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11 Páginas.-- 6 Figuras.-- 2 Tablas, Virgin olive oil (VOO) stability needs to be controlled to guarantee that the oil keeps the quality declared on the label during distribution. However, the stability is changing as storage progresses and its estimation under moderate conditions are difficult to accomplish, due to the challenge of implementing rapid stability evaluation under the environmental variables given in long storage periods. The main objective of this work was to study the dynamic changes of VOO stability taking place during storage. For this purpose, a realistic storage approach of 27 months was designed. The stability of the oils was evaluated at different months by incubating the oil on mesh cell and scanning FTIR spectra during this incubation (mesh cell-FTIR). Although the storage of the oils did not show remarkable spectral changes, the spectra from mesh cell incubation showed variations at different months, which evidenced a change in the stability as the oil aged. The results revealed that the stability changes were abrupt during VOO ageing. In general terms, the results showed that these changes mainly occurred during the first 6 months. The incubation in mesh cell-FTIR spectroscopy is able to detect the minor chemical changes occurring in VOO during storage under moderate conditions., Grants AGL2015-69320-R and RTI2018-101546-B-C21/22 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”.

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Anthocyanins are the largest group of phenolic pigments, being effective hydrogen donors [...]

Since December 2019, we have been in the battlefield with a new threat to the humanity known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we describe the four main methods used for diagnosis, screening and/or surveillance of SARS-CoV-2: Real-time reverse transcription polymerase chain reaction (RT-PCR); chest computed tomography (CT); and different complementary alternatives developed in order to obtain rapid results, antigen and antibody detection. All of them compare the highlighting advantages and disadvantages from an analytical point of view. The gold standard method in terms of sensitivity and specificity is the RT-PCR. The different modifications propose to make it more rapid and applicable at point of care (POC) are also presented and discussed. CT images are limited to central hospitals. However, being combined with RT-PCR is the most robust and accurate way to confirm COVID-19 infection. Antibody tests, although unable to provide reliable results on the status of the infection, are suitable for carrying out maximum screening of the population in order to know the immune capacity. More recently, antigen tests, less sensitive than RT-PCR, have been authorized to determine in a quicker way whether the patient is infected at the time of analysis and without the need of specific instruments.

4 Figuras.-- 3 Tablas, Mesh cell is a rapid tool designed to monitor chemical changes that occurs as a consequence of oxidation at moderate conditions. In this study this accessory has been proposed for assessing virgin olive oil (VOO) stability by Fourier transform infrared (FTIR) spectroscopy. Monocultivar VOOs have been stored in mesh cells under different temperatures (at 23, 35, 65 °C) simulating the real conditions during storage and transport ( < 60 °C). In addition to temperature, the samples have been also stored in mesh cells at different light intensities (400, 1000, 7000 lx) to evaluate the resistance of the samples to photooxidation. The oil stability of the samples determined by using this accessory has been compared with the oil stability determined with the common methods used for this purpose (e.g. Rancimat). Despite the moderate conditions applied, mesh cell-FTIR spectra have revealed the formation of hydroperoxides and the subsequent formation of alcohols and aldehydes. Unlike other methods that require high temperature to accelerate the oxidation rate, mesh cell-FTIR has allowed differentiate the oil stability of the samples from a multi-factor perspective that includes several properties (temperature and light) and chemical species (primary and secondary oxidation products). The information obtained with this method can be relevant for optimizing handling (e.g. packaging and storage temperature) of VOO samples during their shelf life., Financial support by Fundación General CSIC (Programa ComFuturo) is acknowledged. This research has been also funded by AGL2015‐69320‐R project (Spanish State Secretariat of Research, Development and Innovation).

Synopsis The prediction of the stability of fats and oils during their “shelf life” depends on the complex combination of several variables; chemical composition together with packaging and environmental factors. This chapter explains the different mechanisms of oxidation depending on the individual factors responsible for the oxidation (oxygen, temperature and light) and also considers the effect of antioxidant and pro-oxidant agents in the evolution of those mechanisms. This chapter explains the advantages and disadvantages of the existing analytical methods to determine the oxidative stability of fats and oils. Finally, it presents the perspective to design an analytical procedure to determine the oxidative stability of fats and oils under real storage conditions, so avoiding the problems of the existing accelerated stability tests, which do not have a satisfactory correlation with the actual oxidation process. Different spectroscopic techniques applied to this approach are exposed.

10 Páginas.-- 5 Figuras.-- 1 Tabla, Vegetable oils are usually rich in unsaturated fatty acids which are susceptible to oxidation. The oxidation of vegetable oils has been one of the most widely studied fields within lipid chemistry, because it alters their properties and nutritive value, inducing the formation of harmful compounds and off-flavors. Moreover, oxidized vegetable oils display altered physical and chemical properties which are conferred by the newer oxygenated compounds they contain. This is the case of ozonized oils. Ozone is a powerful oxidizing agent that mainly acts on olefinic compounds which generate ozonides and other peroxidic species that can decompose into carbonilic fragments. The action of the oxidant and the later reactions depend on the chemical environment of the reaction as well as the carbonyl termination products resulting from peroxide cleavage. In recent years, sunflower oils with different fatty acid compositions have been developed by breeding and mutagenesis. They displayed higher contents of oleic, stearic or palmitic acids, which mainly alters their triacylglycerol composition. Therefore, four different sunflower oils, common, high oleic, high stearic-high oleic and high palmitic-high oleic, were oxidized with ozone and the progress of the reaction was monitored by measuring the level of oil peroxygenation and the changes in the oils’ fatty acid compositions. The peroxidated species formed during ozonation were studied by FT-IR spectroscopy. The main conclusions of this work were that ozonation caused linear oxidation rates that were similar in all the oils assayed. The addition of water accelerated oxidation, which tended to occur in linoleic polyunsaturated fatty acid The FT-IR pointed to the presence of ozonide-derived peroxides as the major oxygenated species., Caracterización de diferentes aceites de girasol ozonizados I. Cambios químicos durante la ozonización. Los aceites vegetales son generalmente ricos en ácidos grasos insaturados susceptibles de oxidación. La oxidación de aceites vegetales ha sido un campo de estudio intensivo dentro de la química de lípidos ya que este proceso altera sus propiedades y valor nutritivo, induciendo la formación de compuestos perjudiciales y olores y sabores indeseados. Además, los aceites vegetales oxidados muestran propiedades físicas alteradas conferidas por los nuevos compuestos oxigenados que contienen. Este es el caso de los aceites ozonizados. El ozono es un agente oxidante enérgico que actúa sobre los compuestos olefínicos generando ozónidos y otras especies peroxídicas que se descomponen en fragmentos carbonílicos. La acción del oxidante y las reacciones posteriores dependen del entorno químico de la reacción además de los productos carbonílicos de terminación resultante de la rotura de los peróxidos. El aceite de girasol común es rico en oleico y linoleico, susceptibles de ataque oxidativo por parte del ozono. En los últimos años, aceites de girasol con composiciones diferentes de ácidos grasos se han desarrollado por selección y mutagénesis. Estos aceites muestran altos contenidos en oleico, esteárico o palmítico, los cuales alteran de manera importante su composición de triglicéridos. Este trabajo es el primero de una serie de dos en los cuales se estudian los cambios físico-químicos que dichos aceites de girasol experimentan durante la ozonización. Así, se oxidaron con ozono cuatro aceites de girasol diferentes, girasol común, alto oleico, alto esteárico-alto oleico y alto palmítico-alto oleico. Se monitorizaron las cantidades absorbidas de ozono, los niveles de peroxidación y los ácidos grasos que experimentaron oxidación. Las especies formadas en el proceso se estudiaron mediante espectroscopía FT-IR. El modo en que la composición de ácidos grasos del aceite afectó a las cinéticas de oxidación y los productos resultantes se comentaron a la vista de los resultados., This work was funded by the project ICOOP-COOPB20153 from the Consejo Superior de Investigaciones Científicas (CSIC).

7 Figuras.-- 5 Tablas, In order to guarantee food integrity, testing methods should also include the tools needed to verify the geographical origin described on the label. In the particular case of virgin olive oil (VOO), regulatory bodies have yet to establish a standard for geographical identification. This manuscript describes a procedure based on Raman spectroscopy to identify the provenance of these oils based on a classification criterion (European vs non‐European VOOs). The sample collection is considered a relevant step in which multiple factors are taken into account (cultivar distribution, complexity of production in each location, new agricultural practices, and new/old cultivars). A total of 78 virgin olive oils collected around the world allow checking the classification accuracy of the model for identifying sample origin. The PLS‐model built around the Raman spectroscopic data is validated with a blind set of samples, and the results are evaluated in terms of false negative and false positive quality parameters. This study provides an analytical application to detect mislabeling and fraudulent practices related to the geographical provenance of virgin olive oils declared on the labels. Practical Applications: The results of this study provide a robust mathematical model to assess the origin of virgin olive oils (EU vs non‐EU) based on spectroscopic data. Nowadays, the extensive knowledge of olive oil chemical composition has proven that this composition varies according to pedoclimatic conditions, while non‐targeted methods can be proposed in geographical traceability for their ability to analyze the chemical profile of samples. However, it was deemed necessary to conduct a study through a collaborative work initiative. Thus, this study provides a strict evaluation of Raman spectroscopy through a defined strategy for evaluating non‐targeted methods for geographical identification., The authors would like to thank Mr. Quentin Arnould from CRA‐W for the assistance in FT‐Raman analysis. The project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement No. 613688 (FoodIntegrity).

The antioxidant activity of anthocyanins in food is well known. Numerous antioxidant assays have been proposed to measure the capacity of anthocyanins to prevent the oxidation process that naturally occurs. Different solvents, temperatures, and pH levels are applied in each assay, and these factors should be taken into account in order to obtain useful and reproducible results. The concentration and the structure of these compounds are directly related to their antioxidant capacity and their environment. However, the effectiveness of the anthocyanin ingestion against diseases is also influenced by its bioavailability. Novel methodologies that simulate the digestion process have been developed in order to facilitate the current knowledge of anthocyanins bioavailability. Studies highlight the potential synergy effect between parent compounds and their derivatives (metabolites, conjugated products, and microbe-generated metabolites). The aim of this review is to provide an overview of advantages and disadvantages of the most common methods to determine the antioxidant activity of anthocyanins, chemical structure, and concentration of these compounds in different edible fruits, vegetables, and plants; their bioavailability after intake; as well as the main therapeutic effect described in the scientific literature.

The present work aimed at examining the combined effect of chlorophyll content and light filtering packaging material on the photo-stability of virgin olive oil (VOO) via mesh cell-FTIR spectroscopy monitoring. Four different VOOs of Koroneiki cultivar differing in total chlorophyll content (∼12–46 mg/kg) were exposed in parallel to direct visible light (6000 lx, 24 °C, 344 h) and FTIR spectra were recorded periodically with or without applying light protection by an industrial filter used for packaging. Findings suggested that the protective role of light filtering material was more evident in the VOO with the lowest total chlorophyll content. Real time monitoring of VOO by mesh cell-FTIR was found to be a useful tool to follow the combined effect of pro-oxidant chlorophylls and the protective light filtering materials on the photo-oxidation process of VOO employing a minute sample amount., Financial support by Fundación General CSIC (Programa ComFuturo) is acknowledged. This work was also supported by Spanish State Secretariat of Research, Development and Innovation (AGL2015‐69320-R project). DT received funding for an Erasmus + Internship.

Developing new approaches to evaluate the stability of edible oils under moderate conditions is highly demanded today to avoid accelerated experiments that are not well correlated with actual shelf life. In particular, low intensity of visible light (photooxidation) needs to be integrated in stability studies, together with mild temperature. Thus, in this work, a strategy based on a >mesh cell>-FTIR to monitor chemical changes in lipid matrices using a combination of light and mild heating was applied. The results were compared with those obtained for the stability of triolein used as a molecular model. The study showed that the moderate light intensity (400 lx) at a low temperature (23 °C) has an early effect on the degradation of lipid matrices that is not observed when they are stored at 35 °C in the absence of light. Thus, the results proved that the exposure to light (400 lx) was more relevant than mild heating (35 °C) in monounsaturated lipid matrices, while polyunsaturated lipid matrices were more sensitive to mild heating.

9 Páginas; 6 Figuras; 1 Tabla, Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjusted-R2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil., Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espectroscopía de fluorescencia. La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R2-ajustado = 0,91), longitud de onda que coincide con la banda distintiva de pigmentos., This work was supported by the Spanish State Secretary for Research, Development and Innovation (AGL2015-69320-R).

Food traceability is a growing consumer concern worldwide. Traceability is undertaken primarily at the administrative level, where the use of advanced analytical tools is not available. Nevertheless, the determination of geographical origin is a requirement of the traceability system for the import and export of foodstuffs (EU regulation 178/2002). The topics covered in this book include the history of traceability; legislations and rules; the actual traceability techniques and the potential analytical techniques for food traceability such as molecular methods (e.g. DGGE, SSCP), next generation sequencers (NGS), bio-captors, chromatographic techniques, isotopic analysis that are used for discrimination of organic food, fish, oils. The chromatographic techniques help in the use of volatile compounds analysis. The isotope analysis helps in distinguishing between chicken meat and vegetable oils. Ambient mass spectrometry is used for studying mycotoxines and alkaloids in foodstuffs and their management, food and feed authentication in olive and other plant oils, and wine. Vibrational methods (e.g. NMR and NIRS) are used to trace food by global spectrum. The book reviews the current and future techniques including metabolomic techniques. (Resume d'auteur)

3 Figuras.-- 3 Tablas, The new health claim on >olive oil polyphenols> recently approved by the European Commission has produced a dramatic increase in the interest in these antioxidant compounds. Although this interest has been focused mostly on extra virgin olive oils (EVOOs), virgin olive oils (VOOs) qualified as having non-oxidative sensory defects, mostly caused by fermentation and the action of fungi on olives, may still have a considerable amount of phenols, even though their sensory quality is not flawless. This study is focused on the phenol composition of all the VOO categories: EVOOs with their ample variability in phenolic composition, VOOs with slight defects, lampante virgin olive oils (LVOO), and reference materials of defective VOOs. The average content of phenols in the analyzed EVOOs (410±16mg/kg) is higher than the recommended consumption by the health claim (250mg/kg). VOOs qualified with non-oxidative defects contain high concentrations of phenols (234±27mg/kg), but only samples characterized by the wet-wood sensory defect show concentrations of phenols close to 250mg/kg. Practical application: This study has demonstrated that VOOs with slight sensory defects still have a high concentration of phenols, providing antioxidant properties regarding health benefits and stability. The health claim should be not only applied to the extra virgin olive oil category, but also to some virgin olive oils with sensory defects., This work was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT‐EU, Spanish and European Government), Spanish State Secretary for Research (Ramón y Cajal Program) and FEDER (CE) in the projects AGL 2011‐30371‐C01‐01 and ‐02. Extra virgin olive oils were supplied by Spanish producers: Vaga de la Estrella SA, Oleoestepa SCA, Aceites 1881 y Aceites del Sur. Commercial virgin olive oils were supplied by FAECA. Standards of defects were supplied by the International Olive Council.

18 Tablas; 22 Páginas, The definitions of olive oil categories are common or very similar for all the international regulatory bodies, and in many cases the text is even literally the same. However, the values of some parameters which chemically define the different categories do not have the same degree of agreement. These disagreements mean a difficult task for importers and exporters who have to deal with these differences when they need to defend the quality and genuineness of their product. This work analyzes the differences found when scrutinizing the current trade standards and regulations from a critical viewpoint, with comments and useful tips for improving the current International Olive Council methods when possible, as well as alternatives from non targeted techniques. The values of precision associated with the International Olive Council methods are also examined and the need for re-validating methods to update the analytical quality parameters is discussed., Estudio de las diferencias entre las normas comerciales dentro y fuera de Europa. Las definiciones de las categorías de aceite de oliva son comunes o muy similares para todos los organismos reguladores internacionales y, en muchos casos, el texto es incluso literalmente el mismo. Sin embargo, los valores de algunos parámetros que definen químicamente las diferentes categorías no tienen el mismo grado de acuerdo. Estos desacuerdos originan una tarea difícil para los exportadores e importadores que tienen que lidiar con estas diferencias para demostrar la calidad y la autenticidad de su producto. Este trabajo analiza las diferencias encontradas al examinar las normas y regulaciones comerciales actuales desde un punto de vista crítico, con comentarios y sugerencias útiles para mejorar los métodos actuales del Consejo Oleícola Internacional, cuando ha sido posible, así como alternativas de técnicas no dirigidas a analitos específicos. También se examinan los valores de precisión asociados a los métodos del Consejo Oleícola Internacional y se discute la necesidad de volver a validar los métodos para actualizar los parámetros de calidad analítica., The research leading to these results has received funding from the European Union’s Seventh Framework Program for research, technological development and demonstration under grant agreement No. 613688 (Food Integrity project).

Capítulo 13; 29 Páginas, This chapter discusses the strength, weaknesses and alternatives of the standard analytical determinations available to verify authenticity of virgin olive oil. The classical adulterations can be detected at low percentages by the combination of standard methods proposed to guarantee the quality and purity of olive oil described in the regulations. Other adulterations that are more sophisticated require further studies. The authenticity of olive oil is also linked to traceability, and in this respect, geographical traceability has brought new methods into play. Some of these methods that have been suggested to develop a traceability system for olive oil are discussed. This chapter also exposes some recommendations to develop efficient authenticity methods that can be useful in the detection of current authenticity and traceability problems in the olive oil sector based on: (i) identifying chemical markers with causal relationships; (ii) validating the proposed methods in an appropriate way; and (iii) creating large databases that included the peculiarities associated with the cultivar and with the agricultural practices.

Current and future legislation regarding the use of processed animal proteins in animal nutrition requires the availability of robust analytical methods that allow for proper implementation of corresponding legal restrictions. Near-infrared microscopy (NIRM) is a spectroscopic method that allows for the differentiation between meat and bone meal and fishmeal and it is assumed that the different content and composition of the fat is one of the factors responsible for the observed differences. Here a study of the NIRM method has been conducted in order to check for the influence of intentionally introduced reduction of the fat content on the capability of the NIRM method to correctly classify defatted samples. This has practical implications, since processed animal proteins may be defatted by solvents under real world conditions. The results confirmed that the scope of the NIRM method could be successfully extended to samples that have been previously extracted with nonpolar solvents. Only after the use of stricter techniques such as extraction with chlorinated solvents or hydrolysis the NIRM method produced a higher portion of wrong classifications. However, since these extraction techniques are not often used under real world conditions, the impact upon the use of the NIRM method in the feed sector for the specific application of the differentiation between meat and bone meal and fishmeal is minor.

Trade standards are continuously updated to give plausible solutions to situations created by fraudsters who apply the most sophisticated procedures to their objectives of olive oil adulteration. Clustered inside targeted and profiling approaches, methods based on spectroscopic, isotopic and chromatographic techniques are reviewed. Chromatographic methods, most of them being official methods, compete with newer methods based on spectroscopic, isotopic and trace element techniques for ensuring that the pace of research in the detection of malpractices is rapid enough. The speed of the analyses, the need of statistical interpretation of the results, the quality parameters of the methods, limit of detection of the adulterants, and the applicability range among others are on the basis for the absolute and comparative analyses of the most known methods, which results are unpacked in the paper. The new frontiers of research in the field of olive oil authenticity are also dissected together with the challenges for the near future. The extensive and deep analysis of the methods for quantifying the chemical compounds responsible for olive oil authenticity will contribute to a better comprehension of the complex analytical world of olive oil for the analyst working with this food product for the first time, as well as for experienced professionals.

14 Páginas.-- 4 Figuras.-- 3 Tablas, Functional magnetic resonance imaging (fMRI) has been used to collect information from neurons that receive direct input from olfactory bulbs when subjects smell virgin olive oil. The pleasant aroma of three extra virgin olive oils (var. Royal, Arbequina and Picual) and three virgin olive oils with sensory defects (rancid, fusty and winey/vinegary) were presented to 14 subjects while a fMRI scan acquired data from the brain activity. Data were subjected to a two-sample t test analysis, which allows a better interpretation of results particularly when data are studied across different subjects. Most of the activations, which were located in the frontal lobe, are related to the olfactory task regardless of the hedonic component of perception (e.g. Brodmann areas 10, 11). Comparing the samples with pleasant and unpleasant aromas, differences were found at the anterior cingulate gyrus (Brodmann area 32), at the temporal lobe (Brodmann area 38), and inferior frontal gyrus (Brodmann area 47), while intense aromas activated Brodmann area 6. The actual perceptions described by the subjects and the concentration of the odorant compounds in the samples were considered in the interpretation of the results. Copyright, This work was supported by the State Secretariat for Research, Development and Innovation (Ramón y Cajal Program, AGL2008-01411 and AGL2011-30371-C02-01/02 projects).

[EN] The protected designations of origin (PDOs) have proven to be a successful regulatory framework to protect singular virgin olive oils that have distinctive properties. However, sometimes the registration of new PDOs and the demarcation of the geographical areas associated to them are based on administrative issues rather than objective chemical data. In this work, the chemical compositions of fatty acids, hydrocarbons, alcohols, sterols and methyl sterols have been used to prove the differences between a PDO virgin olive oil and the oils produced in the surrounding areas. Three cases were studied (PDO Estepa, PDO Montoro-Adamuz, and Campiña de Jaén) which actually mean three different situations that combine variations in cultivar and pedoclimatic characteristics. The chemical compounds that showed a better ability to classify samples were selected by the Brown-Forsythe test, a particular modification of ANOVA, and this ability was later visualized in a principal component analysis. The oils from PDOs Estepa and Montoro-Adamuz showed clear differences in their chemical compositions, while the oils from Campiña de Jaén formed a group of samples which greatly overlapped with the oils from surrounding areas, probably due to the lack of variation in cultivar (Picual) throughout the province of Jaén., [ES] Las denominaciones de origen protegidas (DOPs) han demostrado ser un marco de regulación de éxito para la protección de aceites de oliva vírgenes singulares que tienen propiedades particulares. Sin embargo, en ocasiones, el registro de DOPs nuevas y la demarcación de las áreas geográficas asociadas a ellas se basan en aspectos administrativos más que en datos químicos objetivos. En este trabajo se emplea la composición química de ácidos grasos, hidrocarburos, alcoholes, esteroles y metilesteroles para demostrar las diferencias entre aceites de oliva vírgenes de denominaciones de origen protegidas y los aceites producidos en las áreas circundantes. Se han estudiado tres casos (DOP Estepa, DOP Montoro-Adamuz y Campiña de Jaén) que realmente representan tres situaciones que combinan variaciones de cultivar y de características pedoclimáticas. Se seleccionaron, con el test de Brown-Forsythe, una modificación de ANOVA, los compuestos químicos que mostraban buenas características para la clasificación de muestras, y esta capacidad se comprobó posteriormente mediante análisis de componentes principales. Los aceites de las DOPs Estepa y Montoro-Adamuz mostraron diferencias claras en su composición química, mientras que los aceites producidos en Campiña de Jaén formaron un grupo de muestras que se solapó en gran medida con los aceites de las áreas geográficas próximas, probablemente debido al casi exclusivo monocultivar (Picual) en toda la provincia de Jaén., This research has been partially funded by the Spanish Ministry of Science and Innovation (Ramón y Cajal Program and AGL2008-01411).

Organic production benefits from fair competition and sustained consumer confidence. The latter can only be assured by paper trailing and verification assessments. Traditional analytical strategies for guaranteeing quality and uncovering adulteration have relied on the determination of the amount of a marker compound or compounds in a material and a subsequent comparison of the value(s) obtained with those established for equivalent material. Since it is unlikely to find a unique marker that allows discrimination between organic and conventional produce, selective fingerprinting (profiling) combined with chemometrics is a more promising approach. In this study, carotenoid High Performance Liquid Chromatography-Diode Array Detection profiling combined with k-nearest neighbour classification chemometrics was used to predict the production system (organic vs. non-organic) of chicken eggs. A proof-of-concept set (training set for the model) was composed of eggs from 24 organic farms, 12 free range, and 12 barn farms in the Netherlands. The identities of organic, free range, and barn eggs were predicted with success rates of 100%, 100%, and 84%, respectively. The identity of eggs determined using an additional market test set with eggs from 12 organic, 12 free range, and 12 barn farms originating from the Netherlands and New Zealand resulted in correct classifications for 35 of the 36 samples. The results of this study indicate that this fingerprint approach is a promising tool for analytical verification of the production system of organic eggs. © 2010 Elsevier Ltd. All rights reserved., This study has been carried out with financial support of the Dutch Department of Agriculture, Nature and Food Quality (WOT Voedselveiligheid).

The monitoring of frying oils by an effective and rapid method is one of the demands of food companies and small food retailers. In this work, a method based on ATR-FTIR has been developed for monitoring the oil degradation in frying procedures. The IR bands changing during frying in sunflower, soybean, and virgin olive oils have been examined in their linear relationship with the content of total polar compounds, which is a preferred parameter for frying control. The bands assigned to conjugated and isolated trans double bonds that are commonly used for the determination of trans content provided the best relationships. Then, the area covering 978−960 cm−1 was chosen to build a model for predicting polar material content for the particular case of virgin olive oil. A virgin olive oil was heated up to 94 h, and samples collected every 2 h constituted the training set. These samples were analyzed to obtain their FTIR spectra and to determine the composition of fatty acids and the content of total polar compounds. The excellent results predicting the polar material content (adjusted R2 0.997) was successfully validated with an external set of samples. The analysis of the fatty acid composition confirmed the relationship between the trans content and the content of total polar compounds.

The evolution of the fluorescent compounds during the thermal deterioration of virgin olive oil is not yet well-known. Samples of heated virgin olive oils collected from a fryer every 2 h up to 94 h were analyzed to study their fluorescence spectra as well as the evolution of the concentrations of α-tocopherol and individual phenols by high-performance liquid chromatography (HPLC). The regions of the fluorescence spectra of the heated oils, diluted in hexane at 1%, were explained by the content of these compounds with regression coefficients higher than 0.90 (R2 adjusted). The fluorescence intensity recorded at 350 nm and the wavelength of the spectrum maximum in the range of 390−630 nm also allowed for the explanation of the increase of the percentage of polar compounds during the experiment. On the other hand, the spectra of the undiluted heated oils indicated that the maximum of the spectrum of any undiluted oil at 490 nm or beyond is related to a percentage of the polar compounds higher than 25%, which is the maximum percentage accepted for edible oils used in frying processes., The authors express their indebtedness to Junta de Andalucía for financial support of this research (Project AGR678).

This work studies the relationship between 45 volatile compounds and 17 sensory attributes (13 flavour perceptions) of dry-cured hams. Volatile compounds were quantified by SPME-GC while the sensory assessment was carried out by 13 panellists. GC-sniffing was used to determine the odour impact zones of the chromatogram. The odour thresholds of the volatile compounds and their sensory characterisation were determined by dilution analysis. Six sensory attributes (acorn odour and flavour, rancid odour, rancid taste, fat rancid and fat pungent flavours) were explained by regression equations (adjusted –R2 ⩾ 0.70) based on ten compounds: benzaldehyde, 2-heptanone, hexanal, hexanol, limonene, 3-methylbutanal, 3-methylbutanol, 2-nonanone, octanol, pentanol. Acorn flavour attribute was successfully emulated by mixing the volatile compounds selected by the equation. Its odour was evaluated by assessors that gave a sensory description that matches with the target. All the procedures performed for the elucidation of volatile-attribute relations showed a basic agreement in their results.

One of the main challenges that virgin olive oil producers face today is an accurate prediction of the sensory quality of the final product prior to the milling of the olives. The possibility that olive paste aroma can be used as a predictive measurement of virgin olive oil quality is studied in this paper. The study was centered on distinguishing the aroma of olive pastes that produced virgin olive oils without sensory defects from the aroma of olive pastes the virgin olive oils of which showed sensory defects. Olive pastes were analyzed by solid-phase microextraction-gas chromatography and a sensor system based on metal oxide sensors. Forty-four volatile compounds were identified in olive pastes, all of them being also present in virgin olive oil. Six volatile compounds - acetic acid, octane, methyl benzene, (E)-2-hexenal, hexyl acetate and 3-methyl-1-butanol - distinguished both kinds of pastes with only five misclassified samples. Five metal oxide sensors were able to classify the olive pastes with only two erroneous classifications.

© 2015 American Chemical Society. This paper evaluates the performance of the current analytical methods (standard and widely used otherwise) that are used in olive oil for determining fatty acids, triacylglycerols, mono- and diacylglycerols, waxes, sterols, alkyl esters, erythrodiol and uvaol, tocopherols, pigments, volatiles, and phenols. Other indices that are commonly used, such as free acidity and peroxide value, are also discussed in relation to their actual utility in assessing quality and safety and their possible alternatives. The methods have been grouped on the basis of their applications: (i) purity and authenticity; (ii) sensory quality control; and (iii) unifying methods for different applications. The speed of the analysis, advantages and disadvantages, and multiple quality parameters are assessed. Sample pretreatment, physicochemical and data analysis, and evaluation of the results have been taken into consideration. Solutions based on new chromatographic methods or spectroscopic analysis and their analytical characteristics are also presented.

8 Páginas.-- 6 Figuras.-- 1 Tabla, Nowadays there is a strong need for methods capable of differentiating distillers dried grains with solubles (DDGS) according to their geographical and/or botanical origin. In this study, near infrared microscopy (NIRM) has been applied to differentiate corn and wheat DDGS samples and to differentiate corn DDGS from USA, Europe and China. Two multivariate prediction models have been developed for the discriminations. The models have been validated by cross validation and with an external set of samples and have been used to predict the botanical and geographical origin. Furthermore the probability of wrong prediction of the models has been calculated, to assess their performance profile. The prediction showed very good capability of the model to classify samples according to their botanical origin, whereas satisfying results were exclusively obtained when separating samples from China against the pooled set of samples from USA and Europe., The research presented in this paper has received funding from the European Commission's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 265702 (QSAFFE-project). The authors wish to acknowledge the help of Nanta S.A. Madrid, and Servizo de Seguridade Alimentaria nas Productions Ganadiras (Xunta de Galicia) for providing samples with different botanical origins.

6 Tablas.-- 1 Figura, In the context of products from certain regions or countries being banned because of an identified or non-identified hazard, proof of geographical origin is essential with regard to feed and food safety issues. Usually, the product labeling of an affected feed lot shows origin, and the paper documentation shows traceability. Incorrect product labeling is common in embargo situations, however, and alternative analytical strategies for controlling feed authenticity are therefore needed. In this study, distillers' dried grains and solubles (DDGS) were chosen as the product on which to base a comparison of analytical strategies aimed at identifying the most appropriate one. Various analytical techniques were investigated for their ability to authenticate DDGS, including spectroscopic and spectrometric techniques combined with multivariate data analysis, as well as proven techniques for authenticating food, such as DNA analysis and stable isotope ratio analysis. An external validation procedure (called the system challenge) was used to analyze sample sets blind and to compare analytical techniques. All the techniques were adapted so as to be applicable to the DDGS matrix. They produced positive results in determining the botanical origin of DDGS (corn vs. wheat), and several of them were able to determine the geographical origin of the DDGS in the sample set. The maintenance and extension of the databanks generated in this study through the analysis of new authentic samples from a single location are essential in order to monitor developments and processing that could affect authentication., The research described in this paper was funded by the EU Seventh Framework Programme (FP7/2007‐2013) under Grant Agreement 265702, QSAFFE project (www.qsaffe.eu). The information in the paper reflects the authors’ views; the EC is not liable for any use of the information contained herein. The authors wish to thank all those who provided samples, particularly the QSAFFE project partners, PROVIMI, THOMPSON, and CAU, as well as those who collected and dispatched samples within the partner network, particularly Rudi Krska (IFA-Tulln) and all the technicians who conducted the analyses. The authors also wish to thank PROVIMI for providing the DDGS NIR spectral databases and Eric Janssen (CRA-W) for the PCR assessment of the botanical origin of mixed samples.

The physicochemical phenomena that explain the sensing mechanisms of gas sensors have been extensively investigated. Nevertheless, it is arduous to interpret the sensor signals in a practical approach when they response to complex mixtures of compounds responsible for food aroma. Thus, the concomitant interactions between the volatiles and the sensor give up a single response affected by synergic and masking effects between compounds. An experimental procedure is proposed to determine the individual contribution of volatile compounds in the sensor response, illustrated with the examples of aroma of dry-cured hams and metal oxide sensors. The results from mathematical correlations and the analyses of pure standards are previously analyzed to describe the behavior of sensors when interacting with individual compounds. A sensor based olfactory detector (SBOD) entailing the use of a capillary column connected to a sensor array as non-destructive detector in parallel with the flame detector served to provide definitive information about the individual contribution of volatile compounds to sensor responses. The sensor responses in this system, which is referred to as sensorgram, were interpreted by taking into account the volatile composition of the samples determined by GC. © 2013 Elsevier B.V., This research has been partially funded by the Spanish State Secretary for Research (Ramón y Cajal Program, AGL2008-01411 and AGL2011-30371-C02-02).

Spectroscopic techniques have emerged in food analysis as rapid and very useful tools for determining a great variety of chemical parameters. They provide elegant, fast, and easy-to-use solutions to tackle analytical challenges as well as a cost reduction. They offer the possibility to control a high number of parameters and properties simultaneously at the different steps of the food and feed chains and can be applied online. Huge instrumental and computer improvements have contributed to the development of near-infrared (NIR), mid-infrared (MIR), Raman, and fluorescence spectroscopies.

The fluorophores present in virgin olive oil evolve during any thermoxidation process and thereby fluorescence spectroscopy can be used as a straightforward approach to study the oxidative degree of oils. Samples of heated virgin olive oils collected from a fryer every two hours up to 94h were analyzed to study their excitation-emission matrix (EEM) and the evolution of the fluorescent composition during the thermoxidation process. The potential usefulness of EEM to study thermoxidized virgin olive oils has been explored. For this purpose, parallel factor analysis (PARAFAC) was used to interpret the results. The emission profile obtained from three-factor PARAFAC model calculated for 47 samples of thermoxidized oil in the range of λ ex=250-298nm and λ em=300-700nm allows the decomposition of the fluorescence landscape in specific information about phenols, pigments and oxidation products respectively. The chemical interpretation from the PARAFAC model was checked with chemical analysis of phenols, tocopherols and chlorophyll pigments. © 2011 Elsevier Ltd.

New cultivars with greater adaptability to modern irrigated (super-) high-density orchards and producing good sensory quality oils are highly demanded by an olive oil industry in continuous change. This work analyzes olive oil sensory quality, in terms of phenols and volatiles that are responsible for virgin olive oil flavor, for three cultivars: Picual, which is used for >15% of world olive oil production; Arbequina, which is cultivated worldwide; and the new progeny Sikitita, which is derived from the other two. The availability of data at three different levels of ripeness allowed quantifying the genetic and olive maturity effects on the oil composition by means of the analysis of variance (ANOVA) and principal component analysis (PCA). Phenols and volatiles varied greatly both with genotype and, to a lesser extent, with olive maturity. With regard to the phenol profile, the crossbred cultivar Sikitita showed a higher degree of similarity with the Arbequina variety. The volatile composition of var. Sikitita, however, varies significantly from that of Arbequina, in the first stages of the olive ripeness, and becomes more similar to that of Picual as the level of ripeness increases., This research was carried out in the course of Project AGL2008-01411 funded by the Spanish Ministry of Science and Innovation.

7 pages, 1 figure, 2 tables., [EN] The study involved the sensory assessment of 8 Iberian hams from the main producer zones and the analysis of their volatile composition by SPME-GC. The latter analysis was carried out independently on 4 well defined locations of the ham (subcutaneous fat, and biceps femoris, semitendinosus, and semimembranosus muscles) in order to know their possible partial contribution to the whole ham aroma. The relation between volatile compounds and sensory attributes was established by the procedure of statistical sensory wheel (SSW), generating 4 different plots, each one of them referring to one of the ham locations. The volatile compounds explain similar information of the sensory attributes independently of the part of the ham from which they are produced although the volatiles quantified in semitendinosus muscle and subcutaneous fat seem to contribute slightly more than the other parts to the sensory profile determined by the panellists.Volatiles compounds with significance in the ham aroma were 3-methylbutanol, hexanal, octanol, nonanol, 2-heptanol, among many others, although their contribution to the aroma varies depending on the location., [ES] El estudio se ha llevado a cabo con 8 jamones ibéricos de las principales zonas productoras mediante panel sensorial y análisis de la fracción volátil con SPME-GC. Los últimos análisis fueron llevados a cabo en cuatro localizaciones independientes del jamón (grasa subcutánea, y los músculos bíceps femoris, semitendinosus y semimembranosus) para conocer sus posibles contribuciones parciales al aroma completo del jamón. La relación entre compuestos volátiles y atributos sensoriales ha sido establecida mediante el procedimiento estadístico de la rueda sensorial (SSW), generando una representación gráfica por cada localización. Los compuestos volátiles explican los mismos atributos sensoriales independientemente de la parte del jamón en que se generen aunque los volátiles cuantificados en el músculo semitendinoso y la grasa subcutánea parece que contribuyen ligeramente más que las otras partes al perfil sensorial detectado por los panelistas. Los compuestos volátiles con significación en el aroma del jamón fueron 3-metilbutanol, hexanal, octanol, nonanol y 2-heptanol entre muchos otros, aunque sus contribuciones al aroma varían dependiendo de la localización.

A total of 33 virgin olive oil samples of the two main Tunisian cultivars, Chemlali and Chetoui, were characterized by their volatile compounds. The olive oil samples were obtained from olives harvested at four stages of ripeness in costal and inland farms of different geographical places. Major volatiles, mostly C6 and C5 compounds produced from linolenic and linoleic acids through the lipoxygenase cascade, were quantified by solid-phase microextraction-gas chromatography. Mathematical procedures allowed for the determination of the volatiles that not only are able to discriminate the olive oils by their olive cultivar (hexanal, E-2-hexenal, and total ketones) and ripeness (pentanal and 1-penten-3-one) but also contribute to their distinctive aroma. Finally, an electronic nose based on metal oxide sensors was checked for a rapid and at-line implementation of Tunisian olive oil varietal traceability. The classification of the samples by the sensors was explained by their sensitivity to volatiles E-2-hexanal, hexanal, 1-penten-3-one, ethanol, and Z-3-hexenol. Multivariate procedures of discriminant analysis and principal component analysis were used in the study.

7 pages, 7 tables, 2 schemes., [EN] 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)., [ES] Dos métodos analíticos, basados en la diferencia entre triglicéridos teóricos y experimentales y razones entre algunos esteroles libres y esterificados, se han evaluado para determinar su utilidad detectando la presencia de pequeñas cantidades de cualquier tipo de aceite de avellana en aceite de oliva. La validación de los métodos se llevó a cabo mediante validación interna y externa, la última llevada a cabo con 21 laboratorios diferentes en tres estudios colaborativos. La información resultante sugiere un valor de corte en la detección de la adulteración del 8% para el método basado en triglicéridos y del 10% para el basado en la cuantificación de esteroles. El primero también muestra mejores valores de los parámetros de fiabilidad en reproducibilidad; por ejemplo, número de falsos positivos, selectividad (90% vs. 82%) e índice de Youden (0.81 vs. 0.77).

Fourier transform infrared (FTIR) spectroscopy has been proposed to study the degradation of virgin olive oils (VOO) in samples undergoing thermoxidation. The polar and nonpolar fractions of oxidized oils have been analyzed by FTIR to provide further information on the minor spectral changes taking place during thermoxidation. This information assists in the interpretation of the spectra of the samples. For this purpose polar and nonpolar fractions of 47 VOO samples thermoxidized (190 °C) in a fryer were analyzed by FTIR. The time-course change of the band area assigned to single cis double bonds was explained by their correlation with the decrease in oleic acid (adjusted-R2=0.93). The bands assigned to the hydroxyl groups and the first overtone of ester groups was better studied in the spectra collected for the polar and nonpolar fractions, respectively. The bands assigned to peroxide, epoxy, tertiary alcohols and fatty acids were clearly observed in the spectra of the polar fraction while they are not noticeable in the spectra of the oils. © 2014 CSIC., This research has been partially funded by the Spanish State Secretary for Research (Ramón y Cajal Program, AGL2008-01411 and AGL2011-30371-C02-02)