Assessment of Virgin Olive Oil Adulteration by a Rapid Luminescent Method

The adulteration of virgin olive oil with hazelnut oil is a common fraud in the food industry, which makes mandatory the development of accurate methods to guarantee the authenticity and traceability of virgin olive oil. In this work, we demonstrate the potential of a rapid luminescent method to characterize edible oils and to detect adulterations among them. A regression model based on five luminescent frequencies related to minor oil components was designed and validated, providing excellent performance for the detection of virgin olive oil adulteration

A neuroimaging study of pleasant and unpleasant olfactory perceptions of virgin olive oil

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 cingu�late 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.Estudio mediante neuroimagen de percepciones olfativas agradables y desagradables de aceites de oliva virgen. La imagen por resonancia magnética funcional (fMRI) ha sido empleada para estudiar la información de la respuesta cerebral producida al estimular las neuronas que participan en el proceso olfatorio tras percibir el aroma del aceite de oliva virgen (AOV). Se utilizó fMRI para la adquisición de los datos de la actividad cerebral de 14 sujetos a los que se presentaron tres aceites de oliva vírgenes de aroma agradable (var. Royal, Arbequina and Picual) y tres aceites de oliva vírgenes con defectos sensoriales (rancio, atrojado, avinado/avinagrado). Los datos se sometieron a una prueba t para observar diferencias entre dos grupos, la cual permite una mejor interpretación de los resultados, particularmente cuando los datos se estudian a través de diferentes sujetos. La mayoría de las activaciones, que se localizaron en lóbulos frontales, se relacionaron con la tarea olfatoria independientemente de la componente hedónica de la percepción (por ejemplo, áreas Brodmann 10, 11). Al comparar las muestras con aromas agradables y desagradables, se encontraron diferencias significativas en el giro cingulado anterior (área Brodmann 32), el lóbulo temporal (área Brodmann 38) y el giro frontal inferior (área Brodmann 47), mientras que los aromas más intensos activaron el área Brodmann 6. En la interpretación de los resultados se tuvo en cuenta tanto la percepción descrita por los sujetos como las concentraciones de los compuestos volátiles en las muestras.Ramón y Cajal Program AGL2008-01411, AGL2011- 30371-C02-01/02

Wild fruits and pulps of frozen fruits: antioxidant activity, polyphenols and anthocyanins

Os sucos de frutas tropicais conquistam cada vez mais o mercado consumidor, sendo o Brasil um dos principais produtores. Existe grande diversidade de produtos derivados de frutos e constante inserção de novos produtos no mercado de consumo, os quais, na maioria das vezes, ainda não foram devidamente pesquisados com respeito às suas propriedades e atividades benéficas à saúde. Neste trabalho, objetiva-se determinar algumas propriedades de frutos tropicais silvestres in natura e polpas de frutos comercializados congelados. Para determinar a atividade antioxidante, utilizou-se o método do radical 2,2-difenil-1-picrilhidrazilo (DPPH•); para determinar os polifenóis totais, o método de Folin-Ciocalteu e, para as antocianinas, o método da diferença de pH. As polpas de frutas analisadas foram de amora, uva, açaí, goiaba, morango, acerola, abacaxi, manga, graviola, cupuaçu e maracujá; e os frutos silvestres, jambolão e baguaçu. Representada em TEAC (atividade antioxidante equivalente a Trolox), a atividade antioxidante global das polpas oscila entre mínimos e máximos 0,5 e 53,2μmol g-1, enquanto que, representada em VCEAC (atividade antioxidante equivalente a vitamina C), entre mínimos e máximos de 64,8 e 1198,9mg100g-1. Para os extratos de polpa dos frutos in natura, a atividade antioxidante oscila entre 13,3 e 111,2μmol g-1 (TEAC) e entre 42,8 e 2533,1mg 100g-1 (VCEAC). Em ordem decrescente de capacidade antioxidante, encontra-se: acerola> manga> morango> uva> açaí> goiaba> amora> graviola> maracujá> cupuaçu> abacaxi. Os frutos de baguaçu apresentam maior atividade antioxidante que os de jambolão.The tropical fruit juices are gaining ever greater space in the consumer market, and Brazil is one of the main producer countries in this market. There is a great diversity of products derived from fruits and new products for consumption are launched constantly, often without the necessary research into their active properties and beneficial activities to health. The objective of this work was to determine some properties of in natura wild tropical fruit and commercialized frozen fruit pulps. Considered as a method of great applicability, 2.2-difenyl-1-picrylhydrazyl radical (DPPH•) was used to determine the antioxidant activity; the Folin-Ciocalteu method was used to determine the total polyphenol concentration and the pH difference was used for anthocyanins. The fruit pulps of greater market consumption in Southern Brazil under analysis were mulberry, grapes, açai, guava, strawberry, acerola, pineapple, mango, graviola, cupuaçu and passion fruit, and the wild fruits were jambolão and baguaçu. When represented in TEAC (Trolox equivalent antioxidant activity), the global antioxidant activity of the frozen fruit pulps oscillated between minimal and maximal TEAC values of 0.5 and 53.2μmol g-1, or between 64.8 and 1198.9mg100 g-1 for VCEAC (vitamin C equivalent antioxidant activity) values. For the in natura fruit pulp extracts, TEAC oscillated between 13.3 and 111.2μmol g-1, and between 42.8 and 2533.1mg100g-1 for VCEAC. The descending order of antioxidant capacity was acerola> mango> strawberry> grapes> açaí> guava> mulberry> graviola> passion fruit> cupuaçu> pineapple. Among the wild fruits, baguaçu presents a greater antioxidant activity than jambolão

Tracking Sensory Characteristics of Virgin Olive Oils During Storage: Interpretation of Their Changes from a Multiparametric Perspective

Virgin olive oil is inevitably subject to an oxidation process during storage that can affect its stability and quality due to off-flavors that develop before the oil surpasses its ‘best before’ date. Many parameters are involved in the oxidation process at moderate conditions. Therefore, a multiparametric study is necessary to establish a link between physico-chemical changes and sensory quality degradation in a real storage experiment. In this context, a storage experiment of 27 months was performed for four monovarietal virgin olive oils, bottled in transparent 500-mL PET bottles and subjected to conditions close to a supermarket scenario. Volatile composition, quality parameters and phenolic compounds were determined monthly. Simultaneously, an accredited sensory panel assessed their sensory characteristics. The stability of the fresh samples was also studied with the oxidative stability index (OSI) and mesh cell-FTIR. (E)-2-hexenal, (Z)-3-hexen-1-ol and (E)-2-hexen-1-ol were identified as markers of the fruity attribute. Hexanal and nonanal were also identified as compounds that were associated with the rise of median of defect during storage. Some disagreements were observed between the sensory assessment and the OSI analyzed by Rancimat. However, the increase of concentration of rancid markers agreed with the increase of aldehyde band measured with mesh cell-FTIR.Spanish Research State Agency (research projects AGL2015-69320-R and RTI2018-101546-B-C21

La plataforma virtual webCT en la enseñanza de la disciplina "Análisis químico" en la licenciatura de Farmacia: evaluación de la actitud del alumnado.

El Departamento de Química Analítica de la Facultad de Farmacia de Sevilla ha desarrollado una experiencia piloto sobre el uso de la plataforma virtual WebCT en la asignatura “Análisis Químico". El presente trabajo pretende reflejar la acogida y actitud del alumnado frente a esta nueva herramienta de aprendizaje. La experiencia se ha llevado a cabo sobre un grupo piloto, con un total de 106 alumnos matriculados. Con este objetivo, durante el curso académico se han elaborado dos encuestas (de opinión/satisfacción y de actitud con escala Likert). Los resultados obtenidos muestran una elevada utilización de algunas de las herramientas puestas a su disposición, así como, un elevado grado de satisfacción.The Department of Analytical Chemistry of the Faculty of Pharmacy of Seville has developed a pilot experience on the use of the virtual platform WebCT in the discipline “Chemical Analysis”. The present paper shows the welcome and attitude of the students concerning this new tool of learning. The experience has been carried out on a pilot group, with a total of 106 registered students. With this objective, during the academic course two surveys have been elaborated (opinion/satisfaction and attitude with Likert scale). The obtained results show a high use of some of the available tools, as well as, a high degree of satisfaction

Vitamina e y aceites vegetales

<font face="Helvetica" size="1"><p align="left">An interest in vitamin E has increased in recent years due to its potent antioxidant properties and its role in preventing age-related diseases, cardiovascular diseases or Alzheimer. This work describes the biogenesis, bioavailability, nutritional requirements, activity and properties of vitamin E. Vegetable oils constitute one of the main sources of vitamin E dietary intake and an extensive bibliographic revision of this vitamin in vegetable oils is carried out from four points of view: antioxidant properties, health benefits, effects of external agents and effects of processing on vitamin E content and analytical techniques used for its analysis.</p></font><br><br><font face="Helvetica" size="1"><p align="left">El inter&eacute;s por la vitamina E ha aumentado en los &uacute;ltimos a&ntilde;os debido a su potente poder antioxidante y a su papel frente a enfermedades relacionadas con la edad, trastornos cardiovasculares o Alzheimer. En este trabajo se detallan la biog&eacute;nesis, biodisponibilidad, requerimientos nutricionales, actividad y propiedades de la vitamina E. Los aceites vegetales constituyen una de las fuentes principales de aporte de vitamina E a trav&eacute;s de la dieta, por lo que se lleva a cabo una amplia revisi&oacute;n bibliogr&aacute;fica desde cuatro puntos de vista: vitamina E y propiedades antioxidantes, beneficios para la salud debidos a la ingesti&oacute;n de aceites vegetales, efecto de agentes externos y procesado sobre el contenido de vitamina E y t&eacute;cnicas anal&iacute;ticas utilizadas para su an&aacute;lisis.</p></font

Interdisciplinary initiative and tran sversal approach in the teaching of analytical chemistry

El proceso de aprendizaje puede favorecerse mediante el uso de metodologías docentes que fomenten el tratamiento transversal de los temas, resultando más adecuado para el estudiante si es abordado desde diferentes vertientes. Este tratamiento implica el trabajo conjunto de profesores con distintas formaciones que muestren la solución del problema de forma interdisciplinar. La disciplina Análisis Químico está en relación continua con otras áreas de conocimiento lo que la hace idónea para la implementación de experiencias docentes mediante las cuales los alumnos experimenten la parte aplicada de la asignatura con el fin de favorecer la comprensión desde un punto de vista global. Este trabajo se ha desarrollado en un contexto real, poniendo en contacto a los alumnos con un proyecto de investigación con el fin de conseguir su implicación en la comprensión de la asignatura permitiendo una visión real del planteamiento y resolución de problemas analíticos y favoreciendo la adquisición de competencias específicas y trasversales. Se ha contado con la participación de diferentes profesores y se ha desarrollado en varias etapas: Impartición de charlas, establecimiento del problema analítico, colocación de material en plataforma virtual, análisis de muestras reales, información de resultados, encuesta opinión/satisfacción, evaluación y calificación. La utilización de esta herramienta de aprendizaje ha permitido fomentar en los alumnos la capacidad de aplicar los conocimientos teóricos adquiridos a la práctica, el trabajo en grupo, la identificación y resolución de problemas, la interdisciplinariedad y la colaboración. Y a los profesores evaluar los resultados del aprendizaje expresados en términos de competencias.The learning process can be favoured by using teaching methodologies that encourage the transversal treatment of the issues, resulting more adequate for the student if it is approached from different aspects. This treatment implies the joined work of professors with different trainings showing the solution of the problem from an interdisciplinary way. Analytical Chemistry is continuously related to other knowing areas which make it suitable for the implementation of teaching experiences that favours the students to know the applied part of the subject with the aim of facilitating the comprehension from a global point of view. This work has been developed in a real context, putting the students in contact with a research project with the aim of getting their implication in the comprehension of the subject and favouring the acquisition of specific and transversal competencies. The initiative has relied on the participation of different professors and has been developed in several stages: oral teaching, setting the analytical problem, putting material in the virtual platform, analysis of real samples, giving information of the results, evaluation and grading. The use of this learning tool has allowed to encourage the students the ability to apply the theoretical knowing to the practice, the making of decisions, the identification and solving of problems, the interdisciplinary and the collaboration. And to the professors to evaluate the results of the learning process in terms of competencies

Resolution of practical cases in small groups in the teaching of “general and analytical chemistry” subject of degree in pharmacy

El Proyecto realizado por el equipo docente del Departamento de Química Analítica de la Facultad de Farmacia de Sevilla, ha utilizado la técnica de enseñanza en pequeños grupos (EPG) que constituye una faceta esencial en la renovación de las metodologías docentes para la incorporación y adaptación de las enseñanzas universitarias al Espacio Europeo de Educación Superior. La actividad propuesta se ha llevado a cabo en la asignatura “Química General y Analítica” del Grado en Farmacia. Con el objetivo de mejorar el aprendizaje del alumno y fomentar el trabajo en equipo del mismo, se ha subdividido en tres cada uno de los seis grupos asignados a “Clases Prácticas en el aula”, logrando un número de alumnos presentes en la misma (20 alumnos) que permite la impartición de la docencia con una dinámica distinta a la lección magistral. La actividad desarrollada ha tenido una gran acogida por parte de los alumnos donde un alto porcentaje de los mismos consigue superar sin grandes dificultades el apartado del examen destinado a casos prácticos.The Project developed by the Educational Team of the Department of Analytical Chemistry (Faculty of Pharmacy, Seville), has used the technique of Small Groups Learning (SGL) that constitutes an essential facet in the renovation of the educational methodologies for the incorporation and adaptation of the university lessons to the European Space for Higher Education. The proposed activity has been carried out in the “General and Analytical Chemistry” subject of the Degree in Pharmacy. With the aim of improving the learning of the student and fomenting the work in equipment of the same, it has been subdivided in three each one of the six assigned groups to “Practical exercises in the classroom”, obtaining a number of present students in the same (20 students) that allows the imparting of teaching with a dynamic different from the magisterial lesson. The developed activity has presented a great reception by the students and a high percentage of the same is able to surpass without great difficulties the section of the examination destined to practical cases