RESUMEN
Canola seeds (Brassica napus L.) are among the most commonly used seeds in Mexico for vegetable oil production. This is based on the high yield and content of polyunsaturated and monounsaturated fatty acids. During oil bleaching, it is important to maintain fatty acids in their cis configuration because of the health concerns associated with trans-fatty acid consumption. In this sense, the industrial processing parameters employed for this purpose present some limitations, such as high temperatures and long times, which may change the cis configuration to trans. In addition, the amount of bleaching clay employed for this process could be a source of contamination because it is disposed of after treatment. Therefore, the aim of this study was to develop a bleaching process for canola oil using high-power ultrasound (US). US processing was applied to nine treatments with different processing times (60, 75, and 90 min), clay percentages (1, 2, and 3%), and temperatures (60 and 80 °C) to determine the concentrations of chlorophyll a and b (µg chlo/100 g oil), carotenes (µg ß-carotene/100 g oil), color (L*, a*, b*, C*, and h°), iodine value (g I2/100 g oil), and finally carrying out a spectroscopic analysis (ATR-FTIR and Raman). A conventional bleaching treatment (100 °C for 180 min, 3% bleaching clay) was used as a control. The results revealed that US treatments with 2% clay at 60 °C for 60 and 90 min eliminated most of the chlorophyll compounds (98%). However, in terms of carotenes reduction, these identical treatments exhibited a similar tendency to that of the control (approximately 30% decrease). These findings also affected the sample color, in which US treatments revealed chromatic coordinates that indicated yellow tones with chroma values that were more intense than those in the control samples. In terms of the iodine value, such treatments fulfilled the international standards for vegetable oils (90-100 g I2/100 g oil). Finally, the spectroscopic study revealed no trans configurations or the presence of different chemical compounds after US treatment, because neither of them presented typical peaks for those molecular configurations. In this regard, US can be a useful methodology for bleaching vegetable oils, helping to reduce time, and bleaching clay with similar pigment reduction results.
Asunto(s)
Brassica napus , Yodo , Aceite de Brassica napus , Clorofila A , Arcilla , Aceites de Plantas/química , CarotenoidesRESUMEN
Resumen: Dos de los grandes retos en la biología de las Células Madre (CM) y la Medicina Regenerativa, son el control en la diferenciación de estas células y asegurar la pureza de las células diferenciadas, por lo que es necesario contar con técnicas rápidas, eficientes y precisas para la caracterización de CM y su diferenciación a diferentes linajes celulares. El objetivo de este trabajo fue analizar Células Madre Pluripotentes (CMP) y Células Pancreáticas Diferenciadas (CPD) mediante espectroscopía Infrarroja por Transformada de Fourier (FTIR) y Análisis de Componentes Principales (ACP). Para ello se diferenciaron CMP a CPD, caracterizando el proceso de diferenciación a los días 0, 11, 17 y 21 mediante microscopía óptica y espectroscopia vibracional. Los espectros FTIR se analizaron con el método multivariado de ACP, utilizando su segunda derivada en las regiones de proteínas, carbohidratos y ribosas. Los resultados indican que el ACP permite caracterizar y discriminar CMP y CPD en sus diferentes etapas de diferenciación en las regiones espectrales analizadas. Con lo anterior concluimos que el ACP permite caracterizar química y estructuralmente CMP y diferentes etapas de su diferenciación en una forma rápida, precisa y no invasiva.
Abstract: Two of the greatest challenges in Stem Cells (SCs) biology and regenerative medicine, are differentiation control of SCs and ensuring the purity of differentiated cells. In this sense, fast, efficient and accurate techniques for SCs characterization and their differentiation into different cell lineages are needed. The aim of this study was to analyse Pluripotent Stem Cells (PSCs) and Differentiated Pancreatic Cells (DPCs) by Fourier Transform Infrared (FTIR) spectroscopy and Principal Component Analysis (PCA). For this purpose, we differentiated PSCs toward DPCs, characterizing the differentiation process at different stages (0, 11, 17 and 21 days) through light microscopy and vibrational spectroscopy. FTIR spectra were analysed with the multivariate method of PCA, using the second derivatives in the protein, carbohydrate and ribose regions. The results indicate that the PCA allows to characterize and discriminate PSCs and DPCs at different stages of differentiation in the analysed spectral regions. From these results, we concluded that the PCA allows the chemically and structural characterization of PSCs and the different stages of their differentiation in a fast, accurate and non-invasive way.