Papel del método biplot canónico en el estudio de compuestos volátiles en quesos de composición variable

The canonical biplot method (CB) is used to determine the discriminatory power of volatile chemical compounds in cheese. These volatile compounds were used as variables in order to differentiate among 6 groups or populations of cheeses (combinations of two seasons (winter and summer) with 3 types of cheese (cow, sheep and goat’s milk). We analyzed a total of 17 volatile compounds by means of gas chromatography coupled with mass detection. The compounds included aldehydes and methyl-aldehydes, alcohols (primary, secondary and branched chain), ketones, methyl-ketones and esters in winter (WC) and summer (SC) cow’s cheeses, winter (WSh) and summer (SSh) sheep’s cheeses and in winter (WG) and summer (SG) goat’s cheeses. The CB method allows differences to be found as a function of the elaboration of the cheeses, the seasonality of the milk, and the separation of the six groups of cheeses, characterizing the specific volatile chemical compounds responsible for such differences.El m.todo biplot can.nico (CB) se utiliza para determinar el poder discriminatorio de compuestos qu.micos vol.tiles en queso. Los compuestos vol.tiles se utilizan como variables con el fin de diferenciar entre los 6 grupos o poblaciones de quesos (combinaciones de dos temporadas (invierno y verano) con 3 tipos de queso (vaca, oveja y cabra). Se analizan un total de 17 compuestos vol.tiles por medio de cromatograf.a de gases acoplada con detecci.n de masas. Los compuestos incluyen aldeh.dos y metil-aldeh.dos, alcoholes (primarios de cadena, secundaria y ramificada), cetonas, metil-cetonas y .steres. Los seis grupos de quesos son, quesos de vaca de invierno (WC) y verano (SC); quesos de oveja de invierno (WSh) y verano (SSh) y quesos de cabra de invierno (WG) y verano (SG). El m.todo CB permite la separaci.n de los seis grupos de quesos y encontrar las diferencias en funci.n del tipo y estacionalidad de la leche, caracterizando los compuestos qu.micos vol.tiles espec.ficos responsables de tales diferencias

Control de calidad y de almacenamiento de semillas de girasol mediante tecnología de infrarrojo cercano

This work assesses the application of near infrared spectroscopy technology for the quality control of sunflower seeds direct from farmers and from a storage silo. The results show that the analytical method employing near infrared spectroscopy can be used as a rapid and non-destructive tool for the determination of moisture, fat and high/low oleic acid contents in samples of sunflower seeds. The ranges obtained were comparable to those reported for classic chemical methods, and were between 4.6-21.4% for moisture; 38.4-49.6% for fat, and 60.0-93.1% for oleic acid expressed as percentage of total fatty acids. A stepwise discriminant analysis was performed to determine the most useful wavelengths for classifying sunflower seeds in terms of their (high/low) oleic acid composition. The discriminant model allows the classification of sunflower seeds with high or low oleic acid contents, with a prediction rate of 90.5% for internal validation and of 89.4% for cross-validation.En este trabajo se evalúa la espectroscopía de infrarrojo cercano para su uso en el control de calidad y almacenamiento de semillas de girasol. Los resultados indican que el método analítico empleado puede utilizarse como método de determinación rápida de humedad, grasa y contenidos altos/bajos de ácido oleico. Los rangos de aplicación son comparables con los valores que se han determinado mediante métodos clásicos de análisis, encontrándose entre 4.6-21.4% la humedad, 38.4-49.6% la grasa y 60.0- 93.1% de ácido oleico del total de los ácidos grasos. Además se ha utilizado un análisis discriminarte lineal por pasos determinando las longitudes de onda más adecuadas para la clasificación de semillas de girasol en los grupos alto/bajo oleico. El modelo generado permitió la clasificación de semillas de girasol en los grupos alto y bajo oleico con unos porcentajes de muestras correctamente clasificadas de un 90.5% en validación interna y de un 89.4% en validación cruzada

Dietary α‐Linolenic Acid, Marine ω‐3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvención con DIeta MEDiterránea (PREDIMED) Study

Background: Epidemiological evidence suggests a cardioprotective role of α‐linolenic acid (ALA), a plant‐derived ω‐3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine ω‐3 fatty acids (long‐chain n‐3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to all‐cause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for long‐chain n‐3 polyunsaturated fatty acids (≥500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvención con DIeta MEDiterránea (PREDIMED) trial. Multivariable‐adjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9‐y follow‐up, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56–0.92) for all‐cause mortality and 0.95 (95% CI 0.58–1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for long‐chain n‐3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67–1.05) for all‐cause mortality, 0.61 (95% CI 0.39–0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29–0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22–1.01) for sudden cardiac death. The highest reduction in all‐cause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45–0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to all‐cause mortality, whereas protection from cardiac mortality is limited to fish‐derived long‐chain n‐3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639

Trying to understand the grounds for the high trihalomethanes formation potential of four surface water bodies employed as source waters

Because of their historically high records of disinfection by-products, four water bodies serving as sources for drinking water in four cities of Castilla y León, Spain, were selected for a further study. With moderate to high contents of organic matter, an important part of it corresponded to algal biomass, as confirmed by the enormous values of chlorophyll a (Chl a) – means of 130–140 μg.L−1 in two of them. These two water bodies presented a moderate to low aromatic character of the dissolved organic carbon (DOC), as indicated by their low values of specific ultraviolet absorbance (SUVA means of 1.61 and 1.89 L.mg−1·m), which suggests an important contribution of the algal-derived compounds to this DOC. Upon chlorination, three of the water systems studied presented mean values of trihalomethanes potential formation (THMFP) in the order of 250 μg.L−1, but the specific one (STHMFP) revealed great differences of reactivity between them and, moreover, waters with higher SUVA showed lower STHMFP. This confirms the hypothesis that non-aromatic structures can also be reactive with chlorine. To investigate if the reactivity of the global DOC increases as its algal-derived DOC becomes more abundant, THMFP was tested versus Chl a/DOC, but the regression coefficients did not show any tendency. As compared with other studies, the values for THMFP can be considered of moderate to high (of up to 370 μg.L−1), but those of STHMFP are among the highest ever reported (some of them above 125 μg.mg−1), which means very reactive organic matter and, moreover, in waters with a very low SUVA

Trying to understand the grounds for the high trihalomethanes formation potential of four surface water bodies employed as source waters

Because of their historically high records of disinfection by-products, four water bodies serving as sources for drinking water in four cities of Castilla y León, Spain, were selected for a further study. With moderate to high contents of organic matter, an important part of it corresponded to algal biomass, as confirmed by the enormous values of chlorophyll a (Chl a) – means of 130–140 μg.L−1 in two of them. These two water bodies presented a moderate to low aromatic character of the dissolved organic carbon (DOC), as indicated by their low values of specific ultraviolet absorbance (SUVA means of 1.61 and 1.89 L.mg−1·m), which suggests an important contribution of the algal-derived compounds to this DOC. Upon chlorination, three of the water systems studied presented mean values of trihalomethanes potential formation (THMFP) in the order of 250 μg.L−1, but the specific one (STHMFP) revealed great differences of reactivity between them and, moreover, waters with higher SUVA showed lower STHMFP. This confirms the hypothesis that non-aromatic structures can also be reactive with chlorine. To investigate if the reactivity of the global DOC increases as its algal-derived DOC becomes more abundant, THMFP was tested versus Chl a/DOC, but the regression coefficients did not show any tendency. As compared with other studies, the values for THMFP can be considered of moderate to high (of up to 370 μg.L−1), but those of STHMFP are among the highest ever reported (some of them above 125 μg.mg−1), which means very reactive organic matter and, moreover, in waters with a very low SUVA