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1.
Nutr. clín. diet. hosp ; 32(2): 65-74, mar.-abr. 2012. ilus, tab
Article in Spanish | IBECS | ID: ibc-103405

ABSTRACT

El perfil de ácidos grasos permite caracterizar las materias utilizadas en la elaboración de helados. De la comparación de dichos perfiles con los de otras grasas(aceites, leches, etc.) se deduce que gran parte de los helados comerciales analizados parecen haber sido elaborados con aceite de coco o grasas elaboradas a partir del mismo. Por el contrario los helados artesanales analizados han sido elaborados con leche o derivados (mantequilla). Estas conclusiones cualitativas son confirmadas mediante análisis estadístico multivariante (análisis en factores y análisis clúster). En ambos casos puede comprobarse que gran parte de las muestras industriales se agrupan en las proximidades del aceite de coco. Dentro de los helados artesanales puede observarse un grupo en las proximidades de la leche y derivados (mantequilla), mientras que los helados de almendra y turrón aparecen en la zona del aceite de almendra, de gran parecido con otros aceites vegetales (oliva, girasol etc.) (AU)


By examining fatty acid profiles, the different ingredients used in ice cream production may be characterized. When these profiles were compared to those of other fats (oils, milk, etc.), many of the commercial brands of ice cream tested were found to contain coconut oil or coconut itself. In contrast, our data indicate that the smaller cottage industry-type ice creams examined were elaborated from milk or milk products(butter or cream). These qualitative findings were confirmed by multivariate statistical analysis (factor and cluster analyses). In the cluster diagrams presented, it can be seen that that many of the industrial samples grouped in the vicinity of coconut oil. Within the cottage ice cream grouping, appeared a group close to one clustering milk and butter, while ice-cream made of almond and nougat appeared in the almond oil zone, showing great similarity with other vegetable oils (olive, sunflower etc.) (AU)


Subject(s)
Food Composition , Dietary Fats/analysis , Ice Cream/analysis , Fatty Acids/analysis , Plant Oils/analysis
2.
Talanta ; 78(3): 672-5, 2009 May 15.
Article in English | MEDLINE | ID: mdl-19269410

ABSTRACT

Eight amino acids (ethanolamine, glycine, alanine, beta-aminobutyric acid, leucine, methionine, histidine and asparagine) were identified and quantified in Spanish wines by high performance liquid magneto-chromatography (HPLMC) with UV-V spectrophotometry. For this method, the amino acids are first complexed with mono(1,10-phenanthroline)-Cu(II) to confer them paramagnetic properties, and then separated by application of a low magnetic field intensity (5.5 mT) to the stationary phase contained in the chromatographic column. Principal components analysis of the results obtained grouped together the wine samples according to their denomination of origin: "Ribera del Duero", "Rueda" or "Rioja" (Spain). Through cluster analysis, a series of correlations was also observed among certain amino acids, and between these groupings and the type of wine. These clusters were found to reflect the role played by the amino acids as primary or secondary nutrients for the bacteria involved in alcoholic and malolactic fermentation.


Subject(s)
Amino Acids/analysis , Chromatography, High Pressure Liquid/methods , Wine/analysis , Bacteria/metabolism , Copper , Ethanol , Fermentation , Lactic Acid , Magnetics , Phenanthrolines , Spain
3.
Anal Bioanal Chem ; 385(7): 1233-40, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16633788

ABSTRACT

A new chromatographic modality that does not require high pressures and also allows renewal of the stationary phase as desired is reported. The technique is based on a thin layer paramagnetic stationary phase (Fe3O4-SiO2) retained on the inner wall of a minicolumn through the action of an external magnetic field, which also plays an important role in separating the analytes. Accordingly, the name "renewable stationary phase liquid magnetochromatography", or RSP-LMC, has been proposed for it. The technique was used to separate and quantify the sugar substitute alpha-aspartame and its constituent amino acids (hydrolysis products), L-aspartic acid and L-phenylalanine, in diet fizzy soft drinks. When the results obtained for alpha-aspartame were compared with those obtained using HPLC as a reference method, no significant differences were observed. The system proposed is fully automated, making it an economic, competitive alternative to conventional methods of determining alpha-aspartame and its amino acid components.

4.
Nutr. clín. diet. hosp ; 25(3): 9-16, mayo-jun. 2005. tab, graf
Article in Es | IBECS | ID: ibc-036795

ABSTRACT

Se ha llevado a cabo la determinación del contenido en colesterol y de la composición en ácidos grasos en una serie de muestras de los distintos grupos de la rueda de los alimentos(plásticos, reguladores, mixtos y grasos) con el fin de obtener datos que permitan completar algunas observadas en las tablas de composición de estos alimentos. Se ha establecido de este modo la singularidad de los mariscos por su alto contenido en colesterol, o del salmón que contiene la mayor proporción de C16:1 de todas las muestras analizadas y el menor porcentaje de C16:0, junto con los frutos secos. El análisis estadístico de los resultados obtenidos ha permitido diferenciarla contribución de los ácidos grasos insaturados por un lado y la de los saturados por otro. Además, mediante el análisis en componentes principales y cluster, se ha conseguido establecer una serie de agrupaciones en familias muy semejantes a las de la rueda de los alimentos (AU)


Cholesterol amount and fatty acids percentage were determined in samples representing several groups of food (regulators, mixed and fatty foods). The aim was to complete some of the gaps observed in the composition tables for these foods. Shellfish were found to have exceptionally high cholesterol content. Salmon was observed to have the highest C16:1 ratio and the lowestC16:0 proportion, together with nuts. Statistical analysis of the results allowed the differential contribution of unsaturated and saturated fatty acids. By means of principal component and cluster analysis it was possible to establish series of groups for the foods analysed. These groups were highly consistent with the know families of the food (AU)


Subject(s)
Humans , Cholesterol, Dietary/analysis , Fatty Acids/analysis , Food Analysis/methods , Table of Food Composition/methods , Chromatography , Fluorescence
5.
Talanta ; 37(3): 325-7, 1990 Mar.
Article in English | MEDLINE | ID: mdl-18964945

ABSTRACT

A method for determination of arsenic(V) in the range between 1 x 10(-7) and 1.2 x 10(-6)M has been developed. These levels are reached by means of the multiplication factor yielded by use of 12-molybdoarsenic acid and the great sensitivity of polarographic determination of the Mo(VI) in the heteropoly acid. The procedure has been successfully applied to determination of arsenic in copper alloys, after selective extraction of phosphorus.

6.
Talanta ; 32(5): 407-10, 1985 May.
Article in English | MEDLINE | ID: mdl-18963868

ABSTRACT

An indirect polarographic method has been developed for the determination of zirconium by formation of molybdozirconophosphoric acid, its extraction with MIBK or a mixture of diethyl ether and 1-butanol, stripping with alkali and measurement of the Mo(VI) by its catalytic effect on the polarographic reduction of hydrogen peroxide. Depending on the extradant, a detection limit of 2.5 or 8.9 mu/gl, can be achieved.

7.
Talanta ; 30(9): 655-8, 1983 Sep.
Article in English | MEDLINE | ID: mdl-18963439

ABSTRACT

A method has been developed for the determination of phosphorus, as phosphate, by means of the catalytic polarographic wave for the reduction of hydrogen peroxide in the presence of Mo(VI). This reduction is combined with the previous formation and extraction of 12-molybdophosphoric acid. Depending on the extractant chosen, ethyl acetate or methyl isobutyl ketone, the determination limit is 2.3 or 3.1 mug l . respectively. The procedure has been applied to certified steel samples with good results.

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