Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Hergebruik drinkwaterslib beoogt natuurontwikkeling op fosfaatrijke gronden
Dorland, E. ; Fujita, Y. ; Chardon, W.J. ; Lucassen, E.C.H.E.T. ; Smolders, A. ; Ketelaar, R. ; Jong, A.L. de - \ 2016
Vakblad Natuur Bos Landschap (2016)124. - ISSN 1572-7610 - p. 3 - 5.
natuurontwikkeling - drinkwater - slib - fosfaat - bodemverbeteraars - natuurbeheer - afvalhergebruik - veldproeven - ijzer - nature development - drinking water - sludges - phosphate - soil conditioners - nature management - waste utilization - field tests - iron
Natuurbeheerders zitten soms in hun maag met percelen die vanwege hun landbouwkundig verleden een hoge fosfaatlast kennen, omdat dit de ontwikkeling van waardevolle natuur belemmert. Afgraven is duur, uitmijnen tijdrovend, maar wat dan? Kan hergebruik van ijzerrijk drinkwaterslib uitkomst bieden? De eerste resultaten van veldproeven met dit restproduct van drinkwaterwinning zijn hoopgevend.
Recirculatie bij Phalaenopsis technisch goed haalbaar : Investeringsdrempel voor hergebruik drainwater ligt hoog
Arkesteijn, Marleen ; Kromwijk, J.A.M. - \ 2016
Onder Glas 13 (2016)1. - p. 9 - 11.
tuinbouw - glastuinbouw - waterbeheer - potplanten - drainagewater - hergebruik van water - phalaenopsis - gewaskwaliteit - emissiereductie - normen - stikstof - mest - natrium - zink - ijzer - horticulture - greenhouse horticulture - water management - pot plants - drainage water - water reuse - crop quality - emission reduction - standards - nitrogen - manures - sodium - zinc - iron
Hergebruik van drainwater bij phalaenopsis heeft geen nadelige effecten voor de plantengroei. Dat is de eindconclusie uit het onderzoek dat het afgelopen jaar is uitgevoerd en dat de gewascoöperatie Potorchidee deels financierde. De gewascoöperatie is tevreden en wil het komende jaar een vervolgonderzoek naar het effect van gecontroleerd vrijkomende meststoffen. Hiermee kunnen ook niet recirculerende telers een stap zetten.
Iron is essential for photosynthesis and respiration : iron deficiency : the most common deficiency disorder
Heuvelink, E. ; Kierkels, T. - \ 2016
In Greenhouses : the international magazine for greenhouse growers 5 (2016)1. - ISSN 2215-0633 - p. 48 - 49.
horticulture - greenhouse horticulture - rosaceae - chelates - ph - iron - deficiency - plant disorders - crop production - tuinbouw - glastuinbouw - chelaten - ijzer - deficiëntie - afwijkingen, planten - gewasproductie

Iron plays a major role in photosynthesis. That’s why a shortage directly affects the production capacity of the plant. The application of chelates has made iron much more easy to absorb. Nevertheless it’s an element that we have to keep an eye on.
IJzerrijk drinkwaterslib en verschraling landbouwgronden: een proof of principle
Lucassen, E.C.H.E.T. ; Chardon, W.J. ; Dorland, E. ; Sluys, M.L. van der; Poelen, M.D.M. ; Smolders, Alfons J.P. - \ 2015
Landschap : tijdschrift voor Landschapsecologie en Milieukunde 32 (2015)4. - ISSN 0169-6300 - p. 160 - 169.
fosfaat - bodemverbeteraars - ijzer - waterstand - natuurontwikkeling - bodemchemie - slib - phosphate - soil conditioners - iron - water level - nature development - soil chemistry - sludges
Bij de inrichting van het Natuurnetwerk Nederland en van Natura 2000-gebieden worden op grote schaal landbouwgronden heringericht als soortenrijke natuur. Om op korte termijn fosfaatarme bodemcondities te krijgen wordt op locaties waar de bodem te rijk is via maaibeheer en/of uitmijnen te bereiken, vaak gekozen voor verwijdering van de fosfaatrijke bodemlaag. Een mogelijk alternatief voor ontgronden is het toedienen van ijzerslib. Dit restproduct van drinkwaterwinning verbetert de fosfaatbinding van de bodem.
Fonio (Digitaria exilis) in West Africa: towards improving nutrient quality
Koreissi, Y. - \ 2015
University. Promotor(en): Michael Zimmermann, co-promotor(en): Inge Brouwer; Diego Moretti. - Wageningen : Wageningen University - ISBN 9789462574557 - 177
digitaria exilis - digitaria - voedingsstoffenverbetering - voedselkwaliteit - voedingswaarde - ijzer - zink - west-afrika - nutrient improvement - food quality - nutritive value - iron - zinc - west africa

Fonio (Digitaria exilis) in West Africa: Towards improving nutrient quality

Abstract

Hidden hunger affects a far greater percentage of the world’s population with iron and zinc deficiencies being the most common, particularly affecting women of reproductive age. The primary cause of the mineral and vitamin deficiencies in developing countries is inadequate intakes of multiple and bioavailable micronutrients in common cereal-based diets, emphasizing the need for increased quality of diets. Plant genetic diversity, and also indigenous foods and/ or traditional grains as fonio may play a critical role in reduction of the problem for resource poor populations. Fonio (Digitaria exilis) is the most ancient West African cereal representing a key crop in food supply during crop shortfall periods. However, less is known about its potential to contribute improving nutrition and health. In this context, the thesis investigated whether we could improve the nutrient quality of fonio, especially iron, to potentially contribute to the daily intake of population.

Investigations in this thesis comprised: i) the consumption pattern of fonio and its contribution to nutrient intakes (108 women aged 15‐49 year-old selected from 3‐stage cluster sampling procedure in Bamako, Mali for the purpose of the fonio project); ii) the validation of the Mali food composition database (TACAM) for assessing population level intakes of energy and nutrients (36 women out of 108 previously selected); iii) the genetic diversity, nutrient content especially bioavailable iron and zinc content and the effect of processing on fonio landraces (12 fonio landraces collected from farmers in Mali); iv) the sensory variability among fonio landraces (20 fonio landraces collected from farmers in Mali, Guinea and Burkina Faso); v) improved food processing combining dephytinisation with native phytase and fortification of fonio diet with iron to increase iron absorption (16 women aged 18-30 year-old from simple random sampling in Cotonou, Benin).

The results indicated that i) fonio is consumed one to three times/ month by 68% of our study population. The average daily portion size is 152g when consumed. Only 5% of the study population consumed fonio dishes contributing to 16% of the daily energy intake for the consumed portion size, reflecting the low consumption of fonio related to significant barriers such as availability of cooked fonio in urban markets, lack of consistent supply throughout the year, difficult post- harvest processing, high-quality product demand, hard texture coupled with time consuming cooking process, and high cost of fonio products.

The use of the adjusted TACAM is acceptable for estimating average intake at population level for macronutrients, calcium and zinc in a low intake population, but not for carbohydrate and iron intakes which was underestimated and vitamin A which was overestimated, nor for probability of adequate intakes and nutrient densities. At individual level, significant differences were observed between estimated and analyzed intakes for all the nutrients increasing with higher intakes.

The nutrient content of fonio landraces in Mali and the effect of processing of the nutrient values revealed i) a limited genetic variation of studied landraces, polymorphism level (3.5%) compared to 63% reported for 118 fonio accessions collected in West Africa, three different clusters only for Malians landraces compared to two clusters for Mali, Burkina Faso, Guinea and Benin together; ii) no statistically significant differences between fonio landraces for their iron and zinc content, iii) a high iron and phytate concentration in paddy fonio (35 and 514 mg/100 g dry weight) which reduces considerably with traditional processing, the most important losses occurring during processing from paddy to mid wet fonio (approximately 2 and 129 mg/100 g), 96% reduction for iron and 75% for phytate.

Fonio landraces in West Africa were different for their visual (colour and presence/absence of impurities) and their textural (consistency of cooked grain) charactersitics.

Exploring processing to increase iron biavailability from fonio meals confirm that whole wheat flour could be used as a source of natural phytase to produce low phytic acid containing fonio porridge. It showed also that dephytinisation using intrinsic wheat phytase reduced phytate-to-iron molar ratio from 23.7:1 to 2.7:1 after only 1 hour of incubation at 50ºC with pH of 5.0, and iron fortification decreased the molar ratio to 0.3:1. Dephytinisation with wheat phytase and fortification significantly increased iron absorption ratio from 2.6% to 8.2% in fonio porridges.

From these results, we can conclude that the current contribution of fonio to daily bioavailable iron intake is low due to small portion sizes being consumed in low frequency, to considerable losses during processing to mid-wet fonio, and to a high phytate-iron molar ratio. Fonio landraces from Mali, Guinea and Burkina Faso are variable in visual and textural characteristics (colour, presence of impurity and consistency of the cooked grain, respectively), determining the preference of consumers. Selecting landraces for preferred sensory properties may offer an entry point for processors who intend to promote the consumption of fonio and increase its role in diet. In absence of meaningful genetic diversity and variation in iron content in fonio landraces in Mali, there is little benefit in selecting landraces for natural high iron content. Dephytinisation using intrinsic wheat phytase could be a promising processing practice to improve iron bioavailability and fortification is required to increase the amount of absorbed iron from fonio meals.

Afvangen van fosfaat uit bloembollensector met ijzerzand : Test van maatregelen die fosforemissie verminderen
Chardon, W.J. ; Groenenberg, J.E. ; Jansen, S. ; Buijert, A. ; Talens, R. ; Krol, A.F. - \ 2014
Bodem 24 (2014)6. - ISSN 0925-1650 - p. 20 - 22.
vollegrondsteelt - bloembollen - bodemchemie - emissiereductie - fosfaten - adsorptie - ijzer - bollenstreek - outdoor cropping - ornamental bulbs - soil chemistry - emission reduction - phosphates - adsorption - iron
In het oppervlaktewater van de Bollenstreek is de fosfaatconcentratie veel hoger dan de norm van de Europese Kaderrichtlijn Water. Met ijzerzand, een nevenproduct van drinkwaterproductie, kan fosfaat worden afgevangen. Het hoogheemraadschap van Rijnland heeft drie maatregelen op basis van ijzerzand laten onderzoeken op hun effectiviteit. Welke was de beste?
Safety and efficacy of iron supplementation in pregnant Kenyan women
Mwangi, M.N. - \ 2014
University. Promotor(en): Huub Savelkoul; A.M. Prentice, co-promotor(en): Hans Verhoef. - Wageningen : Wageningen University - ISBN 9789461739209 - 220
ijzer - minerale supplementen - veiligheid - risicoschatting - werkzaamheid - zwangerschap - kenya - iron - mineral supplements - safety - risk assessment - efficacy - pregnancy

Since the British doctor Ronald Ross received the 1902 Nobel Prize in medicine for his work on malaria, more people have died from the disease than all world wars combined. This is in spite of the fact that the French chemists Pierre Joseph Pelletier and Joseph Bienaimé Caventou made quinine available from as early as 1820. According to the World Health Organisation (WHO), there were about 219 million cases of malaria in 2010 and an estimated 660,000 deaths majority of which (80% of cases and 90% of deaths) were in Africa.

Of almost two billion people who are anaemic globally, 41.8% are pregnant women. Iron supplements are used to prevent anaemia. There are concerns that iron given in high doses may increase malaria rates. Uncertainties regarding the safety of iron supplementation in malaria endemic regions were propelled by a randomized controlled trial that evaluated the effects of iron and folic acid supplementation in 32,155 children in Pemba, Tanzania. This study found that children who received iron and folic acid supplements were more likely to die or to need hospitalisation for an adverse event. At the same time, malaria is known to exacerbate anaemia; an almost inevitable consequence of malarial infection. As such, the safety of daily oral use of iron supplements by pregnant women, as a public health intervention is still not clearly established; at least not until publication of our main findings.

This thesis assessed the effects of iron supplementation on safety indicators, and on iron status, in pregnant women and their neonates. Several preparatory activities were carried out, including a census of the population in the study area and a pilot study to check the operability of the study protocols. A main study was designed with the hypothesis that consumption of food products fortified with iron combined with intake of iron supplements especially in pregnancy, would be detrimental to the health of pregnant women and their neonates.

The objectives of the study were: 1) to compare the presence of malarial infection in parturient women who received a combination of iron-fortified foods with iron supplements versus iron-fortified foods only; 2) to assess intervention effects on the maternal prevalence of iron deficiency anaemia at 1 month after delivery; 3) to assess intervention effects on neonatal iron stores at 1 month of age; 4) to assess the diagnostic utility of Zinc protoporphyrin (ZPP) in diagnosing iron deficiency in malaria endemic regions; 5) to identify baseline factors that are prognostic for the Non-Transferrin Bound Iron (NTBI) response to consumption of a single iron supplement; 6) to determine the factors that predict Plasmodium infection in pregnancy; 7) to identify factors associated with birth weight; 8) to develop a methodology to predict cases of low birth weight, using a single prognostic score that is based on prognostic variables collected at the second trimester of pregnancy; and 9) to develop methods for community-based flour fortification with iron.

Most countries have enacted, or are in the process of enacting legislation for mandatory fortification of flour with iron. Thus pregnant women may receive iron from fortified foods and from universal iron supplementation programmes. This thesis provides answers to pertinent questions regarding the safety and efficacy of iron supplementation by comparing daily high-dose iron (i.e. iron-fortified foods plus iron supplements) versus low-dose iron (i.e. iron-fortified foods only) during pregnancy. The main outcome measure was the presence of maternal Plasmodium infection at birth, regardless of species. Chapter 1 is a detailed introduction of the background to the study and the design of the study.

This thesis presents concrete evidence that iron supplementation to pregnant women in a highly malaria endemic region does not result in increased risk of malarial infection; percent difference (95%CI) = 0.0% (─9.3% to 9.3%). Programme implementers and governments in malaria endemic regions should not be held back by previous recommendations that cautioned against issuing iron supplements to pregnant women. In light of these findings, there is no need to first screen for malaria before giving iron supplements.

Iron supplementation had major benefits for mothers and their neonates (chapter 2). The findings reported in this thesis showed a mean increase in birth weight of 143 g relative to the low-dose iron group. The effects of iron were influenced by the participants initial iron status. Correction of iron deficiency increased birth weight by 249 g, even though we cannot exclude the possibility that this may have increased malarial infection by 10%. There was no evidence that effects of iron on birth weight were influenced by intermittent preventive treatment against malaria. Iron supplementation also increased fetal growth by 0.27 SD, 95%CI: (0.04 to 0.50) probably as a result of gains in length and weight for gestation age.

We also showed improved neonatal iron stores one month post-partum as indicated by a 17.1 % (95% CI: 2.0% to 34.3%) increase in plasma ferritin concentration in neonates of mothers who received high-dose iron compared to those who received low-dose iron. This provides more impetus to the need to offer iron supplements to pregnant women with the aim of boosting infant iron stores (chapter 2).

ZPP was found to be of unreliable diagnostic utility when discriminating between pregnant women with and without iron deficiency in regions where chronic diseases are prevalent (chapter 3). The current conventional cut off points for whole blood ZPP e.g. >70 μmol/mol heme, can result in gross estimates of the prevalence of iron deficiency especially if the true prevalence is low.

The appearance of non-transferrin bound iron (NTBI) in circulation after oral ingestion of iron supplements has been thought to aid the growth and multiplication of Plasmodium parasites thereby increasing malaria induced morbidity and mortality. We did not observe any increase in NTBI concentrations three hours after oral ingestion of 60 mg of ferrous fumarate (Chapter 4). We cannot exclude the possibility that iron supplementation leads to NTBI production when supplements are not consumed with food, because the lunch meal consumed by majority of our participants during the 3-hour waiting period probably contained natural compounds (phytates) that may have limited an NTBI response.

In chapter 5 of this thesis, we aimed to develop a field friendly tool that can be used to predict asymptomatic Plasmodium infection. This was motivated by the fact that most point-of-care dipstick tests used to detect Plasmodium infection are not able to detect 100% of all the infection present yet asymptomatic infections are increasingly associated with adverse maternal and neonatal outcomes. Although many likely predictive factors were assessed individually or in combination with others, we did not succeed in developing a reliable tool that is easy to apply in resource-poor malaria endemic settings.

In Chapter 6, we aimed to identify factors associated with birth weight and to develop a methodology to predict cases of low birth weight using a single prognostic score that is based on prognostic variables collected at the second trimester of pregnancy. Factors that were found to be independently associated with reduced birth weight were being never married, inflammation, being a girl, and iron deficiency. Being overweight was associated with increased birth weight. The results indicate that we can use variables collected rapidly and at relatively low cost and ease to identify with fair accuracy women in the second trimester of pregnancy who are at high risk of giving birth to a neonate with low birth weight.

The various aspects of the work presented in this thesis including the implications for policy makers are discussed in chapter 7. For policy makers, the findings of this thesis are a welcome relief. The findings therein eliminate all doubt that has hitherto been associated with antenatal iron supplementation in malaria endemic areas. Most countries already have iron supplementation policies that are well aligned to the World Health Organisation policies. Efforts to widen the coverage of antenatal iron supplementation especially in malaria endemic regions should be urgently scaled up. However, the evidence provided in this thesis is only applicable to pregnant women and cannot be extrapolated to children in malaria endemic regions. For this population, the current WHO policy must be used thus before iron supplementation, children must first be screened for malaria.

Although this thesis provides answers to key scientific questions that have hitherto baffled the scientific community, there are still research questions that can be clarified further. The effects of a high iron dose in pregnancy (as per national and international guidelines, the daily supplementation dose for pregnant women should be doubled to 120 mg iron if they are anaemic or if 6 months duration cannot be achieved in pregnancy (Chapter 2)) on maternal and neonatal outcomes need to be elucidated. Further research is needed in order to describe fully, the NTBI response to consumption different types and amounts of oral iron supplements. There is urgent need for diagnostic tools that can be used in resource-poor settings to diagnose asymptomatic infections. Further research in children is needed to provide evidence of the safety and efficacy of iron supplementation in malaria endemic regions and to assess the diagnostic performance of zinc protoporphyrin in children. In addition, since our studies suggest that screening based on Hb concentration as now practiced in many countries, is inaccurate in discriminating between women at high and low risk of delivering neonates with low birth weight, further studies are needed to identify appropriate markers and cut-off points that are suited to this purpose.

In conclusion, this thesis has shown that there is no evidence that antenatal iron supplementation increases Plasmodium infection. Antenatal iron supplementation leads to large improvements in birth weight, fetal growth and infant iron stores, with potentially immense benefits for infant survival and health that should outweigh any possible concerns about risks of malaria. Epidemiological calculations indicate that if our results are applied to all women in developing countries in order to eliminate iron deficiency, we could avoid 3 million births with low birth weight annually and save the lives of more than half a million neonates. Scaling up universal iron supplementation in pregnancy in developing countries will generate major public health gains.

Sterke vermindering van fosfaatuitspoeling uit landbouwgronden met de fosfaatbindende drain
Groenenberg, J.E. ; Chardon, W.J. ; Koopmans, G.F. - \ 2013
draineerbuizen - drainagewater - ijzer - adsorptie - waterkwaliteit - fosfaten - veldproeven - drain pipes - drainage water - iron - adsorption - water quality - phosphates - field tests
Voor gedraineerde landbouwgronden (meer dan 50% in Nederland) heeft Alterra de fosfaatbindende drain ontwikkeld. Dit is een normale buisdrain die is ingebed in ijzerzand. De omhulling met ijzerzand bindt het fosfaat uit het fosfaatrijke water voor het de drainbuis instroomt. Het schone water wordt afgevoerd naar het oppervlaktewater.
Development of iron and zinc enriched mungbean (Vigna radiata L.) cultivars with agronomic traits in consideration
Singh, R. - \ 2013
University. Promotor(en): Richard Visser, co-promotor(en): Sjaak van Heusden. - S.l. : s.n. - ISBN 9789461736840 - 175
vigna radiata - mungbonen (green gram) - mungbonen - sporenelementen - ijzer - zink - plantenveredeling - genetische diversiteit - voeding - india - voedselsoevereiniteit - green gram - mung beans - trace elements - iron - zinc - plant breeding - genetic diversity - nutrition - food sovereignty

Malnutrition in India, particularly among women, children and adolescents is an emergency that needs immediate attention in this fast growing and developing country. Micronutrient deficiencies are threatening public health in India more and more. Deficiencies of micronutrients drastically affect growth, metabolism and reproductive phase in humans as it does in plants and animals. Cereal and pulse based Indian diets are qualitatively deficient in micronutrients such as iron, calcium, vitamin A and zinc. This is due to a low intake of income-elastic protective foods such as pulses, vegetables, fruits, and foods of animal origin. It is presumed that if we restore the geographical connection between food production and consumption in local food networks it will help in solving this nutritional problem in India. This offers new opportunities to tailor science & technology to location specific patterns of food production and consumption, which may lead to environmentally and socially sustainable agriculture. Despite global pressure (including from science and technology) to focus agricultural cultivation on a limited number of food crops, still many so-called orphan crops like mungbean do exist and are cultivated in location-specific crop rotation systems. Particularly, the seed legumes are of major nutritional importance, especially in developing countries, because they have high protein contents of good biological value. Out of the total sales of mungbean, about half of the sales are within the village which clearly establishes the need for development of infrastructure and facilities at the village level to serve the interests of the farm households. Moreover, it is also necessary to shift the focus of development from the urban market centres (largely developed) to the rural market centres. Linking breeding, nutrition, processing and standardisation of food products, may be designed within the experimental framework of empowering poor farmers. Hence, tailoring plant, food and social sciences to empower local mungbean production and consumption patterns has been designed as an interdisciplinary program of plant breeding, food technology, human nutrition and sociology of science and technology. Thus the ‘Tailoring Food Sciences to Endogenous Patterns of Local Food Supply for Future Nutrition’ (TELFUN) project aimed to help people in selecting their own way of local food production, processing and consumption of the best suited local food. The main objective is to strengthen “The Science in Society” approach by remodeling participatory research and development and the general aim of TELFUN was to attune disciplinary research objectives within an interdisciplinary framework to enhance food sovereignty and to improve mungbean based production and consumption pattern in selected research area (Haryana, India). As an example our research focused on further improving one of the potential nutritional crops, namely mungbean. The present work emphasizes on mungbean in general and especially on the available micronutrient variation in the mungbean germplasm. The mungbean (green gram), Vigna radiata (L.) Wilczek is native to the Indian subcontinent. They are warm season annuals, highly branched and having trifoliate leaves like the other legumes. Seeds of mungbean are small, ovoid in shape, and green in color. Mungbean seeds are high in protein (21%–28%), calcium, phosphorus and certain vitamins. Moreover they are easily digested and they replace scarce animal protein in human diets in vegetarian populations of the world. The selected area of research centres contain a high level of local biodiversity and are the locations for domestication of mungbean. This legume has co-evolved with their natural ecosystems and is well-adapted to withstand the local biotic and abiotic stresses. This will help in enabling the reconnection of the cultivation of the mungbean with their natural environments. Moreover, as domestication has taken place by local farmers during many centuries, they have accumulated local endogenous knowledge, which is very relevant for local food networks (www.telfun.info). Thus to explore the potential mungbean network, the present thesis set its objectives. They were: i) identification of the major constraints, limitations and preferences of producer’s with regard to mungbean, ii) assessing the diversity in the available germplasm and assessing the effects of different environments on selected cultivars for their mineral micronutrients and iii) to make a start to develop tools for marker assisted breeding with regard to iron and zinc.

Efficacy of iron fortified cowpea flour in improving iron status of schoolchildren in malaria endemic rural Ghana
Abizari, A.R. - \ 2013
University. Promotor(en): Michael Zimmermann, co-promotor(en): Inge Brouwer; M. Armar-Klemesu. - S.l. : s.n. - ISBN 9789461735263 - 191
vignameel - fortificatie - ijzer - ijzergebrekanemie - voedingstoestand - schoolkinderen - ghana - schoolmaaltijden - edta - biologische beschikbaarheid - voedingsprogramma - malaria - voedselsoevereiniteit - cowpea meal - fortification - iron - iron deficiency anaemia - nutritional state - school children - school meals - bioavailability - nutrition programmes - food sovereignty

Children in sub-Saharan Africa are more likely to have survived the critical first 1000 days of life carrying along unresolved micronutrient deficiencies into the school-age. Iron-deficiency is the most prevalent micronutrient problem affecting school-age children in sub-Saharan Africa and yet the most difficult to resolve. It is necessary to ensure an adequate iron intake through the diet of school-age children and school-based feeding intervention may be a way to improve iron intake of schoolchildren. Such a feeding intervention would be more sustainable if it relies on locally produced food(s) with the potential to support food sovereignty. In this context, this thesis investigated whether foods based on cowpeas, an indigenous legume crop originating from Africa, can be used in a school feeding setting to improve iron status of school-age children in Ghana.

The investigations in this thesis comprised cross-sectional dietary and iron status assessment of schoolchildren (n=383), cowpea acceptability among schoolchildren (n=120 mother-child pairs), chemical analysis of cowpea landraces (n=14), an in vivo iron bioavailability among young women (n=16) and a randomized cowpea intervention trial (n=241) conducted mainly in Tolon-Kumbungu district of Ghana.

The results indicated that iron-deficiency and iron-deficiency anaemia affect 8 and 7 out of every 10 schoolchildren respectively. It also showed that the probability of adequate dietary iron intake is 0.32 but much larger (~0.90) if schoolchildren benefitted from a school feeding programme. Mothers/caregivers intended to give cowpeas to their schoolchildren 2–3 times per week. The positive attitudes of mothers towards cowpea predicted their intention to give them to their schoolchildren but they were worried about the cost, long cooking time and the discomfort their children may suffer after consuming cowpeas. The chemical analysis showed that cowpeas contain appreciable amounts of iron (4.9–8.2 mg/ 100 gd.w) and zinc (2.7–4.1 mg/100 gd.w) but also high amounts of inhibitory phytate (477–1110 mg/100 gd.w) and polyphenol (327–1055 mg/100 gd.w). Polyphenol concentration in particular was higher (P<0.05) in coloured compared to white landraces. Iron bioavailability from red and white cowpeas were 1.4 and 1.7%, respectively, in NaFeEDTA-fortified meals and 0.89 and 1.2%, respectively, in FeSO4-fortified meals. Compared with FeSO4, fortification with NaFeEDTA increased the amount of iron absorbed from white and red cowpea meals by 0.05 and 0.08 mg (P < 0.05) respectively. Irrespective of the fortificant used, there was no significant difference in the amount of iron absorbed from the 2 varieties of cowpea. Finally the results from the intervention trial showed that fortification of whole cowpea flour with NaFeEDTA resulted in improvement of haemoglobin (P<0.05), serum ferritin (P<0.001) and body iron stores (P<0.001), and reduction in transferrin receptor concentration (P<0.001). Fortification also resulted in 30% and 47% reduction in the prevalence of iron-deficiency (ID) and iron-deficiency anaemia (IDA) (P<0.05), respectively.

Overall, this thesis has shown that in a malarious region with high iron-deficiency like (northern) Ghana, iron status of schoolchildren can be improved through the consumption of cowpeas within a school feeding programme. The improvement in iron status is however unlikely to result from the usual/conventional consumption of cowpeas but through fortification of whole cowpea flour with a highly bioavailable iron compound. This thesis has also shown that the most suitable iron compound for such whole cowpea flour fortification is NaFeEDTA irrespective of whether the cowpea has high or low concentration of polyphenols.

Adviesbasis voor de bemesting van akkerbouwgewassen : sporenelementen
Haan, J.J. de; Geel, W.C.A. van - \ 2013
Kennisakker.nl 2013 (2013)20 maart.
akkerbouw - gewassen - mest - sporenelementen - borium - mangaan - koper - ijzer - zink - molybdeen - toepassing - dosering - bemesting - arable farming - crops - manures - trace elements - boron - manganese - copper - iron - zinc - molybdenum - application - dosage - fertilizer application
In dit artikel worden adviezen gegeven voor de bemesting van akkerbouwgewassen met de sporenelementen; borium, mangaan, koper, ijzer, zink en molybdeen.
Nieuwe ijzermeststof blijkt goede aanvulling op ijzerbemesting (interview met Wim Voogt)
Arkesteijn, M. ; Voogt, W. - \ 2013
Onder Glas 10 (2013)5. - p. 37 - 37.
glastuinbouw - plantenvoeding - ijzer - ijzerhoudende meststoffen - meststoffen met sporenelementen - calciumabsorptie - proeven - groenten - komkommers - greenhouse horticulture - plant nutrition - iron - iron fertilizers - trace element fertilizers - calcium absorption - trials - vegetables - cucumbers
IJzer is een belangrijk voedingselement, dat onder andere een rol speelt bij de aanmaak van chlorofyl. IJzergebrek kost productie. IJzerionen zijn moeilijk in oplossing te houden. Op dit moment is ijzer in een opneembare vorm voor de substraatteelt alleen beschikbaar in een chelaatvorm. Chelaten zorgen dat dit nutriënt toch beschikbaar is voor de plant. Nadeel is dat het een vrij dure meststof is. Maar er is een alternatief.
Fonio (Digitaria exilis) as a staple food in Mali : an approach to upgrade nutritional value
Fanou-Fogny, N.M.L. - \ 2012
University. Promotor(en): Frans Kok, co-promotor(en): Inge Brouwer; R.A.M. Dossa. - S.l. : s.n. - ISBN 9789461732927 - 188
digitaria exilis - mali - ijzer - fortificatie - ijzerabsorptie - voedingstoestand - sporenelementtekorten - voedingswaarde - vrouwen - iron - fortification - iron absorption - nutritional state - trace element deficiencies - nutritive value - women

Background
With the increasing nutritional and health problems related to the global food crisis, the potential contribution of traditional foods to alleviation of poverty, nutritional deficiencies and health issues has been emphasized. Fonio (Digitaria exilis) is the most ancient West African cereal representing a key crop in food supply during crop shortfall periods. Less is known about the potential of fonio to contribute to nutrition and health in West Africa. The value chain approach for nutritional goals is a set of strategies through which values are added to products for improvement of nutrition among vulnerable groups, while creating benefits for stakeholders. Strategies in a value chain approach comprise agricultural strategies, processing, and consumer-oriented actions to enhance acceptability.

Objectives
In this thesis we explored value chain strategies as possible solutions to existing nutritional problems among West African women, using fonio as product. To achieve this objective, specific research questions were investigated through the following cross-sectional studies: i) baseline assessment of nutrition (iron) status, iron intake and adequacy to define the nutritional context for operating the value chain approach; ii) assessment of socio-cultural acceptability of fonio as strategic entry point for consumer-oriented activities; iii) investigating processing (dephytinisation and fortification) as strategy for adding nutritional value to fonio.

Methods
Subjects involved were women of reproductive age randomly selected in Bamako, the capital city of Mali (108 women aged 15-49 y-old from 3-stage cluster sampling procedure), and Cotonou, the largest city of Benin (16 women aged 18-30 y-old from simple random sampling for an iron absorption study). Data collection included anthropometric and blood indicators measurement; dietary assessment based on a duplicate 24-h dietary recall, indirect and rapid assessment techniques; food ethnography focused on fonio, including an availability survey on market, a food consumption survey on the uses of fonio, and an acceptability survey based on a behavioral model; and an iron absorption study using stable isotopes.
consumption (68% consuming 1 to 3 times/month) and daily portion size of fonio (152 g) was relatively low as compared to other staples like rice and millet. Fonio consumption was strongly predicted by intention to consume (r = 0.78, P < 0.001), which was influenced by positive beliefs and attributes (β = 0.32, P < 0.05). Subjective norms, namely the opinion of the husband, the family and the neighborhood motivated intention to consume fonio (r = 0.26, P < 0.001). Perceived barriers such as time-consuming processing and lack of skills in cooking fonio had a significant interaction between intention to consume and fonio consumption (β = -0.72, P < 0.05). Exploring processing as strategy for adding nutritional value to fonio showed that dephytinisation with intrinsic wheat phytase reduced phytate-to-iron molar ratio from 23.7:1 to 2.7:1 and iron fortification decreased the molar ratio to 0.3:1. Dephytinisation with wheat phytase and fortification significantly increased iron absorption from 2.6% to 8.2% in fonio porridges.

Conclusions and recommendations
Dephytinisation with native wheat phytase and iron fortification appeared relevant for adding nutritional value to fonio. Nonetheless, the achievement in iron absorption might not be sufficient to consider fonio as an appropriate food for improving iron status through iron fortification. However, as staple food contributing to food security, consumer-oriented activities for enhancing fonio consumption should emphasize positive attitudes and opinions of men, family and neighbors, while strengthening skills of women in cooking good quality fonio meals. For the value chain approach to be relevant, the impact of value-added fonio products on smallholders’ income should be assessed, as well as the effect of the improved income on the nutritional outcome of vulnerable communities

Dietary advice in HFE-hemochromatosis
Doorn, G.M. van; Gosselink, I.M.G. - \ 2012
Wageningen : Wageningen UR Science Shop (Report / Wageningen UR Science Shop 285) - ISBN 9789085857419 - 57
hemochromatose - ijzer - ijzerabsorptie - voeding - dieetrichtlijnen - pigmentatiestoornissen - haemochromatosis - iron - iron absorption - nutrition - dietary guidelines - pigmentation disorders
This report aims to provide dietary advice which is based on what is known so far about the effect of a diet, particularly on iron overload in HFE-hemochromatosis. The reason that the recommendations in principle apply only to the group of individuals with HFE-gene mutations and are focused on the minimization of iron overload is that little research has been done on the effect of food in non-HFE-associated iron overload. Also little research is done into other (than iron overload) related health problems in HFE-hemochromatosis. Individuals with HFE-gene mutations – those with iron overload caused by an abnormality of the HFE-gene – are also the largest group of hemochromatosis patients (>90%) and therefore the advice is intended for the majority of hemochromatosis patients. Based on this dietary advice, patients can make an informed choice of whether and how they adjust their diet.
Verwijdering van fosfaat uit bodemwater met ijzerzand : De omhulde drain
Koopmans, G.F. ; Chardon, W.J. ; Belder, P. ; Groenenberg, B.J. - \ 2011
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 44 (2011)20. - ISSN 0166-8439 - p. 35 - 38.
grondwaterkwaliteit - fosfaatuitspoeling - eutrofiëring - drainagewater - draineerbuizen - zand - ijzer - adsorptie - waterzuivering - ijzeroxiden - oppervlaktewaterkwaliteit - veldproeven - groundwater quality - phosphate leaching - eutrophication - drainage water - drain pipes - sand - iron - adsorption - water treatment - iron oxides - surface water quality - field tests
In het Nederlandse oppervlaktewater zijn de fosfaatconcentraties vaak te hoog en vormt eutrofiëring een groot probleem. Fosfaatuitspoeling uit landbouwgronden draagt flink bij aan de totale fosfaatbelasting van het oppervlaktewater. Met brongerichte maatregelen, zoals evenwichtsbemesting, zal in sommige delen van het landelijk gebied de hoofddoelstelling van de Kaderrichtlijn Water niet worden gerealiseerd. Hiervoor zijn aanvullende maatregelen nodig, die kunnen bijdragen aan het verbeteren van de chemische waterkwaliteit. We hebben de effectiviteit getest van een drainagebuis omhuld met ijzerzand om fosfaatuitspoeling te verminderen. Deze veldproef is uitgevoerd op een duinzandgrond in het bloembollengebied. Het gemiddelde zuiveringsrendement van de omhulde drainagebuis bedraagt 94 procent. Het omhullen van drainagebuizen met ijzerzand lijkt een veelbelovende maatregel voor het verminderen van fosfaatuitspoeling
Voedingsadvies bij HFE-hemochromatose
Doorn, G.M. van; Gosselink, I.M.G. - \ 2011
Wageningen : Wageningen UR, Wetenschapswinkel (Rapport / Wageningen UR, Wetenschapswinkel 279) - 61
hemochromatose - ijzer - dieetadvisering - voeding en gezondheid - voedingsstoffen - haemochromatosis - iron - diet counseling - nutrition and health - nutrients
Voor de erfelijke ziekte HFE-hemochromatose, waarbij ijzer zich in het lichaam stapelt, is aderlaten de standaard behandeling. Meestal worden wel enkele voedingsadviezen gegeven, maar deze zijn niet wetenschappelijk onderbouwd. Dit rapport beschrijft de huidige wetenschappelijke inzichten om tot een gefundeerd voedingsadvies te komen.
Karakterisatie van ijzerslib en -zand : een verkenning van de mogelijkheden van het gebruik van deze reststoffen om fosfaatverliezen vanuit landbouwgronden naar het oppervlaktewater te verminderen
Koopmans, G.F. ; Chardon, W.J. ; Groenenberg, J.E. - \ 2010
Wageningen : Alterra (Alterra-rapport 2047) - 52
landbouwgronden - fosfaat - oppervlaktewater - ijzer - adsorptie - nederland - bodemchemie - intensieve veehouderij - fosfaatuitspoeling - maatregelen - agricultural soils - phosphate - surface water - iron - adsorption - netherlands - soil chemistry - intensive livestock farming - phosphate leaching - measures
Het fosfaatgehalte van Nederlandse landbouwgronden in gebieden met (intensieve) veehouderij is vaak hoog. Dit leidt tot ongewenste fosfaatverliezen naar het oppervlaktewater. Perceelsgerichte maatregelen zijn noodzakelijk om deze verliezen te verminderen en de oppervlaktewaterkwaliteit te verbeteren. Een voorbeeld hiervan is het inwerken van fosfaatbindende materialen in ‘iron reactive barriers’ in de bodem of het toepassen van deze materialen in filters die aan het uiteinde van drainagebuizen kunnen worden gekoppeld. IJzerslib en ijzerzand kunnen worden gebruikt voor het binden van fosfaat.
Selective recovery of nickel over iron from a nickel-iron solution using microbial sulfate reduction in a gas-lift bioreactor
Bijmans, M.F.M. ; Helvoort, P.J. van; Dar, S. ; Dopson, M. ; Lens, P.N.L. ; Buisman, C.J.N. - \ 2009
Water Research 43 (2009)3. - ISSN 0043-1354 - p. 853 - 861.
mijnbouw - metallurgie - mijnafval - slib - waterstof - ijzer - nikkel - bioreactoren - elektroforese - sulfaatreductie - slibzuivering - verwijdering - mining - metallurgy - mine tailings - sludges - hydrogen - iron - nickel - bioreactors - electrophoresis - sulfate reduction - sludge treatment - removal - gradient gel-electrophoresis - sulfide precipitation - metal precipitation - heavy-metals - soils - water - ores
Process streams with high concentrations of metals and sulfate are characteristic for the mining and metallurgical industries. This study aims to selectively recover nickel from a nickel-iron-containing solution at pH 5.0 using a single stage bioreactor that simultaneously combines low pH sulfate reduction and metal-sulfide formation. The results show that nickel was selectively precipitated in the bioreactor at pH 5.0 and the precipitates consisted of >or=83% of the nickel content. The nickel-iron precipitates were partly crystalline and had a metal/sulfur ratio of 1, suggesting these precipitates were NiS and FeS. Experiments focusing on nickel recovery at pH 5.0 and 5.5 reached a recovery of >99.9%, resulting in a nickel effluent concentration
Natuurpotentie projectgebied "Veldweg-Reeënweg"in De Wieden : bodemchemisch- en geografisch onderzoek
Delft, S.P.J. van; Brouwer, F. - \ 2009
Wageningen : Alterra (Alterra-rapport 1917) - 81
bodemchemie - bodemstructuur - kaarten - bovengrond - fosfaat - ijzer - bodemkarteringen - grondwaterstand - nederland - natuurontwikkeling - plaggen steken - natuurgebieden - noordwest-overijssel - soil chemistry - soil structure - maps - topsoil - phosphate - iron - soil surveys - groundwater level - netherlands - nature development - sod cutting - natural areas
Van het projectgebied “Veldweg-Reeënweg” in De Wieden was onvoldoende actuele informatie beschikbaar over bodemopbouw, voedselrijkdom van de bovengrond en de waterhuishouding om een ontwerpplan te kunnen opstellen voor inrichting voor de beoogde natuurdoelen. Er is actuele patrooninformatie verzameld over zand- en veendikte en over het grondwaterstandverloop (bodemgeografisch onderzoek). Het gebied moet als geheel als infiltratiegebied beschouwd worden, maar door de instroom van schoon oppervlaktewater met een lithotroof karakter is de verwantschap met zacht grondwater vrijwel overal groot. Via steekproeven in twee deelgebieden bleek dat de gemiddelde fosfaatverzadigingsindex over het algemeen redelijk gunstig is. In het zuidelijk deelgebied is de fosfaattoestand iets gunstiger dan in het noorden. Afgraven van de bovenste 10 cm met het doel de fosfaattoestand te verbeteren zal weinig winst opleveren, omdat de laag hieronder niet veel minder fosfaat bevat. Dieper afgraven is niet wenselijk omdat de standplaats dan te nat wordt en de draagkracht te gering voor het beheer. Als omvormingsbeheer wordt uitmijnen aanbevolen omdat daarmee de gewenste verlaging van de fosfaattoestand aanzienlijk sneller bereikt kan worden dan met verschralen.
Adsorptive removal of manganese, arsenic and iron from groundwater
Buamah, R. - \ 2009
University. Promotor(en): J.C. Schippers, co-promotor(en): B. Petrusevski. - [S.l.] : S.n. - ISBN 9789085855262 - 183
grondwater - grondwaterverontreiniging - waterbeheer - watervoorziening - volksgezondheid - adsorptie - waterzuivering - mangaan - arsenicum - ijzer - ghana - grondwaterkwaliteit - groundwater - groundwater pollution - water management - water supply - public health - adsorption - water treatment - manganese - arsenic - iron - groundwater quality
To determine the scale of the problem of arsenic, iron and manganese contamination of groundwater in Ghana a survey was performed in the first phase of the research to provide in depth information with respect to these contaminants. Presence of these mentioned contaminants in groundwater is not peculiar to Ghana alone. Many countries in the world have similar problems with their groundwater. Establishing the existence of the problem also calls for the need to find remedies. Over the years much studies have been done in the Unesco-ihe on the adsorptive mechanisms and techniques for iron and arsenic removal from groundwater. Therefore in this study much emphasis is placed on the adsorptive removal of manganese from groundwater. This research has the following as it objectives: 1. The conduction of a survey for the arsenic, iron and manganese content in selected groundwater aquifers in Ghana. 2. Determination of the arsenic, manganese and iron adsorption capacities of different locally available filter media. 3. Determination of the effect of pH on adsorption capacities of the selected media for arsenic, manganese and iron. To determine the effect of iron (II), manganese (II) presence on arsenic adsorption capacity of selected media – (competition). 4. Studies on the rate of oxidation of Fe (II) and Mn (II) adsorbed onto one or more selected media under different conditions (e.g. dissolved oxygen, pH etc.). 5. Determination of the rate of adsorption of Mn (II) onto one or more selected media under different oxic conditions. 6. To develop a conceptual model that describes the processes involved in adsorptive arsenic, manganese and iron removal. To investigate to what extent these processes can be described in a quantitative way with one or more mathematical models . Generally the study has the following relevance: 1. Provide a base line data on the arsenic and manganese content of selected groundwater aquifers in Ghana. 2. Provide information on the adsorption capacities of locally available filter media for manganese. 3. Contribute to the knowledge on the kinetics and mechanisms of catalytic adsorptive iron, manganese removal. 4. Provide an efficient backwashing procedure for regeneration of adsorptive sites in iron-oxide coated filters operating in the oxidative adsorption mode.
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