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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Challenges to Quantify Total Vitamin Activity: How to Combine the Contribution of Diverse Vitamers?
Jakobsen, Jette ; Melse-Boonstra, Alida ; Rychlik, Michael - \ 2019
Current Developments in Nutrition 3 (2019)10. - ISSN 2475-2991
folate - foods - total vitamin activity - vitamer - Vitamin A - Vitamin D

This state-of-the-art review aims to highlight the challenges in quantifying vitamin activity in foods that contain several vitamers of a group, using as examples the fat-soluble vitamins A and D as well as the water-soluble folate. The absorption, metabolism, and physiology of these examples are described along with the current analytical methodology, with an emphasis on approaches to standardization. Moreover, the major food sources for the vitamins are numerated. The article focuses particularly on outlining the so-called SLAMENGHI factors influencing a vitamer's' ability to act as a vitamin, that is, molecular species, linkage, amount, matrix, effectors of absorption, nutrition status, genetics, host-related factors, and the interaction of these. After summarizing the current approaches to estimating the total content of each vitamin group, the review concludes by outlining the research gaps and future perspectives in vitamin analysis. There are no standardized methods for the quantification of the vitamers of vitamin A, vitamin D, and folate in foods. For folate and β-carotene, a difference in vitamer activity between foods and supplements has been confirmed, whereas no difference has been observed for vitamin D. For differences in vitamer activity between provitamin A carotenoids and retinol, and between 25-hydroxyvitamin D and vitamin D, international consensus is lacking. The challenges facing each of the specific vitamin communities are the gaps in knowledge about bioaccessibility and bioavailability for each of the various vitamers. The differences between the vitamins make it difficult to formulate a common strategy for assessing the quantitative differences between the vitamers. In the future, optimized stationary digestive models and the more advanced dynamic digestive models combined with in vitro models for bioavailability could more closely resemble in vivo results. New knowledge will enable us to transfer nutrient recommendations into improved dietary advice to increase public health throughout the human life cycle.

Benchmarking nutritional water productivity of twenty vegetables - A review
Nyathi, M.K. ; Mabhaudhi, T. ; Halsema, G.E. van; Annandale, J.G. ; Struik, P.C. - \ 2019
Agricultural Water Management 221 (2019). - ISSN 0378-3774 - p. 248 - 259.
Hidden hunger - Micronutrients - Nutritional food security - Traditional vegetables - Vitamin A - Water footprint - Water productivity

Traditional vegetables are piloted as champion species for sub-Saharan Africa, a region experiencing high levels of nutritional food insecurity and water scarcity. The important benefits of traditional vegetables over alien vegetables are; (i) their high nutrient density (iron, zinc, and β-carotene), (ii) their productivity under water stress, and (iii) their availability to rural resource-poor households. However, information on these benefits is anecdotal. The objectives of this study were to benchmark nutritional water productivity [NWP = (aboveground edible biomass and/ or storage organ biomass/actual evapotranspiration) × nutritional content of a product] of ten traditional vegetables and compare them with ten alien vegetables. We selected vegetables that are widely utilized by rural resource-poor households. A comprehensive literature search was conducted using common databases. Data [biomass (aboveground biomass and/ or storage organ), water use, and nutrient concentration] sourced from the literature were used to compute water productivity, nutritional yield (NY), and NWP of selected vegetables. Our results revealed that the water productivity of traditional vegetables was comparable to that of alien vegetables. In addition, traditional vegetables were superior in nutritional yield (Fe-NY and Zn-NY) and NWP (Fe-NWP and Zn-NWP) of micronutrients. Alien vegetables were rich in β-carotene-NY and β-carotene-NWP; this is contrary to the anecdotal information. We acknowledge the weakness of our approach; generating the NWP database using two independent datasets (crop water productivity and the nutrient concentration databases). However, this was the only pragmatic approach to establish first-order estimates of NWP for selected groups of vegetables. We propose that future research should be conducted to validate these results.

The dual-purpose use of orange-fleshed sweet potato (Ipomoea batatas var. Bophelo) for improved nutritional food security
Nyathi, M.K. ; Plooy, C.P. Du; Halsema, G.E. Van; Stomph, T.J. ; Annandale, J.G. ; Struik, P.C. - \ 2019
Agricultural Water Management 217 (2019). - ISSN 0378-3774 - p. 23 - 37.
Green leafy vegetable - Micronutrient deficiency - Nutritional water productivity - Vitamin A - Water stress
Orange-fleshed sweet potato (OFSP) leaves can be utilised as a fresh green leafy vegetable, in addition to the traditional use of storage root; therefore, OFSP can be seen as a “dual-purpose’’ crop. We hypothesized that no vine harvesting combined with fertiliser application and irrigation will improve the storage root yield and selected plant parameters (water productivity, leaf and storage root nutrient concentrations, nutritional yield, and nutritional water productivity). The objectives of the study were to (i) evaluate the effect of vine harvesting on the selected plant parameters, and, (ii) assess the effect of irrigation regimes and soil fertilisation on these selected parameters. Field experiments were conducted at ARC-VOP, Pretoria, South Africa, during the 2013/14 and 2014/15 seasons. Treatments included irrigation regimes [well-watered (W1) and supplemental irrigation (W2)], soil fertilisation [well-fertilised (F1) and no fertiliser application (F2)], and vine harvesting [no vine harvesting (H1) and vine harvesting (H2)]. For the 2014/15 season, the well-watered regime improved total storage root yield (W1 = 13.0 t DM ha −1 ; W2 = 7.5 t DM ha −1 ). Under the practice of vine harvesting, soil fertility treatments did not affect (total dry storage root yield and dry marketable storage root yield) storage root production. Our results further revealed that vine harvesting reduced storage root nutrient concentrations (23% for iron; 14% for zinc; 12% for β-carotene). Nevertheless, total nutritional yields increased; the highest total nutritional yields for iron, zinc, and β-carotene were found under the water and nutrient input regime (W1F1). Assessments showed that boiled orange-fleshed sweet potato aboveground edible biomass could potentially contribute to the daily-recommended nutritional requirement of iron and vitamin A for a family of six people. More water was needed to meet the daily-recommended nutrient intake (iron, zinc, and vitamin A) with OFSP grown as a storage root crop only than when grown as a dual-purpose crop. Our results indicated that there is an opportunity to utilise OFSP as a dual-purpose crop for rural resource-poor households because total nutritional yields (iron, zinc, and β-carotene) and total nutritional water productivities (iron, zinc, and β-carotene) were improved. More research is needed to assess the effect of vine harvesting on a range of OFSP varieties and should be conducted on the farm. Rural resource-poor households are encouraged to produce OFSP for their own consumption and the surplus could be sold at the local market.
Symposium 2 : Nutrient interactions and their role in protection from chronic diseases: β-Carotene in the human body: Metabolic bioactivation pathways - From digestion to tissue distribution and excretion
Bohn, Torsten ; Desmarchelier, Charles ; El, Sedef N. ; Keijer, Jaap ; Schothorst, Evert Van; Rühl, Ralph ; Borel, Patrick - \ 2019
Proceedings of the Nutrition Society 78 (2019)1. - ISSN 0029-6651 - p. 68 - 87.
Absorption - Apo-carotenoids - Micellisation - Nuclear hormone receptor - Retinoic acid - SNPs - Vitamin A

β-Carotene intake and tissue/blood concentrations have been associated with reduced incidence of several chronic diseases. Further bioactive carotenoid-metabolites can modulate the expression of specific genes mainly via the nuclear hormone receptors: retinoic acid receptor- and retinoid X receptor-mediated signalling. To better understand the metabolic conversion of β-carotene, inter-individual differences regarding β-carotene bioavailability and bioactivity are key steps that determine its further metabolism and bioactivation and mediated signalling. Major carotenoid metabolites, the retinoids, can be stored as esters or further oxidised and excreted via phase 2 metabolism pathways. In this review, we aim to highlight the major critical control points that determine the fate of β-carotene in the human body, with a special emphasis on β-carotene oxygenase 1. The hypothesis that higher dietary β-carotene intake and serum level results in higher β-carotene-mediated signalling is partly questioned. Alternative autoregulatory mechanisms in β-carotene / retinoid-mediated signalling are highlighted to better predict and optimise nutritional strategies involving β-carotene-related health beneficial mediated effects.

Micronutrient status of populations and preventive nutrition interventions in South East Asia
Roos, N. ; Campos Ponce, M. ; Doak, C.M. ; Dijkhuizen, M. ; Polman, K. ; Chamnan, C. ; Khov, K. ; Chea, M. ; Prak, S. ; Kounnavong, S. ; Akkhavong, K. ; Mai, L.B. ; Lua, T.T. ; Muslimatun, S. ; Famida, U. ; Wasantwisut, E. ; Winichagoon, P. ; Doets, E. ; Greffeuille, V. ; Wieringa, F.T. ; Berger, J. - \ 2019
Maternal and Child Health 23 (2019)1. - ISSN 1092-7875 - p. 29 - 45.
Children - Deficiency - Iron - Micronutrient - Mineral - Southeast Asia - Vitamin - Vitamin A - Women of reproductive age - Zinc

Objectives Since the 1990s, programs for the control of micronutrient deficiencies became a public health priority for many governments, including the countries partnering the project “Sustainable Micronutrient Interventions to Control Deficiencies and Improve Nutritional Status and General Health in Asia” (SMILING): Cambodia, Indonesia, Laos-PDR, Thailand and Vietnam. The aim of this study was to map which micronutrient deficiencies have been addressed and which interventions were in place in the SMILING countries. Methods The mapping covered the period up to 2012. Updated information from relevant surveys after 2012 is included in this paper after the completion of the SMILING project. The mapping of micronutrient status was limited to either national or at least large-scale surveys. Information on nutrition interventions obtained through a systematic mapping of national programs combined with a snowball collection from various sources. Results Among the five SMILING countries, Thailand differed historically by an early implementation of a nationwide community-based nutrition program, contributing to reductions in undernutrition and micronutrient deficiencies. For Cambodia, Indonesia, Laos PDR, and Vietnam, some national programs addressing micronutrients have been implemented following adjusted international recommendations. National surveys on micronutrient status were scattered and inconsistent across the countries in design and frequency. Conclusion for practice In conclusion, some micronutrient deficiencies were addressed in national interventions but the evidence of effects was generally lacking because of limited nationally representative data collected. Improvement of intervention programs to efficiently reduce or eliminate micronutrient deficiencies requires more systematic monitoring and evaluation of effects of interventions in order to identify best practices.

Effect of regular consumption of provitamin a biofortified staple crops on vitamin A status in populations in low-income countries
Haskell, M. ; Tanumihardjo, S.A. ; Palmer, A. ; Melse-Boonstra, A. ; Talsma, E. ; Burri, B. - \ 2017
African Journal of Food, Agriculture, Nutrition and Development 17 (2017)2. - ISSN 1684-5358 - p. 11865 - 11878.
Beta-carotene - Bioavailability - Biofortification - Cassava - Maize - Provitamin A - Sweet potatoes - Vitamin A

Biofortification of staple crops with provitamin A (PVA) carotenoids is an innovative strategy for controlling vitamin A (VA) deficiency in low-income countries (LIC). Plant breeding programs have been successful in developing biofortified varieties of cassava, maize, and orange-fleshed sweet potatoes that contain amounts of PVA-carotenoids that have the potential to impact VA status in human populations. Nutrition studies indicate that beta-carotene in biofortified staple crops is converted efficiently to VA in the body. Randomized, controlled, community-based efficacy and effectiveness trials have been conducted to assess the effect of regular consumption of PVA-carotenoid biofortified staple crops on VA status. Results indicate that regular consumption of biofortified staple crops increases plasma beta-carotene concentrations consistently, but has a moderate effect, or no effect, on VA status, when assessed by serum retinol concentration, breast milk retinol concentration, or total body VA stores. Studies are currently underway to further investigate whether consumption of biofortified staple crops improves VA status in population subgroups at risk of VA deficiency, and to better understand how to optimize the biological impact of these interventions in resource-poor settings.

A multidisciplinary research agenda for the acceptance of Golden Rice
Bongoni, Radhika ; Basu, Soutrik - \ 2016
Nutrition & Food Science 46 (2016)5. - ISSN 0034-6659 - p. 717 - 728.
Consumer acceptance - GM foods - Golden Rice - Vitamin A - β-carotene

Purpose: The world is facing serious global food security challenges such as the need for sufficient food for a growing population and an exponential growth in nutrient deficiency disorders. Agricultural biotechnology, such as genetically modified (GM) crops, offers itself as a promising solution to address one or more of these issues. Golden Rice (GR) is an example of a GM crop which contains high amount of β-carotene, a compound which is an antioxidant and a precursor of vitamin A. In spite of GR’s promised potential benefits in combating vitamin A deficiency (VAD) disorders it is still not cultivated. This viewpoint paper aims to present the reader with a need for multidisciplinary research agenda, the outcomes of which can contribute towards the acceptance of GR. Design/methodology/approach: This viewpoint paper is based on an extensive literature review to identify the “gaps” which contributed to low acceptance of GR. This paper presents a systematic discussion on the importance of GR in tackling VAD and discusses controversies around GR and a scientific approach to tackle them. Findings: The literature review clearly indicates that there is a huge gap in information substantiating the potential of GR for consumers as well as for the farming community. Addressing these issues can substantially increase the acceptance and cultivation of GR. This viewpoint paper proposes food technologists’ and social scientists’ research agenda for GR and further indicates how the involvement of other research disciplines can improve the acceptance of GR. Originality/value: The literature review indicates the potential of GR in tackling VAD disorders but clearly lacks information to substantiate these arguments. This paper presents authors’ opinions, urging scientists to take up a multidisciplinary research approach to emancipate GR from the clutches of GM food controversies.

Biofortified yellow cassava and Vitamin A status of Kenyan children : A randomized controlled trial
Talsma, E.F. ; Brouwer, I.D. ; Verhoef, Hans ; Mbera, G.N.K. ; Mwangi, A.M. ; Demir, A.Y. ; Maziya-Dixon, B. ; Boy, Erick ; Zimmermann, M.B. ; Melse-Boonstra, Alida - \ 2016
American Journal of Clinical Nutrition 103 (2016)1. - ISSN 0002-9165 - p. 258 - 267.
Biofortification - Efficacy - Food-based approach - Nutrition-sensitive intervention - Vitamin A

Background: Whereas conventional white cassava roots are devoid of provitamin A, biofortified yellow varieties are naturally rich in b-carotene, the primary provitamin A carotenoid. Objective: We assessed the effect of consuming yellow cassava on serum retinol concentration in Kenyan schoolchildren with marginal vitamin A status. Design: We randomly allocated 342 children aged 5-13 y to receive daily, 6 d/wk, for 18.5 wk 1) white cassava and placebo supplement (control group), 2) provitamin A-rich cassava (mean content: 1460 μg β-carotene/d) and placebo supplement (yellow cassava group), and 3) white cassava and β-carotene supplement (1053 mg/d; β-carotene supplement group). The primary outcome was serum retinol concentration; prespecified secondary outcomes were hemoglobin concentration and serum concentrations of β-carotene, retinol-binding protein, and prealbumin. Groups were compared by using ANCOVA, adjusting for inflammation, baseline serum concentrations of retinol and β-carotene, and stratified design. Results: The baseline prevalence of serum retinol concentration

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