Thesis (M.A.)--Miami University, Dept. of History, 2009. / Title from first page of PDF document. Includes bibliographical references (p. 58-66).

Magister Scientiae - M.Sc. / Aspalathus linearis (A. linearis), commonly known as Rooibos tea or Red bush tea and Camellia sinensis (C. sinensis) or Black tea are beverages that are consumed throughout the world. These teas possess antioxidant, immunomodulating and anti-cancer actions. The aim of this study was to use in vitro assays to screen Rooibos and Black tea for endocrine modulation. The immune modulating effects of Rooibos and Black tea were investigated using an in vitro whole blood culture (WBC) assay. Unstimulated WBCs treated with Rooibos tea secreted higher levels of IL-6, IL-10 and IFNγ than cultures treated with DMSO control. Rooibos treatment of stimulated WBCs resulted in higher IL-6, lower IL-10 and no effect on IFNγ secretion compared to DMSO treated stimulated WBC. Black tea treatment of stimulated WBC resulted in decreased IL-6, IL-10 and IFNγ secretion compared to the DMSO treated stimulated WBC. Extracts of Rooibos and Black tea were assessed for phytoestrogens using quantitative estrogen ELISAs. Both teas contain phytoestrogens. The quantitative ELISAs showed that Rooibos tea contained significantly lower estrone (E1), estradiol (E2) and estriol (E3) levels than Black tea. The effects of Rooibos and Black tea on proliferation of the estrogen dependant MCF-7 cell line was determined to further characterise the phytoestrogenic properties of the teas. Both Rooibos and Black tea extracts caused a significant inhibition of MCF-7 proliferation. This study shows that Rooibos tea and Black tea are beverages that can either stimulate or suppress the immune system. Also, both teas contain significant levels of phytoestrogens as determined by quantitative ELISAs. The current study confirms previous reports showing inhibition of growth in breast cancer cell lines by phytoestrogens. The findings extend related observations on the anti-carcinogenic potential of the two teas. / South Africa

Thesis (M. Sc. (Horticulture)) -- University of Limpopo, 2020 / Tea is globally regarded as the second most consumed in the world after water. It is associated with various health benefits such as anti-cancer, anti-inflammation, anti-obesity and reduction in cholesterol blood levels. Jatropha zeyheri indigenous tea has medicinal and nutritional properties, therefore knowledge of its chemical compositions is essential for increasing its quality. This indigenous tea is currently harvested in rural areas when the leaves are already dry, which is in contrary to what is practised in most tea industries. Therefore, the determination of harvesting time has an opportunity to contribute towards increasing the quality of J. zeyheri indigenous tea. The study investigated whether harvesting times has an effect on essential and non-essential mineral elements and phytochemicals and antioxidant activity of J. zeyheri leaves. The study materials were collected in the wild at Khureng village, Lepelle-Nkumpi Municipality, Limpopo Province, South Africa. Five treatments constituting of harvesting times (February, March, April, May and June) were arranged in a randomised complete block design, with 10 replications. Leaves were harvested, oven-dried at 60°C for 24 hrs and pulverised. A microwave digestion system (PerkinElmer, Titan MPS, United States) was used to prepare the samples prior analysis. After the preparations, mineral elements were determined using Inductively Coupled Plasma Emission Spectrometer-9000 (Shimadzu, Japan). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay was used to quantify the antioxidant activity of the acetone extracts of plants. The total phenol and tannin contents in each plant extract were determined using the Folin-Ciocalteu assay method. The total flavonoid contents were determined using the Aluminium Chloride colorimetric assay. The absorbance for antioxidant activity and phytochemicals were recorded using UV/visible spectrophotometer (Beckman Coulter-DU730, USA). Harvesting times had highly significant effects on Cr, Fe, K, Mg, Ni, P and S contributing 58, 65, 73, 62, 55, 67 and 69%, respectively, in total treatment variation, but were significant on Ca, Cu, Mn, Al, Co and Na contributing 62, 58, 66, 53 and 57%, respectively, in total treatment variation (TTV). However, harvesting times did not influence Zn and Si amounts in J. zeyheri leaves. Harvesting times increased majority of essential and non-essential mineral elements, except for K which was gradually decreased. Essential and non-essential mineral elements over different harvesting times exhibited positive quadratic relations. Using the optimisation equation (x = –b1/2b2) from the quadratic equation, harvesting of J. zeyheri was optimised at 2.46 months. Harvesting times had highly significant effects on the antioxidant activity, total phenol and flavonoid contents contributing 62, 88 and 60% in total treatment variation, respectively, but was not significant on total tannin contents. The negative quadratic relationship models explained 51, 90 and 95% of the observed variation in antioxidant activity, total phenol and flavonoid contents, respectively. In conclusion, findings of this study suggested that harvesting of J. zeyheri leaves be done between April-May for improved accumulation of mineral elements, whereas, for phytochemicals and antioxidant activity the results suggested that further studies be conducted from early summer until winter to find the optimum harvesting time of J. zeyheri indigenous tea. / National Research Foundation (NRF)

Thesis (M.Sc. (Horticulture)) --University of Limpopo, 2007 / Bush tea (Athrixia phylicoides DC) has been used for many years by the people of South Africa for medicinal purposes. The herbs was only harvested from the wild, therefore data on the effects of mineral nutrition on total antioxidant activity had not been established. The objective of this study was to determine the seasonal effect of nitrogen (N), phosphorus (P) and potassium (K) nutrition on total antioxidant activity (TAA) in cultivated bush tea leaves. Treatments consisted of 0, 100, 200, 300, 400 or 500 kgha-1 N, P or K in a randomized complete block design with four replications under 50 % shade nets. Three (N, P and K) parallel trials were conducted per season (autumn, winter, spring and summer). TAA was determined using 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) method and analyzed in a spectrophotometer. Results of this study demonstrated that regardless of season, the application of N, P and K fertilizers increased quadratically levels of TAA in bush tea with most of the increase occurring between 0 and 300 N, 300 P and 200 K kgha-1. Therefore, for improved total antioxidant content in bush tea leaves, 300 N, 300 P and 200 K kgha-1 N are recommended. / National Research Foundation (NRF), Agricultural Research Council(ARC-LNR)

Packaging is a topic under debate and scrutiny intoday’s society, due to its obvious environmentaldetriment – but also the business opportunities – tied tominimizing or even eliminating packaging.therefore, in this thesis, the aim is to introduce Chinesetea culture to the Swedish through packaging design,By tea culture studies and surveys of the Swedishmarket, with less is more, and minimalism designtheory to design elegant and Sustainable package. Withthis design, convey the Chinese tea ceremony cultureand Zen philosophy.Through the study of Chinese tea culture, then analysiscurrent tea packaging on Chinese and Swedish markets,from the structure, color, material...every aspects ofpackaging design to show the Chinese tea culture in theSwedish market.4According to our respondents and theory, packaging isa big component in a brand's marketing strategy and tocommunicate the brand’s message and values.Marketing information can be designed into visualelements that are used on the package to communicatea message which could speak out the consumers'emotions. But packaging is a topic under debate andscrutiny in today’s society, due to its obviousenvironmental detriment – but also the businessopportunities.So, how to balance the commercial and environmentalthose two aspects and how to express sustainabledesign in my project, is the major issues I have to figureout.Key words: Chinese tea culture, less is more,sustainable packaging design, graphic design, Zen andtea ceremony, tea business marketing

Thesis (MSc Food Sc) (Food Science)--University of Stellenbosch, 2005. / Near infrared spectroscopy (NIRS) and UV/Vis spectrophotometric methods were investigated as rapid and/or more economical methods to quantify the major monomeric phenolic compounds, soluble solid content (SSC), total polyphenol content (TPC) and total antioxidant activity (TAA) of green rooibos and Cyclopia genistoides.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2005. / Antimutagenic activity of aqueous extracts of fermented and unfermented Cyclopia spp., i.e. C. intermedia, C. subternata, C. genistoides and C. sessiliflora against metabolically activated aflatoxin B1 (AFB1) in the Salmonella mutagenicity assay with tester strain TA100, was compared to that of fermented and unfermented Aspalathus linearis (rooibos) and Camellia sinensis (black, oolong and green) teas. Possible mechanisms involved in in vitro antimutagenic activity of these teas were investigated, i.e. the stabilising effect of the unfermented Cyclopia spp., unfermented rooibos and green tea on rat liver cytochrome P450 in the S9 fraction from Aroclor 1254 treated rats and their modulation of aniline-induced Type II difference spectra in the microsomal fraction. Inhibition of lipid peroxidation in rat liver S9, by the teas, was assessed to determine whether protection against lipid peroxidation may play a role in cytochrome P450 stability in vitro. Correlation of the antimutagenic activity of the teas with their stabilising effect on cytochrome P450 and inhibition of lipid peroxidation, provided insight into possibly related mechanisms. Antimutagenic activity correlated weakly with a decreased stabilising effect of the teas on cytochrome P450 (r = 0.411, P = 0.013) and the inhibition of lipid peroxidation (r = 0.475, P = 0.003). Decreased stability of cytochrome P450 was associated with substantial lipid peroxidation occurring in rat liver S9. Effective inhibition of lipid peroxidation and stabilising of cytochrome P450 in S9 was evident in the presence of the teas, but no correlation (r = 0.018, P = 0.915) existed for the effect of unfermented teas on cytochrome P450 stability with inhibition of lipid peroxidation. Black tea exhibited the highest protection against AFB1-induced mutagenesis and fermented C. intermedia offered the least protection. “Fermentation” resulted in increased antimutagenic activity of Camellia sinensis and rooibos teas, while the antimutagenic activity of Cyclopia spp. decreased with fermentation except for C. genistoides. Unfermented teas significantly (P < 0.05) stabilised cytochrome P450, with rooibos more effective (P < 0.05) than green tea, but similar (P < 0.05) to Cyclopia spp. Green tea demonstrated the highest inhibition of lipid peroxidation, while the inhibition exerted by rooibos was similar (P > 0.05) to unfermented Cyclopia spp., except for C. genistoides exhibiting the least inhibition. Total polyphenol, flavanol and flavonol/flavone contents of the respective teas were correlated with activity in terms of antimutagenicity, stabilising of cytochrome P450 and inhibition of lipid peroxidation. Antimutagenic activity of Cyclopia spp. correlated with its total polyphenol (r = 0.805, P < 0.0001) and flavanol (r = 0.653, P < 0.0001) contents, while a weak negative correlation (r = -0.456, P = 0.026) was observed for the inhibition of lipid peroxidation by unfermented Cyclopia spp. with the flavonol/flavone content. Antimutagenicity of Cyclopia spp. correlated weakly (r = 0.363, P = 0.012) with its hesperidin content. Antimutagenic activity of rooibos tea correlated moderately (r = 0.751, P < 0.005) with its flavonol/flavone content and specifically the flavones orientin (r = 0.674, P < 0.023) and iso-orientin (r = 0.728, P < 0.011). A strong negative correlation (r = -0.918, P < 0.0001) of antimutagenicity of rooibos with its aspalathin content was observed. Antimutagenic activity of Camellia sinensis teas did not correlate with their total polyphenol, flavanol or flavonol/flavone contents. The flavanol content of green tea showed a good, but marginal (P < 0.1) correlation (r = 0.824, P = 0.086) with decreased cytochrome P450 stability. The modulation of aniline-induced Type II binding to microsomal cytochrome P450 by green tea differed significantly (P < 0.05) from the modulation exhibited by rooibos and Cyclopia spp. Flavonoid glycosylation appeared to influence antimutagenic activity, stabilising of cytochrome P450 and modulation of substrate binding of selected phenolic compounds. The present study indicates that rooibos and Cyclopia spp. have in vitro antimutagenic activity against AFB1, suggesting that consumption of these two herbal teas may have beneficial health effects. It is also suggested that stabilising of cytochrome P450 by tea, and interaction of tea constituents with cytochrome P450, may influence their in vitro antimutagenic activity.

No description available.

This study aims to determine the concentrations of fluoride in UK tea products and their infusions. This is related to the uptake and distribution of fluoride within tea plants Camellia sinensis (L.). Human oral bioaccessibility of fluoride from the consumption of tea infusions was estimated, using an in vitro approach. The possible health significance from fluoride exposure is discussed. Fluoride in tea products and the distribution within the tea plant was determined using a method, involving alkali fused digestion with ion chromatography and a conductivity detector for the instrumentation. For the aqueous infusions and the supernatants in the bioaccessibility experiments, ion selective electrode with a voltmeter was adopted. Mean fluoride concentrations in tea products and their infusions varied significantly (p<0.001; n=3) and were related to the type of tea product and the retail cost. The higher priced teas, such as Darjeeling, Assam and Oolong, had lower fluoride concentrations. The lower priced supermarket Economy ranged teas were significantly higher (p<0.05) in fluoride and exhibited concentrations similar to Chinese Brick tea, which is prepared using mature tea leaves. The higher quality products are prepared by selecting the finest tips of tea (buds), whereas an Economy products use coarser harvesting techniques to include mature leaves in the product. Fluoride affinity and tolerance of C. sinensis was assessed by a series of fluoride dosing experiments, ranging from 0 to 200 mg. Following fluoride dosing, a rapid uptake and accumulation occurred throughout the tea plants, resulting in partial necrosis of random leaves. Despite the necrosis, the plants tolerated the fluoride and continued to increase in height, although at a significantly slower rate (p<0.05) compared to the control plants. Accumulation of fluoride was observed to be mostly in the mature leaves followed by younger buds, then the roots. This relates to the part of the plant used to produce the tea types, with mature leaves for Economy products and the buds for the finer teas. The in vitro bioaccessibility assessment of fluoride estimated that over 91.4% of fluoride from a tea infusion is available in the human gastric compartment, with 92.1% in the gastro-intestinal compartment. The addition of milk reduced fluoride absorption in the gastric and gastro-intestinal compartments to 73.8 and 83.1%, respectively, possibly reacting to form calcium fluoride. Despite the percentage bioaccessibility, the concentration of fluoride available for absorption in the human gut was dependent upon choice of tea product. Based on an adult male, the findings suggest that consuming a litre of Economy tea can fulfil or exceed (75 to 120%) the recommended dietary reference intake (DRI) of fluoride at 4 mg a day, but only partially fulfil (25 to 40%) when consuming a more expensive Pure blend such as Assam. With regards to health, tea consumption is a source of fluoride in the diet and is highly available for absorption in the human gut. Tea alone can fulfil an adult fluoride DRI, but is dependent upon choice of tea product. Excess fluoride in the diet can lead to detrimental health effects such as fluorosis of the teeth and skeletal fluorosis and consuming economy branded tea can lead to a higher exposure.

published_or_final_version / Chinese / Master / Master of Philosophy