No abstract

The results obtained and their analysis by chemometric techniques established COP formation in food samples after e-beam irradiation. Increase in COP concentration depended on both irradiation doses and food composition, mainly water and fat content, although linear correlations among variables were not found. © 2016 Society of Chemical Industry.

No abstract

Determinación de la formación de óxidos de colesterol en el proceso de preparación de frito pastuso usando como técnica de análisis HPLC Determination of the formation of cholesterol oxides in the process of preparation of frito pastuso using HPLC as the analysis techniqueJuan José Lozada-Castro ResumenIntroducción: Los procesos de preparación de los alimentos inducen a la formación de compuestos nocivos para la salud, entre estos se encuentran los óxidos de colesterol (COPs). Objetivo: Determinar la formación de 25-hidroxicolesterol (5-colesten-3β,25-diol), 6-cetocolesterol (3β-hidroxi-5α-colestan-6-ona) y 7-cetocolesterol (3β-hidroxi-5α-colestan-7-ona), en el proceso de preparación de frito pastuso (alimento típico de Nariño, Colombia). Materiales y métodos: La determinación de los COPs se realizó mediante extracción en fase sólida (SPE) y cromatografía liquida de alta eficiencia (HPLC-UV) en fase reversa. Los factores evaluados fueron: receta de preparación, tipo de grasa o aceite utilizado y tipo de carne de cerdo, aplicando un diseño experimental DCA con tres factores y tres niveles en cada caso, se realizaron 10 ensayos totalmente aleatorizados por duplicado, para verificar la reproducibilidad de los resultados. El análisis de óxidos de colesterol (COPs) se aplicó a los diferentes insumos para la preparación y en el alimento listo para el consumo. Resultados: El 7-cetocolesterol se determinó en la mayoría de las muestras; los niveles más altos se encontraron en las muestras de los experimentos donde se utilizó: carne de costilla, grasa de cerdo y la receta de fritura directa de la carne. Los niveles más bajos se encontraron para los experimentos donde se utilizó lomo y pierna, aceite reutilizado y preparaciones de la carne a cocción en agua y posterior fritura. Conclusiones: Las desviaciones estándar relativas fueron inferiores al 4,76% obteniendo resultados reproducibles. La identificación de óxidos de colesterol en la presente investigación permitió establecer la influencia que tienen las formas de preparación de los alimentos de consumo frecuente, en la formación de compuestos que presentan reconocidos efectos adversos para la salud humana.Palabras clave: Colesterol, análisis de alimentos, HPLC, extracción en fase sólida. (Fuente: DeCS, Bireme). AbstractIntroduction: Food preparation processes lead to the formation of harmful compounds to health, some of these include oxides of cholesterol (COPs). Objective: To determine the formation of 25-hydroxycholesterol (5-cholesten-3β, 25-diol), 6-cetocolesterol (3β-hidroxi-5α-colestan-6-ona) and 7-cetocolesterol (3β-hidroxi-5α-colestan-7-ona) in the process of preparation of "frito pastuso" (a typical dish in Nariño, Colombia). Materials and methods: The COPs were determined by extraction in solid phase (SPE) and liquid chromatography of high efficiency (HPLC-UV) in reversed phase. The evaluated factors were: recipe, type of grease or oil used and type of pork by using a DCA experimental design with three factors and three levels in each case. 10 totally rand...

No abstract

A new sorbent material based on modified clay with ionic liquid immobilized into an agarose film was developed as part of this study. It was applied to determine organochlorine pollutants, like disinfection byproducts, through headspace solid-phase microextraction-gas chromatography-electron capture detection (HS-SPME-GC-ECD). The disinfection byproducts determined in this study were used as model molecules because they were volatile compounds, with proven severe effects on human health. Their presence in aquatic environments is in trace concentrations (from pg L−1 to mg L−1). They are classified as emergent pollutants and their determination is a challenge for analytical chemists. The parameters which affected the extraction efficiency, i.e., number and distance between SPME discs, salt concentration, the temperature of extraction, extraction time, and desorption time, were optimized. A wide linear dynamic range of 10–1000 ng mL−1 and coefficients of determination better than 0.997 were achieved. The limits of detection and the limits of quantitation were found in the ranges of (1.7–3.7) ng mL−1 and (5.6–9.9) ng mL−1, respectively. The precision, expressed as relative standard deviation (RSD), was better than 8%. The developed sorbent exhibits good adsorption affinity. The applicability of the proposed methodology for the analysis of trihalomethanes in environmental and water samples showed recoveries in the range of 86–95%. Finally, the newly created method fully complied with the principles of green chemistry. Due to the fact that the sorbent holder was made of agarose, which is a wholly biodegradable material, sorbent clay is a widespread material in nature. Moreover, the reagents intercalated into the montmorillonite are new green solvents, and during the whole procedure, low amounts of organic solvents were used.