Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Wine knowledge has increased drastically in recent years with the aid of scientific experimentation. The producers of wine have increasingly incorporated new wine knowledge into the marketing and innovation of wine products. In parallel with the above, the consumer market has become more aware of winemaking practices and their influence on consumer health. The use of alternative methods and additives in wine are means by which producers have been able to create innovative wine products. This study focused on the addition of rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) plant material to red wine. Consumer liking, as well as descriptive sensory analysis (DSA) of different red wines made from a range of cultivars with the addition of rooibos and honeybush plant material, was investigated. Another aim of the study was to observe the effect of oxygen addition to red wines treated with rooibos and honeybush plant material. The consumer studies included a number of events where wines treated with rooibos and honeybush material were compared with other commercial wines. The results could not clearly indicate whether consumers liked or disliked the wine products with added rooibos and honeybush plant material. Further refinement of wines with the addition of rooibos and honeybush can serve as topics for future research. Focus on the potential health benefits which can be added to wine from rooibos and honeybush plant material, as a result of inherent antioxidants within both these species, may serve as a novel research topic. The DSA panels identified aroma descriptors that could be related to the addition of wood and leaf or only rooibos and honeybush wood to wine. The addition of oxygen to wines treated with rooibos and honeybush plant material indicated that aromas associated with these treatments are relatively stable in wine undergoing oxidation. This could possibly pave the way for future research on the topic of low sulphur dioxide containing wines. As a result of this study, a commercial wine product called “Rooibos wine” was developed and became available in retail. Further research on this topic and the impact of the addition of rooibos and honeybush material to wine may be of great benefit for the production of innovative wines with unique aroma profiles. / AFRIKAANSE OPSOMMING: Kennis oor wyn het oor die afgelope paar jaar vooruitgegaan met behulp van wetenskaplike eksperimentering. Wynprodusente sluit toenemend nuwe wynkennis in die bemarking en innovering van wynprodukte in. Parallel hiermee het die verbruikersmark baie meer bewus geword van wynbereidingspraktyke en die invloed daarvan op verbruikersgesondheid. Die gebruik van alternatiewe metodes en byvoegings in wyn is maniere waarop produsente innoverende wynprodukte kan skep. Hierdie studie het gefokus op die byvoeging van rooibos (Aspalathus linearis) en heuningbos (Cyclopia spp.) plantmateriaal by rooiwyn. Verbruikers se voorkeur, sowel as die beskrywende sensoriese analise (descriptive sensory analysis [DSA]) van diverse rooi wyn kultivars waarby rooibos en heuningbos plantmateriaal gevoeg is, is geanaliseer. Nóg ’n doelwit van die studie was om die effek van suurstofbyvoeging by rooiwyne wat met rooibos en heuningbos plantmateriaal behandel is waar te neem. Vir die verbruikerstudies is geleenthede aangebied waar wyne wat met rooibos en heuningbos materiaal behandel is met kommersiële wyne vergelyk is. Die resultate kon nie duidelik aandui of die verbruikers gehou het of nie van wynprodukte wat met rooibos en heuningbos behandel is. Verdere verfyning van wyne met bygevoegde rooibos en heuningbos kan as onderwerpe vir toekomstige navorsing dien. Die verhoogde gesondheidvoordele van wyn wat met rooibos en heuningbos plantmateriaal behandel is as gevolg van die inherente anti-oksidante eie aan die spesies, kan dien as fokus vir ʼn nuwe navorsingstema. Die DSA-panele het beskrywende terme vir aromas geïdentifiseer wat verband kan hou met die byvoeging van die hout/blaar of slegs die rooibos- en heuningboshout by die wyn. Die aromas in wyn wat met rooibos en heuningbos behandel is, is gevind om relatief stabiel te bly tydens oksidasie. Dit kan moontlik die weg baan vir toekomstige navorsing oor lae swaweldioksied-bevattende wyne. As gevolg van hierdie studie is ‘n kommersiële wynproduk, genaamd “Rooiboswyn”, ontwikkel en is dit in die handel beskikbaar. Verdere navorsing oor hierdie onderwerp en die impak van die byvoeging van rooibos en heuningbos materiaal by wyn sal moontlik van groot voordeel wees vir die produksie van innoverende wyne met unieke aroma profiele.

<p>Camellia sinensis (tea) and Aspalathus linearis (rooibos) may improve reproductive function owing to their antioxidant properties. To test this<br /> hypothesis, male and female rats were given 2% and 5% green tea (Gt), black tea (Bt), unfermented rooibos (Ur) or fermented rooibos (Fr) as sole source of drinking for 52 and 21 days respectively. Control rats received tap water. In addition, TM3 Leydig cells were exposed to 0.025, 0.05, 0.1 and 0.5 % aqueous extracts of green tea, black tea, unfermented and fermented rooibos for 24h. In vitro analysis of tea and the herbal infusion revealed the phenolic property and antioxidant capacity (FRAP) in the order Gt &gt / Bt &gt / Ur &gt / Fr. Camellia sinensis and Aspalathus linearis revealed no significant effect on serum antioxidant capacity (p &gt / 0.05) and lipid peroxidation (MDA) in the kidney or liver in both male and female rats and in the testes of the male rats (p &gt / 0.05). In addition, the antioxidant levels were maintained in the testes, liver and kidneys in both the male and female rats. In the male rats, no significant alterations were observed in body weight gain, liver and reproductive organs weight, and serum testosterone (p &gt / 0.05). Only, 5% green tea significantly increased testosterone level (p &lt / 0.05). Seminiferous tubules displayed complete spermatogenesis with abundant sperm in the lumen in all treated groups. However, a significant decrease in diameter and germinal epithelial height of these tubules were observed (p &lt / 0.05). In the epididymides, epithelial height of caput region showed a significant increase (p &lt / 0.01), while the cauda region was increased by Camellia sinensis but decreased by Aspalathus linearis. Sperm concentration improved significantly by green tea and unfermented rooibos (p &lt / 0.05), while black tea and fermented rooibos produced a non significant effect (p &gt / 0.05). Sperm viability was enhanced in all treatment groups (p &lt / 0.05). Furthermore, green tea, black tea and unfermented rooibos significantly improved the motility of rat sperm (p &lt / 0.05) / fermented rooibos tended to improve it (p &gt / 0.05). In addition, green tea, black tea and fermented rooibos enhanced acrosome reaction (p &lt / 0.05). Creatinine activity was significantly higher in rats treated with black tea, unfermented rooibos or fermented rooibos (p &lt / 0.05), green tea tended to increase it (p &gt / 0.05) reflecting the significant increased kidney weight in the treatment groups at high concentrations. Liver markers, ALT and AST, decreased significantly in all treated groups (p &lt / 0.05), except in 5% fermented rooibos where a significant increase in AST level was observed (p &lt / 0.01). In the female rats, the body weight gain, and reproductive organs weight was no affected (p &gt / 0.05). However, 5% fermented rooibos reduced the ovarian weight (p &lt / 0.05), while 5% unfermented rooibos significantly increased the uterine weight (p &lt / 0.05). Liver weight increased significantly by black tea and unfermented rooibos (p &lt / 0.05) while the kidney weight increased significantly by 5% black tea (p &lt / 0.05). No significant effect was observed in the level of FSH produced, on the other hand, Camellia sinensis significantly lowered the level of LH (p &lt / 0.05), while Aspalathus linearis had no effect (p &gt / 0.05). Creatinine activity was enhanced significantly only by 5% fermented rooibos (p &lt / 0.05). Liver markers, ALT and AST were reduced in most treated groups except in fermented rooibos where an increase was observed. In addition, histological sections revealed no obvious alteration in the ovaries, uteri, kidneys and liver of all treated female rats. Camellia sinensis and Aspalathus linearis significantly reduced the level of testosterone produced in TM3 Leydig cells under stimulated conditions in vitro (p&lt / 0.05). Furthermore, both plants maintained the viability and morphology of the cells. However, at 0.5% of either plant extracts, a significant decrease in the viability (p &lt / 0.05) and altered morphology of the TM3 Leydig cells was observed. In conclusion, Camellia sinensis and Aspalathus linearis significantly improved certain sperm function which might be attributed to their high level of antioxidant activity. However, the prolonged exposure of both plant extracts might result in subtle structural changes in the male reproductive system and impair kidney function. In addition, fermented rooibos at high concentration may also impair the functions of the liver. In vitro, both plants were shown to possess anti-androgenic property on TM3 Leydig cells. Furthermore, both Camellia sinensis and Aspalathus linearis may be classified as weak phytoestrogens due to the changes in the weight of the uterus and ovaries observed.</p>

<p>Camellia sinensis (tea) and Aspalathus linearis (rooibos) may improve reproductive function owing to their antioxidant properties. To test this<br /> hypothesis, male and female rats were given 2% and 5% green tea (Gt), black tea (Bt), unfermented rooibos (Ur) or fermented rooibos (Fr) as sole source of drinking for 52 and 21 days respectively. Control rats received tap water. In addition, TM3 Leydig cells were exposed to 0.025, 0.05, 0.1 and 0.5 % aqueous extracts of green tea, black tea, unfermented and fermented rooibos for 24h. In vitro analysis of tea and the herbal infusion revealed the phenolic property and antioxidant capacity (FRAP) in the order Gt &gt / Bt &gt / Ur &gt / Fr. Camellia sinensis and Aspalathus linearis revealed no significant effect on serum antioxidant capacity (p &gt / 0.05) and lipid peroxidation (MDA) in the kidney or liver in both male and female rats and in the testes of the male rats (p &gt / 0.05). In addition, the antioxidant levels were maintained in the testes, liver and kidneys in both the male and female rats. In the male rats, no significant alterations were observed in body weight gain, liver and reproductive organs weight, and serum testosterone (p &gt / 0.05). Only, 5% green tea significantly increased testosterone level (p &lt / 0.05). Seminiferous tubules displayed complete spermatogenesis with abundant sperm in the lumen in all treated groups. However, a significant decrease in diameter and germinal epithelial height of these tubules were observed (p &lt / 0.05). In the epididymides, epithelial height of caput region showed a significant increase (p &lt / 0.01), while the cauda region was increased by Camellia sinensis but decreased by Aspalathus linearis. Sperm concentration improved significantly by green tea and unfermented rooibos (p &lt / 0.05), while black tea and fermented rooibos produced a non significant effect (p &gt / 0.05). Sperm viability was enhanced in all treatment groups (p &lt / 0.05). Furthermore, green tea, black tea and unfermented rooibos significantly improved the motility of rat sperm (p &lt / 0.05) / fermented rooibos tended to improve it (p &gt / 0.05). In addition, green tea, black tea and fermented rooibos enhanced acrosome reaction (p &lt / 0.05). Creatinine activity was significantly higher in rats treated with black tea, unfermented rooibos or fermented rooibos (p &lt / 0.05), green tea tended to increase it (p &gt / 0.05) reflecting the significant increased kidney weight in the treatment groups at high concentrations. Liver markers, ALT and AST, decreased significantly in all treated groups (p &lt / 0.05), except in 5% fermented rooibos where a significant increase in AST level was observed (p &lt / 0.01). In the female rats, the body weight gain, and reproductive organs weight was no affected (p &gt / 0.05). However, 5% fermented rooibos reduced the ovarian weight (p &lt / 0.05), while 5% unfermented rooibos significantly increased the uterine weight (p &lt / 0.05). Liver weight increased significantly by black tea and unfermented rooibos (p &lt / 0.05) while the kidney weight increased significantly by 5% black tea (p &lt / 0.05). No significant effect was observed in the level of FSH produced, on the other hand, Camellia sinensis significantly lowered the level of LH (p &lt / 0.05), while Aspalathus linearis had no effect (p &gt / 0.05). Creatinine activity was enhanced significantly only by 5% fermented rooibos (p &lt / 0.05). Liver markers, ALT and AST were reduced in most treated groups except in fermented rooibos where an increase was observed. In addition, histological sections revealed no obvious alteration in the ovaries, uteri, kidneys and liver of all treated female rats. Camellia sinensis and Aspalathus linearis significantly reduced the level of testosterone produced in TM3 Leydig cells under stimulated conditions in vitro (p&lt / 0.05). Furthermore, both plants maintained the viability and morphology of the cells. However, at 0.5% of either plant extracts, a significant decrease in the viability (p &lt / 0.05) and altered morphology of the TM3 Leydig cells was observed. In conclusion, Camellia sinensis and Aspalathus linearis significantly improved certain sperm function which might be attributed to their high level of antioxidant activity. However, the prolonged exposure of both plant extracts might result in subtle structural changes in the male reproductive system and impair kidney function. In addition, fermented rooibos at high concentration may also impair the functions of the liver. In vitro, both plants were shown to possess anti-androgenic property on TM3 Leydig cells. Furthermore, both Camellia sinensis and Aspalathus linearis may be classified as weak phytoestrogens due to the changes in the weight of the uterus and ovaries observed.</p>

Thesis (MSc Food Sc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Rooibos tea, produced from the endemic South African fynbos plant Aspalathus linearis, has various healthpromoting benefits which can largely be attributed to its phenolic composition. In this study, the reversedphase liquid chromatographic (RP-LC) separation of the principal phenolic constituents of aqueous rooibos infusions was optimised on conventional high-performance liquid chromatography (HPLC) instrumentation. The phenolic constituents comprised dihydrochalcones (aspalathin and nothofagin), flavones (orientin, isorientin, vitexin, isovitexin, luteolin, luteolin-7-O-glucoside and chrysoeriol), flavonols (quercetin, isoquercitrin, hyperoside and rutin), a hydroxycinnamic acid (ferulic acid) and a phenylpropanoid (phenylpyruvic acid glucoside, PPAG). A systematic approach towards method development was adopted: resolution was optimised by simultaneous optimisation of gradient conditions and temperature on a sub-2 6m phase to exploit the benefits of this phase for fast routine analyses. The developed HPLC method, utilising photodiode-array (PDA) detection, yielded complete separation of the 15 target analytes on the 1.8 µm C18 column, thermostatted to 37°C, within 37 min (total analysis time: 50 min). The method was successfully validated and demonstrated its suitability for the fast, quantitative analysis of aqueous infusions of unfermented and fermented rooibos. Mass spectrometric (MS) and tandem MS detection confirmed peak purity and permitted the tentative identification of 13 additional phenolic compounds, including a flavonol Odiglycoside (quercetin-3-O-robinobioside), a luteolin-6-C-pentoside-8-C-hexoside and a novel C-8-hexosyl derivative of aspalathin reported here for the first time. The HPLC-PDA method was subsequently applied to a large number of fermented rooibos samples representative of different production seasons (2009, 2010 and 2011) and quality grades (grades A, B, C and D) to capture as much potential variation in the phenolic composition as possible. Production season had no clear effect on the levels of the individual phenolic compounds in ‘cup-of-tea’ rooibos infusions, whilst high quality tea (grades A and B) was associated with higher levels of phenolic compounds and soluble solids than low quality tea (grades C and D). Steam-pasteurisation of the plant material, required to obtain a product of high microbiological quality, induced significant reductions in the mean values of most of the phenolic compounds in rooibos infusions. The major phenolic constituents of steam-pasteurised, fermented rooibos were isoorientin and orientin, whilst quercetin-3-O-robinobioside, PPAG and aspalathin were also present in high concentrations. Representative content values of the major phenolic compounds present in a typical ‘cup-of-tea’ rooibos infusion were thus obtained and the generated data are suitable for inclusion in food composition databases. The application of comprehensive two-dimensional liquid chromatography (LCxLC) was investigated as an alternative approach for the detailed investigation of rooibos phenolics. The combination of hydrophilic interaction chromatography (HILIC) in the first dimension and RP-LC in the second dimension offered different separation selectivities and hence a high degree of orthogonality. HILICxRP-LC provided a significant improvement in resolution, as is evident from practical peak capacities in excess of 2000 and 800 for the off-line and on-line methods, respectively. Further optimisation, particularly of the first dimension separation, is however required to improve the LCxLC separation of complex rooibos phenolic fractions. / AFRIKAANSE OPSOMMING: Gebruik van rooibostee, berei vanaf die eg Suid-Afrikaanse fynbosplant Aspalathus linearis, hou verskeie gesondheidsvoordele in wat grootliks toegeskryf kan word aan sy fenoliese samestelling. Die skeiding van die hoof fenoliese verbindings van ’n koppie rooibos is in hierdie studie deur middel van omgekeerde-fase vloeistof chromatografie (RP-LC) op konvensionele hoë-druk vloeistof chromatografiese (HPLC) toerusting geoptimiseer. Die fenoliese verbindings was verteenwoordigend van dihidrogalkone (aspalatien en notofagien), flavone (orientien, isoorientien, viteksien, isoviteksien, luteolien, luteolien-7-O-glukosied en krisoeriol), flavonole (kwersetien, isokwersetrien, hiperosied en rutien), ‘n hidroksiekaneulsuur (ferulasuur) en ‘n fenielpropanoied (fenielpirodruiwesuurglukosied, PPAG). Die ontwikkeling van die metode was sistematies benader: resolusie is op ‘n geselekteerde 1.8 6m stationêre fase met welombekende kinetiese voordele geoptimiseer deur die gradiëntkondisies en kolomtemperatuur gelyktydig te optimiseer. Die ontwikkelde HPLC metode, gekoppel aan ultraviolet-fotodiode deteksie (PDA), het binne 37 min (totale analiese tyd: 50 min) volledige skeiding van die 15 standaard verbindings op die 1.8 µm C18 kolom teen 37°C bewerkstellig. Die metode is suksesvol gevalideer en het sy toepaslikheid vir vinnige, kwantitatiewe analiese van ongefermenteerde en gefermenteerde rooibos gedemonstreer. Piek suiwerheid is deur middel van massa spektrometrie (MS) en tandem MS bevestig, wat ook die identifikasie van 13 addisionele verbindings toegelaat het, insluitende ‘n flavonol O-diglukosied (kwersetien-3-O-robinobiosied), ‘n luteolien-6-Cpentosied- 8-C-heksosied en ‘n unieke C-8-heksosiel afgeleide van aspalatien wat vir die eerste keer hier gemeld is. Die geoptimiseerde HPLC-PDA metode is gevolglik toegepas vir die analiese van ‘n groot aantal gefermenteerde rooibos monsters, verteenwoordigend van verskillende produksie seisoene (2009, 2010 en 2011) en kwaliteitsgrade (A, B, C en D). Hierdie lukraak-geselekteerde monsters het soveel as moontlik potensiële variasie in die fenoliese samestelling verseker. Produksie seisoen het geen definitiewe effek op die vlakke van die individuele fenoliese verbindings in ’n koppie rooibos gehad nie, terwyl hoë kwaliteit rooibos (grade A en B) geassosieër was met hoër vlakke van die individuele fenoliese verbindings en oplosbare vastestowwe in vergelyking met lae kwaliteit rooibos (grade C en D). Stoompasteurisasie van rooibos plantmateriaal, noodsaaklik om ‘n produk van hoë mikrobiologiese gehalte te verseker, het gelei tot ‘n betekenisvolle afname in meeste fenoliese verbindings in ’n koppie rooibos. Die hoof fenoliese verbindings van ‘n koppie stoom-gepasteuriseerde, gefermenteerde rooibos was orientien en isoorientien, terwyl kwersetien-3-O-robinobiosied, PPAG en aspalatien ook in noemenswaardige hoeveelhede aanwesig was. Verteenwoordigende waardes van die hoof fenoliese verbindings aanwesig in ‘n tipiese koppie rooibos is derhalwe verkry en die data is geskik vir insluiting in voedsel-samestelling databasisse. Die analiese van rooibos fenole met omvattende twee-dimensionele vloeistof chromatografie (LCxLC) is bestudeer as ‘n alternatiewe metode om verdere insig tot hierdie komplekse fenoliese fraksie te verkry. Die kombinasie van hidrofiliese interaksie chromatografie (HILIC) in die eerste dimensie en RP-LC in die tweede dimensie het ‘n uiters gesogte lae graad van korrelasie verskaf. HILICxRP-LC het ‘n besonderse toename in resolusie teweeg gebring, gekenmerk deur praktiese piek kapasiteite hoër as 2000 en 800 vir die af-lyn en aan-lyn metodes, onderskeidelik. Verdere optimisering, veral van die eerste dimensie skeiding, is egter nodig om die LCxLC skeiding van rooibos fenole te verbeter.

Thesis (MSc Food Sc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The sensory characteristics and chemical composition of rooibos infusions were analysed to establish the extent of variation in sensory attributes and compositional parameters, and investigate whether correlations exist between the sensory characteristics and the phenolic composition. To capture as much potential variation as possible, 69 rooibos samples were collected throughout the 2009 harvesting season from different production areas. The samples were also representative of the different quality grades (A, B, C or D) which are based on the appearance of the leaves, and the colour and flavour of the infusion. Quantitative descriptive analysis was used to develop sensory profiles for each of the rooibos infusions. Considerable variation in the sensory characteristics was observed, highlighting the need for standardised terminology that can be used to describe what is often referred to as “characteristic” rooibos flavour. Aroma, flavour, taste, and mouthfeel descriptors were generated and assembled into a rooibos sensory wheel. The most recurring attributes were selected to compile a rooibos sensory lexicon which provides a definition and a reference standard for clarification of each term. A combination of “honey”, “woody” and “fynbos-floral” notes with a slightly sweet taste and subtle astringency may be regarded as “characteristic” rooibos attributes indicative of good quality tea. Pleasant “caramel” and “fruity-sweet” notes were also observed in a number of infusions, whereas negative descriptors, associated with poor quality rooibos, included “green” and “hay” flavours. Large variation in the composition of rooibos infusions was revealed through the quantification of soluble solids (SS), total polyphenols (TP), tannins and 14 monomeric phenolic compounds, as well as spectrophotometric colour measurements. High quality rooibos was associated with higher levels of SS, TP, tannins and phenolic compounds than low quality rooibos. Correlations between the compositional parameters and sensory attributes of the infusions indicated that several non-volatile compounds, including enolphenylpyruvic acid-2-glucoside, quercetin-3-glucoside, and iso-orientin, were associated with the characteristic sweet taste of rooibos, while bitterness was related to certain flavonoids such as luteolin, quercetin and aspalathin. The only compound significantly correlated to astringency was rutin, although it is likely that aspalathin and several other monomeric flavonoids also contribute to astringency. The tannin content was not associated with astringency possibly because of the limitations associated with the tannin quantification method. To determine whether compositional changes resulting from steam pasteurisation of rooibos leaves influence the sensory quality of rooibos infusions, differences in the phenolic composition and sensory attributes of infusions, prepared from unpasteurised and pasteurised rooibos, were analysed. Steam pasteurisation significantly reduced the SS, TP and aspalathin content of rooibos infusions, as well as the absorbance, especially at a wavelength of 450 nm. It also resulted in significant reductions in the intensities of most of the aroma and flavour attributes, especially the “green” notes associated with low quality rooibos. After steam pasteurisation the prominent “green” flavour of certain samples was frequently replaced by a “hay” flavour. The taste attributes, sweetness and bitterness, remained unchanged, whereas the astringency of rooibos infusions decreased significantly. / AFRIKAANSE OPSOMMING: Die sensoriese eienskappe en chemiese samestelling van rooibostee is geanaliseer ten einde die mate van variasie van die sensoriese sowel as die chemiese profiel te bepaal, asook om vas te stel of korrelasies bestaan tussen die sensoriese eienskappe en die fenoliese samestelling van rooibostee. Om soveel as moontlik potensiële variasie in te sluit, is 69 rooibos monsters tydens die 2009 oesseisoen van verskillende produksiegebiede versamel. Die monsters is ook verteenwoordigend van die verskillende kwaliteitgrade (A, B, C en D), wat op grond van die voorkoms van die teeblare, en die kleur en geur van die tee toegeken is. Kwantitatiewe beskrywende analise is gebruik om ‘n sensoriese profiel vir elke rooibostee op te stel. Aansienlike variasie in die sensoriese eienskappe is waargeneem. Dit het die behoefte aan gestandaardiseerde terminologie onderskryf, wat gebruik kan word om die term “karakteristieke” rooibos geur in meer detail te omskryf. Spesifieke terme vir aroma, geur, smaak en mondgevoel is geformuleer, en gebruik om ‘n sensoriese wiel vir rooibostee saam te stel. Terme wat die meeste voorgekom het, is gekies om in ‘n sensoriese leksikon vervat te word wat ‘n definisie en ‘n verwysingstandaard vir elke term voorstel. Die “karakteristieke” sensoriese eienskappe van goeie kwaliteit rooibostee kan soos volg gedefinieer word: ’n kombinasie van “heuning”, “houtagtige” en “fynbos-blom” geure met ‘n effense soet smaak en ‘n sagte vrankheid. Aangename “karamel” en “vrugtige-soet” geure is ook waargeneem, terwyl terme soos “groen” en “hooi” met swak kwaliteit rooibostee geassosieer is. Groot variasie in die samestelling van rooibostee is verkry deur kwantifisering van die inhoud van oplosbare vastestowwe (SS), totale polifenole (TP), tanniene, en 14 monomeriese fenoliese verbindings, asook spektrofotometriese kleurmetings. Hoë kwaliteit rooibostee is geassosieer met hoër vlakke van SS, TP, tanniene en fenoliese verbindings in vergelyking met lae kwaliteit rooibos. Korrelasies tussen laasgenoemde parameters en die sensoriese eienskappe het aangedui dat sekere nie-vlugtige verbindings, bv. fenielpirodruiwesuurglukosied, kwersetien-3-glukosied en iso-orientien, geassosieer is met die kenmerkende soet smaak van rooibos, terwyl ‘n bitter smaak geassosieer is met spesifieke flavonoïede soos luteolien, kwersetien and aspalatien. Die enigste verbinding wat betekenisvol gekorreleer het met vrankheid was rutien, maar dit is waarskynlik dat aspalatien en ander monomeriese flavonoïede ook bygedra het tot vrankheid. Die tannieninhoud het nie verband gehou met vrankheid nie, vermoedelik as gevolg van die beperkinge van die chemiese metode vir tannienbepaling. Om te bepaal of stoompasteurisasie van rooibos die sensoriese kwaliteit en chemiese samestelling van rooibostee beïnvloed, is die verskille in fenoliese samestelling en sensoriese eienskappe van die tee, berei van ongepasteuriseerde en gepasteuriseerde rooibos, ondersoek. Stoompasteurisasie het ‘n betekenisvolle verlaging teweegebring van die SS, TP en aspalatien inhoud, sowel as van die absorbansie van die tee, veral by ‘n golflengte van 450 nm. Dit het ook gelei tot ‘n statisties betekenisvolle vermindering van die intensiteit van die meeste aroma en geur eienskappe, veral die sogenaamde “groen” eienskap wat met swak kwaliteit rooibos verbind word. As gevolg van stoompasteurisasie is die opmerklike “groen” geur van sekere ongepasteuriseerde monsters herhaaldelik vervang deur ‘n “hooi” geur. Die smaakeienskappe, soet en bitter, was onveranderd, terwyl vrankheid statisties betekenisvol afgeneem het as gevolg van pasteurisasie.

Philosophiae Doctor - PhD / Camellia sinensis (tea) and Aspalathus linearis (rooibos) may improve reproductive function owing to their antioxidant properties. To test this hypothesis, male and female rats were given 2% and 5% green tea (Gt), black tea (Bt), unfermented rooibos (Ur) or fermented rooibos (Fr) as sole source of drinking for 52 and 21 days respectively. Control rats received tap water. In addition, TM3 Leydig cells were exposed to 0.025, 0.05, 0.1 and 0.5 % aqueous extracts of green tea, black tea, unfermented and fermented rooibos for 24h. In vitro analysis of tea and the herbal infusion revealed the phenolic property and antioxidant capacity (FRAP) in the order Gt > Bt > Ur > Fr. Camellia sinensis and Aspalathus linearis revealed no significant effect on serum antioxidant capacity (p > 0.05) and lipid peroxidation (MDA) in the kidney or liver in both male and female rats and in the testes of the male rats (p > 0.05). In addition, the antioxidant levels were maintained in the testes, liver and kidneys in both the male and female rats. In the male rats, no significant alterations were observed in body weight gain, liver and reproductive organs weight, and serum testosterone (p > 0.05). Only, 5% green tea significantly increased testosterone level (p < 0.05). Seminiferous tubules displayed complete spermatogenesis with abundant sperm in the lumen in all treated groups. However, a significant decrease in diameter and germinal epithelial height of these tubules were observed (p < 0.05). In the epididymides, epithelial height of caput region showed a significant increase (p < 0.01), while the cauda region was increased by Camellia sinensis but decreased by Aspalathus linearis. Sperm concentration improved significantly by green tea and unfermented rooibos (p < 0.05), while black tea and fermented rooibos produced a non significant effect (p > 0.05). Sperm viability was enhanced in all treatment groups (p < 0.05). Furthermore, green tea, black tea and unfermented rooibos significantly improved the motility of rat sperm (p < 0.05); fermented rooibos tended to improve it (p > 0.05). In addition, green tea, black tea and fermented rooibos enhanced acrosome reaction (p < 0.05). Creatinine activity was significantly higher in rats treated with black tea, unfermented rooibos or fermented rooibos (p < 0.05), green tea tended to increase it (p > 0.05) reflecting the significant increased kidney weight in the treatment groups at high concentrations. Liver markers, ALT and AST, decreased significantly in all treated groups (p < 0.05), except in 5% fermented rooibos where a significant increase in AST level was observed (p < 0.01). In the female rats, the body weight gain, and reproductive organs weight was no affected (p > 0.05). However, 5% fermented rooibos reduced the ovarian weight (p < 0.05), while 5% unfermented rooibos significantly increased the uterine weight (p < 0.05). Liver weight increased significantly by black tea and unfermented rooibos (p < 0.05) while the kidney weight increased significantly by 5% black tea (p < 0.05). No significant effect was observed in the level of FSH produced, on the other hand, Camellia sinensis significantly lowered the level of LH (p < 0.05), while Aspalathus linearis had no effect (p > 0.05). Creatinine activity was enhanced significantly only by 5% fermented rooibos (p < 0.05). Liver markers, ALT and AST were reduced in most treated groups except in fermented rooibos where an increase was observed. In addition, histological sections revealed no obvious alteration in the ovaries, uteri, kidneys and liver of all treated female rats. Camellia sinensis and Aspalathus linearis significantly reduced the level of testosterone produced in TM3 Leydig cells under stimulated conditions in vitro (p< 0.05). Furthermore, both plants maintained the viability and morphology of the cells. However, at 0.5% of either plant extracts, a significant decrease in the viability (p < 0.05) and altered morphology of the TM3 Leydig cells was observed. In conclusion, Camellia sinensis and Aspalathus linearis significantly improved certain sperm function which might be attributed to their high level of antioxidant activity. However, the prolonged exposure of both plant extracts might result in subtle structural changes in the male reproductive system and impair kidney function. In addition, fermented rooibos at high concentration may also impair the functions of the liver. In vitro, both plants were shown to possess anti-androgenic property on TM3 Leydig cells. Furthermore, both Camellia sinensis and Aspalathus linearis may be classified as weak phytoestrogens due to the changes in the weight of the uterus and ovaries observed. / South Africa

Dissertation (PhD)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: This thesis provides the first scientific evidence on the cancer modulating properties of two unique South African herbal teas, rooibos (Aspalathus Iinearis) and honeybush (Cyclopia intermedia) utilizing in vitro as well as in vivo carcinogenesis assays by: • Demonstrating the in vitro antimutagenic activity of aqueous extracts of the herbal teas against the metabolic activated mutagens, 2-acetylaminofluorene (2- AAF) and the mycotoxin, aflatoxin B1 (AFB,) as well as, to a certain extent, against the direct acting mutagen, hydrogen peroxide, utilizing the Salmonella typhimurium mutagenicity assay. • Increasing the activity of hepatic drug metabolizing enzymes, glutathione Stransferase alpha and UPD-glucuronosyl transferase, and reduced the oxidative stress by stabilizing the level of reduced glutathione (GSH) resulting in an increased hepatic reduced to oxidized glutathione ratio (GSG:GSSG). No toxic effects were noticed in rats consuming the herbal teas for 10 weeks as their sole source of drinking fluid. • Demonstrating the ex vivo modulation of 2-AAF- and AFB1-induced mutagenesis by sub- cellular hepatic fractions of rats consuming the herbal teas in the Salmonella mutagenicity assay. Hepatic cytosolic fractions protected against mutagenesis of both mutagens, while the microsomal fractions exhibited a reduced capacity to metabolize AFB1 to its active mutagenic metabolite. • Providing evidence for the in vivo modulation of tumour promotion using the liver as well as the two-stage skin carcinogenesis animal models. The unprocessed herbal teas arrested proliferation of the placental form of glutathione-Stransferase (GSTP+) altered cells as well as reduced the total number of enzyme altered foci in the liver of rats. Topical application of polyphenolic fractions of the various herbal teas prior to 12-0-tetra-decanoylphorbol-13-acetate (TPA) tumour promotion, reduced tumour formation in mouse skin initiated with 7,12-dimethylbenz[ ajanthracene (DMBA). The protective effect was illustrated by a decreased tumour incidence, a reduction in tumour volume as well as a delayed onset of tumour development. The f1avanol/proanthocyanidin content of the fractions could playa major role in the protection against skin tumour promotion. • Proposing possible mechanisms whereby rooibos and honeybush herbal teas could exert their cancer modulating properties with respect to in vitro and ex vivo antimutagenicity, in vivo oxidative status and reduced tumour promotion. • Providing evidence that the herbal teas mimic the cancer modulating properties of green and black teas although differences exist, presumably due to differences in the polyphenolic constituents. • Suggesting that rooibos and honeybush herbal teas may play an important role as chemopreventive agents in the modulation of cancer. / AFRIKAANSE OPSOMMING: Hierdie tesis bevat die eerste ondersoek na die effek van waterige en polifenoliese ekstrakte van rooibos (Aspalathus Iinearis) en heuningbos (Cyclopia intermedia) op verskeie aspekte van kankerontwikkeling. Die twee kruietees is uniek aan Suid-Afrika en kan 'n belangrike rol speel in die voorkoming van kanker. Verskillende in vitro so wei as in vivo studies het die volgende getoon: • Antimutageniese aktiwiteite teen die metabolies-geaktiveerde mutagene, 2- asetielaminofluoreen (2-AAF) en die mikotoksien, aflatoksien B1 (AFB1) in die Salmonella fyphimurium mutagenisiteitstoets. 'n Beperkte mate van beskerming is ook verleen teen die oksidatiewe mutageen, waterstofperoksied, sonder metaboliese aktivering. • Verhoogde aktiwiteite van die fase II ensieme, glutatioon S-tranferase alfa en UDP-glukuronidase, wat liggaamsvreemde verbindings metaboliseer. Die kruietees verlaag die oksidasietoestand soos weerspieel word deur 'n toename van gereduseerde glutatioon tot die geoksideerde vorm in die lewer van rotte wat 10 weke hierdie kruietees gedrink he!. Die kruietees het geen toksiese uitwerking op die rotte gehad nie. • Antimutageniese aktiwiteite van subselluiE~re fraksies van die lewer teenoor 2- AAF en AFB1 in die Salmonella toets. Die sitosolfraksie van die rotlewer bied beskerming teen die ge"induseerde mutagenese van beide mutagene, terwyl die mikrosomale fraksie ook die metaboliese aktivering van AFB1 na die aktiewe mutageniese metaboliet verminder. • In vivo modulering van kankerpromosie met behulp van bekende rotlewer en muisvel kankerontwikkelingsmodelle. In die lewermodel het die ongeprosesseerde kruietees beide die ontwikkeling en getal van GSTP+ fokusse onderskeidelik vertraag en verminder. In die geval van die velkankermodel het aanwending van polifenoliese fraksies van die kruietees beskerming gebied teen die ontwikkeling van velkankers by muise. Die aantal en grootte van die tumors het afgeneem terwyl die verskyning daarvan ook vertraag is. • Verskeie meganismes waardeur rooibos- en heuningboslee moonllik kanker kan moduleer word voorgeslel. Verskille in die polifenoliese sameslelling asook hul onderskeie konsenlrasies kan 'n belangrike rol speel in die kankerveranderende effekle van die lees. • Oal gereelde inname van rooibos- en/of heuningboslee moonllik 'n belangrike rol kan speel in die voorkoming van dieel- en omgewings-geYnduseerde kankers.

Thesis (MSc Food Sc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT:Aspalafhus linearis is an indigenous fynbos plant cultivated in the Clanwilliam area of the Western Cape, South Africa. The rooibos tea that is prepared from this plant, has become popular worldwide mainly due to the alleged health properties. Studies on the anti-microbial properties of green, black and oolong teas have shown that these teas have strong anti-microbial activity against a wide range of microbes. No studies have been done on the anti-microbial activity of rooibos tea and the aim of this study was to determine what impact rooibos tea extracts would have on the growth of different food spoilage and potential pathogenic microbes. Water and ethyl acetate extracts of fermented and unfermented rooibos tea were used to determine the inhibitory effect on the growth of an Escherichia coli strain. The E. coli culture was grown in tea-MRS with either added fermented or unfermented rooibos tea extracts. Both the water and ethyl acetate extracts showed a strong inhibitory effect against the E. coli strain in that there was a decrease in the final bacterial cell density (Nmax)(from 0.59 00 to 0.25 00) and the maximum specific growth rate (~max)(from 1.12 h-1 to 0.20 h-1) and an increase in the doubling time (~) (from 0.59 h to 1.80 h) and lag time (tlag)(from 4.81 h to 6.60 h) as the concentration of the soluble solids of the tea extracts was increased from 0.5 to 5.0 g.r1 . Furthermore, it was found that the fermented rooibos tea had a much stronger inhibitory effect (69% decrease in growth at 5.0 g.r1 soluble solids) compared to the unfermented rooibos tea extracts (35.1% decrease in growth at 5.0 g.r1 soluble solids). The resulting data indicated that rooibos tea had a very strong inhibitory effect on the growth of the E. coli strain. It was also found that the water extracts of rooibos tea showed a stronger inhibitory effect on the growth of the E. coli than the ethyl acetate extracts, indicating that the antimicrobial activity of rooibos tea is not exclusively due to the polyphenolic content - individual compounds. It was also determined that the rooibos tea water extracts showed a bacteriostatic action against the E. coli strain in that as soon as the tea is no longer part of the growth medium, the E. coli resumed a normal growth pattern. The data obtained showed that the inhibitory effect of rooibos tea water extracts (69% decrease in growth) against the growth of E. coli was more pronounced than that found when black tea water extracts (25.7% decrease in growth) at the same concentrations were used.Rooibos tea water extracts (0.5 - 5.0 g.r1) of fermented and unfermented tea were also used to determine the inhibitory effect on other food spoilage microbes and potential pathogens. Strains of Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus mutans, Saccharomyces cerevisiae and Zygosaccharomyces rouxii were grown in the presence of fermented and unfermented rooibos tea water extracts. The effect that fermented rooibos tea had on the growth of all the microbes tested was in the following order: Staph. aureus (90.8% decrease in growth) > L. monocytogenes (89.2% decrease in growth) > Strep. mutans (84.1% decrease in growth) > B. cereus (80.3% decrease in growth) > Sacch. cerevisiae (77.7% decrease in growth) > E. coli (69.0% decrease in growth). The rooibos tea clearly had an inhibitory effect on the growth of all the microbes, with the exception of the Z. rouxii strain where the presence of the tea water extracts was found to enhance the growth. The inhibitory effect of rooibos tea on the growth of these microbes was shown by changes in the growth parameters with Nmax and IJmaxshowing decreases, while the ld and tlagincreased as the concentration of the tea soluble solids was increased. As with E. coli, the fermented rooibos tea water extracts showed the stronger inhibitory effect on the growth of the various microbes. The data obtained in this study suggests that rooibos tea is not effective as an anti-microbial agent against all yeast species, but will strongly retard the growth of specific Gram-positive and Gram-negative bacteria. As long as rooibos tea is present, strong anti-microbial activity will be observed at a cup of tea concentration of 2.5 g.r1 soluble solids. These results may be of value to support the health claims associated with rooibos tea and may in the future lead to the use of rooibos tea as a "natural" food preservative. / AFRIKAANSE OPSOMMING:Aspalathus linearis is 'n inheemse fynbosplant wat gekultiveer word in die Clanwilliam area van die Wes Kaap, Suid-Afrika. Rooibostee, wat gemaak word van hierdie plante, het baie gewild geword wereldwyd a.g.v. die gesondheidsaspekte van hierdie tee. Studies toon dat groen, swart en oolong tee sterk anti-mikrobiese aktiwiteit het teen 'n wye reeks mikrobes. Aangesien daar voorheen geen studies gedoen is op die anti-mikrobiese aktiwiteit van rooibostee nie, was die doel van hierdie studie om die effek van rooibostee te bepaal op die groei van verskillende voedselbederwers en potensiele patogeniese mikrobes. Water- en etielasetaat-ekstrakte van gefermenteerde en ongefermenteerde rooibos tee is gebruik om die inhiberende effek op die groei van Escherichia coli te bepaal. Escherichia coli is gegroei in tee-MRS met bygevoegde gefermenteerde of ongefermenteerde rooibostee-ekstrakte. Seide die water- en etielasetaatekstrakte van rooibostee het 'n sterk inhiberende effek gewys teen E. coli en dit word gestaaf deur 'n afname in die finale bakteriese seldigtheid (Nmax)(vanaf 0.59 00 tot 0.25 00) en die maksimum spesifieke groeitempo (lJmax) (vanaf 1.12 h-1 tot 0.20 h-1) en 'n toename in die verdubbelingstyd (~) (vanaf 0.59 h tot 1.80 h) en die sloerfase (tlag)(vanaf 4.81 h tot 6.60 h) 5005 wat die konsentrasie van oplosbare vastestowwe van die tee toeneem van 0.5 tot 5.0 g.r1 . Verder is daar gevind dat die gefermenteerde rooibostee 'n baie sterker inhiberende effek het (69% afname in groei by 5.0 g.r1 oplosbare vastestowwe) in vergelyking met die ongefermenteerde rooibostee-ekstrakte (35.1% afname in groei by 5.0 g.r1 oplosbare vastestowwe). Die resultate van die data dui aan dat rooibos tee 'n baie sterk inhiberende effek het op die groei van die E. coli spesie. Die waterekstrakte van rooibostee het 'n sterker inhibisie getoon teen die groei van E. coli as die etielasetaat-ekstrakte, wat aandui dat die anti-mikrobiese aktiwiteit van rooibostee nie eksklusief toegeskryf kan word aan die polifenoliese samestelling nie. Daar is ook gevind dat rooibostee water-ekstrakte 'n bakteriostatiese effek het teen E. coli, want sodra die tee ekstrakte nie meer teenwoordig is in die groeimedium nie, hervat E. coli normale groei. Die data wys ook dat die inhiberende effek van rooibostee water-ekstrakte (69.0% afname in goei) teen E. coli baie sterker is as die van swart tee water-ekstrakte (25.7% afname in groei) by dieselfde konsentrasies.Rooibostee water-ekstrakte (0.5 - 5.0 g.r1) van gefermenteerde en ongefermenteerde rooibostee is ook gebruik om die inhiberende effek te bepaal teen ander voedselbederwers en potensiele patogene. Spesies van Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus mutans, Saccharomyces cerevisiae en Zygosaccharomyces rouxii is gegroei in die teenwoordigheid van gefermenteerde en ongefermenteerde rooibostee waterekstrakte. Die effek wat gefermenteerde rooibostee het op die groei van die getoetste mikrobes is 5005 volg: Staph. aureus (90.8% afname in groei) > L. monocytogenes (89.2% afname in groei) > Strep. mutans (84.1% afname in groei) > B. cereus (80.3% afname in groei) > Sacch. cerevisiae (77.7% afname in groei) > E. coli (69.0% afname in groei). Rooibostee het 'n duidelike inhiberende effek gehad teen al die organismes, behalwe teen Z. rouxii spes ie, waar die teenwoordigheid van rooibostee die groei van die organisme bevorder het. Die inhiberende effek van rooibostee teen die groei van hierdie mikrobes word ondersteun deur die groei parameters waar die Nmaxen IJmaxafgeneem het terwyl die ~ en tlagtoegeneem het 5005 wat die konsentrasie van die oplosbare vastestowwe toeneem. Die gefermenteerde rooibostee water-ekstrakte het ook 'n sterker inhiberende effek op die groei van die verskillende mikrobes net 5005 met E. coli. Die data wat verkry is van hierdie studie dui aan dat rooibostee nie effektief sal wees as 'n anti-mikrobiese middel teen aile gis spesies nie, maar dit sal die groei van spesifieke Gram-positiewe en Gram-negatiewe bakterie sterk vertraag. So lank as wat rooibostee teenwoordig is, sal sterk anti-mikrobiese aktiwiteit waargeneem word by 'n koppie-tee konsentrasie van 2.5 g.r1 oplosbare vastestowwe. Hierdie resultate kan help om die gesondheidseienskappe geassosieer met rooibostee te ondersteun en help om die gebruik van rooibostee as 'n "natuurlike" preserveermiddel te bevorder. dedicated to my parents

Magister Scientiae - MSc (Physics) / Zinc oxide (ZnO) is a wide and direct semiconductor with a wurtzite crystal structure. Its multifunctionality as the ideal candidate in applications such as blue-UV light emitting diodes, transparent conducting oxide, selective gas sensor and efficient catalyst support among others, has attracted a significant interest worldwide. Nano-scaled ZnO has been synthesized in a plethora of shapes. A rich variety of physical and chemical methodologies have been used in the synthesis of undoped or doped ZnO. However, such methods either necessitate relatively high vacuum infrastructures, elevated temperatures, or the use of toxic reagents. The "green chemistry" synthesis of metal oxide nanoparticles which is based on using natural plant extract as an effective 'reducing agent' of metal precursor, has been reported to be a cleaner and environment-friendly alternative to the physical and chemical methods. The thesis is based on the synthesis and the main physical properties of pure ZnO nanoparticles synthesized by a completely green chemistry process using the natural extract of Aspalathus Linearis to bio-reduce the zinc acetate precursor. The obtained ZnO nanopowdered samples were annealed at different temperatures from 300 °C to 600 °C. The samples were characterized using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Transmission Electron Microscopy, X-ray Diffraction, Differential Scanning Calorimetry, Thermogravimetric Analysis and Fourier Transform Infrared. Highly pure quasi-spherical ZnO nanoparticles with an average crystallite size of 24.6 nm (at 300 °C), 27.2 nm (at 400 °C), 27.6 nm (at 500 °C), and 28.5 nm (at 600 °C) were found. The results also showed that the average crystallite size increased with an increase in annealing temperature. It was successfully demonstrated that the natural plant extract of Aspalathus Linearis can be used in the bio-reduction of zinc acetate dihydrate to prepare highly pure ZnO nanoparticles.

Magister Scientiae - MSc (Medical BioSciences) / In the past three decades there has been a huge increase in the use of herbal medicine globally. The active principles of these herbal medicines are mostly unknown with supportive evidence for safety and efficacy very rare. SeptilinTM is a phytopharmaceutical formulation which is recommended for the treatment and management of various infections. It has been claimed to have immunomodulatory actions that potentiates the body's immune response. The immunomodulatory activity of SeptilinTM has not been well investigated via appropriate in vitro models. Therefore this study was undertaken to investigate the in vitro effects of SeptilinTM on biomarkers of specific immune pathways by using WBC. Stimulated and unstimulated WBC were incubated with the product. Enzyme linked immunosorbent assays were used to screen for IL-6, IL-10, and IFN? as biomarkers for inflammation, humoral immunity, and cell mediated immunity, respectively. Results show that the presence of SeptilinTM in LPS stimulated WBC has no effect on the release of IL-6 and IFN? production but stimulated IL-10 production. SeptilinTM in unstimulated WBC has no effect on the release of IL-10 and IFN? production but stimulatory effects on IL-6 production.