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1.
Proc Natl Acad Sci U S A ; 106(19): 7762-7, 2009 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-19416835

RESUMEN

Vitamin deficiency affects up to 50% of the world's population, disproportionately impacting on developing countries where populations endure monotonous, cereal-rich diets. Transgenic plants offer an effective way to increase the vitamin content of staple crops, but thus far it has only been possible to enhance individual vitamins. We created elite inbred South African transgenic corn plants in which the levels of 3 vitamins were increased specifically in the endosperm through the simultaneous modification of 3 separate metabolic pathways. The transgenic kernels contained 169-fold the normal amount of beta-carotene, 6-fold the normal amount of ascorbate, and double the normal amount of folate. Levels of engineered vitamins remained stable at least through to the T3 homozygous generation. This achievement, which vastly exceeds any realized thus far by conventional breeding alone, opens the way for the development of nutritionally complete cereals to benefit the world's poorest people.


Asunto(s)
Alimentos Fortificados , Transgenes , Zea mays/genética , Ácido Ascórbico/metabolismo , Ácido Fólico/metabolismo , Técnicas de Transferencia de Gen , Ingeniería Genética/métodos , Vectores Genéticos , Homocigoto , Modelos Genéticos , Plantas Modificadas Genéticamente , Vitamina A/metabolismo , Vitaminas , beta Caroteno/metabolismo
2.
Eur J Nutr ; 48(6): 365-71, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19387717

RESUMEN

BACKGROUND AND AIMS: To investigate the efficiency of [6S]-5-methyltetrahydrofolate or Metafolin ([6S]-5-CH(3)-H(4)folate) on the recovery of folate status, we conducted a depletion-repletion rat model study using a growing-up milk as the folate carrier. METHODS: The effect of [6S]-5-CH(3)-H(4)folate was compared to that of folic acid (PGA or Pte-Glu), by feeding two groups of folate-depleted rats a diet of fortified growing-up milk containing either 1,000 microg/l (2.2655 micromol/l) of Pte-Glu or 1,041.91 microg/l (2.2655 micromol/l) of [6S]-5-CH(3)-H(4)folate over a 4-week period. At the end of the study, the folate concentration in plasma, erythrocytes and liver was measured to establish the folate status of the animals. The folate content was determined in the plasma and erythrocytes by a time-resolved fluoroimmunoassay method and in the liver by a HPLC method. RESULTS: Plasma, erythrocyte and liver folate concentrations were significantly (P < 0.001) lower after a depletion period in rats fed the folate-deficient diet compared to rats fed a control diet. The folate form used significantly influenced the folate concentration in erythrocytes and liver, but not in plasma, after the rats' body folate reserves were replenished by consuming the fortified growing-up milk. Thus, rats fed [6S]-5-CH(3)-H(4)folate-fortified growing-up milk showed significantly higher folate content in erythrocytes and liver (1,100.37 ng/ml and 4.22 microg/g, respectively), than did those fed Pte-Glu-fortified growing-up milk (827.71 ng/ml and 3.04 microg/g, respectively, in erythrocytes and liver). CONCLUSION: We conclude that the natural diastereomer [6S]-5-CH(3)-H(4)folate may adequately serve as an alternative to folic acid for the folate fortification of infant foods.


Asunto(s)
Deficiencia de Ácido Fólico , Ácido Fólico/análisis , Estado Nutricional , Tetrahidrofolatos/administración & dosificación , Análisis de Varianza , Animales , Animales Recién Nacidos , Peso Corporal , Dieta , Eritrocitos/química , Ácido Fólico/sangre , Deficiencia de Ácido Fólico/sangre , Deficiencia de Ácido Fólico/prevención & control , Fórmulas Infantiles/administración & dosificación , Límite de Detección , Hígado/química , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados , Estereoisomerismo
3.
Eur J Nutr ; 47(8): 470-8, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18953478

RESUMEN

BACKGROUND AND AIMS: Food iron (Fe) fortification is an adequate approach for preventing Fe-deficiency anemia. Poorly water-soluble Fe compounds have good sensory attributes but low bioavailability. The reduction of the particle size of Fe fortificants and the addition of ascorbic acid might increase the bioavailability of low-soluble compounds. The present work aims to compare the Fe absorption and bioavailability of micronized dispersible ferric pyrophosphate (MDFP) (poorly soluble) to ferrous sufate (FS) (highly soluble) added to a fruit juice in presence or absence of ascorbic acid (AA) by using the hemoglobin repletion assay in rats. METHODS: After a hemoglobin depletion period, four fruit juices comprised of (1) FS, (2) MDFP, (3) FS + AA, (4) MDFP + AA were produced and administered to a different group of rats (n = 18) over 21 days. During the repletion period, Fe balance, hemoglobin regeneration efficiency (HRE), relative bioavailability (RBV) and Fe tissue content were determined in the short, medium and long term. RESULTS: Fe absorption and bioavailability showed no significant differences between fortifying the fruit juice with FS or MDFP. The addition of AA to the juice enhanced Fe absorption during the long-term balance study within the same Fe source. HRE and Fe utilization increased after AA addition in both FS and MDFP groups in every period. CONCLUSION: Fe absorption and bioavailability from MDFP were comparable to FS added to a fruit juice in rats. Further, the addition of AA enhanced Fe absorption in the long term, as well as Fe bioavailability throughout the repletion period regardless of the Fe source employed.


Asunto(s)
Ácido Ascórbico/farmacología , Difosfatos/farmacocinética , Alimentos Fortificados , Hemoglobinas/análisis , Hierro de la Dieta/farmacocinética , Hierro/farmacocinética , Anemia Ferropénica/prevención & control , Animales , Antioxidantes/farmacología , Bebidas , Disponibilidad Biológica , Suplementos Dietéticos , Absorción Intestinal/efectos de los fármacos , Masculino , Tamaño de la Partícula , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Solubilidad
4.
Arch Latinoam Nutr ; 58(2): 117-25, 2008 Jun.
Artículo en Español | MEDLINE | ID: mdl-18833987

RESUMEN

The first studies indicating polyamines as important growth factors in breast milk began during the nineties of last century. Nevertheless, it is still not well known the role they play in infant nutrition or what the recommended intake would be for this population group. In recent years, there has been increased attention of the international scientific community towards polyamines, not only due to the important role they play in the cellular metabolism, but also to their possible implication in some diseases and during the development of the human organism. Bearing in mind that the content in polyamines of the infant formula is around tenfold less than in breast milk, it would be recommended to gain insight into this theme in order to guarantee correct nutrition during lactation.


Asunto(s)
Fórmulas Infantiles/química , Leche Humana/química , Poliaminas/administración & dosificación , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Lactante , Mucosa Intestinal/química , Poliaminas/análisis
5.
Arch Latinoam Nutr ; 52(2): 193-202, 2002 Jun.
Artículo en Español | MEDLINE | ID: mdl-12184155

RESUMEN

The effect of technological process on essential and non essential amino acids contents in infant cereals, the protein and essential amino acids infant dietary requirements cover by infant cereals, and its quality using some chemical scores has been studied. Mix of raw flours, mix of roasted flours, mix of enzymatically, hydrolysed and drum dried flours and commercial infant cereals of four different types of infant cereals: "Multicereal" and "Wheat" (both with gluten), "Growth" and "Rice and carrot" (both gluten free) were evaluated. The technological process only show a significant effect on lysine, arginine (P < 0.05) and valine (P < 0.01) contents in "Rice and carrot" infant cereal. Protein of any studied infant cereals covers 17.4% of the daily infant requirements in, while for essential amino acids will cover about 25 to 200% until the third year of life. As we expected, the limitant amino acid was lysine in all flours. Chemical scores only were affected by technological treatment in "Rice and carrot" infant cereal, showing the gluten-free infant cereals higher values (36.7-69.5%) than gluten infant cereals (18.1%-30.7%) at the end of the processing. It should be standing out "Growth" infant cereal, because of it has a higher lysine content than other infant cereals due to the main ingredients rice and corn.


Asunto(s)
Aminoácidos/análisis , Grano Comestible/química , Harina/análisis , Manipulación de Alimentos , Alimentos Infantiles/análisis , Valor Nutritivo , Análisis de Varianza , Humanos , Lactante
6.
J Agric Food Chem ; 57(11): 4739-45, 2009 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-19449809

RESUMEN

The effects of cultivar, on-vine ripening, and year of harvest on the folate content of raw tomatoes were studied. Folate content in hot-break tomato puree (HTP) subjected to pasteurization at different temperatures and its evolution during the shelf life of tomato juice were also investigated. 5-Methyltetrahydrofolate (5-CH(3)-H(4)-folate) was the only folate compound identified in raw tomatoes and HTP, but tetrahydrofolate (H(4)-folate) was 10% of the folate detected in tomato juice. The content of folates in raw tomatoes ranged from 4.1 to 35.3 microg/100 g of fresh weight and was highly influenced by all of the factors studied. No clear trend of folate content with ripening stage was observed. The extractability of 5-CH(3)-H(4)-folate from HTP increased significantly after pasteurization at 98 degrees C for 40 s, but higher temperatures decreased its content. Tomato juice showed folate losses during storage independent of the storage temperature. Folate losses were higher when tomato juice was packed in glass bottles than in Tetra Pak.


Asunto(s)
Bebidas/análisis , Ácido Fólico/análisis , Manipulación de Alimentos/métodos , Industria de Procesamiento de Alimentos/métodos , Solanum lycopersicum/química , Temperatura , Factores de Tiempo
7.
J Agric Food Chem ; 57(15): 6815-22, 2009 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-19586031

RESUMEN

Tomatoes provide an optimal mix of dietary antioxidants that may be responsible for the reported health benefits of tomato consumption. However, technological processing, packaging materials, and storage conditions have an impact on the nutritional quality of tomato products by affecting the stability of antioxidant nutrients to different extents. In this study, we evaluated the stability of the antioxidant compounds (lycopene, ascorbic acid, total phenols, and total flavonoids) present in commercially available tomato juices during storage extended for 12 months at three different temperatures (8, 22, and 37 degrees C). To further characterize the impact of storage conditions, two commonly used packaging materials (Tetra pack and glass bottles) were used to determine whether packaging materials affect antioxidant stability. Overall, the total lycopene, total phenolic compounds, and total flavonoids remained almost stable during storage for 12 months, regardless of the packaging material used, indicating that tomato juices maintain their nutritional value in terms of antioxidant composition during their shelf life. However, ascorbic acid was the most labile antioxidant and was markedly affected by storage conditions. The hydrophilic total antioxidant activity (TAA) paralleled the losses in ascorbic acid content, whereas the lipophilic TAA remained substantially stable throughout the storage trial.


Asunto(s)
Antioxidantes/análisis , Bebidas/análisis , Manipulación de Alimentos/métodos , Embalaje de Alimentos/instrumentación , Solanum lycopersicum/química , Ácido Ascórbico/análisis , Carotenoides/análisis , Flavonoides/análisis , Manipulación de Alimentos/instrumentación , Embalaje de Alimentos/métodos , Licopeno
8.
Arch. latinoam. nutr ; 58(2): 117-125, jun. 2008. ilus, tab
Artículo en Español | LILACS | ID: lil-630292

RESUMEN

Durante la década de los 90 del siglo pasado comenzaron los primeros estudios que señalaban a las poliaminas como importantes factores de crecimiento de la leche materna. Sin embargo, todavía se desconoce mucho sobre el papel que desempeñan en la alimentación infantil y cual sería la ingesta recomendada para este grupo poblacional. En los últimos años va siendo cada vez mayor la atención que muestra la comunidad científica internacional hacia las poliaminas, debido no sólo al importante papel que desempeñan en el metabolismo celular, sino por su posible participación en diversas patologías y durante el desarrollo del organismo. Sería recomendable, teniendo en cuenta que el contenido en poliaminas de las fórmulas infantiles es unas 10 veces menor al de la leche materna, profundizar más en este campo, con el fin de garantizar una correcta alimentación durante la etapa de lactancia.


Role of polyamines in diet. Importance of polyamines in infant nutrition. The first studies indicating polyamines as important growth factors in breast milk began during the nineties of last century. Nevertheless, it is still not well known the role they play in infant nutrition or what the recommended intake would be for this population group. In recent years, there has been increased attention of the international scientific community towards polyamines, not only due to the important role they play in the cellular metabolism, but also to their possible implication in some diseases and during the development of the human organism. Bearing in mind that the content in polyamines of the infant formula is around tenfold less than in breast milk, it would be recommended to gain insight into this theme in order to guarantee correct nutrition during lactation.


Asunto(s)
Humanos , Lactante , Fórmulas Infantiles/química , Leche Humana/química , Poliaminas/administración & dosificación , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Mucosa Intestinal/química , Poliaminas/análisis
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