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OBJECTIVE: To review studies examining the nutritional value of street foods and their contribution to the diet of consumers in developing countries. DESIGN: The electronic databases PubMed/MEDLINE, Web of Science, Cochrane Library, Proquest Health and Science Direct were searched for articles on street foods in developing countries that included findings on nutritional value. RESULTS: From a total of 639 articles, twenty-three studies were retained since they met the inclusion criteria. In summary, daily energy intake from street foods in adults ranged from 13 % to 50 % of energy and in children from 13 % to 40 % of energy. Although the amounts differed from place to place, even at the lowest values of the percentage of energy intake range, energy from street foods made a significant contribution to the diet. Furthermore, the majority of studies suggest that street foods contributed significantly to the daily intake of protein, often at 50 % of the RDA. The data on fat and carbohydrate intakes are of some concern because of the assumed high contribution of street foods to the total intakes of fat, trans-fat, salt and sugar in numerous studies and their possible role in the development of obesity and non-communicable diseases. Few studies have provided data on the intake of micronutrients, but these tended to be high for Fe and vitamin A while low for Ca and thiamin. CONCLUSIONS: Street foods make a significant contribution to energy and protein intakes of people in developing countries and their use should be encouraged if they are healthy traditional foods.
Assuntos
Países em Desenvolvimento , Dieta , Fast Foods , Comportamento Alimentar , Abastecimento de Alimentos , Valor Nutritivo , HumanosRESUMO
BACKGROUND: Rooibos types and forms and how prepared and flavoured influence the total polyphenol content and total antioxidant capacity (TAC). AIM: To denote an optimal rooibos cup as having the highest total polyphenol content and TAC, considering the different types, forms, preparation methods and flavourings and amounts (Phase 1), and determine the demographic, lifestyle and rooibos consumption characteristics of adult rooibos consumers, and the association of these characteristics with drinking the optimal cup (Phase 2). SETTING: Assays: Oxidative Stress Research Centre, Cape Peninsula University of Technology; Consumer survey: George area, South Africa. METHOD: Phase 1 entailed determining the total polyphenol content (Folin-Ciocalteau method) and TAC (Trolox equivalent antioxidant capacity and ferric-reducing antioxidant power assay) of the prepared rooibos samples. For Phase 2, a developed, pilot tested questionnaire was used to profile adult rooibos consumers. RESULTS: Phase 1: the following samples delivered higher total polyphenol content and TAC: green (type), green leaves and powdered extract (forms), and sample steeped for 10 min or longer (preparation method). The identified optimal cup was sample steeped for 10 min or longer. Phase 2: a total of 308 respondents completed the questionnaire. Few consumed more than one rooibos cup per day (25.3%; n = 78) and the optimal cup (15.9%; n = 49). These latter respondents comprised those who steeped rooibos in a teapot (not a cup or mug) (p < 0.05). CONCLUSIONS: The optimal cup was identified as sample steeped for 10 min or longer. The rooibos consumers did not consume it sufficiently, nor steeped it long enough.
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ETHNOPHARMACOLOGICAL RELEVANCE: In South Africa, the plant Aspalathus linearis (Brum.f) Dahlg. (Fabaceae) is traditionally used as a "tea" referred to as rooibos or redbush. This plant has been listed as a medicinal plant based mostly on anecdotal evidence. AIMS OF THE STUDY: Despite a long history of traditional use in South Africa, very little scientific data are available from controlled clinical trials confirming its popular use. The aim of the present study was to investigate the effect of rooibos on biochemical and oxidative stress parameters in adults at risk for cardiovascular disease. MATERIALS AND METHODS: After a washout period of 2 weeks, 40 volunteers consumed six cups of fermented/traditional rooibos daily for 6 weeks, followed by a control period. Blood biochemical parameters indicative of antioxidant activity and content (total polyphenols), lipid peroxidation (conjugated dienes - CDs, thiobarbituric acid reactive substances - TBARS), redox status (total glutathione - tGSH, ratio of reduced to oxidized glutathione - GSH:GSSG), lipid profile (total cholesterol, low density lipoprotein - LDL and high density lipoprotein - HDL cholesterol and triacylglycerol levels) and liver and kidney function were measured at the end of each study period. RESULTS: Plasma antioxidant capacity was not altered, but plasma total polyphenol levels increased significantly after rooibos consumption compared with the control levels (from 79.8±16.9 mg/L to 89.8±14.1 mg/L). Significant decreases in plasma markers of lipid peroxidation were found after rooibos consumption, as reported by levels of CDs (167.3±29.5 nmol/mL vs. 108.8±20.1 nmol/mL) and TBARS (1.9±0.6 µmol/L vs. 0.9±0.3 µmol/L). Reduced glutathione (797±238 µmol/L vs. 1082±140 µmol/L) and the GSH:GSSG ratio (41±14 vs. 76±17) were both significantly increased after consumption of rooibos. The lipid profiles showed that rooibos consumption, compared with the control values, significantly decreased serum LDL-cholesterol (4.6±1.3 mmol/L vs. 3.9±0.7 mmol/L) and triacylglycerols (1.7±0.8 mmol/L vs. 1.2±0.7 mmol/L), while HDL-cholesterol (0.9±0.1 mmol/L vs. 1.2±0.2 mmol/L) was significantly increased. CONCLUSION: Confirming its popular use, consumption of fermented, traditional rooibos significantly improved the lipid profile as well as redox status, both relevant to heart disease, in adults at risk for developing cardiovascular disease.