17 research outputs found

    Optical absorption coefficient of different tortillas by photoacoustic spectroscopy

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    The color of the tortilla is one of the properties that determine the purchasing decision and acceptance for the consumer. This sensory attribute is altered, when making tortillas with elements to improve digestion and nutrition. Therefore, the objective of this investigation was to determine some information about the color in different types of tortilla found in the commercial market in gEcatepec, Edo de Mexicoh. Optical absorption coefficients (尾) were obtained from them by photoacoustic spectroscopy technique of closed cell, one of the photothermal techniques. Optical absorption spectra of each tortilla were recorded by means of photoacoustic spectroscopy (PAS) in the 350 to 700 nm range. Thirteen types of tortillas were evaluated, the experimental unit comprised three tortillas, among which one tortilla was selected at random for each repetition. The 尾 values were determined from the photoacoustic (PA) signals amplitude and using the Rosencwaig and Gersho model. Data was subjected to variance analysis (ANOVA) using the SAS GLM procedures. The ANOVA revealed significant (p . 0.05) differences among tortillas. The results were analyzed statistically and correlated with preferences of a group of people in the same area, when a sensory test was applied; the test evaluated the color attribute by using the hedonic scale.Key words: Tortilla, color, optical absorption coefficient, photoacoustic spectroscopy, sensory evaluation

    Correlaci贸n entre diferentes contaminantes atmosf茅ricos de la Ciudad de M茅xico y el 脕rea Metropolitana

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    Se lleva a cabo un estudio de correlaci贸n estad铆stica entre datos num茅ricos correspondientes a la concentraci贸n de las part铆culas suspendidas y a la concentraci贸n de gases contaminantes que son obtenidos de las mediciones registradas en la base de datos de la Red Autom谩tica de Monitoreo Atmosf茅rico (RAMA) para la Ciudad de M茅xico y el 脕rea Metropolitana. Se reporta una importante dependencia entre los pares de gases NO2-NOX, NO-NOX, CO-NO, CO-NOX y los pares de part铆culas PM2.5-PM10, PMCO-PM10 cuando el estudio se realiza tomando como referencia una sola estaci贸n de monitoreo. Por otra parte, se encuentra una estrecha relaci贸n entre el ozono (O3) de una estaci贸n con el de otra para diferentes pares de estaciones.A statistical correlation study is carried out between numerical data corresponding to the concentration of the suspended particles and the concentration of polluting gases which are obtained from the measurements registered in the Automatic Atmospheric Monitoring Network database (RAMA) for Mexico City and the Metropolitan Area. An important dependency between the gas pairs NO2-NOX, NO-NOX, CO-NO, CO-NOX and the PM2.5-PM10, PMCO-PM10 particle pairs is reported when the study is carried out with reference to a single monitoring station. On the other hand, there is a close relationship between ozone (O3) from one station with ozone to another for different pairs of stations
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