Efecto de la refinación física sobre la calidad química y sensorial del aceite de coco

The effect of the physical refining stages (degumming, bleaching and deodorization) on some coconut oil quality and sensory parameters was evaluated. The fatty acid profile was within the range reported for this oil. The free fatty acids level (FFA) and the moisture content were significantly reduced (p 0.05) were found in p-anisidine value (AV). The tocopherols content was lower than the reported for this oil (6.57 ppm).The sterol level (899 ppm) was similar to the level reported for this oil. Both tocopherols and sterols content were significantly reduced (p 0.05) en ninguna de las etapas. El contenido de tocoferoles (6.57 ppm) estuvo por debajo de lo reportado para aceite de coco. El nivel de esteroles (899 ppm) determinado correspondió a lo reportado en la bibliografía. Tanto los tocoferoles como los esteroles se redujeron significativamente (p < 0.05) en todas las etapas de la refinación, siendo la etapa de blanqueo donde hubo mayor pérdida de estos compuestos. Se evaluó sensorialmente el aceite de coco usando una prueba con escalas. La calidad sensorial fue mejorada por el proceso de refinación. El aceite de coco desodorizado obtuvo la mejor calificación sensorial

Cinética de adsorción de pigmentos, peróxidos y tocoferoles durante el proceso de blanqueo del aceite de soja

Bleaching is an important process of refining and removes impurities from edible oils. During this process, suspended materials are adsorbed at different adsorption rates, on clay particles. These adsorption rates are important to the design of the process. For this reason, both empirical and theoretical mathematical models were applied in this work in order to predict the adsorption kinetic parameters for tocopherols, peroxides and pigments. The experimental part consisted of mixing neutralized soybean oil with different concentrations of bleaching clays (0.16, 1.0 and 2.0 % w/w) in a laboratory reactor at 96 °C for a 64 min period. Results showed that the theoretical model of first order made better predictions (R2 >0.93) than the empirical models of the kinetic adsorption for tocopherols, peroxides and pigments. The determined kinetic parameters suggest that these bleaching clays presented a high capacity for pigment and peroxide adsorption. The tocopherols were lost as the bleaching clay dosage was increased.El blanqueo es un proceso importante de la refinación para remover impurezas en los aceites comestibles. Durante este proceso, el material suspendido en el aceite se adsorbe sobre las partículas de las tierras de blanqueo a diferentes velocidades, las cuales son importantes para el diseño del proceso. Por esta razón, en este trabajo se aplicaron modelos empíricos y teóricos para predecir los parámetros cinéticos de adsorción de los tocoferoles, peróxidos y pigmentos. La parte experimental consistió en mezclar aceite de soja neutralizado con diferentes concentraciones de tierras de blanqueo (0.16, 1.0 y 2.0 % p/p) en un reactor de laboratorio a 96 °C por 64 minutos. Los resultados mostraron que el modelo teórico de primer orden predice mejor (R2 >0.93) que los modelos empíricos la cinética de adsorción para tocoferoles, peróxidos y pigmentos. Los parámetros cinéticos determinados sugieren que estas tierras presentan una capacidad de adsorción alta para pigmentos y peróxidos. La pérdida de tocoferoles se incremento al aumentar la cantidad de tierra

Simplified Self-Consistent Theory of Colloid Dynamics

One of the main elements of the self-consistent generalized Langevin equation (SCGLE) theory of colloid dynamics [Phys. Rev. E {\bf 62}, 3382 (2000); ibid {\bf 72}, 031107 (2005)] is the introduction of exact short-time moment conditions in its formulation. The need to previously calculate these exact short-time properties constitutes a practical barrier for its application. In this note we report that a simplified version of this theory, in which this short-time information is eliminated, leads to the same results in the intermediate and long-time regimes. Deviations are only observed at short times, and are not qualitatively or quantitatively important. This is illustrated by comparing the two versions of the theory for representative model systems.Comment: 1 text archive, 3 figure

Evaluación de un método sensorial sencillo y efectivo para determinar la rancidez en aceite de soja

The purpose of this study was to evaluate the efficacy of the 2 Alternative Forced Choice (2-AFC) sensory method in detecting rancidity in soybean oils. Additionally, correlations between the physico-chemical quality and the sensory attributes of edible soybean oils were studied. Soybean oil samples from four different plants were analyzed for their fatty acid profile, Free fatty acid (FFA), Anisidine Value (AV), Peroxide Value (PV), Conjugated Dienes (CD), Colour, Rancimat and TOTOX. The sensory attributes of the oils were measured using The American Oil Chemists Society (AOCS) sensory method and additionally, rancidity was assessed using the 2-AFC sensory method. All oil samples fit the quality control criteria for edible soybean oil. The 2-AFC The purpose of this study was to evaluate the efficacy of the 2 Alternative Forced Choice (2-AFC) sensory method in detecting rancidity in soybean oils. Additionally, correlations between the physico-chemical quality and the sensory attributes of edible soybean oils were studied. Soybean oil samples from four different plants were analyzed for their fatty acid profile, Free fatty acid (FFA), Anisidine Value (AV), Peroxide Value (PV), Conjugated Dienes (CD), Colour, Rancimat and TOTOX. The sensory attributes of the oils were measured using The American Oil Chemists Society (AOCS) sensory method and additionally, rancidity was assessed using the 2-AFC sensory method. All oil samples fit the quality control criteria for edible soybean oil. The 2-AFC  method was sensitive to small differences in rancidity. Differences in anisidine value and Rancimat were correlated to the difference in rancidity (d') among oilsEl propósito de este trabajo fue evaluar la eficacia de la prueba de selección forzada de dos alternativas (2-AFC) para determinar la rancidez en aceite de soja. La correlación entre la calidad química y los atributos sensoriales de los aceites fue el segundo objetivo del trabajo. El perfil de ácidos grasos, ácidos grasos libres (AGL), índice de anisidina (VA), índice de peróxidos (VP), dienos conjugados (DC), color, Rancimat y TOTOX se midieron en aceites de cuatro plantas procesadoras de aceite comestible de soja. Los atributos sensoriales del aceite se midieron utilizando la prueba oficial de la Sociedad Americana de Químicos de Aceites (AOCS) y el atributo de rancidez se evaluó usando la prueba 2-AFC. Todos los aceites satisficieron los criterios de calidad química para los aceites de soja. El método sensorial 2-AFC fue eficaz en determinar diferencias pequeñas en rancidez. Se encontró correlación entre los valores de anisidina y Rancimat y las diferencias sensoriales en rancidez (d')

Composición nutricional de nuevas variedades de cacahuate (Arachis Hypogaea L.)

Six peanut (Arachis hypogaea L.) cultivars (Col-24-Gro, Col-61-Gto, VA-81-B, Ranferi Díaz, NC-2 and Florunner) were studied for agricultural yield, chemical composition (protein, fat, carbohydrates, fiber and ash), amino acid profile, digestibility, fatty acid profile, tocopherol and sterol contents. Results indicated that Ranferi Díaz and Col-61-Gto presented the highest yield (6.3 Ton/ha). Protein content was from 23.5 to 26.6% and fat content ranged from 49.8-53.4%. Mean digestibility was 86%. Lysine and threonine levels in all cultivars were sufficient to meet human requirements. Total saturated fatty acids ranged from 15-18%. The oleic/linoleic ratio was estimated 1.3-1.4. Tocopherol levels varied from 390 to 706 ppm. The highest tocopherol levels corresponded to the cultivars with the lowest yield. The alpha tocopherol content was estimated at 90-150 ppm, while gamma tocopherol was 270-570 ppm.The main sterol present was βsitosterol (approx. 65%). Ranferi Diaz variety presented the highest agronomic yield and the highest protein content but low oleic acid, low sterols and low total tocopherols. The differences among cultivars suggest differences in their applications.Se estudio el rendimiento agrícola y composición química (proteína, grasa, carbohidratos, fibra y cenizas), perfil de amino ácidos, digestibilidad, perfil de ácidos grasos, contenido de tocoferol y de esteroles de seis variedades de cacahuate (Arachis hypogaea L.) Col-24-Gro, Col-61-Gto, VA-81B, Ranferi Díaz, NC-2 y Florunner. Los resultados mostraron que el mayor rendimiento se logró en las variedades Ranferi Díaz y Col-61-Gto (6.3 Ton/ha). El contenido de proteína fue de 23.5 a 26.6% y el contenido de grasa en un intervalo de 49.8 a 53.4%. La digestibilidad promedio de las seis variedades fue de 86%. El contenido de lisina y treonina en la proteína de todas las variedades fue suficiente para satisfacer los requerimientos del humano. La composición del aceite de las diferentes variedades de cacahuate se caracterizó por contener de 15-18% de ácidos grasos saturados. La relación oleico/linoleico fue de 1.3-1.4. El contenido de tocoferoles totales fue entre 390 a 706 ppm. El mayor contenido de tocoferol correspondió a las variedades con los rendimientos más bajos. Con respecto al contenido de alfa tocoferol se encontró entre 90-150 ppm y el gamma tocoferol fue entre 270570 ppm. El contenido de beta-sitosterol fue similar en las seis variedades (aprox. 65%). La variedad Ranferi Diaz presentó el más alto rendimiento agronómico y el más alto contenido de proteína. Sin embargo, esta variedad presento el más bajo contenido de ácido oleico, bajo contenido de esteroles y bajo contenido de tocoferoles totales. Estas diferencias entre las variedades de cacahuate sugieren que cada una de ellas deberá tener diferente uso como alimento

Amplified Genes May Be Overexpressed, Unchanged, or Downregulated in Cervical Cancer Cell Lines

Several copy number-altered regions (CNAs) have been identified in the genome of cervical cancer, notably, amplifications of 3q and 5p. However, the contribution of copy-number alterations to cervical carcinogenesis is unresolved because genome-wide there exists a lack of correlation between copy-number alterations and gene expression. In this study, we investigated whether CNAs in the cell lines CaLo, CaSki, HeLa, and SiHa were associated with changes in gene expression. On average, 19.2% of the cell-line genomes had CNAs. However, only 2.4% comprised minimal recurrent regions (MRRs) common to all the cell lines. Whereas 3q had limited common gains (13%), 5p was entirely duplicated recurrently. Genome-wide, only 15.6% of genes located in CNAs changed gene expression; in contrast, the rate in MRRs was up to 3 times this. Chr 5p was confirmed entirely amplified by FISH; however, maximum 33.5% of the explored genes in 5p were deregulated. In 3q, this rate was 13.4%. Even in 3q26, which had 5 MRRs and 38.7% recurrently gained SNPs, the rate was only 15.1%. Interestingly, up to 19% of deregulated genes in 5p and 73% in 3q26 were downregulated, suggesting additional factors were involved in gene repression. The deregulated genes in 3q and 5p occurred in clusters, suggesting local chromatin factors may also influence gene expression. In regions amplified discontinuously, downregulated genes increased steadily as the number of amplified SNPs increased (p<0.01, Spearman's correlation). Therefore, partial gene amplification may function in silencing gene expression. Additional genes in 1q, 3q and 5p could be involved in cervical carcinogenesis, specifically in apoptosis. These include PARP1 in 1q, TNFSF10 and ECT2 in 3q and CLPTM1L, AHRR, PDCD6, and DAP in 5p. Overall, gene expression and copy-number profiles reveal factors other than gene dosage, like epigenetic or chromatin domains, may influence gene expression within the entirely amplified genome segments

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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