Magister Scientiae (Nutrition Management) - MSc(NM) / Orange-fleshed sweet potato consumption promotion is one of the key nutrition sensitive interventions implementedto address high vitamin A deficiency among the rural population of Zambia since 2011. However, to date no study has been completed regarding household consumption of orange-fleshed sweet potato and factors related to their consumption. The study detailed here therefore sought to establish the consumption of orange-fleshed sweet potato, and to identify factors associated with its household consumption in the Integrating Orange Project areas in Chipata district of Zambia. The study randomly sampled 295 households, and collected information on the household characteristics, production, procurement, consumption and knowledge on orange-fleshed sweet potato. Cross tabulation chi square and one-way analysis of variance were used to identify associated consumption factors. The study found that 86.8% of the households ate orange-fleshed sweet potato; 49.5% ate it 1 to 3 days per week and 30.2% ate it at least 4 or more days per week, and only 13.2% did not consume orange-fleshed sweet potato at all. A relationship was found between having children younger than five years old and consumption of orange-fleshed sweet potato (P < 0.001). Results showed that 8.7% of households with children (n=183) never ate orange-fleshed sweet potato, versus 20.5% of households without children (n=112). Production of orange-fleshed sweet potato (n=178) was found to have a relationship with household conusmption of orange-fleshed sweet potato (P < 0.001). Only 1.1% of households that produced orange-fleshed sweet potato did not consume any, versus 31.6% who did not produce orange-fleshed sweet potato. Purchasing of orange-fleshed sweet potato (n=118) was found to have a relationship with its household consumption (P < 0.001); 56.2% of the households that ate orange-fleshed sweet potato 1 to 3 days during the previous week bought it, compared to only 27.0% of households who ate orange-fleshed sweet potato more than 4 days per week among those that bought it. The respondent‘s knowledge of the health benefits of orange-fleshed sweet potato was found to have a relationship with its consumption in the household (P < 0.001). Only 7.8% of the households where respondents knew the benefits of orange-fleshed sweet potato (n=215) never ate orange-fleshed potato, compared to 50.0% of households where the respondents did not know any benefit (n=80). In contrast, 33.5% of the households where the respondents knew the health benefits ate orange-fleshed sweet potato at least 4 days a week compared to only 7.9% of households where the respondents did not know any benefit. Overall, the study showed that most households consumed orange-fleshed sweet potato. The highconsumption might be due to seasonality, as the study was done during the harvesting season of orange-fleshed sweet potato. Also, prodcution of orange-fleshed sweet potato was promoted in the study area through the Integrating Orange Project. These results therefore suggest that projects seeking to promote consumption of orange-fleshed sweet potato as an intervention for vitamin A deficiency control should promote production of orange-fleshed sweet potato and sensitization of communities on the health benefits of orange-fleshed sweet potato consumption.

Vitamin A deficiency has been recognised as a widespread problem affecting about 750 million people, mostly in developing countries. Mortality due to vitamin A deficiency can be reduced by as much as 23% with improved vitamin A status. Vitamin A's immuneenhancing aspects strengthen the body's defence system against infectious diseases such as measles, malaria and diarrhoea, thus preventing death. Children beyond the weaning age (6 months to 6 years) are most at risk. In South Africa, one in three children has a low vitamin A status, with the rural areas being most affected. Orange-fleshed sweet potato (OFSP) has emerged as a promising plant source with a high beta-carotene content that can make a significant contribution to the vitamin A intake of individuals at risk of vitamin A deficiency. The purpose of this study was to determine the nutrient and sensory quality of OFSP. To this end, the nutrient content of different cultivars of OFSP was determined as well as the sensory characteristics and consumer acceptability was established. During the first phase, four different cultivars of OFSP i.e. Resisto, W119, Jewel and A 15, plus one composite sample, all cultivated by the Agricultural Research Council (ARC)-Roodeplaat, South Africa, were sampled for nutrient analysis. During the second phase (descriptive sensory analysis), four OFSP cultivars and one white-fleshed sweet potato (WFSP) cultivar i.e. Blesbok, were evaluated. A trained sensory panel was used to establish terminology for describing the sensory attributes of the different sweet potato cultivars in terms of its aroma, texture, flavour and aftertaste attributes. Consumer preference (n=180) for OFSP and WFSP was measured by means of a paired preference test. Focus group discussions were conducted to verify findings of the consumer preference test. The results obtained from the nutrient analysis confirmed that OFSP is an excellent source of beta-carotene. A 100 g portion of cooked OFSP can provide up to 6528 ~g beta-carotene, which is approximately 136% of the RDA for vitamin A for children four to eight years. High levels of other nutrients present in OFSP were identified namely vitamin C, calcium and zinc. OFSP further contributes 28% vitamin C, 13% calcium, 15% magnesium and 75.6% zinc of their daily requirements. This study confirms the valuable contribution that OFSP can make as a food-based approach to reduce vitamin A deficiency in individuals at risk. The sensory profiles indicated that OFSP differed from WFSP in colour, flavour and texture. OFSP is generally less moist and subsequently more dense and adhesive compared to WFSP. The latter being more fibrous and less firm than OFSP. Overall OFSP had and earthy aroma which was not typical of WFSP and had a sweeter flavour. The flavour of OFSP was described as similar to that of yellow vegetables such as butternut and pumpkin. Although the different OFSP cultivars had similar characteristics, differences were found in the moist, adhesive and grainy texture attributes as well as the vegetable sweet flavour. Resisto had the sweetest in flavour, with the most dense and pasty texture of the four OFSP cultivars. W119 had the grainiest texture. No significant differences were found in the earthy aroma, sweet potato and yellow vegetable flavour attributes. It can be concluded that in flavour, few differences were found among the OFSP, except in sweetness. OFSP differed primarily from each other in texture. The consumer preference test results showed that overall 85% of respondents preferred the taste of OFSP to that of WFSP, 53% liked the orange colour a lot while 24% liked the colour a little and the remaining 22 % disliked the colour (either a lot, a little, neither like nor dislike). The majority of the consumers (86%) indicated a willingness to buy OFSP. From these results it can be concluded that the taste and colour of OFSP are acceptable to consumers of sweet potato and that it has potential to be successful in the marketplace. Given the high level of consumer acceptability of OFSP, an opportunity exists to address vitamin A deficiency through commercially viable decentralised vine production centres. Such centres could be managed by commercial-, small-scale- and subsistence farmers in South Africa in key sweet potato production areas, with adequate water supply throughout the year. However, availability of commercially produced OFSP in retail sores in recent months, may change this prospect. / Dissertation (MConsSci)--University of Pretoria, 2008. / Consumer Science / unrestricted

La mancanza di una buona dieta ben bilanciata nutrizionalmente, porta al persistente sottosviluppo, in particolare per la capacità fisica e intellettuale delle persone e ha un impatto negativo sullo sviluppo del Paese. La presente tesi di dottorato mirava a valutare le strategie per produrre un cibo appropriato sufficiente, sicuro e sostenibile attraverso la sperimentazione di diverse tecniche di coltivazione e cultivar locali di manioca per identificare quali tecniche e cultivar sono più performanti per aumentare la resa. Dall’altra parte, al fine di contribuire alla diversificazione della produzione del cibo e al miglioramento del piatto tradizionale congolese costituita da più di 80% di carboidrati in particolare la manioca, studi su nuove colture riconosciute contenere dei buoni livelli in proteine, vitamine e minerali come Patata dolce a polpa arancione (Ipomoea batatas) riconosciuta essere ricca soprattutto in provitamina A e quinoa (Chenopodium quinoa Willd.) riconosciuta in particolare per il suo buon contenuto di aminoacidi ben bilanciato sono state condotte. Come risultato, tra tre tecniche di coltivazione (Ridge, Mound e Flat) per la produzione di manioca e 5 cultivar locali di manioca (Dunda, Kakuanga, Kasongoy, Kasonie, Ngoymuamba) valutati, la coltivazione su Ridge e il culltivar Ngoymuamba hanno dato il risultato più alto (19,2 Mg ha-1 di tuberi freschi), mentre Dunda è stata la cultivar che ha prodotto molto meno (6,8 Mg ha-1 di tuberi freschi). Le cultivar di patata dolce a polpa arancione studiati, hanno dimostrato che il contenuto in β-carotene è ragionevolmente alto perché 87 g di tuberi fresche sono sufficienti per coprire la dose giornaliera raccomandata in vitamina A per gli adulti. Per quinoa, tre cultivar (Pasankalla, Puno, Titicaca) hanno dimostrato di produrre una resa considerevole in quanto la produzione in granella è stata rispettivamente di 2,2 Mg ha-1; 1,9 Mg ha-1; 1,3 Mg ha-1 per Titicaca, Pasankalla e Puno. / The lack of a good diet well balanced nutritionally, leads to the persistent underdevelopment, particularly for the physical and intellectual capacity of the people and impacts negatively on the development of the country. The present doctoral thesis aimed to assess strategies to produce an appropriate food sufficient, safe and sustainable through experimenting different cultivating techniques and local cultivars of cassava for identifying which techniques and cultivars are more performant to increase yield. On the other hand, in order to contribute to the diversification of food production and improvement of the traditional Congolese diet constituted by more than 80% of carbohydrates particularly cassava, new crops recognized to have a better content in protein, minerals, and vitamins such as Orange-Fleshed Sweet Potato (Ipomoea batatas) recognized to be rich especially in provitamin A and quinoa (Chenopodium quinoa Willd.) recognized particularly for its well-balanced amino acids content were studied. As results, among three Planting methods (Ridge, Mound, and Flat) for producing cassava and 5 local cultivars of cassava (Dunda, Kakuanga, Kasongoy, Kasonie, Ngoymuamba) assessed, ridge and culltivar Ngoymuamba resulted to give the highest yield (19.2 Mg ha-1 in fresh roots), while Dunda was the cultivar which produced the lowest yield (6.8 Mg ha-1 in fresh roots). The Orange-Fleshed Sweet Potato cultivars studied showed that its content in β-carotene is reasonably high as 87 g per day can cover the whole daily allowances of vitamin A in adults’ people. On the quinoa side, three cultivars (Pasankalla, Puno, Titicaca) demonstrated to produce considerable yield as the production in grain was 2.2 Mg ha-1, 1.9 Mg ha-1, 1.3 Mg ha-1, respectively for Titicaca, Pasankalla and Puno.

Household food security has been described with a three-factor definition: 1) the availability of food, 2) the access thereto, and lastly 3) the food utilization patterns and practices. In previous research, both the availability and access to food were studied in a farming community in the Free State Province to understand how these factors contribute to household food security. However food utilization was not investigated at the time. Food consumption patterns of households deserve attention, particularly in relation to food gardens and nutrition, including the cultivation cycle, dietary norms and practices, and methods of food preparation and preservation. By studying utilization patterns of foods, the context of food insecurity and the resultant malnutrition can be better understood. The purpose of this study was to investigate whether the food utilization strategies of a known food crop (spinach) can be used to establish efficient utilization of a new, unfamiliar crop (orange-fleshed sweet potato) in a farm worker community. Three focus group interviews were conducted with a total of 21 participants to determine current food utilization patterns of spinach and orange-fleshed sweet potato (OFSP). The women were asked to describe how they currently utilize these crops in the same focus iv group discussion (although the focus was on the known crop (spinach)) to understand what actions they take during the process of utilization, from access to disposal. They were asked to describe which tools and methods they apply, and who participates in all these various activities. Subsequently, the respondents were asked to perform all these steps while being observed to record current practices. Data from the focus group interviews and the observations were transcribed and categorized under themes. It was found that in addition to a lack of dietary diversity and subsequent malnutrition found discovered in another study of this community, that they are also not optimally utilizing their food. This is as a direct result of lack of access to a variety of food due to monetary constraints, lack of nearby shops, a lack of cultivation and production education about crops that can be home-produced, and a lack of knowledge about nutrition and the importance of a varied diet. A food-based approach to improve the lack of knowledge of home-produced crops and nutrition was, consequently, the focus of this utilization strategy. This information was used to design a food-based strategy to improve the utilization of an unfamiliar crop (OFSP), in areas where the food crop was not being utilized optimally. Although the strategy was developed based on observations and lessons from one specific community, the principal findings were used to develop a strategy that is generic to the implementation of an unfamiliar food crop, and can then be refined for a specific community before implementation. A complete training manual was developed to complement the food-based strategy. The researcher then tested the strategy with agricultural extension officers who are active in communities where food insecurity and malnutrition exist during a training programme hosted by the Agricultural Research Council - Roodeplaat. The agricultural extension officers provided input on the strategy and identified areas for improvement. These recommendations were adapted in a manual to ensure that the developed strategy could be broadly implemented in other communities. The overall conclusion of the study is that it is necessary to investigate and understand all elements of the food utilization system to truly understand the reasons for observed behaviour, habits and practices. Planning and developing a nutrition education programme requires systematic analysis of nutrition and health-related problems in a given community. It is evident that each step of the utilization cycle is equally critical and should enjoy comparable attention to facilitate delivery of nutrient-rich foodstuffs to the end user. / Dissertation (MConsumer Science)--University of Pretoria, 2012. / gm2014 / Consumer Science / unrestricted

Le β-carotène (Bc) est un caroténoïde connu pour son activité pro vitaminique A. La consommation de fruits et légumes riches en Bc est donc particulièrement encouragée, principalement dans les pays en développement. Cependant, au cours d'un repas, la biodisponibilité du Bc est influencée par la présence des macro et microconstituants des aliments. L'objectif général de ce travail a été d'étudier les interactions alimentaires pouvant survenir au cours des différentes étapes du processus d'absorption du Bc. La bioaccessibilité du Bc, évaluée à l'aide d'un modèle de digestion in vitro, a révélé que la quantité de Bc micellarisé des aliments de base (patate douce orange (PDO) et banane plantain) des pays du Sud se retrouve augmentée dans certaines préparations tratitionnelles. De plus, dans une simple association de deux aliments, nos résultats ont montré que la naringine de jus d'agrumes diminuait la bioaccessibilité du Bc de la PDO car ce flavanone se micellarise et entre en compétition avec le Bc. L'effet de flavanones sur l'absorption intestinale du Bc a ensuite été étudié à l'aide d'un modèle cellulaire de type Caco-2. L'ensemble des glycosides de flavanones testés, mais principalement l'hespéridine (Hes), ont augmenté l'absorption du Bc. L'expérimentation in vivo chez la gerbille n'a quant à elle pas montré d'effet de l'Hes sur la bioefficacité du Bc de la PDO. Par contre, nos données suggèrent que l'Hes, dans le cas d'un régime carencé en caroténoïdes et vitamine A, pourrait stimuler l'activité de la β,β-carotène mono-oxygénase par un mécanisme impliquant le facteur de transcription PPARγ. / Β-carotene (Bc) is a carotenoid mainly known for its provitaminic A activity. Therefore, the consumption of fruits and vegetables rich in Bc are promoted, especially in developing countries. However, during a meal, the Bc bioavailability was modulated by other macro or micronutrients from food. The main objective of this study was to evaluate food interaction occurring during the different steps of Bc absorption. The Bc bioaccessibility, evaluated through an in vitro digestion, showed that the micellarization of Bc staple foods from South countries (orange fleshed sweet potato (OFSP) and plantain) increases in some traditional food preparations. Moreover, we observed that the Bc bioaccessibility from OFSP decreases in the presence of Citrus juice because of the naringin which competes for incorporation into mixed micelles. Effects of flavanones were then assessed on intestinal Bc uptake using Caco-2 cells. Among flavanone glycosides tested, mainly hesperidin (Hes), increased Bc uptake. In vivo experimentation with gerbil did not shown any effect of Hes on the bioefficacity of Bc from OFSP. By contrast, our data suggest that under a low Bc or vitamin A free diet, Hes might enhance BCMO1 activity through its action as agonist of PPARγ.