Rooibos herbal tea: An optimal cup and its consumers

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 (Folin­Ciocalteau 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

Comparative toxicity effect of bush tea leaves (Hyptis suaveolens) and orange peel (Citrus sinensis) oil extract on larvae of the yellow fever mosquito Aedes aegypti

The ethanolic extracts of the orange peel (Citrus sinensis) and bush tea leaves (Hyptis suaveolens) were compared for their toxicity effect on the larvae of the yellow fever mosquito Aedes aegypti collected from disused tyres beside College of Natural Sciences building University of Agriculture, Abeokuta, Nigeria. Eight graded concentrations, 0.9ppm, 0.8ppm, 0.7ppm, 0.6ppm, 0.5ppm, 0.4ppm, 0.3ppm and 0.2ppm of both plant extracts were tested on the larvae. The mean lethal dose LD10, was 0.15 ppm for C. sinensis, 0.01 for H. suaveolens, while LD50 for C. sinensis was 0.4ppm, H.suaveolens 0.60ppm and LD90 for C. sinensis was 0.9ppm and H.suaveolens was 1.45ppm. LD10 for the control 0.65ppm, LD50 0.9ppm and LD90 2.0 ppm. The extract of C. sinensis peel caused higher mortality rate at concentrations 0.8ppm (95%) and 0.3ppm (90%) of the larvae while the extract of H. suaveolens caused high mortality rate on the larvae at concentrations of 0.9ppm (80%) and 0.3ppm (80%). Significant differences were observed between untreated and treated larvae (exposed to either of the extract) at the various concentrations (P< 0.05)

Effects of Tea Consumption on Plasma Lipids and Lipoproteins in Apparently Healthy Individuals

Possible alterations in total plasma cholesterol; triglyceride; HDL-cholesterol and LDL-cholesterol concentrations were studied in forty healthy human subjects (twenty-two males and eighteen adult females) after twenty eight days of tea consumption. A commercial brand of tea preparation was drunk by each of the subjects and they were made to take two standard cups (4.0g) of tea infusion per day. The result showed a significant decrease in mean HDL-cholesterol and increase in LDL-cholesterol concentrations compared with the mean control values. The mean total cholesterol was statistically unchanged. When the subjects were grouped into males and females; the mean LDL-C concentration was significantly elevated in both male and female groups while the mean HDL-C and triglyceride levels only in female subjects when compared with the corresponding control group. The difference observed in the value of the mean total cholesterol was not statistically significant in individual male and female groups.Findings from this study suggest that tea consumption could affect the metabolism of atherogenic lipid fractions and may thus be important in the aetiology of coronary heart disease