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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Mobilidade de boro (10B) em cajueiro (Anacardium occidentale L.) e pessegueiro (Prunus persica L.)

Souza, Juliana Aparecida de [UNESP] 24 October 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-10-24Bitstream added on 2014-06-13T19:39:05Z : No. of bitstreams: 1 souza_ja_me_ilha.pdf: 3840702 bytes, checksum: d1b78493b8f0c387c60f40d0693771e5 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Recentemente foi demonstrado que o boro exibe rápida e significante mobilidade no floema de algumas espécies produtoras de polióis. Os polióis como os açúcares alcoóis sorbitol, dulcitol e manitol possuem a capacidade de complexar o B conferindo a esse elemento alguma mobilidade dentro da planta. As espécies selecionadas foram o cajueiro (não produtora de sorbitol) e o pessegueiro (produtora de sorbitol). O trabalho teve por objetivo verificar a mobilidade de B aplicado via foliar em mudas de cajueiro e pessegueiro. As espécies foram conduzidas separadamente em dois experimentos em casa de vegetação pertencente a UNESP/FEIS no município de Ilha Solteira-SP. O delineamento experimental foi em blocos ao acaso, com três repetições, em parcelas subdivididas, em duas épocas (30 e 60 dias). Foram avaliados nas parcelas cinco tratamentos e nas subparcelas dois tipos de folha (folhas velhas e folhas novas). Os tratamentos estudados constituiram-se da adubação via solo e/ou via foliar com boro marcado ou não com 10B, da seguinte forma: sem adubação via solo e foliar com B (Sol -B Fol -B); sem adubação via solo com B e adubação foliar com 10B (Sol -B Fol 10 B); adubação via solo com B e sem adubação foliar (Sol B Fol -B); adubação via solo com B e foliar com 10B (Sol B Fol10B) e adubação via solo com 10B e foliar com B (Sol10B Fol B). Na adubação via solo o mesmo foi acrescido de B na dose de 0,5 mg kg-1 de solo e na adubação via foliar aplicação de solução com B na doses de 255 mg L-1, utilizando-se como fonte de B o ácido bórico e ácido bórico enriquecido com átomos de 10 B (99%). Foram avaliados quinzenalmente a altura e o número de folhas e o teor total de B e a porcentagem de B na folha velha e folha nova proveniente do fertilizante aos 30 e 60 dias após a aplicação dos tratamentos / Recently it was demonstrated the boron mobility in the phloem of some species producing polyols. The polyols or such alcohols sugar as sorbitol, mannitol and dulcitol are capable of complexing B giving to this element some mobility within the plant. This work had the objective to study the effect of fertilization with boron in the soil and leaves of cashew and peach seedling. They were conducted two experiments for 120 days in the greenhouse at UNESP, Ilha Solteira/SP. The experimental design was randomized blocks with three replications in a split plot, in two times for collection of leaves (30 and 60 days after application of treatments). We studied five treatments in plots and two ages of leaves in the subplots (old leaves and new leaves). The treatments studied were: no fertilizer with B in the soil and leaves (Sol -B Fol -B); without fertilizer with B in the soil and leaves with 10B (Sol - B Fol10B); fertilizing in the soil with B and leaves without B (Sol B Fol -B); fertilizing in the soil with B and leaves with 10B (Sol B fol10B) and fertilizing in the soil with 10 B and leaves with B (Sol10B Fol B). Were evaluated the height and the number of leaves biweekly and B total content and B percentage at the leaf from the fertilizer (% Bfopf) at 30 and 60 days. There was no fertilization effect with boron in the cashew seedling growing . The foliar fertilization with boron showed higher increase in the leaves number on peach seedlings at 60 days after fertilization. Boron foliar application is restricted or intermediate mobility in mobile cashew and peach evaluated at 30 and 60 days after fertilization
32

Efeito residual de elementos potencialmente tóxicos oriundos de fertilizantes: qualidade dos produtos agrícolas / Residual effects of potentially toxic elements from the fertilizing: quality of agricultural products

Luiz Henrique Marcandalli 29 October 2012 (has links)
Devido à presença de contaminantes (Elementos Potencialmente Tóxicos - EPT) nos fertilizantes, seja pelo material de origem das rochas fosfatadas ou pelo uso de subprodutos que contém altos teores de metais pesados, tem provocado muita polêmica e discussões. O conhecimento das frações dos elementos no solo pode indicar na disponibilidade dos mesmos para as plantas e, por fim, subsidiar as práticas de adubação de forma mais segura. O presente projeto teve como objetivo: (1) avaliar a produção de massa seca e determinar os teores de P, (Ni e Zn) e EPT (Cr, Cd, Pb) na parte comestível da alface (folhas) e do rabanete (raízes), em resposta a fertilização com fontes de fósforo e de zinco aplicadas em cultivo anterior (efeito residual); (2) avaliar o estado nutricional da alface e do rabanete em relação aos nutrientes P e Zn sob efeito da fertilização com fontes de fósforo e de zinco aplicadas em cultivo anterior (efeito residual); (3) determinar os teores residuais disponíveis de P (resina), micronutrientes (Ni, Zn) e EPT (Cr, Cd, Pb) extraídos por Mehlich-1, DTPA, CaCl2 0,01 mol L-1 e solução de ácidos orgânicos, em dois solos fertilizados com fontes de fósforo e de zinco após cultivo de alface e de rabanete. Serão desenvolvidos os cultivos residuais com as culturas da alface e rabanete em casa de vegetação, utilizando dois solos contrastantes quanto ao teor de argila. Os tratamentos foram aplicados por ocasião do cultivo do arroz de terras altas e, assim, serão realizadas apenas adubações de base e cobertura. Os tratamentos são assim constituídos: três fontes de Zn (subproduto, fertilizante comercial obtido da acidulação do subproduto e uma mistura de reagentes pró-análise) e três fontes de P (rocha fosfática de Togo, superfosfato simples obtido pela acidulação da rocha de Togo e uma mistura de reagentes pró-análise) em doses equivalentes a 0; 2,5; 5; 10 e 20 vezes a dose recomendada (em média, 4 kg de Zn e 90 kg de P2O5 por ha). Após as analises realizadas no solo com os diferentes extratores e as analises de folhas (alface) e raízes (rabanete) para determinarmos os níveis de elementos potencialmente tóxicos presentes no solo e partes comestíveis pode-se concluir que os teores no solo de fósforo e zinco aumentaram com o uso de doses crescente desses elementos no Latossolo Vermelho-Amarelo (LVA) e Latossolo Vermelho (LV);o uso dos extratores solução de ácidos orgânicos, mehlich-1 e DTPA, determinaram uma maior disponibilidade dos metais no solo;as doses crescentes de fósforo elevaram os teores de cádmio disponível no solo, porém esse aumento não apresentou diferenças significativas nas partes comestíveis;o uso de diferentes fontes e doses de fósforo e zinco não apresentaram diferenças significativas na produção de material vegetal das culturas;as doses de zinco elevaram os teores de chumbo disponível no solo, porém esse aumento não foi observado nas partes comestíveis das culturas;o crômio não foi alterado com as diferentes doses dos fertilizantes / Due to the presence of contaminants (Potentially Toxic Elements - EPT) in fertilizers, is the source material of PRs or the use of products which contain high levels of heavy metals, has caused much controversy and discussion. The knowledge of the fractions of the elements in the soil can indicate the availability thereof to the plants and finally subsidize fertilizer practice in a safer way. This project aimed to: (1) evaluate the dry matter production and determine the levels of P (Ni and Zn) and EPT (Cr, Cd, Pb) in the edible portion of the lettuce (leaves) and radish (roots ) in response to fertilization with phosphorus sources and zinc applied in previous crop (residual effect), (2) assess the nutritional status of lettuce and radish in relation to nutrients P and Zn fertilization under the effect of phosphorus sources and Zinc applied in previous crop (residual effect): (3) determining the residue content of available P (resin), trace elements (Ni, Zn) and EFA (Cr, Cd, Pb) extracted by Mehlich-1, DTPA, CaCl2 0 , 01 mol L-1 solution and organic acids in soils fertilized with phosphorus sources and zinc after growing lettuce and radish. Residual crops are developed with the lettuce and radishes in a greenhouse using two contrasting soils as the clay content. Treatments were applied during the cultivation of upland rice and thus will be conducted only fertilizers and basic coverage. Treatments are divided as follows: three sources of Zn (byproduct, commercial fertilizer obtained from acidulation by product and a mixture of reagents for analysis) and three sources of P (phosphate rock from Togo, superphosphate obtained by acidulation of rock and Togo a mixture of reagents for analysis) at doses of 0, 2.5, 5, 10 and 20 times the recommended dose (average of 4 kg Zn and 90 kg P2O5 per ha). The analyzes carried out on the ground with different extractants and analysis of leaves (lettuce) and roots (radish) to determine the levels of potentially toxic elements present in the soil and edible parts can be concluded that the levels of phosphorous in soil and zinc increased with increasing doses of the use of these elements in the Oxisol (LVA) and Oxisol (LV), the use of organic acid solution extractants, Mehlich-1 and DTPA, led to an increased availability of metals in soil; doses increasing phosphorus elevated levels of cadmium in the soil available, but this increase did not show significant differences in the edible parts, the use of different sources and levels of phosphorus and zinc showed no significant differences in the production of plant material cultures; doses of zinc elevated levels of lead in the soil available, however this increase was not observed in the edible parts of crops, chromium has not changed with the different fertilizer levels
33

Papel da dieta na pressão arterial de pacientes com diabetes melito tipo 2

Mattos, Carolina Benvenuti de January 2011 (has links)
A hipertensão arterial sistêmica (HAS) é uma condição clínica multifatorial que acomete parte significativa da população mundial sendo sua prevalência no diabetes melito (DM) mais elevada do que na população em geral. Modificações no estilo de vida, entre elas intervenções dietoterápicas são importantes ferramentas para a prevenção e manejo da HAS, sendo o efeito destas relacionado à composição dos alimentos. Poucos estudos avaliaram o papel dos micronutrientes na pressão arterial (PA) de pacientes com DM e as recomendações atuais de consumo são baseadas em estudos populacionais ou em pacientes sem DM. O objetivo deste manuscrito foi revisar os efeitos da ingestão de micronutrientes consumidos sob a forma de alimentos ou suplementação sobre a PA de pacientes com DM. Foi realizada uma revisão sistemática de ensaios clínicos randomizados (ECR) nas bases Medline e Lilacs. Foram incluídos ECRs realizados em pacientes adultos com DM que avaliaram o efeito de micronutrientes da dieta ou suplementos sobre a PA e com no mínimo duas semanas de intervenções. Foram excluídos ECRs com intervenção múltipla de micronutrientes ou outras (fármacos, exercício). Os dados foram extraídos por dois pesquisadores independentes. Dos 607 estudos inicialmente selecionados foram excluídos 555 com base no título ou resumo; 52 estudos potencialmente relevantes para inclusão tiveram então seu texto completo avaliado e destes, 12 ECR foram incluídos, totalizando 16 intervenções. Em conclusão, a restrição de sódio, a suplementação de magnésio e a suplementação de vitamina D nos pacientes com hipovitaminose D podem conferir melhora nos valores da PA de pacientes com DM. Já o possível efeito benéfico da vitamina C permanece incerto e a administração de vitamina E não é recomendada. A indicação de aumento da ingestão de potássio não foi testada em pacientes com DM. Novos estudos para confirmar e esclarecer o papel destes e de outros micronutrientes sobre a PA de pacientes com DM são necessários. / Hypertension is a multifactorial clinical condition that affects a significant part of the world population, with a higher prevalence in patients with diabetes mellitus (DM) than in the general population. Changes in lifestyle, including dietary intervention, are important tools for prevention and management of hypertension, this effect being related to food composition. Few studies evaluated the role of micronutrients in blood pressure (BP) in patients with DM and the current recommendations were based on population studies in patients without DM. The aim of this study was to review the effects of micronutrients from diet or supplements on BP in patients with DM. A systematic review of randomized controlled trials (RCT) was performed in Medline and Lilacs. It was conducted in adult patients with diabetes and evaluated the effect of micronutrients from diet or supplements on BP after at least two weeks of intervention, RCT trials with multiple micronutrient intervention or other (drugs, exercise) were excluded. Data were extracted by two independent researchers to record changes in BP at the end of the studies. Of the 607 studies initially selected 555 were excluded based on title or abstract; 52 potentially relevant studies for inclusion were then evaluated with their complete text and, from these, 12 RCTs were included, with a total of 16 interventions. In conclusion, sodium restriction, magnesium and vitamin D supplementation in patients with hypovitaminosis D may improve BP values of diabetic patients. However, the possible beneficial effect of vitamin C remains uncertain and the administration of vitamin E is not recommended. The indication of increased potassium intake has not been tested in patients with DM. Further studies are needed to confirm and clarify the role of these and other micronutrients in BP in patients with DM.
34

Estado nutricional do zinco e cobre após seis meses da cirurgia bariátrica / Zinc and copper nutritional status of after six months of bariatric surgery

Gobato, Renata Cristina, 1985- 01 September 2013 (has links)
Orientador: Elinton Adami Chaim / Dissertação (mestrado) - Universidade Estaduasl de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T20:05:58Z (GMT). No. of bitstreams: 1 Gobato_RenataCristina_M.pdf: 664324 bytes, checksum: f4cb1996e3e4b9708c687287f2012cdb (MD5) Previous issue date: 2013 / Resumo: A cirurgia bariátrica é considerada um método efetivo de perda e manutenção de peso, mas pode causar várias complicações nutricionais. O objetivo deste estudo foi avaliar o estado nutricional do zinco e cobre em pacientes obesos no momento em que entram no grupo de obesidade e no pós-operatório de seis meses da gastroplastia redutora em Y de Roux. A população de estudo, composta por 36 pacientes, foi avaliada prospectivamente antes e após seis meses da gastroplastia redutora em Y de Roux. Em cada fase, o peso, altura, índice de massa corpórea (IMC), circunferência abdominal (CA), níveis séricos de proteína total, albumina, préalbumina, zinco e cobre foram mensurados. A média da porcentagem de perda de peso desde o início até seis meses após a cirurgia foi 35.34±4.82%. Dentre os micronutrientes mensurados, 31 pacientes apresentaram algum tipo de deficiência, houve grande porcentagem de deficiência de zinco tanto no pré (55.55%) quanto no pós-operatório (61.11%), no pós-operatório 8,33% dos pacientes apresentaram deficiência de cobre e 33.33% apresentaram deficiência de pré-albumina. A ingestão protéica após seis meses de cirurgia estava abaixo do recomendado (<70g/dia) em 88,88% dos pacientes. Houve diminuição na média quando se comparou as análises laboratoriais no pré e pós-operatório para proteína total (p<0,05) e pré-albumina (p<0,05). A deficiência de Zn foi frequente e apresentou alta prevalência antes e após seis meses da gastroplastia redutora em Y de Roux e, suplementos protéicos são necessários para a adequação da ingestão protéica até os 6 meses de pós-operatório / Abstract: Background Bariatric surgery is considered as an effective method for sustained weight loss, but may cause various nutritional complications. The aim of this study was to evaluate the nutritional status of zinc and copper in obese patients before and after 6 months of Roux-en-Y gastric bypass surgery (RYGBP). Methods 36 patients who underwent RYGBP were prospectively evaluated before and 6 months after surgery. At each phase their weight, height, body mass index (BMI), waist circumference, serum levels of total protein, albumin, prealbumin, zinc and copper were assessed. Results The mean weight loss from baseline to 6 months after surgery was 35.34±4.82%. Among the micronutrients measured 31 patients had some kind of deficiency, there was a high percentage of zinc deficiency both in pre (55.55%) and post-operative (61.11%) and after surgery 8,33% of the patients were deficient in copper and 33.33% in pre-albumin. The protein intake after 6 months of surgery was below the recommendations (<70g/day) for 88,88% of the patients. There was a decrease between the laboratory analysis pre and post-surgery on average for total protein (p<0,05) and pre-albumin (p<0,05). Conclusions Hypozincaemia was frequent and had high prevalence after 6 months of RYGBP and protein supplements are needed to maintain an adequate protein intake up to 6 months after surgery / Mestrado / Fisiopatologia Cirúrgica / Mestra em Ciências da Cirurgia
35

Micronutrient Intake During Pregnancy: Effects of Excessive Folic Acid on Placental Health and Function

Ahmed, Tasfia January 2015 (has links)
Background: In addition to a diet including fortified dietary staples, the use of prenatal multivitamin supplements among women has been shown, in some cases, to lead to excessive micronutrient intake levels for nutrients such as folic acid (FA). It was therefore hypothesized that prenatal vitamin supplementation, in addition to a standard Canadian diet, would place pregnant Canadians at risk for excessive FA intake. With little available research on the potential negative impact of excess FA intake in pregnancy, it was further proposed that high concentrations of FA may adversely affect placental health and function. Thus, the aim of the current study was three-fold: 1) To determine micronutrient intake in a large Canadian cohort of pregnant women; 2) To determine the extent to which FA intake in this cohort may exceed the tolerable upper intake level (UL) after prenatal supplementation; and 3) To determine the effects of excessive FA exposure on placental health and function in vitro. Methodology: Second trimester 3-day food records of pregnant women (N=216) were analyzed for micronutrient intake using ESHA Food ProcessorTM. Nutrient intake values were compared to established Dietary Reference Intake (DRI) values. In a series of experiments, the effects of exogenous folic acid (2-4000 ng/ml) on placental health and function were examined in two placental cell lines [HTR-8/SVneo (N=3) and BeWo (N=3)], and a human placenta explant model (N=6). Following a 48-hour incubation period, the effects of excessive folic acid exposure on placenta cell proliferation, viability, and apoptosis were determined, along with evaluation of placenta cell function via cell invasion and B-hCG hormone release assays. Results: Through dietary sources alone, most pregnant women studied were consuming adequate levels of most micronutrients. However the majority of examined women (>50%) demonstrated a risk of dietary inadequacy for vitamin D, vitamin E, folate, and iron. In the examined cohort, 83% of study participants reported prenatal supplement usage. In vitro exposure of human placenta cells and explants to excessive FA concentrations resulted in no significant differences in cellular proliferation, apoptosis, invasion, or B-hCG hormone production. However, decreased cell viability was observed in BeWo cells at increased FA concentrations (200-2000 ng/mL). Conclusion: Food sources alone do not appear to provide women in Canada with adequate intake of all micronutrients recommended for a healthy pregnancy. Though a prenatal supplement containing FA may be necessary for most women, current FA levels in many prenatal supplements may lead to excessive FA intake above the established UL. Yet, as measured in this study, high FA concentrations do not seem to adversely affect most primary indicators of placental cell health or function.
36

Význam mikronutrientů u pacientů s celiakií / Importance of micronutrients in patients with celiac disease

Dolanská, Pavla January 2021 (has links)
This diploma thesis deals with the issue of celiac disease with a focus on the importance of micronutrients in treatment and clinical monitoring of patients with celiac disease. The thesis is divided into two parts, theoretical and practical. The theoretical part is divided into two chapters. The first chapter deals with celiac disease in general - history, epidemiology, pathogenesis, clinical classification, clinical manifestations, diagnostics and complications of celiac disease. Procedures for clinical monitoring of patients with celiac disease are also discussed. Last but not least, cereal proteins are analysed with a focus on gluten and its importance in the pathogenesis of celiac disease. The second chapter describes gluten-free diet as the only available possibility how to treat celiac disease. Furthermore, the pitfalls of the gluten-free diet and its possible nutritional imbalances associated with a gluten-free diet. The issue of gluten-free products is discussed, both in terms of legislation and in terms of selecting suitable foods. The possibilities of supplementation of micronutrients in celiac and other investigated possibilities of treatment of celiac disease outside the gluten-free diet are also mentioned. The practical part of this diploma thesis has two main goals. The first goal is...
37

Alcohol contribution to total energy intake and its association with nutritional status and diet quality in eight latina american countries

Brenes, Juan Carlos, Gómez, Georgina, Quesada, Dayana, Kovalskys, Irina, Rigotti, Attilio, Cortés, Lilia Yadira, García, Martha Cecilia Yépez, Liria-Domínguez, Reyna, Herrera-Cuenca, Marianella, Guajardo, Viviana, Fisberg, Regina Mara, Leme, Ana Carolina B., Ferrari, Gerson, Fisberg, Mauro 01 December 2021 (has links)
Alcohol consumption is a modifiable risk factor for non-communicable diseases. This study aimed to characterize alcohol consumers at the nutritional, anthropometric, and sociodemographic levels. Data from 9218 participants from Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Peru, and Venezuela participating in “Latin American Health and Nutrition Study (ELANS)”, a multi-country, population-based study, were used. Dietary intake was collected through two, 24 h recalls. Participants were classified into consumers (n = 1073) and non-alcohol consumers (n = 8145) using a cut-off criterium of ≥15 g/day of alcohol consumption calculated from the estimation of their usual daily intake. Among alcohol consumers, the mean alcohol consumption was 69.22 ± 2.18 grams (4.6. beverages/day), contributing to 484.62 kcal, which corresponded to 16.86% of the total energy intake. We found that the risk of alcohol consumption was higher in young and middle-aged men from low and middle socioeconomic status. Argentine, Brazil, and Chile had the highest percentage of consumers, while Ecuador showed the highest alcohol consumption. Alcohol drinkers were characterized by having higher body weight and wider neck, waist, hips circumferences. Alcohol drinkers had a higher energy intake, with macronutrients providing relatively less energy at the expense of the energy derived from alcohol. Alcohol drinkers showed lower and higher consumptions of healthy and unhealthy food groups, respectively. In addition, adequacy ratios for all micronutrients assessed were lower in alcohol consumers. All these deleterious effects of alcohol on nutritional and anthropometric parameters increased with the number of alcoholic beverages consumed daily. Altogether, these findings suggest that limiting alcohol consumption can contribute to reducing the risk of obesity, metabolic syndrome, and diet-related diseases. / Universidad de Costa Rica / Revisión por pares
38

Effect of Micronutrient Rate on the Growth of Containerized Quercus palustris Seddlings in Pine Bark

Kelk, Lisa 05 February 2003 (has links)
The objectives for this research were to determine: 1) the rate of Micromax which will produce maximum growth of pin oak (Quercus palustris Munchh.), a landscape tree which has shown a previous growth response to the addition of Micromax at the manufacturer's recommended rate, 2) which micronutrient(s) is most associated with maximum growth, and 3) the rate of Cu, Fe, Mn, and Zn required to produce maximum growth of Quercus palustris. Q. palustris seedlings were container-grown in pine bark amended with the following rates of Micromax: 0, 0.15, 0.3, 0.6, 0.9, 1.8, or 2.7 kg(m-3 in 2000, 2001, and 2002. For all three years, the maximum growth was obtained at rates near the manufacturer's recommended rate of 0.9 kg(m-3. A micronutrient mix was formulated by increasing the levels of Zn, Mn, Fe, and Cu individually while holding the other micronutrients constant based on the grams of each micronutrient contained in Micromax at 0, 0.15, 0.3, 0.6, 0.9, 1.8, or 2.7 kg(m-3 for 2001 and 0, 0.45, 0.9, or 1.8 kg(m-3 for 2002. In addition, Cu, Fe, Mn, and Zn were also applied alone to pine bark at rates of 0, 0.45, 0.9, or 1.8 kg(m-3 without the addition of any other micronutrients. Holding all other micronutrients constant and increasing the rate of one micronutrient did not increase growth. However, when Cu, Fe, Mn, or Zn was added to pine bark alone at increasing rates, growth increased. For Cu and Zn, the growth increased was linear suggesting that a higher rate of Cu and Zn than that provided by Micromax at the manufacturer's recommended rate might be advantageous. / Master of Science
39

The effect of African leafy vegetables on the alleviation of micronutrient deficiencies in school children residing in the North West Province of South Africa / Marinka van der Hoeven

Van der Hoeven, Marinka January 2014 (has links)
Background - Food and nutrition insecurity severely compromises the quality of life in farm communities in South Africa. Although food‐based approaches are more sustainable strategies to address malnutrition, most other strategies only target the alleviation of single micronutrients. Synergies between nutrients demand a wider scope; food‐based strategies need to focus on improving both overall diet quality and the well‐being of rural and urban populations. Agricultural biodiversity is crucial in such strategies to improve food security and health. This thesis aims to investigate the effect of African leafy vegetables (ALVs) on the alleviation of micronutrient deficiencies in school children residing in the North West Province of South Africa. Methods - Four focus group discussions assessed primary caregivers’ (n=29) knowledge, perceptions and use of indigenous and traditional plants. Thereafter, the research focused on the leaves of Amaranthus cruentus (amaranth), Cleome gynandra (spiderplant), Cucurbita maxima (pumpkin) and Vigna unguiculata (cowpea). Sensory acceptability to children of selected ALV dishes, prepared in a traditional way (n=98) and prepared with gravy, was assessed (n=80). The nutrient composition and the bio‐accessibility of iron and zinc in these ALVs were determined. A randomised controlled trial to investigate the effect of consumption of these ALVs on the iron, vitamin A en zinc status of primary school children (grade R – grade 4) followed. Children of two rural farm schools were randomly allocated per grade and school to receive either daily (five days/week) 300 gram cooked ALVs with the school meal starch (N=86) or the normal school meal (N=81) for three months. Results - Caregivers were positive about using ALVs, transferring knowledge from generation to generation. Children found dishes made with ALVs, prepared in the traditional way as well as with gravy, acceptable in terms of colour, smell and taste. ALVs contributed 11.6 ‐ 15.8 mg iron and 1.4 ‐ 3.7 mg zinc per meal. Amaranth‐and‐spiderplant has the highest amount of bio‐accessible iron (0.42 mg iron). All dishes contain 0.3 mg bio‐accessible zinc. At baseline, intervention and control children were deficient for Hb <11.5 g/dL (16.0% and 10.5%), serum ferritin <15 μg/L (16.3% and 18.5%), serum retinol <20 μg/dL (7.0% and 2.5%) and serum zinc <65 μg/dL (75.6% and 75.3%). No significant estimated intervention effect was found. Conclusion - Caregivers possessed knowledge of ALVs and were positive about their use. Based on dialyzable iron and zinc, the contribution of the ALV dishes towards dietary requirements is more substantial for iron than zinc. The randomised controlled trial showed that ALVs unable to improve serum retinol, serum ferritin or hemoglobin in mildly deficient children or those with low status zinc. Furthermore, despite the low zinc status in our population, ALV consumption did not improve serum zinc concentrations. Based on the more theoretical and indirect study results, including both caregivers’ and children’ positive image of ALVs, and the nutrient composition and iron and zinc bio‐accessibility of the ALVs, these selected vegetables do have the potential to contribute to the micronutrient intake of school children. However, the importance of ALVs might not necessary be to serve as a strategy for micronutrient deficiency alleviation, but rather in the diversification of the diet in resource‐poor settings and thereby contribute to the micronutrient intake. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2014
40

The effect of African leafy vegetables on the alleviation of micronutrient deficiencies in school children residing in the North West Province of South Africa / Marinka van der Hoeven

Van der Hoeven, Marinka January 2014 (has links)
Background - Food and nutrition insecurity severely compromises the quality of life in farm communities in South Africa. Although food‐based approaches are more sustainable strategies to address malnutrition, most other strategies only target the alleviation of single micronutrients. Synergies between nutrients demand a wider scope; food‐based strategies need to focus on improving both overall diet quality and the well‐being of rural and urban populations. Agricultural biodiversity is crucial in such strategies to improve food security and health. This thesis aims to investigate the effect of African leafy vegetables (ALVs) on the alleviation of micronutrient deficiencies in school children residing in the North West Province of South Africa. Methods - Four focus group discussions assessed primary caregivers’ (n=29) knowledge, perceptions and use of indigenous and traditional plants. Thereafter, the research focused on the leaves of Amaranthus cruentus (amaranth), Cleome gynandra (spiderplant), Cucurbita maxima (pumpkin) and Vigna unguiculata (cowpea). Sensory acceptability to children of selected ALV dishes, prepared in a traditional way (n=98) and prepared with gravy, was assessed (n=80). The nutrient composition and the bio‐accessibility of iron and zinc in these ALVs were determined. A randomised controlled trial to investigate the effect of consumption of these ALVs on the iron, vitamin A en zinc status of primary school children (grade R – grade 4) followed. Children of two rural farm schools were randomly allocated per grade and school to receive either daily (five days/week) 300 gram cooked ALVs with the school meal starch (N=86) or the normal school meal (N=81) for three months. Results - Caregivers were positive about using ALVs, transferring knowledge from generation to generation. Children found dishes made with ALVs, prepared in the traditional way as well as with gravy, acceptable in terms of colour, smell and taste. ALVs contributed 11.6 ‐ 15.8 mg iron and 1.4 ‐ 3.7 mg zinc per meal. Amaranth‐and‐spiderplant has the highest amount of bio‐accessible iron (0.42 mg iron). All dishes contain 0.3 mg bio‐accessible zinc. At baseline, intervention and control children were deficient for Hb <11.5 g/dL (16.0% and 10.5%), serum ferritin <15 μg/L (16.3% and 18.5%), serum retinol <20 μg/dL (7.0% and 2.5%) and serum zinc <65 μg/dL (75.6% and 75.3%). No significant estimated intervention effect was found. Conclusion - Caregivers possessed knowledge of ALVs and were positive about their use. Based on dialyzable iron and zinc, the contribution of the ALV dishes towards dietary requirements is more substantial for iron than zinc. The randomised controlled trial showed that ALVs unable to improve serum retinol, serum ferritin or hemoglobin in mildly deficient children or those with low status zinc. Furthermore, despite the low zinc status in our population, ALV consumption did not improve serum zinc concentrations. Based on the more theoretical and indirect study results, including both caregivers’ and children’ positive image of ALVs, and the nutrient composition and iron and zinc bio‐accessibility of the ALVs, these selected vegetables do have the potential to contribute to the micronutrient intake of school children. However, the importance of ALVs might not necessary be to serve as a strategy for micronutrient deficiency alleviation, but rather in the diversification of the diet in resource‐poor settings and thereby contribute to the micronutrient intake. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2014

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