quality and typicality of product. Some oil genuineness parameters were affected as well by the environmental variables.
Multivariate models to classify Tuscan virgin olive oils by zone.
Authors: Alessandri Stefano , Cimato Antonio , Modi Giuseppe , Crescenzi Angela , Caselli Simona
Published: March 2010

In order to study and classify Tuscan virgin olive oils, 179 samples were collected. They were obtained from drupes harvested during the first half of November, from three different zones of the Region. The sampling was repeated for 5 years. Fatty acids, phytol, aliphatic and triterpenic alcohols, triterpenic dialcohols, sterols, squalene and tocopherols were analyzed. A subset of variables was considered. They were selected in a preceding work as the most effective and reliable, from the univariate point of view. The analytical data were transformed (except for the cycloartenol) to compensate annual variations, the mean related to the East zone was subtracted from each value, within each year. Univariate three-class models were calculated and further variables discarded. Then multivariate three-zone models were evaluated, including phytol (that was always selected) and all the combinations of palmitic, palmitoleic and oleic acid, tetracosanol, cycloartenol and squalene. Models including from two to seven variables were studied. The best model shows by-zone classification errors less than 40%, by-zone within-year classification errors that are less than 45% and a global classification error equal to 30%. This model includes phytol, palmitic acid, tetracosanol and cycloartenol.
Oleochemicals I: Studies on the preparation and the structure of lithium soaps.
Authors: Shoeb Zein E. , Hammad Bayed M. , Yousef A. A.
Published: March 2010

Lithium stéarate, palmitate, myristate, laurate, caprate and caprylate were prepared by means of fusion method. Elementary analysis and the infrared absorptions spectra of the prepared lithium soaps as well as their X-ray diffractions and the thermogravimetric analyses were carried out. The anhydrous lithium salts of fatty acids with 12 carbon atoms or less showed thermal stability up to ca. 300 ± 78 °C depending on the chain length. On other hand the salts with 14 carbon atoms or more were decomposed at 126 ± 4 °C leading to formation of lithium carbonate. The homologous lithium soaps had very similar crystal structure among them and their metal -to- oxygen bonds were similar for the acyl chains between 8 and 18 carbons. However the angle of inclination of the molecular axes to the basal plane increased with the decreasing of the number of carbon atoms of the fatty acid chain, as determined by X-ray diffraction. In addition, the ionic character of the metal -to- oxygen bond was enhanced with the decrease of the number of carbon atoms as shown by infrared spectroscopy.
Influence of the critical parameters on the density estimate of some fatty acids by the Rackett's method.
Authors: Cedeño González F. O. , Prieto González M. M. , Alonso Suárez R. , Bada Gancedo J. C.
Published: March 2010

In this work a comparative study is carried out of the critical properties of temperature and pressure applied for the palmitic, stearic and oleic fatty acids, provided by different bibliographical sources. These properties are used in the Rackett's equation to estimate the density of the pure substances. The most commonly employed methods are described and applied in these cases to estimate these critical properties. A group of values of critical properties is selected to estimate the density using the Rackett's equation. The values of the critical properties that give a better estimation of the density, according to Rackett's equation, when compared with the experimental results are proposed. It is demonstrated that the selection of the critical properties influences in a decisive way in the estimation of physical properties by means of the Rackett's equation.
Analytical study of the composition of fatty acid of mustard and mustard sauces.
Authors: López Argüello E. , Barrera Vázquez C. , Bosch Bosch N.
Published: March 2010

In order to characterise mustard (whole seed or flour), mustard sauces with grain and mustard sauces in relation to their base seed, the concentrations of fatty acid were determinated by gas chromatography (GC). Erucic acid was the most abundant fatty acid component in mustard and mustard sauces (27,7 % and 24,6 % of total fatty acid content), followed by oleic acid (20,0 % and 21,1 %) and linolenic acid (16,3 % and 16.2%). The major acid in mustard sauces with grain was linolenic (21,4 %), followed by linoleic acid (20,3 %) and oleic acid (19,3 %). By means of correlation and discriminant analysis the samples have been grouped and classified. It is shown that fatty acid are usefull parameters for quality control analysis of mustard sauces.
Volatile constituents and oxidative stability of virgin olive oils: influence of the kneading of olive-paste.
Authors: Lercker G. , Frega N. , Bocci R. , Mozzon M.
Published: March 2010

Olive crushing, olive-paste kneading and separation of the oil the most important technological steps in olive oil production since they directly influence the future quality of the product. The contact between the oil and the olive-paste increases lipolysis and lipid oxidation, which are mainly due to the highly-active lipases present in the paste and the lipoxygenase action, respectively. The choice of the technological parameters is directly related to the oil future stability and its organoleptic characteristics. This study confirms and emphasizes the fact that the oxidative degradation, simultaneously with the well-known formation of the flavor compounds, is related to the time required for the separation of the oil-water emulsion. Loss of the natural antioxidants (minor polar components) by an oxidative effect was demonstrated to be also influenced by the time required for oil separation.