In this article the term ‘African leafy vegetables’ was adopted to refer to the collective of plant species which are used as leafy vegetables and which are referred to as morogo or imifino by African people in South Africa. Function is central in this indigenous concept, which is subject to spatial and temporal variability in terms of plant species that are included as a result of diversity in ecology, culinary repertoire and change over time. As a result, the concept embraces indigenous, indigenised and recently introduced leafy vegetable species but this article is concerned mainly with the indigenous and indigenised species. In South Africa, the collection of these two types of leafy vegetables from the wild, or from cultivated fields where some of them grow as weeds, has a long history that has been intimately linked to women and their traditional livelihood tasks. Among poor people in remote rural areas the use of these types of leafy vegetables is still common but nationwide there is evidence of decline, particularly in urban areas. Cultivation of indigenous or indigenised leafy vegetables is restricted to a narrow group of primarily indigenised species in South Africa. Seven groups of indigenous or indigenised African leafy vegetables that are important in South Africa were given special attention and their local nomenclature, ecology, use and cultivation are discussed.

Objectives: The aim of this study was to assess the bioaccessibility of iron and zinc in African leafy vegetables (ALV) and maize porridge composite dishes using an in vitro dialysability assay and to estimate the antinutrient content in ALV and maize porridge composite dishes. Methods: ALV leaves were collected, cooked and mixed with either cooked fortified or unfortified maize porridge to simulate the way it is usually consumed. Mineral and antinutrient levels were determined using standard methods and the bioaccessibility of iron and zinc was determined using an in vitro dialysability assay. Findings: The findings of the present study indicated that ALV dishes contain a reasonable amount of iron and zinc, but combining the ALV dishes with unfortified maize porridge resulted in dilution and hence a lower iron content. The amaranth-pumpkin dish contained most iron (24 mg/100 g). ALV dishes in the study had zinc contents ranging from 2.6 to 3.2 mg/100 g, with amaranth mixed with spider plant having the highest zinc content. Regarding antinutrients, the amaranth-cowpea dish had the highest phytate content of 2078 mg/100 g dry weight. ALV dishes also contained tannins and phenolic compounds. Iron percentage bioaccessibility was high in an amaranth-spider plant dish (25%), while other dishes had lower iron bioaccessibility of less than 11%. The percentage bioaccessibility of zinc in ALV dishes ranged from 7 to 8%. The amaranth-spider plant dish had higher zinc bioaccessibility when composited with fortified maize meal (13%). The percentage zinc bioaccessibility is negatively associated with phytate:zinc and phyate-calcium:zinc molar ratios. Conclusions: ALV and maize meal composite dishes have a high iron and zinc content, though they also have a high antinutrient content that has some inhibitory effects. Despite the inhibiting factors, the amount of bioaccessible iron and zinc from ALV and maize porridge composite dishes could play a significant role in planning food security strategies. However, there is a need to understand the possible effects of consuming them in different combinations with other foods. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2015

Objectives: The aim of this study was to assess the bioaccessibility of iron and zinc in African leafy vegetables (ALV) and maize porridge composite dishes using an in vitro dialysability assay and to estimate the antinutrient content in ALV and maize porridge composite dishes. Methods: ALV leaves were collected, cooked and mixed with either cooked fortified or unfortified maize porridge to simulate the way it is usually consumed. Mineral and antinutrient levels were determined using standard methods and the bioaccessibility of iron and zinc was determined using an in vitro dialysability assay. Findings: The findings of the present study indicated that ALV dishes contain a reasonable amount of iron and zinc, but combining the ALV dishes with unfortified maize porridge resulted in dilution and hence a lower iron content. The amaranth-pumpkin dish contained most iron (24 mg/100 g). ALV dishes in the study had zinc contents ranging from 2.6 to 3.2 mg/100 g, with amaranth mixed with spider plant having the highest zinc content. Regarding antinutrients, the amaranth-cowpea dish had the highest phytate content of 2078 mg/100 g dry weight. ALV dishes also contained tannins and phenolic compounds. Iron percentage bioaccessibility was high in an amaranth-spider plant dish (25%), while other dishes had lower iron bioaccessibility of less than 11%. The percentage bioaccessibility of zinc in ALV dishes ranged from 7 to 8%. The amaranth-spider plant dish had higher zinc bioaccessibility when composited with fortified maize meal (13%). The percentage zinc bioaccessibility is negatively associated with phytate:zinc and phyate-calcium:zinc molar ratios. Conclusions: ALV and maize meal composite dishes have a high iron and zinc content, though they also have a high antinutrient content that has some inhibitory effects. Despite the inhibiting factors, the amount of bioaccessible iron and zinc from ALV and maize porridge composite dishes could play a significant role in planning food security strategies. However, there is a need to understand the possible effects of consuming them in different combinations with other foods. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2015

Using farmer surveys the smallholder commodity systems of Brassica rapa L. subsp. chinensis and Solanum retroflexum Dun. in Vhembe District, Limpopo Province, South Africa were described and analysed. Production, transaction and consumption of the two vegetables were deeply embedded in the food, trade and farming systems of local people. The cultivation systems, which appeared effective, were developed by borrowing elements from the systems of other crops to which new knowledge specific to B. chinensis and S. retroflexum were added. Several elements of the production systems that could benefit from scientific enquiry were identified. These included genetic improvement and the optimisation of planting density and nutrient supply.

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

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

Background: Children in South Africa are still affected by micronutrient deficiencies and children living in farm communities are especially vulnerable. African Leafy Vegetables (ALVs) are well endowed with micronutrients such as iron, zinc and vitamin A and might contribute to the nutritional status of children. However, these vegetables have been perceived as “poor people’s food” and over the years knowledge of and use of ALVs has decreased. Aim: This study assessed the potential contribution of ALVs to the nutritional status of children in a semi-rural farm community. Method: In this cross-sectional study, anthropometric indices, serum iron, zinc and retinol concentrations were determined in school children aged 5−13 years (n=155). Dietary intake of iron, zinc and vitamin A was evaluated by three 24-hour diet recalls of children (n=154). The iron, zinc and β-carotene content of selected ALVs was determined. Knowledge of and use of ALVs by primary caregivers was established using focus group discussions (FGDs). Descriptive statistics, independent t-tests, the Pearson Chi-Square Test and Mann-Whitney U Test were used. Anthropometric data were analysed using the World Health Organization Reference 2007 data. Dietary data were analysed using FoodFinder (version 3). Qualitative data from FGDs were translated, transcribed and color-coded to generate emerging themes. Results: Stunting (11%) was the most prevalent anthropometric indicator of malnutrition. This was supported by the low socio-economic status of households. Deficiency prevalence in iron (serum ferritin <15 μg/L; 15.5%) and vitamin A (serum retinol <20 μg/dL; 3.2%) was low. Zinc deficiency was the most prevalent (serum zinc <65 μg/dL; 74.8%) deficiency. Median dietary intake of iron, zinc and vitamin A was generally above the Estimated Average Requirement. ALVs were potentially good sources of iron, zinc and β-carotene and could contribute substantially to the Recommended Dietary Allowance for these nutrients in children, without taking into account inhibiting factors that might affect the bioavailability. Iron content of the ALVs studied ranged from 1.4−3.2 mg/100 g edible portion. Amaranthus cruentus was the best source of iron. Zinc content of the ALVs ranged from 0.7−1.4 mg/100g edible portions, with Cleome gynandra having the highest zinc composition. The β-carotene content of the ALVs ranged from 182−314 μg RAE/100 g edible portion, with both Amaranthus cruentus and Cleome gynandra being the best sources. Knowledge of ALVs and their use was indigenous and was transferred between generations. Caregivers had positive attitudes towards the use of ALVs. Conclusion: Although the prevalence of deficiencies was not severe (with exception of zinc deficiency), micronutrient deficiencies exist in the rural farm community studied. ALVs are potentially good sources of iron, zinc and β-carotene and might contribute to the nutritional status of school children. Knowledge of ALVs and the positive attitude and perceptions regarding their use by primary caregivers implied a potentially positive future response to interventions promoting consumption of ALVs in order to contribute to the alleviation of micronutrient deficiencies. / Thesis (MSc (Nutrition))--North-West University, Potchefstroom Campus, 2013.

Background: Children in South Africa are still affected by micronutrient deficiencies and children living in farm communities are especially vulnerable. African Leafy Vegetables (ALVs) are well endowed with micronutrients such as iron, zinc and vitamin A and might contribute to the nutritional status of children. However, these vegetables have been perceived as “poor people’s food” and over the years knowledge of and use of ALVs has decreased. Aim: This study assessed the potential contribution of ALVs to the nutritional status of children in a semi-rural farm community. Method: In this cross-sectional study, anthropometric indices, serum iron, zinc and retinol concentrations were determined in school children aged 5−13 years (n=155). Dietary intake of iron, zinc and vitamin A was evaluated by three 24-hour diet recalls of children (n=154). The iron, zinc and β-carotene content of selected ALVs was determined. Knowledge of and use of ALVs by primary caregivers was established using focus group discussions (FGDs). Descriptive statistics, independent t-tests, the Pearson Chi-Square Test and Mann-Whitney U Test were used. Anthropometric data were analysed using the World Health Organization Reference 2007 data. Dietary data were analysed using FoodFinder (version 3). Qualitative data from FGDs were translated, transcribed and color-coded to generate emerging themes. Results: Stunting (11%) was the most prevalent anthropometric indicator of malnutrition. This was supported by the low socio-economic status of households. Deficiency prevalence in iron (serum ferritin <15 μg/L; 15.5%) and vitamin A (serum retinol <20 μg/dL; 3.2%) was low. Zinc deficiency was the most prevalent (serum zinc <65 μg/dL; 74.8%) deficiency. Median dietary intake of iron, zinc and vitamin A was generally above the Estimated Average Requirement. ALVs were potentially good sources of iron, zinc and β-carotene and could contribute substantially to the Recommended Dietary Allowance for these nutrients in children, without taking into account inhibiting factors that might affect the bioavailability. Iron content of the ALVs studied ranged from 1.4−3.2 mg/100 g edible portion. Amaranthus cruentus was the best source of iron. Zinc content of the ALVs ranged from 0.7−1.4 mg/100g edible portions, with Cleome gynandra having the highest zinc composition. The β-carotene content of the ALVs ranged from 182−314 μg RAE/100 g edible portion, with both Amaranthus cruentus and Cleome gynandra being the best sources. Knowledge of ALVs and their use was indigenous and was transferred between generations. Caregivers had positive attitudes towards the use of ALVs. Conclusion: Although the prevalence of deficiencies was not severe (with exception of zinc deficiency), micronutrient deficiencies exist in the rural farm community studied. ALVs are potentially good sources of iron, zinc and β-carotene and might contribute to the nutritional status of school children. Knowledge of ALVs and the positive attitude and perceptions regarding their use by primary caregivers implied a potentially positive future response to interventions promoting consumption of ALVs in order to contribute to the alleviation of micronutrient deficiencies. / Thesis (MSc (Nutrition))--North-West University, Potchefstroom Campus, 2013.