Mineral bioavailability in vegetarian and omnivorous meals served in a university restaurant

Objetivo: Avaliar a biodisponibilidade de cálcio, ferro e zinco nas dietas vegetarianas e onívoras, servidas no Restaurante Universitário da Universidade de Brasília. Métodos: Foram coletadas três amostras de cada refeição, durante 5 dias, para determinação do conteúdo de fitato. O conteúdo em cálcio ferro e zinco foi estimado a partir de tabelas de composição de alimentos. A razão molar entre o ácido fítico e o mineral dietéticos foi utilizada como critério para avaliar a biodisponibilidade. Resultados: As concentrações médias de ácido fítico, cálcio e ferro foram significantemente maiores na dieta vegetariana (p=0,0002; p=0,0015 e p=0,0227, respectivamente), enquanto a concentração de Zinco foi maior na dieta onívora (p=0,0205). Ambas as dietas apresentaram razões molares ácido fítico: cálcio e ácido fítico: ferro inferiores aos valores críticos (1,56 e 14, respectivamente), sugerindo que o fitato não deve comprometer a biodisponibilidade do cálcio ou do ferro nessas refeições. A razão molar ácido fítico: zinco, na dieta vegetariana, foi de 9,3 e na onívora de 4,9, caracterizando-as como refeições de média e alta biodisponibilidade para o zinco, respectivamente. O feijão e a soja eram os componentes dietéticos mais ricos em fitato nas duas refeições. Conclusão: Devido aos teores de cálcio e ferro nas duas refeições, a presença de fitato não deve representar risco de deficiência desses minerais para indivíduos que se alimentam diariamente no Restaurante Universitário da Universidade de Brasília. Entretanto, devido ao baixo teor de zinco nas refeições, a presença do fitato pode representar um risco de deficiência desse mineral, principalmente, para homens vegetarianos.Objective: To assess the bioavailability of calcium, iron and zinc in vegetarian and omnivorous meals served in the university restaurant of the Universidade de Brasília. Methods: Three samples of each meal were collected during 5 days to determine the concentration of phytate. Calcium, iron and zinc contents were estimated by using food composition tables. The molar ratio between phytic acid and the dietary mineral was used as a criterion to evaluate mineral bioavailability. Results: The mean concentrations of phytate, calcium and iron were significantly higher in the vegetarian meal (p=0.0002; p=0.0015 e p=0.0227, respectively), while zinc concentration was higher in the omnivorous meal (p=0.0205). Both meals presented molar ratios of phytate to calcium and phytate to iron below the critical values (1.56 and 14, respectively) suggesting that phytate in these meals should not impair calcium and iron bioavailability. The molar ratio of phytic acid to zinc in the vegetarian meal was 9.4, while in the omnivorous meal it was 4.3, characterizing them as medium and high bioavailability meals for zinc, respectively. Beans and soy were the highest sources of phytate in both meals. Conclusion: Due to the calcium and iron contents in both meals served in the university restaurant of the Universidade de Brasília, phytate content should not induce calcium and iron deficiency in individuals that consume these meals daily. However, given the low zinc content in the meals, phytate content may represent a risk for the development of zinc deficiency, especially in vegetarian men

Análise eletroforética para detectar e quantificar soro de leite adicional em leite e bebidas lácteas

Polyacrylamide gel electrophoresis, SDS-PAGE system, was adjusted to detect the presence of additional whey in dairy beverages distributed in a Brazilian Government School Meals Program. Aqueous solutions of samples in 8 M urea were submitted to a polyacrylamide gel gradient (10% to 18%). Gel scans from electrophoresis patterns of previously adulterated milk samples showed that caseins peak areas decreased while peak areas of b -lactoglobulin plus a -lactalbumin increased as the percentage of raw milk powder replaced by whey powder increased. The relative densitometer areas of caseins or b -lactoglobulin plus a -lactalbumin plotted against the percentage of whey added to the raw milk showed a linear correlation coefficient square higher than 0.97. The caseins plot was used to determine the percentage of additional whey in 116 dairy beverages, chocolate or coffee flavor. Considering that the lowest relative caseins concentration found in commercial milk powder samples by the present method was 72%, the dairy beverages containing caseins percentages equal to or higher than this value were considered free of additional whey. Based on this criterion, about 49% of the coffee-flavor dairy beverages and 29% of the chocolate-flavor beverages, among all the samples analyzed were adulterated with whey protein to reach the total protein contents specified on their labels. The present method showed a sensitivity of 5% to additional whey.A adulteração de bebidas lácteas, distribuídas no Programa Nacional da Merenda Escolar, pela adição de soro, foi investigada através da análise eletroforética em sistema de SDS-PAGE. Soluções aquosas de amostras em uréia 8M, foram submetidas a um gradiente de 10% a 18% de gel de poliacrilamida. Após a eletroforese, o gel corado com "Comassie Blue" foi submetido à densitometria para identificação e quantificação das proteínas lácteas. A partir de amostras de leite em pó, previamente adulteradas com diferentes proporções de soro em pó (0 a 100%) foi observada alta correlação linear entre a concentração relativa de soro adicionado ao leite e as concentrações de proteínas lácteas. Esta correlação foi inversamente proporcional ao percentual de caseínas (r2 = 0,987) e diretamente proporcional à soma dos percentuais de b -lactoglobulina e a -lactalbumina (r2 = 0,979) apresentados nos densitogramas. A partir da curva padrão de caseínas versus soro adicionado foi estimada a magnitude das adulterações encontradas nas bebidas lácteas sabor chocolate e café do programa da merenda escolar. Tendo em vista que, amostras de leite em pó comerciais analisadas através deste método apresentaram uma concentração mínima de 72% de caseínas, as bebidas lácteas, contendo percentual igual ou superior a este valor, foram consideradas livres de soro adicional. Baseado neste critério, cerca de 49 % das bebidas lácteas, sabor café, e 29 % sabor chocolate, de um total de 58 amostras analisadas por sabor, apresentaram adulteração. O método proposto apresenta uma sensibilidade de 5% de soro adicionado

Associação dos marcadores do estado oxidativo e inflamatório com a desnutrição em pacientes hemodialisados com ferritina menor do que 500 ng/mL

Introduction: Enhanced inflammatory-oxidative status is well established in chronic kidney disease. Objective: The objective of this study was to evaluate the oxidative- inflammatory status and iron indices in patients undergoing maintenance hemodialysis (HD) with serum ferritin lower than 500ng/mL, and to correlate them with nutritional status. Method: In a cross-sectional survey 35 HD patients (23 with normal nutritional status, 12 with Protein-Energy-Wasting syndrome, PEW), and healthy volunteers (n = 35) were studied. Serum concentration of iron, ferritin, transferrin saturation, malondialdehyde (MDA), protein carbonyl (PC), high-sensitive serum C - reactive protein (hs-CRP) and blood counts were determined. The nutritional status was determined by anthropometric and biochemical criteria. Results: HD patients showed low values of hemoglobin and higher values of ferritin, MDA and PC when compared with healthy volunteers. HD subjects with PEW had higher values of PC and hs-PCR as compared to HD patients with normal nutritional status. A multiple logistic regression analysis showed that the independent variables PC (Wald Statistic 4.25, p = 0.039) and hs-CRP (Wald Statistic 4.83, p = 0.028) where related with the patients' nutritional condition. Conclusion: In HD patients with serum ferritin below 500 ng/mL was observed one association of the markers of oxidative stress and inflammation with poor nutritional status independently of serum ferritin, gender and age. ________________________________________________________________________________________________________________ RESUMOIntrodução: Na doença renal crônica, a presença de um estado inflamatório-oxidativo aumentado está bem estabelecida. Objetivo: O objetivo do presente estudo foi avaliar o estado oxidativo e inflamatório e o perfil do ferro em pacientes submetidos à hemodiálise crônica de manutenção, com ferritina menor do que 500 ng/mL, e correlacioná-los com o estado nutricional. Método: Em estudo transversal, em 35 pacientes sob hemodiálise (23 com estado nutricional normal, 12 com desnutrição energético- proteica (DEP) e 35 voluntários sadios foram determinados os índices hematimétricos e as concentrações séricas do ferro, da ferritina e avaliada a saturação de transferrina. O estado oxidativo foi determinado por meio das concentrações séricas do malondialdeído (MDA) e da proteína carbonil (PC). Nos indivíduos sob hemodiálise o estado inflamatório foi avaliado por meio da proteína C reativa ultrassensível determinada no soro (hs-PCR). O estado nutricional foi determinado por critérios antropométricos e bioquímicos. Resultados: Os pacientes da hemodiálise mostraram anemia e um estado oxidativo mais elevado do que os voluntários sadios. Os pacientes hemodialisados com DPE mostraram ferritina e um estado inflamatório- oxidativo mais elevado se comparados aos com boa condição nutricional. Em análise de regressão logística múltipla, os níveis séricos de PC e hs-CRP foram correlacionados com o estado nutricional. PC (Estatística Wald 4.25, p = 0,039), CRP (Estatística Wald 4.83, p = 0,028). Conclusão: Em indivíduos submetidos à hemodiálise, com ferritina menor do que 500 ng/mL. Observou- se uma associação entre os marcadores de estresse oxidativo e inflamatório com o estado nutricional, independentemente da idade, gênero e dos índices do ferro

Dietary iron concentration may influence aging process by altering oxidative stress in tissues of adult rats

Iron is an essential element. However, in its free form, iron participates in redox-reactions, leading to the production of free radicals that increase oxidative stress and the risk of damaging processes. Living organisms have an efficient mechanism that regulates iron absorption according to their iron content to protect against oxidative damage. The effects of restricted and enriched-iron diets on oxidative stress and aging biomarkers were investigated. Adult Wistar rats were fed diets containing 10, 35 or 350 mg/kg iron (adult restricted-iron, adult control-iron and adult enriched-iron groups, respectively) for 78 days. Rats aged two months were included as a young control group. Young control group showed higher hemoglobin and hematocrit values, lower levels of iron and lower levels of MDA or carbonyl in the major studied tissues than the adult control group. Restricted-iron diet reduced iron concentrations in skeletal muscle and oxidative damage in the majority of tissues and also increased weight loss. Enriched-iron diet increased hematocrit values, serum iron, gammaglutamyl transferase, iron concentrations and oxidative stress in the majority of tissues. As expected, young rats showed higher mRNA levels of heart and hepatic L-Ferritin (Ftl) and kidneys SMP30 as well as lower mRNA levels of hepatic Hamp and interleukin-1 beta (Il1b) and also lower levels of liver protein ferritin. Restricted-iron adult rats showed an increase in heart Ftl mRNA and the enriched-iron adult rats showed an increase in liver nuclear factor erythroid derived 2 like 2 (Nfe2l2) and Il1b mRNAs and in gut divalent metal transporter-1 mRNA (Slc11a2) relative to the control adult group. These results suggest that iron supplementation in adult rats may accelerate aging process by increasing oxidative stress while iron restriction may retards it. However, iron restriction may also impair other physiological processes that are not associated with aging

Brazilian savanna fruits contain higher bioactive compounds content and higher antioxidant activity relative to the conventional red delicious apple

The bioactive compounds content and the antioxidant activity (AA) of twelve fruits native to the Cerrado were compared with the Red Delicious apple by means of the antiradical efficiency (using the 2,2-diphenyl-1-picrylhydrazil assay/DPPH), ferric reducing antioxidant power (FRAP) and the b-carotene/linoleic system. The antiradical efficiency (AE) and the kinetic parameters (Efficient concentration/EC50 and time needed to reach the steady state to EC50 concentration/TEC50) of the DPPH curve were also evaluated for comparison with the Trolox equivalent (TE) values. A strong, significant and positive correlation was observed between the TE and AE values, whereas a weak and negative correlation was observed between TE and EC50, suggesting that the values of AE and TE are more useful for the determination of antiradical activity in fruits than the widely used EC50. The total phenolic content found in the fruits corresponded positively to their antioxidant activity. The high content of bioactive compounds (flavanols, anthocyanins or vitamin C) relative to the apple values found in araticum, cagaita, cajuzinho, jurubeba, lobeira, magaba and tucum corresponded to the high antioxidant activity of these fruits. Flavanols and anthocyanins may be the main bioactive components in these Cerrado fruits. The daily consumption of at least seven of the twelve Cerrado fruits studied, particularly, araticum, cagaita, lobeira and tucum, may confer protection against oxidative stress, and thus, they may prevent chronic diseases and premature aging. The findings of this study should stimulate demand, consumption and cultivation of Cerrado fruits and result in sustainable development of the region where this biome dominates

The association of markers of oxidative-inflammatory status with malnutrition in hemodialysis patients with serum ferritin lower than 500 ng/mL

INTRODUCTION: Enhanced inflammatory-oxidative status is well established in chronic kidney disease. OBJECTIVE: The objective of this study was to evaluate the oxidative- inflammatory status and iron indices in patients undergoing maintenance hemodialysis (HD) with serum ferritin lower than 500ng/mL, and to correlate them with nutritional status. METHOD: In a cross-sectional survey 35 HD patients (23 with normal nutritional status, 12 with Protein-Energy-Wasting syndrome, PEW), and healthy volunteers (n = 35) were studied. Serum concentration of iron, ferritin, transferrin saturation, malondialdehyde (MDA), protein carbonyl (PC), high-sensitive serum C -reactive protein (hs-CRP) and blood counts were determined. The nutritional status was determined by anthropometric and biochemical criteria. RESULTS: HD patients showed low values of hemoglobin and higher values of ferritin, MDA and PC when compared with healthy volunteers. HD subjects with PEW had higher values of PC and hs-PCR as compared to HD patients with normal nutritional status. A multiple logistic regression analysis showed that the independent variables PC (Wald Statistic 4.25, p = 0.039) and hs-CRP (Wald Statistic 4.83, p = 0.028) where related with the patients' nutritional condition. CONCLUSION: In HD patients with serum ferritin below 500 ng/mL was observed one association of the markers of oxidative stress and inflammation with poor nutritional status independently of serum ferritin, gender and age