African leafy vegetables consumed by households in the Limpopo and KwaZulu-Natal provinces in South Africa

Objectives: The objectives of this study were to determine the availability of, access to and nutrition-related uses of African leafy vegetables in rural and urban households; and to determine the β-carotene content of the dominant African leafy vegetable.Design: The study consisted of a qualitative explorative phase (field walks, semi-structured interviews with key informants, focus group discussions) at two rural sites; and a quantitative household survey (questionnaire) at two rural and one urban site. Amaranth leaves were analysed for β-carotene content. Setting and subjects: The household survey included households at a rural site in Limpopo province (n = 100); and a rural (n = 101) and urban (n = 391) site in KwaZulu-Natal province, South Africa. Results: A variety of edible plants were identified during field walks at the two rural sites. Focus group discussions narrowed this down to ten plants at the rural Limpopo site and six at the rural KwaZulu-Natal site. The most popular leaves were amaranth (Amaranthus spp), spider plant (Cleome gynandra), wild watermelon (Citrullus lanatus) and blackjack (Bidens spinosa), consumed individually or mixed with other leaves. Rural households procured leaves mostly from the wild whereas urban households relied more on informal markets. In Limpopo, leaves were dried and stored for consumption during winter. KwaZulu-Natal households considered African leafy vegetables food for the poor. Leaves were boiled in salted water, or steamed and then fried in oil. Fried and boiled amaranth leaves contained 627 and 429 μg retinol activity equivalents/100 g respectively. Conclusions: Availability of, access to and nutrition-related uses of African leafy vegetables are context-specific, with inter- and intraprovincial rural/urban differences. Information collected during small studies within a specific area can therefore not be generalised for the overall South- African population. Amaranth can potentially contribute significantly to vitamin A requirements of nutritionally vulnerable communities.Keywords: African leafy vegetables; rural; urban; β-carotene; South Afric

ß-carotene–rich orange-fleshed sweet potato improves the vitamin A status of primary school children assessed with the modified-relative-dose-response test

PRNutrition; IFPRI3; HarvestPlusHarvestPlu

Retention of B-carotene in boiled, mashed orange-fleshed sweet potato (In: After Processing: The Fate of Food Components)

Complementary to an efficacy trial carried out under the vitamin A for Africa Partnership, the retention of ?-carotene in boiled, mashed orange-fleshed sweet potato (OFSP), variety Resisto, was evaluated. The OFSP contained almost exclusively trans-?-carotene. Studies were done to establish and evaluate the analytical procedure and to assess the natural variability of the ?-carotene content of OFSP. Because it was more efficient than other solvents, tetrahydrofuran:methanol (1:1) was chosen for extraction. The high-performance liquid chromatographic method established showed good reproducibility. No loss of ?-carotene was observed in chopped/grated raw OFSP allowed to stand for 4 h, indicating that it was not prone to enzymatic oxidation. The ?-carotene content of medium-sized OFSP from the same harvest batch ranged from 132 to 194 ?g/g. True retention (TR) was assessed using paired samples and a formula that compensated for loss or gain of moisture and soluble solids. TR was 92% when medium-sized OFSP covered with water was boiled for 20 min in a pot with the lid on; without the lid, boiling took 30 min and TR was 88%. When OFSP of different sizes were boiled 30 min, covered with water in a pot with the lid on, TR was 70–80%. Although degradation occurred, the ?-carotene content of boiled/mashed OFSP was still substantial

African leafy vegetables consumed by households in the Limpopo and KwaZulu-Natal provinces in South Africa

OBJECTIVES: The objectives of this study were to determine the availability of, access to and nutrition-related uses of African leafy vegetables in rural and urban households; and to determine the β-carotene content of the dominant African leafy vegetable. DESIGN: The study consisted of a qualitative explorative phase (field walks, semi-structured interviews with key informants, focus group discussions) at two rural sites; and a quantitative household survey (questionnaire) at two rural and one urban site. Amaranth leaves were analysed for β-carotene content. SETTINGS AND SUBJECTS: The household survey included households at a rural site in Limpopo province (n = 100); and a rural (n = 101) and urban (n = 391) site in KwaZulu-Natal province, South Africa. RESULTS: A variety of edible plants were identified during field walks at the two rural sites. Focus group discussions narrowed this down to ten plants at the rural Limpopo site and six at the rural KwaZulu-Natal site. The most popular leaves were amaranth (Amaranthus spp), spider plant (Cleome gynandra), wild watermelon (Citrullus lanatus) and blackjack (Bidens spinosa), consumed individually or mixed with other leaves. Rural households procured leaves mostly from the wild whereas urban households relied more on informal markets. In Limpopo, leaves were dried and stored for consumption during winter. KwaZulu-Natal households considered African leafy vegetables food for the poor. Leaves were boiled in salted water, or steamed and then fried in oil. Fried and boiled amaranth leaves contained 627 and 429 μg retinol activity equivalents/100 g respectively. CONCLUSIONS: Availability of, access to and nutrition-related uses of African leafy vegetables are context-specific, with inter- and intraprovincial rural/urban differences. Information collected during small studies within a specific area can therefore not be generalised for the overall South-African population. Amaranth can potentially contribute significantly to vitamin A requirements of nutritionally vulnerable communities

Exercise training alters red blood cell fatty acid desaturase indices and adipose tissue fatty acid profile in African women with obesity.

Objective This study assessed the changes in red blood cell total phospholipid (RBC-TPL) and subcutaneous adipose tissue (SAT) fatty acid (FA) composition in response to 12 weeks of exercise training in South African women with obesity and the associations with changes in cardiometabolic risk factors. Methods Previously sedentary women were randomized into control (n = 15) or exercise (n = 20) groups. RBC-TPL and SAT FA profiles, SAT gene expression, systemic inflammatory markers, liver fat, and insulin sensitivity (S-I) were measured before and after the intervention. Results Compared with control, exercise training induced decreases in RBC-TPL dihomo-gamma-linolenic acid content and stearoyl-CoA desaturase-1 and increased delta-5 desaturase-estimated activity (P < 0.05). In the combined group, these changes correlated with changes in circulating leptin and TNF alpha (P < 0.05), as well as lower liver fat (P < 0.01). Exercise training decreased saturated FA (lauric and myristic acids) and increased polyunsaturated FA (eicosadienoic and adrenic acids) (P < 0.05) in abdominal SAT, whereas gamma-linolenic acid decreased (P < 0.01) in gluteal SAT. These changes in RBC-TPL and SAT FA compositions were not associated with changes in SAT gene expression and S-I. Conclusions Exercise training alters RBC-TPL desaturase activities, which correlate with lower liver fat and systemic inflammation but not with the improvement of S-I