ABSTRACT
Phenolic compounds are ubiquitous in plant-based foods. High dietary intake of fruits, vegetables and cereals are related to a decreased rate in chronic diseases. Phenolic compounds are thought to be responsible, at least in part, for those health effects. Nonetheless, the bioaccessibility of phenolic compounds is not often considered in these studies; thus, a precise mechanism of action of phenolic compounds is not known. In this review, we aim to present a comprehensive knowledge of the potential health promotion effects of polyphenols and the importance of considering the factors that affect their bioavailability on research projects(AU)
Los compuestos fenólicos son ubicuos en alimentos de origen vegetal. La alta ingesta de frutas, vegetales y cereales está relacionada con un bajo índice en padecimientos crónicos. Se cree que los compuestos fenólicos son, en parte, responsables de este efecto benéfico. Sin embargo, la bioaccesibilidad y biotransformación de los compuestos fenólicos generalmente no es considerada en este tipo de estudios. Por lo tanto, no se ha podido obtener un mecanismo de acción de los compuestos fenólicos. En este trabajo, presentamos una revisión de literatura del potencial benéfico de los compuestos fenólicos y cómo diversos factores pueden afectar su absorción y metabolismo(AU)
Subject(s)
Humans , Male , Female , Plants/metabolism , Edible Grain/metabolism , Phenolic Compounds/analysis , Fruit , Eating , Absorption , Diet, Food, and NutritionABSTRACT
Objective: To investigate the association between carbohydrate intakes and β-cell function (HOMA-β) in Japanese-Brazilians with impaired glucose tolerance (IGT). Methods: Dietary intakes were assessed by a validated food frequency questionnaire in a cross-sectional survey carried out in 2000. The associations between diet and HOMA-β were verified in 270 newly diagnosed IGT in multiple linear regression models. Results: The mean (SD) age was 58 (11) years and the mean HOMA-β was 65 (47). The glycemic load was inversely associated with HOMA-β, β1 -0.140 (95%CI = -1.044; -0.078), p = 0.023. The inverse association was also observed for refined grains intakes: -0.186 (95%CI = -0.4862; -0.058), p = 0.012. After adjustments for body mass index, the glycemic index was inversely associated with HOMA-β: -0.1246 (95%CI = -2.2482, -0.0257), p < 0.001. Conclusions: These data suggested that dietary glycemic load, glycemic index, and refined grains intakes are associated with reduced β-cell function, and the quality of dietary carbohydrates may be relevant for maintaining β-cell function among individuals with IGT.
Objetivo: Investigar a associação entre o consumo de carboidratos e função das células-β (HOMA-β) em nipo-brasileiros portadores de tolerância à glicose diminuída (TGD). Métodos: O consumo alimentar habitual foi avaliado por meio do questionário quantitativo de frequência alimentar previamente validado em estudo transversal conduzido em 2000. A associação entredieta e HOMA-β foi verificada em 270 indivíduos portadores de TGD em modelos de regressão logística ajustados. Resultados: A média (DP) de idade foi 58 (11) anos e do HOMA-β foi 65 (47). A carga glicêmica foi inversamente associada ao HOMA-β, β1 -0.140 (95%CI = -1.044; -0.078), p = 0,023. Associação inversa com o consumo de cereais refinados também foi observada: -0.186 (95%CI = -0.4862; -0.058), p = 0,012. Após ajuste pelo índice de massa corpórea, foi verificada a associação inversa entre índice glicêmico e HOMA-β: -0.1246 (95%CI = -2.2482, -0.0257), p < 0,001. Conclusões: Os dados indicam que a carga glicêmica da dieta, o índice glicêmico e o consumo de cereais refinados estão associados a uma função reduzida das células-β e que aqualidade dos carboidratos da dieta habitual pode ser relevante na manutenção da função de células-β entre indivíduos portadores de TGD.
Subject(s)
Female , Humans , Male , Middle Aged , Edible Grain/metabolism , Dietary Carbohydrates/metabolism , Glycemic Index/physiology , Insulin-Secreting Cells/metabolism , Prediabetic State , Brazil , Edible Grain/classification , Epidemiologic Methods , Glucose Intolerance/metabolism , Japan/ethnology , Prediabetic State/ethnology , Prediabetic State/metabolism , Transients and Migrants/statistics & numerical dataABSTRACT
The texture of corn grains is a fundamental characteristic for the industry as well as for grain producers and processors. To further understand the mechanisms involved in grain hardness, contrasting corn cultivars for grain hardness and protein quality were evaluated. The cultivars were Cateto L237/67 (hard endosperm and low protein value), QPM BR 451 (semi-hard endosperm and high protein value); Bolivia-2 (floury endosperm and low protein value), and Opaque-2 (floury endosperm and high protein value). Evaluations were carried out at 10, 20, 30, 40, 50, and 60 days after pollination in developing corn grains and in the mature grain. In developing grains, evaluation consisted in the determination of the area, percentage of starch granules, distribution of starch granules, and protein bodies in the endosperm. In mature corn grains, the parameters evaluated were: density, percentage of total proteins, levels of lysine and tryptophan, and banding pattern of zeins. The results indicate that the higher physical resistance of corn grains from the cultivars analyzed is influenced by the high percentage of total proteins, high synthesis of 27-kDa zeins, presence of protein bodies, and perfect organization of starch granules in the endosperm, independent of their sizes.
Subject(s)
Edible Grain/metabolism , Zea mays/metabolism , Starch/metabolism , Edible Grain/growth & development , Edible Grain/standards , Transcription Factors/metabolism , Molecular Weight , Plant Proteins , DNA-Binding Proteins/metabolism , Seeds/metabolism , Zea mays/growth & development , Zea mays/standards , Zein/metabolism , Zein/chemistryABSTRACT
The essential amino acids lysine and threonine are synthesized in higher plants via a pathway starting with aspartate that also leads to the formation of methionine and isoleucine. Lysine is one of most limiting amino acids in plants consumed by humans and livestock. Recent genetic, molecular, and biochemical evidence suggests that lysine synthesis and catabolism are regulated by complex mechanisms. Early kinetic studies utilizing mutants and transgenic plants that over-accumulate lysine have indicated that the major step for the regulation of lysine biosynthesis is at the enzyme dihydrodipicolinate synthase. Despite this tight regulation, recent strong evidence indicates that lysine catabolism is also subject to control, particularly in cereal seeds. The challenge of producing crops with a high-lysine concentration in the seeds appeared to be in sight a few years ago. However, apart from the quality protein maize lines currently commercially available, the release of high-lysine crops has not yet occurred. We are left with the question, is the production of high-lysine crops still a challenge?.
Subject(s)
Humans , Crops, Agricultural/metabolism , Lysine/biosynthesis , Threonine/biosynthesis , Edible Grain/metabolism , Plants, Genetically Modified/metabolismABSTRACT
Free sugar interconversion and activities of soluble acidic (pH 4.8) and neutral (pH 7.5) invertases, sucrose synthase (synthesis) and sucrose phosphate synthase were investigated in the growing nodes and internodes of sorghum (Sorghum vulgare). The results were substantiated with incorporation of 14C from supplied sucrose and hexoses into endogenous sugars of these stem tissues. With the advancement in plant growth, the content of total free sugars in apical nodes and internodes increased till 70 DAS (flowering stage) followed by a decline. In the corresponding basal tissues, the sugar build-up continued even beyond this stage of plant growth. Compared with basal stem tissues, the apical ones contained high activities of soluble invertases and a low proportion amongst free sugars of sucrose. The activities of sucrose-hydrolyzing enzymes were higher as compared with those of sucrose-synthesizing ones in both nodes and internodes and with the growth of plant, the activity of neutral invertase increased in these tissues. More 14C from supplied sucrose and hexoses appeared in extracted sugars from cut discs of apical nodes and internodes in comparison with their basal counterparts. 14C from supplied sucrose appeared in glucose, fructose and from supplied hexoses appeared in sucrose. The results suggest that in apical nodes and internodes, where a rapid cell division and cell expansion occur, sucrose is obligatorily inverted to meet the increased requirement of hexoses and there is a compartmentalized synthesis and cleavage of sucrose in the nodes and internodes of growing sorghum plant.
Subject(s)
Carbohydrate Metabolism , Edible Grain/metabolism , Glucosyltransferases/isolation & purification , Glycoside Hydrolases/isolation & purification , Hexoses/metabolism , Plant Stems/growth & development , Sucrose/metabolism , beta-FructofuranosidaseABSTRACT
Detached ears of sorghum (Sorghum vulgare) were cultured in complete liquid medium containing Ca2+(0, 3, 10 and 30 mM) and effect of this ion on the conversion of sucrose to starch with respect to the activities of amylases, sucrose synthase, sucrose phosphate synthase and soluble invertases were studied in developing grains. Presence of 3 mM Ca2+ in culture medium enhanced both accumulation of starch and activity of alpha-amylase in grain but without having any influence on the activity of beta-amylase. However, with 10 and 30 mM Ca2+, the accumulation of starch and activities of both amylases decreased and with advancement in culturing period, starch accumulation was further decreased. Irrespective of its concentration, Ca2+ enhanced the activities of sucrose synthase (synthesis), sucrose-phosphate synthase, soluble acid invertase and soluble-neutral invertase. Increase in the concentration of Ca2+ in culture medium was concomitant with an elevation in relative proportion of sucrose in the grain reflecting a net balance in per cent increase with Ca2+ in the activities of sucrose-synthesizing enzymes over sucrose-hydrolysing ones. Based on the results, it is suggested that assimilation of Ca2+ by grain is essential for maintaining high activity of alpha-amylase to generate starch primers required for the conversion of sucrose to starch during grain filling in sorghum.
Subject(s)
Amylases/metabolism , Calcium/metabolism , Edible Grain/metabolism , Starch/biosynthesis , Sucrose/metabolismABSTRACT
Fluorescence of Calcofluor and Congo Red was observed in stained sections of sorghum grain (Sorghum bicolor (L.) Moench), especially in the sub-aleurone cells indicating the presence of mixed linkage beta-D-glucan. Relatively less fluorescence intensity was observed in the single layered (approximately 20 microns thick) aleurone. Alkali extracted beta-D-glucan (fraction 2) of sorghum showed 30% activation of rat peritoneal macrophages (in vitro) at 100 micrograms ml-1 concentration in 10 min. This activation was found mediated mainly through PLA2 pathway. A phagocytic index k of 0.102 +/- 0.008 was observed in vivo carbon clearance test in mice in the group treated with fraction 2. Accumulation of colloidal carbon particles in spleen and liver of mice was moderate in this group, compared to control.
Subject(s)
Animals , Edible Grain/metabolism , Glucans/metabolism , Histocytochemistry , Liver/drug effects , Macrophage Activation/drug effects , Macrophages, Peritoneal/drug effects , Male , Mice , Rats , Rats, Wistar , Spleen/drug effects , beta-GlucansABSTRACT
Introducción. Objetivo. comprobar si el atole de maíz es igual o más eficaz que el Vida Suero Oral (VSO) para reducir el gasto fecal alto en niños con diarrea aguda no colérica. Material y métodos. Se realizó un ensayo clínico terapéutico en 34 niños masculinos de 6 a 24 meses de edad, con diarrea aguda no colérica de gasto fecal alto (mayor de 10 mL/kg/hora). Se distribuyeron al azar en 1 de 2 grupos, el grupo A (n=17 recibió una solución de atole de maíz y el grupo B (n=17) recibió VSO. Resultados. La muestra fue homogénea referente a: edad, porcentaje de deshidratación, gasto fecal e ingesta de líquidos totales. Se consideró éxito cuando se obtenía una reducción de 30 por ciento en el gasto fecal durante las primeras 2 horas en relación a su ingreso. En el grupo A se obtuvieron 16 éxitos y 1 frascaso, en el grupo B se lograron 4 éxitos y 13 fracasos (P=0.001). Se observó buena respuesta clínica en ambos grupos, el sodio sérico mostró una diferencia significativa entre grupos al final del estudio, pero siempre en límites de normalidad. Conclusiones. El atole de maíz reduce más eficaz que el VSO el gasto fecal alto en niños con diarrea aguda no colérica