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1.
Biomed Chromatogr ; 29(7): 1035-41, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25425119

RESUMEN

In recent years it has been confirmed that the consumption of olive oil prevents the oxidation of biomolecules owing to its monounsaturated fatty acids (MUFA) and phenolic content. The main objective of the study was to develop an ultra-high-performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS) method for the determination of phenolic compounds in human high-density lipoprotein (HDL) samples. At the same time, the influence of olive oil consumption on the phenolic metabolite levels was evaluated in a European population. The participants were 51 healthy men, aged 20-60. They were randomized to two consecutive intervention periods with the administration of raw olive oil with low and high polyphenolic content. The UHPLC-MS/MS analytical method has been validated for hydroxytyrosol and homovanillic acid in terms of linearity (r(2) = 0.99 and 1.00), repeatability (5.7 and 6.5%) reproducibility (6.2 and 7%), recovery (98 to 97%), limits of detection (1.7 to 1.8 ppb) and quantification (5.8 and 6.3 ppb).The levels of the studied metabolites increased significantly after high polyphenolic content virgin olive oil ingestion (p <0.05) compared with lowpolyphenolic content olive oil. Virgin olive oil consumption increases the levels of phenolic metabolites in HDL and thus provides human HDL with more efficient antioxidant protection.


Asunto(s)
Lipoproteínas HDL/sangre , Lipoproteínas HDL/química , Aceite de Oliva/química , Fenoles/análisis , Adulto , Cromatografía Líquida de Alta Presión/métodos , Humanos , Límite de Detección , Modelos Lineales , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodos , Adulto Joven
2.
Clin Exp Allergy ; 42(6): 918-28, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22909163

RESUMEN

BACKGROUND: In developed countries World Health Organization recommendation of 6 months' exclusive breastfeeding is under debate. OBJECTIVE: We assessed the impact of predominant breastfeeding (PBF) duration and colostrum long-chain polyunsaturated fatty acids (LC-PUFAs) profile on the risk of allergic manifestations (wheezing and atopic eczema) and infections [low respiratory tract infections (LRTIs) and gastroenteritis] in infancy. METHODS: Information on child feeding practices was obtained from 580 infants of a pregnancy cohort. Presence of infant's health outcomes was documented through questionnaires at 6 and 14 months of age. The LC-PUFAs were measured in colostrum. Adjusted odds ratios (adjOR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression models. RESULTS: In comparison with never breastfeeding, PBF for 4-6 months was associated with lower risk of wheezing (adjOR = 0.53; 95% CI, 0.32, 0.89), LRTIs (adjOR = 0.51; 95% CI, 0.31, 0.83) and atopic eczema (adjOR = 0.58; 95% CI, 0.32, 1.04) between months 7 and 14 of life. Results of a risk period-specific analysis (restricted to infants at risk for outcome onset after 6 months of age), showed no indication for reverse causation (results were not very different compared with an overall analysis). Predominantly breastfeeding for 4-6 months was associated with lower risk of gastroenteritis during the first 6 months of life (adjOR = 0.34; 95% CI, 0.18, 0.64). Among breastfed infants higher doses of arachidonic acid (AA), docosahexaenoic acid, and total n-3 in were associated with a decreased risk of gastroenteritis, but no association was found for allergic manifestations or LRTI. CONCLUSIONS AND CLINICAL RELEVANCE: Promotion of PBF for 4-6 months could reduce the burden of allergic manifestations and infections in infancy. Beneficial effects of breastfeeding on gastroenteritis were explained in part by exposure to higher doses of n-3 and AA received from colostrum. No significant effects from fatty acid dose were found on risk of allergic manifestations or LRTIs.


Asunto(s)
Lactancia Materna , Calostro/química , Ácidos Grasos Insaturados/fisiología , Hipersensibilidad/etiología , Infecciones/etiología , Adulto , Femenino , Humanos , Hipersensibilidad/epidemiología , Lactante , Recién Nacido , Infecciones/epidemiología , Masculino , Oportunidad Relativa , Embarazo , Riesgo
3.
J Dairy Sci ; 95(5): 2319-25, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22541460

RESUMEN

Breast milk constitutes the best form of newborn alimentation because of its nutritional and immunological properties. Banked human milk is stored at low temperature, which may produce losses of some bioactive milk components. During lactation, colostrum provides the requirements of the newborn during the first days of life. The aim of this study was to evaluate the effect of cooling storage at 4°C and freezing storage at -20°C and -80°C on bioactive factors in human colostrum. For this purpose, the content of IgA, growth factors such as epidermal growth factor, transforming growth factor (TGF)-ß1 and TGF-ß2, and some cytokines such as IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α, and its type I receptor TNF-RI, were quantified. Some colostrum samples were stored for 6, 12, 24, and 48 h at 4°C and others were frozen at -20°C or -80°C for 6 and 12 mo. We quantified IgA, epidermal growth factor, TGF-ß1, and TGF-ß2 by indirect ELISA. Concentrations of IL-6, IL-10, and TNF-α cytokines, IL-8 chemokine, and TNF-RI were measured using the BD Cytometric Bead Array (BD Biosciences, Erembodegem, Belgium). Bioactive immunological factors measured in this study were retained in colostrum after cooling storage at 4°C for at least 48h, with the exception of IL-10. None of the initial bioactive factor concentrations was modified after 6 mo of freezing storage at either -20°C or -80°C. However, freezing storage of colostrum at -20°C and -80°C for 12 mo produced a decrease in the concentrations of IgA, IL-8, and TGF-ß1. In summary, colostrum can be stored at 4°C for up to 48 h or at -20°C or -80°C for at least 6 mo without losing its immunological properties. Future studies are necessary to develop quality assurance guidelines for the storage of colostrum in human milk banks, and to focus not only on the microbiological safety but also on the maintenance of the immunological properties of colostrum.


Asunto(s)
Calostro/química , Frío , Calostro/diagnóstico por imagen , Factor de Crecimiento Epidérmico/análisis , Femenino , Almacenamiento de Alimentos/métodos , Congelación , Humanos , Inmunoglobulina A/análisis , Interleucina-10/análisis , Interleucina-6/análisis , Interleucina-8/análisis , Embarazo , Radiografía , Factor de Crecimiento Transformador beta1/análisis , Factor de Crecimiento Transformador beta2/análisis , Factor de Necrosis Tumoral alfa/análisis
4.
J Dairy Sci ; 93(3): 877-83, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20172207

RESUMEN

Human milk is considered the optimal nutritional source for infants. Banked human milk is processed using low-temperature, long-time pasteurization, which assures microbial safety but involves heat denaturation of some desirable milk components such as IgA. High-pressure processing technology, the subject of the current research, has shown minimal destruction of food macromolecules. The objective of this study was to investigate the influence of pressure treatments on IgA content. Moreover, bacterial load was evaluated after pressure treatments. The effects of high-pressure processing on milk IgA content were compared with those of low-temperature, long-time pasteurization. Mature human milk samples were heat treated at 62.5 degrees C for 30min or pressure processed at 400, 500, or 600MPa for 5min at 12 degrees C. An indirect ELISA was used to measure IgA in human milk whey obtained after centrifugation at 800xg for 10min at 4 degrees C. All 3 high-pressure treatments were as effective as low-temperature, long-time pasteurization in reducing the bacterial population of the human milk samples studied. After human milk pressure processing at 400MPa, 100% of IgA content was preserved in milk whey, whereas only 72% was retained in pasteurized milk whey. The higher pressure conditions of 500 and 600MPa produced IgA retention of 87.9 and 69.3%, respectively. These results indicate that high-pressure processing at 400MPa for 5min at 12 degrees C maintains the immunological protective capacity associated with IgA antibodies. This preliminary study suggests that high-pressure processing may be a promising alternative to pasteurization in human milk banking.


Asunto(s)
Manipulación de Alimentos/métodos , Inmunoglobulina A/análisis , Leche Humana/inmunología , Presión , Adulto , Femenino , Humanos , Leche Humana/microbiología , Reproducibilidad de los Resultados
5.
Eur J Clin Nutr ; 62(4): 570-4, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17375118

RESUMEN

OBJECTIVES: To assess the effect of two similar olive oils, but with differences in their phenolic compounds (powerful antioxidant compounds), on inflammatory markers in stable coronary heart disease patients. DESIGN: Placebo-controlled, crossover, randomized trial. SETTING: Cardiology Department of Hospital del Mar and Institut Municipal d'Investigació Mèdica (Barcelona). SUBJECTS: Twenty-eight stable coronary heart disease patients. INTERVENTIONS: A raw daily dose of 50 ml of virgin and refined olive oil (ROO) was sequentially administered over two periods of 3-weeks, preceded by 2-week washout periods in which ROO was used. RESULTS: Interleukin-6 (P<0.002) and C-reactive protein (P=0.024) decreased after virgin olive oil intervention. No changes were observed in soluble intercellular and vascular adhesion molecules, glucose and lipid profile. CONCLUSIONS: Consumption of virgin olive oil, could provide beneficial effects in stable coronary heart disease patients as an additional intervention to the pharmacological treatment.


Asunto(s)
Antioxidantes/administración & dosificación , Proteína C-Reactiva/metabolismo , Enfermedad Coronaria/dietoterapia , Grasas Insaturadas en la Dieta/administración & dosificación , Interleucina-6/sangre , Aceites de Plantas , Anciano , Antioxidantes/metabolismo , Enfermedad Coronaria/sangre , Estudios Cruzados , Grasas Insaturadas en la Dieta/metabolismo , Método Doble Ciego , Femenino , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Aceite de Oliva , Aceites de Plantas/química
6.
Nutr Hosp ; 23(6): 584-90, 2008.
Artículo en Español | MEDLINE | ID: mdl-19132267

RESUMEN

BACKGROUND: Maternal genetics and feeding before and during pregnancy, different maternal metabolic pathologies, as well as nutrient intakes of newborns in their first months of life may be involved in the obesity aetiology and its long-term consequences. The possible role of these and others factors, the mechanisms and the effects on the metabolism, and the development of this disease need further research. OBJECTIVE: To acquire more knowledge about foetal adipose tissue development and the influence of genetic, dietetic and environmental factors on the risk to suffer from obesity. METHODOLOGY: Four study groups have been established with 30 pregnant women in each one: 1) control group; 2) mothers with glucose intolerance/gestational diabetes; 3) women with low weight gain during pregnancy, and 4) women with overweight/obesity at the beginning of the pregnancy. The magnitudes to be studied are: 1) dietary intake; 2) life-style habits; 3) physical activity; 4) anthropometry and body composition; 5) haematological study; 6) biochemical study (lipid and metabolic biomarkers); 7) immune function profile related to nutritional status; 8) psychological profile; 9) genetic biomarkers, and 10) microbiological markers; all of them in relation to the development of the foetal adipose tissue in the first stages of life and the risk of suffering from obesity in the future. CONCLUSION: This project, coordinated by the Department of Paediatrics of the School of Medicine in the University of Granada, and with the collaboration of well-known and expert research groups, tries to contribute to the knowledge about the obesity aetiology in infancy and its subsequent development in later periods of life.


Asunto(s)
Tejido Adiposo/embriología , Desarrollo Fetal/genética , Fenómenos Fisiologicos de la Nutrición Prenatal , Adolescente , Adulto , Femenino , Humanos , Persona de Mediana Edad , Embarazo , Adulto Joven
7.
J Chromatogr A ; 1157(1-2): 422-9, 2007 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-17532324

RESUMEN

A new method for the determination of the main isomers of conjugated linoleic acid (CLA) in human and animal plasma was developed by gas chromatography coupled to flame ionization detection (GC-FID). The new method introduces three main advantages in comparison to the current available methodologies: firstly it does not require previous lipid extraction, secondly the chromatographic separation of CLA isomers was performed on an Rtx-2330 column significantly shorter and thinner than the typical long highly polar capillary columns in use that allows a faster analysis than in current methodologies, and thirdly the amount of sample needed to perform the analyses was substantially lower than the amount used in current routine methodologies. Its application to human plasma and rat plasma showed to be robust and reliable for quick and correct identification of the main CLA isomers in particular, and the total fatty acid profile in general, in routine analysis.


Asunto(s)
Cromatografía de Gases/métodos , Ácido Linoleico/sangre , Animales , Humanos , Ratas
8.
Eur J Clin Nutr ; 61(12): 1345-51, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17299472

RESUMEN

OBJECTIVE: To analyze compliance with the current European and Spanish nutritional objectives in a representative sample from Catalonia, a Spanish Mediterranean region; and to examine relationships between diet and plasma fatty acid composition. DESIGN: Cross-sectional nutritional survey. SETTING: Population based random sample derived from the Catalan Nutrition Survey. SUBJECTS: A total of 516 healthy adult men (n=203) and women (n=313). METHODS: Dietary habits were assessed by means of a quantitative food frequency questionnaire. A physical exam included height, weight, waist and hip circumferences, and a fasting blood draw. RESULTS: Gender differences were observed in nutrient and energy intakes. Women showed a better compliance with the nutritional recommendations for monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) than did men. Men showed a better compliance for saturated fatty acid (SFA) and carbohydrate than did women. However, the SFA:MUFA:PUFA ratio was similar in both gender (1.6:2.3:1.0 for men; 1.7:2.5:1.0 for women). The highest compliance was observed for nutritional goals of sodium, calcium and fruit and vegetable intakes for both genders. In addition, the present study showed that levels of certain fatty acids in plasma are clearly associated with dietary intake of foods rich in these components. The highest correlations were found for n-3 long chain polyunsaturated fatty acids with blue fish intake in both men and women (r (men)=0.36 and r (women)=0.42; P<0.001). CONCLUSIONS: The diet followed in Catalonia seems to ensure compliance with most of the intermediate nutritional objectives for the Spanish population. However, a reduction in the SFA intake and an increase in the carbohydrate intake could be recommended in order to reduce the current prevalence of overweight and obesity in this Mediterranean region. SPONSORSHIP: This study was supported by the Catalan Department of Health, the Nutrition Catalan Centre of the Institute of Catalan Studies, and Mercadona SA.


Asunto(s)
Dieta Mediterránea , Grasas Insaturadas en la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Política Nutricional , Obesidad/epidemiología , Estatura , Peso Corporal , Calcio de la Dieta/administración & dosificación , Estudios Transversales , Carbohidratos de la Dieta/administración & dosificación , Ingestión de Energía/fisiología , Femenino , Frutas , Humanos , Masculino , Encuestas Nutricionales , Obesidad/prevención & control , Sobrepeso/epidemiología , Sobrepeso/prevención & control , Distribución por Sexo , Cloruro de Sodio Dietético/administración & dosificación , España/epidemiología , Encuestas y Cuestionarios , Verduras , Relación Cintura-Cadera
9.
Artículo en Inglés | MEDLINE | ID: mdl-16326086

RESUMEN

Here we studied whether the chemical structure of dietary arachidonic and docosahexaenoic acids in full-term infant diets affects their incorporation into erythrocyte membrane phospholipids. From birth to 3 months, infants were fed breast milk (n = 9) or formula milk containing arachidonic acid and docosahexaenoic acid provided by egg phospholipids (n = 10) or by low-eicosapentaenoic acid fish oil and fungal triglycerides (n = 10). We compared the fatty acid composition of erythrocyte phosphatidylethanolamine, phosphatidylcholine and sphingomyelin before and after administration of the experimental diet. At 3 months, infants on formula milk showed lower concentrations of docosahexaenoic acid (in phosphatidylcholine and in phosphatidylethanolamine) and arachidonic acid (in phosphatidylcholine) than those receiving breast milk. We conclude the incorporation of the two fatty acids into erythrocyte phospholipids depends mainly on the lipid composition of the diet received rather than the chemical form in which they are delivered.


Asunto(s)
Ácidos Araquidónicos/análisis , Membrana Celular/química , Ácidos Docosahexaenoicos/análisis , Eritrocitos/química , Fórmulas Infantiles , Disponibilidad Biológica , Huevos , Femenino , Humanos , Lactante , Fórmulas Infantiles/administración & dosificación , Fórmulas Infantiles/química , Recién Nacido , Masculino , Fosfolípidos/administración & dosificación
10.
J Chromatogr A ; 1116(1-2): 204-8, 2006 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-16584741

RESUMEN

A new method for the determination of phospholipid fatty acids in biological samples, combination of solid-phase extraction (SPE) and fast gas chromatography (GC) was developed. Its application to human plasma and human erythrocytes showed to be robust and reliable for quick and correct identification in routine analysis.


Asunto(s)
Cromatografía de Gases/métodos , Ácidos Grasos/análisis , Fosfolípidos/química , Eritrocitos/química , Humanos , Estándares de Referencia , Reproducibilidad de los Resultados
11.
J Chromatogr A ; 1114(1): 132-7, 2006 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-16574129

RESUMEN

A rapid direct method (Method I) for measuring gamma- and alpha-tocopherols in human milk was developed and validated using reversed-phase high-performance liquid chromatography with ultraviolet/visible (UV-vis) detection. Human milk, with an internal standard (alpha-tocopherol acetate) added, was diluted in hexane. The chromatographic system consisted of a short column (50 mm x 2.1mm I.D., 3 microm particle size) that allowed the separation of the gamma- and alpha-tocopherols in less than 6 min. The new direct method (Method I) was compared with other methods. Method II (saponification with ultraviolet/visible detection) determined 24% and 22% less gamma- and alpha-tocopherols, respectively. Method III (saponification with evaporative light scattering detection) gave the same values for alpha-tocopherol content as Method II. However, the amount of sample used in the application of Method III was higher than that used in Method II. Furthermore, Method I uses smaller amounts of solvents, and it is simpler and faster than Methods II or III. Only a small volume of sample is needed, which is an additional advantage for biological assays.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Leche Humana/química , Espectrofotometría Ultravioleta/métodos , alfa-Tocoferol/análisis , gamma-Tocoferol/análisis , Humanos , Luz , Dispersión de Radiación
12.
Artículo en Inglés | MEDLINE | ID: mdl-16263341

RESUMEN

Vitamin C is an antioxidant that can be considered a possible biomarker of oxidative stability in human milk. A high-performance liquid chromatographic method was developed and validated for determining the total Vitamin C (ascorbic acid and dehydroascorbic acid) and ascorbic acid levels in human milk. This method was then compared with an enzymatic method (a Colorimetric technique) for quantifying ascorbic acid levels. Repeatability and reproducibility were acceptable for all methods. However, the high-performance liquid chromatography (HPLC) technique provided more satisfactory results than the enzymatic method due to this last method detected 37% less ascorbic acid and does not determine the total Vitamin C because of the enzymatic method cannot reduce the dehydroascorbic acid (DHA) to ascorbic acid. Furthermore, the HPLC method has the added advantages that it requires less reagents and material, and is simpler and less time consuming than the enzymatic method. In conclusion, the drawbacks of this enzymatic method would justify its substitution for a HPLC method.


Asunto(s)
Ácido Ascórbico/análisis , Cromatografía Líquida de Alta Presión/métodos , Enzimas/química , Leche Humana/química , Humanos , Espectrofotometría Ultravioleta
13.
Atherosclerosis ; 181(1): 149-58, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15939067

RESUMEN

The Mediterranean diet, in which olive oil is the main source of fat, has been associated with a reduced incidence of coronary heart disease (CHD) and low blood pressure levels. Virgin olive oil (VOO), besides containing monounsaturated fat, is rich in phenolic compounds (PC) with antioxidant properties. The aim of this study was to examine the antioxidant and anti-hypertensive effect of two similar olive oils, but with differences in their PC (refined: 14.7 mg/kg versus virgin: 161.0 mg/kg), in 40 males with stable CHD. The study was a placebo controlled, crossover, randomized trial. A raw daily dose of 50 mL of VOO and refined olive oil (ROO) were sequentially administered over two periods of 3 weeks, preceded by 2-week washout periods in which ROO was used. Lower plasma oxidized LDL (p < 0.001) and lipid peroxide levels (p = 0.003), together with higher activities of glutathione peroxidase (p = 0.033), were observed after VOO intervention. Systolic blood pressure decreased after intake of VOO (p = 0.001) in hypertensive patients. No changes were observed in diastolic blood pressure, glucose, lipids, and antibodies against oxidized LDL. Consumption of VOO, rich in PC, could provide beneficial effects in CHD patients as an additional and complementary intervention to the pharmacological treatment.


Asunto(s)
Antioxidantes/análisis , Antioxidantes/uso terapéutico , Enfermedad Coronaria/dietoterapia , Grasas Insaturadas en la Dieta/uso terapéutico , Aceites de Plantas/química , Aceites de Plantas/uso terapéutico , Anciano , Presión Sanguínea , Enfermedad Coronaria/sangre , Enfermedad Coronaria/fisiopatología , Estudios Cruzados , Glutatión Peroxidasa/sangre , Humanos , Peroxidación de Lípido , Lipoproteínas LDL/sangre , Masculino , Aceite de Oliva
14.
J Chromatogr A ; 1394: 62-70, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25846262

RESUMEN

For the first time, a procedure for the simultaneous determination of the iodinated drug amiodarone and its major metabolite, N-desethylamiodarone, in sludge from urban sewage treatment plants (STPs) is proposed. Matrix solid-phase dispersion (MSPD) followed by on-line cationic exchange clean-up, in modular configuration, was used as sample preparation technique. Liquid chromatography with tandem mass spectrometry (LC-MS/MS), based on a hybrid quadrupole time-of-flight (QTOF) system, was employed for the selective determination of target compounds. The optimized procedure provided exhaustive recoveries with little effect of the sample matrix in the efficiency of electrospray ionization (ESI). The overall recoveries of the method ranged between 95 and 111%, for samples spiked at different concentration levels. The achieved limits of quantification (LOQs) remained below 10ngg(-1) for both compounds, and the linear response range extended up to 2500ngg(-1). Amiodarone and N-desethylamiodarone were ubiquitous in sludge samples, from different STPs located in the Northwest of Spain, with maximum concentrations above 300ngg(-1) referred to the freeze-dried matrix. They were also present in stabilized sludge (mixed with lime and thermally dehydrated), which is mostly disposed in agriculture fields as fertilizer. Furthermore, mono-iodinated analogues of amiodarone and N-desethylamiodarone were also tentatively identified in some samples from their accurate MS and MS/MS spectra.


Asunto(s)
Amiodarona/análogos & derivados , Fármacos Cardiovasculares/análisis , Contaminantes Ambientales/análisis , Aguas del Alcantarillado/química , Amiodarona/análisis , Cromatografía Liquida/métodos , España , Espectrometría de Masas en Tándem/métodos
15.
J Chromatogr A ; 881(1-2): 591-7, 2000 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-10905738

RESUMEN

Inulin is a naturally occurring carbohydrate with beneficial nutritional and technological properties. A high-performance liquid chromatographic (HPLC) method was developed for the quantitative determination of these beta-fructans in meat products, containing this type of additive. The method includes extraction of inulin with hot water, followed by hydrolysis with inulinase enzyme, and determination of the released fructose by HPLC with refractive index detection. An internal standard of rhamnose was used to quantify fructose. The method incorporates a sample blank (without inulinase hydrolysis) for each specimen to subtract contributions of free fructose and fructose from sucrose. The results showed good precision with average RSDs of 2.4% for repeatability and 5.2% for reproducibility. Analytical recovery ranged from 102 to 106%. Satisfactory linearity (r=0.999) was obtained.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Inulina/análisis , Productos de la Carne/análisis , Refractometría , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
16.
J Chromatogr A ; 1046(1-2): 235-9, 2004 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-15387193

RESUMEN

Powder infant milk formula quality deterioration and consequently the termination of shelf life results in the appearance of off-flavors mainly determined by a composite effect of spoilage volatiles. A headspace gas chromatographic method to determine propanal, pentanal and hexanal as the main volatiles present in the headspace of powder infant formula oxidation is described as a rapid indication of oxidative status. Under optimum conditions the limits of detection for propanal, pentanal and hexanal were 17.19, 16.87 and 19.60 ng and the limits of quantification were 37.37, 31.96 and 35.97, respectively. The calibration graphs of the method were linear from 25 to 1500, 20 to 3500 and 30 to 8500 ng for propanal, pentanal and hexanal, respectively, with determination coefficients exceeding 0.99. The precision results showed that the relative standard deviations of the repeatability and reproducibility were between 2.2 and 5.5%. The analytical method was simple, rapid, and reliable and permitted the analysis of a large number of formulas using small sample volumes.


Asunto(s)
Cromatografía de Gases/métodos , Alimentos Infantiles/análisis , Calibración , Humanos , Recién Nacido , Reproducibilidad de los Resultados , Volatilización
17.
J Chromatogr A ; 1008(1): 73-80, 2003 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-12943251

RESUMEN

We developed and validated a new high-performance liquid chromatographic method for the separation of phospholipid classes in human milk, infant formulas and phospholipidic sources of long-chain polyunsaturated fatty acids (LC-PUFAs) used in paediatric nutrition. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine and sphingomyelin were separated in less than 25 min using an Extrasil silica column (150 x 4.0 mm I.D., 3-microm particle size) by isocratic elution with a mixture of isopropanol-hexane-water. Phospholipids were determined by an evaporative light-scattering detector. Several chromatographic conditions were assayed to optimise the method, whose suitability is shown by the detection limits, linearity ranges and precision rates obtained. The main advantages of the proposed method are its speed and the direct determination of the main phospholipids present in human milk, infant formulas and the phospholipid sources of LC-PUFAs used in paediatric nutrition.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ácidos Grasos Insaturados/análisis , Alimentos Infantiles/análisis , Leche Humana/química , Fosfolípidos/química , Humanos , Lactante , Luz , Dispersión de Radiación
18.
J Chromatogr A ; 1018(2): 197-202, 2003 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-14620570

RESUMEN

A rapid, sensitive method has been developed for the simultaneous determination of retinol acetate, delta-, gamma-, alpha-tocopherol and alpha-tocopherol acetate. We compare two experimental procedures for simultaneous direct solvent extraction of these vitamins without previous saponification. Method I: the fat milk sample was extracted with ethanol-hexane and injected directly into the chromatographic column. Method II: the power milk sample was extracted with ethanol-hexane and also injected directly into the column. Under optimum conditions the limits of detection for retinol acetate, delta-, gamma-, alpha-tocopherol and alpha-tocopherol acetate were 0.33, 21.2, 32.9, 32.5 and 3.2 ng and the limits of quantification were 0.42, 25.3, 37.9, 36.8 and 6.3 ng, respectively. The precision results showed that the relative standard deviations of repeatability and reproducibility were between 0.74 and 5.7%.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Alimentos Infantiles/análisis , Vitamina A/análisis , Vitamina E/análisis , Humanos , Lactante , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
19.
J Chromatogr A ; 881(1-2): 251-4, 2000 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-10905708

RESUMEN

A quick and direct method for measuring tocopherols (alpha, beta+gamma and delta) in vegetable oils has been developed using RP-HPLC with UV detection. Previous extraction of tocopherols is not required. The oil is diluted in hexane and an aliquot is mixed with ethanol containing an internal standard (alpha-tocopherol acetate). The chromatographic system consists of an ODS-2 column with a methanol-water mobile phase. Tocopherols are detected at 292 nm in less than 5 min after injection. The method is precise (RSD=2.69%) and has a high mean recovery (98.14%).


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Aceites de Plantas/química , Vitamina E/análisis , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrofotometría Ultravioleta
20.
J Chromatogr A ; 881(1-2): 255-9, 2000 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-10905709

RESUMEN

A reversed-phase high-performance liquid chromatographic method was developed for the determination, in one run, of alpha-tocopherol and beta-carotene in virgin olive oil. The method involved a rapid saponification and a later extraction with a mixture of hexane-ethyl acetate. The chromatographic system consists of an ODS-2 column with a mobile phase of methanol-water-butanol and a diode-array detector. Linearity, precision, recovery and sensitivity were satisfactory. The main advantage of the proposed method is the speed and simultaneous determination of both compounds at the same time.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Aceites de Plantas/química , Vitamina E/análisis , beta Caroteno/análisis , Aceite de Oliva , Sensibilidad y Especificidad , Espectrofotometría Ultravioleta
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