The main aim of this master thesis was to introduce an optimal method which could be used for study of a decompostion of an organic matter in a soil. For this purpose was chosen based on a literaly review so-called tea bag method. With regard to the completeness of the work, a physico-chemical characterization of the soil environment and HS isolated from it was also performed. The degraded organic material was then further characterized using thermogravimetric analysis, elemental analysis, FT-IR spectroscopy, and the total content of water-extractable polyphenolic substances in the samples was also determined.

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2020 / Most rural communities harvest different plant parts of Jatropha zeyheri for nutritional and medicinal purposes. However, the decision of choosing to harvest the plant part with desired chemical components is essential for quality purposes. Nevertheless, there is a lack of information regarding the distribution of chemical composition in different plant parts of J. zeyheri tea. Therefore, the objectives of the study were to: (1) investigate the effect of different plant parts (stems, roots and leaves) of J. zeyheri on mineral composition and, (2) determine the effect of different plant parts (stems, roots and leaves) of J. zeyheri on phytochemicals and antioxidant activity. A study was conducted with three treatments, namely stems, roots and leaves arranged in a randomised complete block design (RCBD), with 10 replications. Plant materials were collected in the wild from mature plants between June-July 2018. Leaves and stems were manually separated, while roots were cut into smaller pieces, dried at 60°C for 48 hours in an air-forced oven and later finely ground using an electric grinder. Mineral elements were determined using Inductive Coupled Plasma Emission (ICPE-9000 Shimadzu, Japan). Phytochemical tests were performed to detect the presence of flavonoids, tannins, alkaloids and saponins, whereas 2,2-Diphenyl-1-picrylhydrazyl (DPPH) antioxidant qualitative test was performed using TLC plates. Antioxidant activity and phytochemicals constituents were quantified using UV/Visible spectrophotometer. Results of this study demonstrated that plant parts had a highly significant effect on essential mineral elements, copper (Cu), iron (Fe), potassium (K), magnesium (Mg), zinc (Zn), manganese (Mn), phosphorus (P) and nickel (Ni) contributing 82, 75, 97, 88, 86, 96, 79 and 82% to total treatment variation (TTV), respectively, whereas, calcium (Ca) had a significant effect contributing 69%, while no significant effect on sulphur (S) was observed. Among the tested essential mineral elements, Ca, Zn, Cu and Ni were consistently the highest in the leaf, followed by stem whereas, the root had the lowest contents. Manganese and Mg were consistently the highest in the stem, followed by leaf whereas, the root had the lowest content. Iron was highest in the leaf followed by root and was lowest in the stem. Also, the stem had the highest content of K whereas, the leaf and the root had moderately lower content, and P was high in the leaf, whereas, stem and root had lower content. Similarly, plant parts had a highly significant effect on non-essential mineral elements, aluminium (Al), sodium (Na), cobalt (Co) and chromium (Cr) contributing 85, 72, 84 and 81% in TTV, respectively, whereas, not significant on silicon (Si). Among the tested non-essential mineral elements, the leaf had the highest content of Al, Na, Cr, and Co followed by the stem, whereas, the root had the lowest. The screening of phytochemicals showed that flavonoids, tannins, alkaloids and saponins were present within different plant parts of J. zeyheri. The results from DPPH qualitative assay of J. zeyheri plant parts showed more yellow spots in leaf and root whereas, there was lesser amount in stem indicating that the plant exhibited antioxidant activity. Plant parts had highly significant effect on total flavonoids contributing 72% in TTV, however, had a significant effect on tannins and antioxidant activity contributing 56 and 79% in TTV, respectively. In contrast, plant parts were not significant on total phenols. The leaf had the lowest of total flavonoids content, whereas root and stem reported the higher contents and root had a lower content of tannins and antioxidant activity, whereas stem and leaf reported higher contents. In conclusion, the majority of chemical properties were recorded in leaves followed by stems and lastly in the roots. The result of this study suggested that J. zeyheri tea beverage can be brewed from leaves predominantly followed by stems or alternatively they can be combined. / National Research Foundation (NRF) and Limpopo Agro-Food Technology Station (LATS)

Thesis (PhD)--Macquarie University, Division of Society, Culture, Media & Philosophy, Dept. of Media, 2007. / Bibliography: leaves 281-305. / Introduction -- Advertising, branding & consumerism: a literature survey -- Methodology: from Barthes to Bushells -- A taste for tea: how tea travelled to and through Australian culture -- Class in a tea cup -- A tale of two brands -- Thrift, sacrifice and the happy housewife -- 'He likes coffee SHE likes tea' -- 'Is it as good?': Bushells beyond Australia -- 'The one thing we all agree on' -- Conclusion. / Since its introduction in 1883, the Bushells brand of tea has become increasingly identified with Australia's national identity. Like Arnott's, QANTAS and Vegemite, Bushells has become a part of the nation's cultural vocabulary, a treasured store of memories and myths. This thesis investigates how Bushells acquired this status, and the transformation by which an otherwise everyday item evolved from the ordinary to the iconic. In short, through Bushells, I will demonstrate the cultural logic of branding. -- Bushells is ideally suited for an historical analysis of branding in Australia. Firstly, tea has been a staple of the Australian diet since the time of the First Fleet. So, it proves a fitting example of consumer processes since the early days of White settlement. From this, I will consider the rise of an environment sensitive to status, and therefore conducive to branding. In the late nineteenth century, Bushells was challenged to appeal to the burgeoning corps of middle class consumers. To this end, the brand integrated those ideals and associations that turned its tea into one that flattered a certain sensibility. Secondly, having established its affinity with a particular market group, the middle class, Bushells was well positioned to track, acknowledge and incorporate some of the most dominant trends of the twentiethcentury; specifically, the rise of a particular suburban ideal in the 1950s, and changing conceptions of gender, labour and technology. Finally, in the last two decades, Bushells has had to concede decisive shifts in fashion and taste; as Australia's population changed, so too did tea's place and prominence in the market. This thesis thus canvasses all these issues, chronologically and thematically. To do this, I will contextualise Bushells' advertisements in terms of the contemporary conditions that both informed their content, and underpinned their appeal. -- Considering the breadth and depth of this analysis, I argue that in the case of Bushells there is a cultural logic to branding. As brands strive for relevance, they become screens off which major societal processes can be identified and examined. As such, I will show that, in its address to consumers, Bushells broached some of the most significant discourses in Australia's cultural history. / Mode of access: World Wide Web. / v, 305 leaves ill

Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its temporal dynamics are of significant importance, since their effects might change over the course of the decomposition process. Within the TeaComposition initiative, we incubated Green and Rooibos teas at 524 sites across nine biomes. We assessed how macroclimate and atmospheric inorganic N deposition under current and predicted scenarios (RCP 2.6, RCP 8.5) might affect litter mass loss measured after 3 and 12 months. Our study shows that the early to mid-term mass loss at the global scale was affected predominantly by litter quality (explaining 73% and 62% of the total variance after 3 and 12 months, respectively) followed by climate and N deposition. The effects of climate were not litter-specific and became increasingly significant as decomposition progressed, with MAP explaining 2% and MAT 4% of the variation after 12 months of incubation. The effect of N deposition was litter-specific, and significant only for 12-month decomposition of Rooibos tea at the global scale. However, in the temperate biome where atmospheric N deposition rates are relatively high, the 12- month mass loss of Green and Rooibos teas decreased significantly with increasing N deposition, explaining 9.5% and 1.1% of the variance, respectively. The expected changes in macroclimate and N deposition at the global scale by the end of this century are estimated to increase the 12-month mass loss of easily decomposable litter by 1.1– 3.5% and of the more stable substrates by 3.8–10.6%, relative to current mass loss. In contrast, expected changes in atmospheric N deposition will decrease the mid-term mass loss of high-quality litter by 1.4–2.2% and that of low-quality litter by 0.9–1.5% in the temperate biome. Our results suggest that projected increases in N deposition may have the capacity to dampen the climate-driven increases in litter decomposition depending on the biome and decomposition stage of substrate.

Thesis (MScAgric (Agronomy)--Stellenbosch University, 2008. / Honeybush (Cyclopia spp. Fabaceae) is indigenous to the fynbos botanical biome of the Eastern and Western Cape of South Africa. The increase in the international demand for honeybush tea for health benefits, concern over exploitation of wild populations and the lack of published agronomic information necessitated this study to evaluate different aspects of honeybush propagation. The main objectives of this study were to evaluate the effect of species and cutting position on rooting of cuttings of Cyclopia species using different rooting hormones, to evaluate the effect of an organic plant fertilizer and cutting position on growth and establishment of rooted cuttings and to study the influence of different seed pre-treatments on germination of Cyclopia species. Terminal and sub-terminal cuttings of C. intermedia and C. genistoides treated with different rooting hormones were rooted under day/night temperature controlled glasshouse conditions. Intermittent mist was used as means of moisture supply to the cuttings for 45-60 seconds daily every 30 minutes. C. genistoides rooted significantly better compared to C. intermedia as measured by rooting percentage, number of roots per cutting, length of longest root and mean root length during the summer season. The cutting position had a significant effect on rooting of the cuttings in summer compared to winter and spring season. The interactive effect of species, treatment and cutting position resulted into 86% of rooting in summer from the terminal cuttings of C. genistoides, while only 4% was recorded as the highest rooting percentage in both winter and spring seasons. The highest number of roots and the greatest root length per cutting were obtained with 2 and 4 g L-1 IBA from terminal cuttings of C. genistoides and these hormone concentrations were not significantly different to each other. To evaluate the effect of an organic plant fertilizer and cutting position on plant growth and establishment, rooted cuttings of two Cyclopia species (C. intermedia and C. genistoides) from two cutting positions (terminal and sub-terminal) were transferred to pots (576 cm3) and treated with Nitrosol fertilizer at application rates of 3.33 ml.L-1, 1.67 ml.L-1 and 0 ml.L-1 (control). Cyclopia plantlets were uniformly inoculated once with a symbiotic Rhizobium bacteria to improve the formation of nodules. Nitrosol® at 3.33 ml.L-1 significantly affected fresh and dry plant weight, fresh and dry root weight, number of shoots and nodules per plant compared to either 1.67 ml.L-1 or the control. Relative to species, C. genistoides performed better in terms of fresh and dry plant weight, fresh and dry root weight, and number of shoots and nodules per plant compared to C. intermedia. The origin of the cutting position did not significantly affect the above mentioned parameters. Plant mineral analysis revealed that most of the essential elements increased with increasing Nitrosol® application rates, with C. genistoides having higher levels of mineral elements than C. intermedia. This could be an indication of the differences between the two species in terms of nutrient uptake, utilization and distribution within the plant tissues. In the germination studies, seeds obtained from different seed sources of Cyclopia species were subjected to different pre-sowing treatments. Seed treatments were sulphuric acid (95%), hot water (100°C), water with smoke paper disk, and demineralised water (control). The study revealed that all the treatments had a significant effect on germination with the exception of eight year old seeds obtained from C. subternata (seed source two). Although hot water treatment improved germination compared to smoked paper disk and the control, seeds treated with hot water degenerated rapidly. The highest overall germination (77.33%) was found with one year old seeds compared to other seed sources older than one year. Although smoked paper disks generally did not improve germination compared to the control, in one year old seeds from seed source one, this treatment greatly influenced germination, suggesting that seed age might have influenced germination of these seeds. In terms of germination rate, germination generally started after four days in most treatments.

Assignment (MPhil)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: From 1954 to 1993 the Rooibos Control Board, a statutory one-channel marketing system, regulated the rooibos industry. In 1993 the industry was deregulated and competition between different role players in the industry emerged. In this study competitiveness is analysed from both a historical as well as a modem -day perspective. Modem economic theory defines that competition is good for all industry and that it leads to economic development. In the case of the rooibos industry, one could be inclined to think that the unique character of the product and the fact that the Control Board had established a marketing mechanism would limit competition and rivalry in the post -Control Board era. Inthis study it was determined that deregulation in this industry coincided with very intense price-driven rivalry in the export market whilst very little rivalry occurred in the domestic market. The information for this thesis was obtained from published Annual Reports of the Rooibos Control Board and from personal interviews with the main role players in the industry. Two strategies that could enhance the competitiveness of this industry are recommended: 1. Repositioning rooibos as a gourmet health tea. 2. Improving supply chain coordination within the industry. / AFRIKAANSE OPSOMMING: Verbetering van die Mededingendheid van die Rooibos Industrie Vanaf 1954 tot 1993 het die Rooibos Beheerraad, 'n statutêre enkelkanaal bemarkingsorganisasie, die rooibosindustrie gereguleer. In 1993 is die bedryf gedereguleer en kon mededinging tussen verskillende rolspelers plaasvind. In hierdie studie word mededinging uit beide 'n historiese sowel as moderne perspektiefbestudeer. Moderne ekonomiese teorie stel dit dat mededinging tot voordeel van alle industrieë is en dat dit lei tot ekonomiese ontwikkeling. In die geval van rooibos sou mens geneig wees om te dink dat die unieke karakter van die produk en die feit dat 'n bestaande bemarkingskanaal alreeds bestaan, mededinging sou beperk in die post-Beheerraad tydvak. In hierdie studie is bevind dat deregulering gepaard gegaan het met intense prys-gedrewe mededinging in die uitvoermark, terwyl die binnelandse mark bykans geen mededinging ervaar rue. Die inligting vir hierdie tesis is verkry uit gepubliseerde Jaarverslae van die Rooibos Beheerraad en deur persoonlike onderhoude wat gevoer is met rolspelers binne die bedryf Twee strategieë word voorgestel waarmee die bedryf meer mededingend gemaak kan word: 1. Produk herposisionering as 'n gourmet gesondheidstee. 2. Verbeterde koordinasie binne die voorsieningskettings.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This study describes: 1. Substrate binding assays investigating the effects of methanolic extracts of unfermented and fermented Rooibos on the binding of natural substrates to ovine adrenal microsomal and mitochondrial P450 enzymes, demonstrating the interference of substrate binding in the presence of the Rooibos extracts. 2. The effects of selected flavonoids (quercetin, rutin and aspalathin) on the binding of natural substrates to ovine adrenal microsomal and mitochondrial P450 enzymes, demonstrating interference of substrate binding in the presence of the flavonoid compounds. 3. Substrate conversion assays in non-steroidogenic COS-1 cells to investigate the effects of methanolic extracts of unfermented and fermented Rooibos on the activity of key steroidogenic P450 enzymes (CYP17A1, CYP21A2, CYP11B1, and CYP11B2), demonstrating inhibition of the catalytic activity in the presence of Rooibos extracts. 4. The effects of selected flavonoids on the substrate conversion of the aforementioned key steroidogenic enzymes expressed in COS-1 cells. 5. An investigation of the effect of methanolic extracts of unfermented and fermented Rooibos on steroid hormone production in human adrenal H295R cells under basal and stimulated conditions, demonstrating the modulating effects of unfermented and fermented Rooibos extracts. Basal and stimulated steroid hormone production was decreased in the presence of unfermented and fermented Rooibos. / AFRIKAANSE OPSOMMING: Hierdie studie beskryf: 1. Die gebruik van substraatbindings-essais om die effek van metanoliese ekstrakte, van gefermenteerde- en ongefermenteerde Rooibos, op die binding van die natuurlike substrate aan skaap adrenale mikrosomale en -mitochondriale P450 ensieme te bepaal. Daar is getoon dat die ekstrakte 'n beduidende inhiberende effek op ensiemsubstraatinteraksie gehad het. 2. Die die inhiberende effek van geselekteerde flavonoïede (kwersetien, rutien and aspalatien) op die binding van die natuurlike substrate aan skaap adrenale mikrosomale en -mitochondriale P450 ensieme. 3. Die gebruik van substraatomsettings-essais in nie-steroïedogeniese COS-1 selle, om die effek van gefermenteerde- en ongefermenteerde Rooibos ekstrakte op die aktiwiteit van die steroïedogeniese P450 ensieme (CYP17A1, CYP21A2, CYP11B1, and CYP11B2) se katalitiese aktiwiteit te bepaal. Daar kon aangetoon word dat die katalitise aktiwiteite van bg. ensieme beduidend beïnvloed word deur die Rooibos ekstrakte. 4. Die gebruik van substraatomsettings-essais in nie-steroïedogeniese COS-1 selle, om die effek van geselekteerde flavonoïede op die aktiwiteit van bogenoemde steroïedogeniese P450 ensieme te bepaal. 5. 'n Ondersoek na die invloed van metanoliese ekstrakte van gefermenteerde- en ongefermenteerde Rooibos op steroïedhormoon biosintese in die menslike adrenale H295R-selmodel. Die ondersoek, onder basale en gestimuleerde toestande, het getoon dat beide Rooibosekstrakte in bogenoemde toestande steroïedhormoon produksie geinhibeer het.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: In this study, the influence of rooibos on the catalytic activity of enzymes 17β -hydroxysteroid dehydrogenase type 3 (17βHSD3), 17β-hydroxysteroid dehydrogenase type 5 (AKR1C3), 17β-hydroxysteroid dehydrogenase type 2 (17βHSD2), 5α-reductase type 1 (SRD5A1) and 5α-reductase type 2 (SRD5A2), which catalyse prostate androgen metabolism, was investigated. The activities of both 17βHSD3 and AKR1C3 heterologously expressed in CHO-K1 and HEK293 cells were inhibited significantly by rooibos, with rooibos reducing the conversion of androstenedione (A4) and 11keto-androstenedione (11KA4) to testosterone (T) and 11ketotestosterone (11KT), respectively. The catalytic activity of 17βHSD2 towards T, 11hydroxytestosterone (11OHT) and 11KT was also significantly inhibited by rooibos in transiently transfected HEK293 cells. In transiently transfected HEK293 cells rooibos did not inhibit SRD5A1 while the rate of T conversion to dihydrotestosterone (DHT) by SRD5A2 was decreased. Analysis of steroid metabolism in PNT2 cells also suggests that rooibos does not modulate the catalytic activity of endogenously expressed SRD5A towards A4, however, the conversion of T to DHT was reduced. In addition, reductive 17βHSD activity towards A4 was inhibited in the presence of rooibos in both PNT2 and BPH-1 cells. In contrast, the conversion of 11KA4 to 11KT was inhibited in BPH-1, PC-3 and LNCaP cells, with negligible conversion of 11KA4 in PNT2 cells. Interestingly, data suggests inhibition of 3α-hydroxysteroid dehydrogenase type 3 (AKR1C2) activity in the production of androsterone (AST) from 5α–androstenedione (5α-dione), as well as the dehydrogenase reaction of T to A4 in PNT2 cells by rooibos. Androgen metabolism pathways were subsequently investigated in LNCaP cells to determine androgen metabolism by endogenous enzymes. Rooibos resulted in the reduced conversion of A4 in LNCaP cells to the same extent as indomethacin, a known AKR1C3 inhibitor. Rooibos also modulated T, DHT and AST metabolism in LNCaP cells. Furthermore, uridine diphosphate glucuronosyltransferase (UGT) activity in LNCaP cells was inhibited by rooibos, decreasing T-, DHT– and AST-glucuronide formation. These data prompted subsequent investigations into the influence of rooibos at cellular level, and prostatespecific antigen (PSA) levels were assayed in the presence of rooibos. PSA was significantly inhibited by rooibos in the absence and presence of DHT, suggesting possible interaction of rooibos with the mutated androgen receptor (AR) or estrogen receptor-β (ERβ) expressed in LNCaP cells. Taken together, rooibos inhibited the catalytic activity of key enzymes that catalyse the activation of androgens in the prostate, as well as inhibiting enzymes involved in the conjugation of androgens. At cellular level, PSA levels were also decreased by rooibos, possibly through AR or ERβ interactions – clearly indicating a modulatory role for rooibos in active androgen production. / AFRIKAANSE OPSOMMING: In hierdie studie was die invloed van rooibos ten opsigte van die katalitiese aktiwiteite van die ensieme 17β-hidroksi-steroïed-dehidrogenase tipe 2, tipe 3 en tipe 5 (17βHSD2, 17βHSD3, AKR1C3), asook 5α-reduktase tipe 1 en tipe 2 (SRD5A1, SRD5A2) ondersoek. Hierdie ensieme is betrokke in die produksie van androgene in die prostaat. Rooibos het die katalitiese aktiwiteit van 17βHSD3 en AKR1C3 in CHO-K1 en HEK293 selle beïnvloed en het vermindere omskakeling van androstenedioon (A4) en 11keto-androstenedioon (11KA4) na testosteroon (T) en 11-ketotestosteroon (11KT), afsonderlik, veroorsaak. Die katalitiese aktiwiteit van 17βHSD2 teenoor T, 11-hidroksie-testosteroon (11OHT) en 11KT was ook beïnvloed in die teenwoordigheid van rooibos in HEK293 selle. Die katalitiese aktiwiteit van SRD5A1 teenoor A4 en T is nie beïnvloed deur rooibos nie, alhoewel dit voorkom asof rooibos die omsettingstempo van T na dihidrotestosteroon (DHT) deur SRD5A2, getransfekteer in HEK293 selle, verminder het. Verdere ondersoeke is in normale prostaat epiteel selle, in die teenwoordigheid van rooibos uitgevoer. Rooibos het geen invloed op die katalitiese aktiwiteit van SRD5A teenoor A4 gehad nie, alhoewel vermindere omskakeling van T na DHT aangetoon kon word. Rooibos het ook die omskakeling van A4 na T in beide PNT2 en BPH-1 selle tot „n mate geïnhibeer. Die omskakeling van 11KA4 na 11KT was ook verminder in BPH-1, PC-3 en LNCaP selle. Die omskakeling van 11KA4 na 11KT was beduidend laer in PNT2 selle en kon die invloed van rooibos nie aangetoon word nie. Bykomende data toon dat rooibos ook die omskakeling van 5α-androstenedioon (5α-dione) na androsteroon (AST), gekataliseer deur 3α-hidroksi-dehidrogenase tipe 3 (AKR1C2), verminder, gesamentlik met die vermindere omskakeling van T na A4, deur 17βHSD2, in PNT2 selle. Hierdie studie het ook ondersoek ingestel, na die metabolisme van androgene in LNCaP selle. Vermindere A4 metabolisme is in die teenwoordigheid van rooibos asook in die teenwoordigheid van indometasien, „n bekende AKR1C3 inhibitor, gevind. Rooibos verminder dus die aktiwiteit van reduktiewe 17βHSD in LNCaP selle. Verandering in die metabolisme van T, DHT en AST in LNCaP selle, in die teenwoordigheid van rooibos, is ook gevind. Verdere ondersoek in LNCaP selle het gewys dat rooibos „n vermindering in die produksie van gekonjugeerde T, DHT en AST veroorsaak. Die studie het die invloed van rooibos op prostaat-spesifieke antigeen (PSA) ook ondersoek. Daar is vasgestel dat rooibos die vlakke van PSA verminder in die afwesigheid en teenwoordigheid van DHT in LNCaP selle. Hierdie resultaat dui op moontlike interaksie van rooibos met die androgeen (AR) of estrogeen-reseptor-β (ERβ), teenwoordig in LNCaP selle. Rooibos het die katalitiese aktiwiteit van ensieme, wat bydra tot androgeen produksie, geïnhibeer, asook die konjugasie van androgene. Op „n sellulêre vlak, het rooibos die vlakke van PSA-sekresie verminder, wat moontlike interaksie met die AR en ERβ aandui. Hierdie bevindings dui daarop dat rooibos wel n rol het om te speel in die modulasie van aktiewe androgene in die prostaat.

published_or_final_version / Pharmacology / Doctoral / Doctor of Philosophy

published_or_final_version / Community Medicine / Master / Master of Public Health