Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2015. / The increase in antibiotic resistant bacterial and fungal infections and the prevalence of oxidative stress-related conditions including cancers, cardiovascular diseases and diabetes has led to a consensus among pharmaceutical companies, clinicians and researchers that novel antimicrobial and antioxidant approaches are needed. These should be ideally efficacious, non toxic, easily accessible and affordable. There has been an increased interest in the identification of medicinal plants that possess both these bioactivities in an intrinsically related manner, allowing the simultaneous prevention of these ailments. Two South African herbal teas, rooibos and honeybush have been associated with a long history of medicinal use, hence their consideration for the current study. Numerous studies have been performed to evaluate the antioxidant activities of these South African herbal teas, however limited information about their antimicrobial activity currently exists. / National Research Foundation

Thesis (MTech(Food and Nutrition))--Cape Peninsula University of Technology, 2010 / Oxidative stress had been linked to the development of certain chronic diseases, but can be delayed or prevented by the consumption of dietary antioxidants. Fruits, vegetables, wholegrains and beverages, such as, teas are the major dietary antioxidant contributors. The majority of South Africans do not consume adequate daily servings of fruits and vegetables, neither sufficient minimally processed grains nor wholegrains. One way to incorporate antioxidants in the South African diet is by adding antioxidant-rich foods or beverages to recipes as ingredients. The objective of this study was to determine the effect on the total antioxidant capacity (TAC) of substituting water with rooibos herbal tea in soup recipe formulations. Rooibos is a proudly South African beverage rich in antioxidants. Soup is a readily available and relatively inexpensive meal item regularly consumed during the winter months in South Africa. Three popularly consumed soups in the City of Cape Town Metropolitan Municipality namely chunky vegetable, butternut and chicken noodle were selected for the experimental study. The water in each of the soup recipe formulations (control) was substituted with fermented and unfermented / “green” rooibos (experimental recipe formulations). The study was of comparative nature as the results (i.e. the TAC as the factor investigated) of three different soup recipe formulations on fluid manipulations of each (with fermented and unfermented rooibos) was compared to the control soup recipe formulations of each (no fluid manipulation). The results (i.e. the TAC) of the three prepared control and experimental soup recipe formulations were also compared to that of the raw soup mixtures of each of the soup recipe formulations to determine the effect of thermal processing on each. The main variable identified in the preparation of the soup recipe formulations that may impact the TAC (the dependent variable) and needed to be controlled was the heat application. Other variables that may influence the results were the soup recipe formulation ingredients, the prepreparation of the raw ingredients, the standing time of ingredients before use and the equipment used. Before determination of the heat applications and the fixed time allocations of the soup recipe formulations to ensure recipe standardisation, the pre-preparation procedures of the raw recipe ingredients were also standardised.

No description available.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The consumption of herbal teas is an increasing phenomenon among tea consumers globally. However, herbal teas that are not pre-treated to reduce their microbial load are a health risk to consumers, in spite of their potential health-promoting properties. The aim of this study was to develop a steam pasteurisation treatment to reduce the microbial load on Lippia multiflora Moldenke (Verbanaceae) tea leaves, a herbal tea from Ghana, identify the bacteria present, and to evaluate the effect of the steam treatment on the bioactive constituent of the leaves. An HPLC method was developed and optimised for the identification and quantification of verbascoside, the major antioxidant compound of L. multiflora herbal infusion. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used to confirm the presence of the compound in the infusion. Ascorbic acid was used as a stabilising agent during the quantification process to prevent the degradation of verbascoside. The hot water infusion of L. multiflora was compared to those of Aspalathus linearis (rooibos) and Cyclopia spp. (honeybush) on the basis of their soluble solids and total polyphenol contents, as well as on their antioxidant activities. In addition to verbascoside, another compound with the same parent and fragment ions as verbascoside was present in the infusion. A 100 ml infusion of L. multiflora had significantly (P < 0.05) higher soluble solids and total polyphenol contents, and antioxidant activities than those of rooibos and honeybush. The rooibos infusion showed significantly (P < 0.05) higher soluble solids and total polyphenol contents as well as antioxidant activities than honeybush. On the basis of soluble solids, rooibos showed a significantly (P < 0.05) higher total polyphenol content and a lower ferric-reducing activity than L. multiflora. Both teas, however, did not differ significantly with respect to the DPPH antioxidant activity. The effect of steam pasteurisation on the microbial load of L. multiflora herbal tea leaves was evaluated. Five samples of the tea were steam pasteurised at 99.8°C for 2.5 min and five samples were unpasteurised. Microbial enumeration was conducted in duplicate on potato dextrose agar (PDA), plate count agar (PCA), violet red bile agar (VRBA), yeast peptone dextrose agar (YPDA), and de Man Rogosa Sharpe agar (MRS). Morphologically distinct colonies were isolated, sub-cultured and their Gram reaction recorded. These bacteria were identified to the species level using 16S ribosomal DNA (rDNA) sequence data. Most of the bacteria identified belonged to the genus Bacillus. One species each from the genera Pantoea and Kocuria were also identified, but only the Bacillus species survived the steam treatment. Coliform bacteria detected prior to pasteurisation were not detected after steam treatment. Steam pasteurisation reduced the microbial load from 104 to 102 cfu.g-1. The effects of the steam pasteurisation on the soluble solid, total polyphenol, and the active compound contents of L. multiflora, as well as the antioxidant activities were studied. Pasteurisation did not significantly (P > 0.05) change the soluble solids, total polyphenol and active compound contents, or the antioxidant activity. Steam pasteurisation is potentially an effective method to treat L. multiflora herbal teas prior to consumption. However, the steam treatment should complement good agricultural and hygienic practices rather than replace them as some bacteria can survive this treatment. The identification and quantification of verbascoside in L. multiflora infusion, as well as the relatively higher antioxidant contents compared to rooibos and honeybush should provide the basis for future studies on the therapeutic application of this herbal tea. Also, verbascoside could potentially form the basis for future quality control of L. multiflora. / AFRIKAANSE OPSOMMING: Daar is 'n wêreldwye toename in die verbruik van kruietee. Kruietee wat egter nie vooraf-behandelings ontvang om die mikrobiese lading te verlaag nie kan, ten spyte van moontlike gesondheidsvoordele, ook 'n potensiële gesondheidsrisiko vir verbruikers inhou. Die doel van hierdie studie was om 'n stoompasteurisasie-behandeling te ontwikkel wat die mikrobiese lading op Lippia multiflora teeblare, 'n kruietee van Ghana, te verlaag. Verder is die teenwoordige bakterieë geïdentifiseer en die effek van 'n stoombehandeling op die bio-aktiewe komponente in die teeblare is ook geëvalueer. 'n Hoë-druk vloeistof-chromatografie metode is ontwikkel en ge-optimiseer vir die identifikasie en kwantifisering van verbaskosied, 'n hoof antioksidant komponent in L. multiflora kruie aftreksels. Vloeistof chromatografie, gekoppel aan in-lyn massa spektroskopie is ook gebruik om die teenwoordigheid van die komponent in die aftreksel te bevestig. Tydens die kwantifiseringsproses is askorbiensuur as 'n stabiliseringsagent gebruik om die degradasie van verbaskosied te voorkom. Die warm water aftreksel van L. multiflora is vergelyk met die van Aspalathus linearis (rooibos) en Cyclopia spp. (heuningbos) in terme van hul opgeloste vastestof- en totale polifenol inhoude, asook hul antioksidant aktiwiteite. 'n Ander komponent buiten verbaskosied, maar met dieselfde ouer en fragment ione, was ook in die aftreksel teenwoordig. 'n 100 ml L. multiflora aftreksel het beduidend (P < 0.05) meer opgeloste vastestowwe, totale polifenole en antioksidant aktiwiteit getoon as rooibos en heuningbos. Rooibos het weer beduidend (P < 0.05) meer opgeloste vastestowwe, totale polifenole, en antioksidant aktiwiteit as heuningbos. In terme van opgeloste vastestowwe het rooibos 'n beduidende (P < 0.05) hoër totale polifenol inhoud en laer ferriet-reduserende aktiwiteit as L. multiflora. Beide tee het egter nie beduidend verskil ten opsigte van hul antioksidant aktiwiteit nie. Die effek van stoompasteurisasie op die mikrobiese lading van L. multiflora kruieteeblare is geëvalueer. Vyf teemonsters is gestoompasteuriseer by 99.8°C vir 2.5 min en 5 verdere monsters is nie gepasteuriseer nie. Mikrobe-tellings is in Mikrobe-tellings is in v duplikaat op potato dextrose agar (PDA), plate count agar (PCA), violet red bile agar (VRBA), yeast peptone dextrose agar (YPDA), en de Man Rogosa Sharpe agar (MRS) gedoen. Morfologies onderskeibare kolonies is geïsoleer, her-gekweek en hul Gram status genotuleer. Hierdie bakterieë is daarna tot op spesie-vlak geïdentifiseer deur 16S ribosomale DNS (rDNS) volgorde bepalings. Die meerderheid van die geïdentifiseerde bakterieë behoort tot die genus Bacillus en een spesie elk van die genera Pantoea en Kocuria is ook geïdentifiseer. Slegs Bacillus spesies het egter die stoompasteurisasie behandeling oorleef. Kolivorme bakterieë wat voor pasteurisasie waargeneem is was afwesig na die stoom behandeling. Stoompasteurisasie het ook die mikrobiese lading van 104 na 102 kve.g-1 verminder. Die effek van stoompasteurisasie op die opgeloste vastestowwe, totale polifenole en die aktiewe-komponent inhoud van L. multiflora, asook die antioksidant aktiwiteit is bestudeer. Pasteurisasie het die opgeloste vastestowwe, totale polifenole, aktiewe komponente en die antioksidant aktiwiteit nie-beduidend (P > 0.05) verander. Stoompasteurisasie kan potensieël 'n effektiewe metode wees vir die behandeling van L. multiflora kruietee voor verbruik. Die stoombehandeling moet egter saam met goeie landbou- en higiëniese praktyke gebruik word eerder as om dit te vervang aangesien sommige bakterieë hierdie stoombehandeling kan oorleef. Die identifikasie en kwantifisering van verbaskosied in L. multiflora aftreksels, asook die hoër antioksidant inhoud vergeleke met rooibos en heuningbos verskaf moontlikhede vir verder navorsing in die terapeutiese aanwending van hierdie kruietee. Verbaskosied kan ook moontlik die basis vorm vir toekomstige kwaliteitskontrole van L. multiflora.

Thesis (MSc Food Sc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The sensory profiles and the phenolic composition of C. genistoides, C. longifolia, C. maculata and C. subternata, used for commercial production of honeybush tea, were determined with the aim to develop quality control tools, such as sensory wheels and statistical models to predict the basic taste and mouthfeel modalities using compositional data. Optimum fermentation parameters for C. longifolia in terms of aroma and flavour development were determined by investigating eight temperature/time regimes (80°C and 90°C for 8, 16, 24 and 32 h), using descriptive sensory analysis (DSA). Fermentation at 80°C/24 h or 90°C/24 h significantly reduced the negative sensory attributes present and produced a tea of good sensory quality. Previously, 80°C/24 h and 90°/16 h were shown to deliver optimum quality for the other three Cyclopia species. A large sample set (N = 150) consisting of C. genistoides, C. maculata and C. subternata, harvested during three production years (2010, 2012 and 2013), as well as C. longifolia harvested in 2013, was used to develop sensory wheels. All the samples were produced by fermentation at the two optimum fermentation temperature/time regimes of each species. The plant material was sourced from different production regions and plantations to ensure inherent plant variation was accommodated. The “characteristic” and generic sensory profile of honeybush was defined as a “fynbos-floral”, “woody”, “fynbos-sweet” aroma and flavour, with a sweet taste and slightly astringent mouthfeel. Species-specific sensory profiles were also identified. Cyclopia genistoides had a strong “rose geranium” flavour and a perceptible bitter taste, whereas C. longifolia had a similar sensory profile to that of C. genistoides, however, C. longifolia’s “rose geranium” flavour was less prominent and its bitter taste not perceptible. Cyclopia maculata and C. subternata were both described as having “caramel” and other “sweet-associated” notes and a slightly astringent mouthfeel. These results were used to develop a generic sensory wheel for both aroma and flavour, as well as similar wheels for each of the four Cyclopia species. Each sensory wheel reflects the relative intensity of the sensory attributes, while prevalence of the major attributes were accommodated in accompanying bar graphs. Sorting was investigated as a rapid profiling technique to serve as an alternative to the standard profiling method, descriptive sensory analysis (DSA). Instructed sorting was identified as a possible rapid sensory profiling tool for the honeybush industry, especially when samples need to be classified according to a selected list of sensory attributes. Uninstructed sorting can be used when the aim is to categorise a group of samples freely according to similarities and thus determine the natural grouping of samples within a broader sample set. The phenolic content of the respective four Cyclopia species differed qualitatively and quantitatively. Of the compounds quantified only four compounds were present in all four species, i.e. hesperidin, vicenin-2, mangiferin and isomangiferin. A larger number of compounds were present in three out of four species. The predictive value of the phenolic compounds towards the intensity of the taste and mouthfeel attributes (sweet, sour, bitter and astringent) was investigated using Pearson‟s correlation analysis, partial least squares regression (PLS) and step-wise regression analysis. Potential “candidate predictors” for taste and mouthfeel attributes were identified such as the xanthones, mangiferin and isomangiferin, being responsible for bitter taste and astringency. / AFRIKAANSE OPSOMMING: Die sensoriese profiel en fenoliese samestelling van C. genistoides, C. longifolia, C. maculata en C. subternata, waarvan heuningbostee geproduseer word, is bepaal om gehaltebeheer hulpmiddels te ontwikkel soos sensoriese wiele en statistiese modelle wat die fenoliese samestelling kan gebruik om die basiese smaak en mondgevoel eienskappe van infusies te voorspel. Die optimum fermentasie parameters vir C. longifolia in terma van aroma- en geurontwikkeling is bepaal deur agt temperatuur/tyd kombinasies (80°C en 90°C vir 8, 16, 24 en 32 h) te ondersoek met behulp van beskrywende sensoriese analise (BSA). Fermentasie by 80°C/24 h of 90°C/24 h het „n beduidende afname in die negatiewe sensoriese eienskappe veroorsaak en tot die ontwikkeling van tee met ʼn goeie sensoriese kwaliteit gelei. Die fermentasie parameters, 80°C/24 h en 90°/16 h, is voorheen aangedui as die optimale kondisies vir die ontwikkeling van „n goeie kwaliteit tee vir die ander drie Cyclopia spesies. 'n Groot stel monsters (N = 150), bestaande uit C. genistoides, C. maculata en C. subternata en ge-oes gedurende drie produksiejare (2010, 2012 en 2013), sowel as C. longifolia ge-oes in 2013, is gebruik om die sensoriese wiele te ontwikkel. Die twee optimum fermentasie temperatuur/tyd kombinasies van elke spesie is gebruik om die monsters te produseer. Plantmateriaal afkomstig van verskillende produksiegebiede en plantasies is versamel ten einde te verseker dat die monsters „n betekenisvolle hoeveelheid inherente variasie dek. Die generiese en "karakteristieke" sensoriese profiel wat met heuningbos geassosieer word, is gedefinieer as 'n "fynbos-blomagtige", "houtagtige", "fynbos-soet" aroma en geur, met 'n soet smaak en effense vrank mondgevoel. Spesies-spesifieke sensoriese profiele is ook geïdentifiseer. Cyclopia genistoides het 'n sterk "roos malva" geur en „n merkbare bitter smaak. Die sensoriese profiel van C. longifolia is soortgelyk aan dié van C. genistoides, maar sy "roos malva" geur was minder prominent en 'n bitter smaak was nie sensories waarneembaar nie. Beide C. maculata en C. subternata het waarneembare "karamel" en ander "soet-verwante" eienskappe, asook 'n effense vrank mondgevoel getoon. Die volle stel data is uiteindelik gebruik om 'n generiese sensoriese wiel vir heuningbostee, asook spesies-spesifieke sensoriese wiele vir elk van die vier Cyclopia spesies saam te stel. Die onderskeie sensoriese wiele weerspieël die relatiewe intensiteit van elk van die sensoriese eienskappe, terwyl die voorkoms-frekwensie van die onderskeie sensoriese eienskappe in gepaardgaande kolomgrafieke geillustreer is. Sortering, 'n vinnige profileringsmetode, is as alternatief tot die standaard profileringsmetode, beskrywende sensoriese analise (BSA), ondersoek. Gestrukteerde sortering is geïdentifiseer as 'n moontlike hulpmiddel vir die heuningbosbedryf om die sensoriese profiel van heuningbos te bepaal, veral wanneer „n groot aantal monsters vinning geklassifiseer moet word volgens 'n lys geselekteerde sensoriese eienskappe. Ongestrukteerde sortering kan gebruik word wanneer die doel is om „n groot aantal monsters vrylik te kategoriseer volgens hul sensoriese ooreenkomste of verskille. Die fenoliese saamestelling van die vier Cyclopia spesies het kwalitatief en kwantitatief verskil. Slegs vier van die gekwantifiseerde verbindings was teenwoordig in al vier spesies, naamlik hesperidien, visenien-2, mangiferien en isomangiferien. Meer verbindings was egter teenwoordig in drie van die vier spesies. Die voorspellingswaarde van die fenoliese verbindings tot die intensiteit van die smaak en mondgevoel eienskappe (soet, suur, bitter en vrank) is ondersoek met behulp van Pearson se korrelasie, gedeeltelike kleinste-kwadrate regressie (PLS) en stapsgewyse regressie analises. Potensiële "kandidaat voorspellers" vir die smaak en mondgevoel eienskappe, soos die xantone, mangiferien en isomangiferien, verantwoordelik vir 'n bitter smaak en vrank mondgevoel, is geïdentifiseer.

Thesis (MTech (Consumer Science: Food and Nutrition))--Cape Peninsula University of Technology, 2011.Includes bibliographical references (leaves 139-156). / Oxidative stress has been implicated in the development of a number of chronic degenerative diseases. These diseases can often be prevented by dietary and lifestyle changes. One major dietary aspect is increasing the intake of plant foods, such as fruit and vegetables as they are rich in the major nutrient and nonnutrient antioxidants. The South African population does not have an adequate intake of fruit and vegetables and many barriers have been noted against increasing the intake of these foods. Other avenues should therefore be sought to increase the antioxidant intake. One such avenue is to use a basic food item consumed often as an antioxidant carrier to increase the antioxidant intake. Much interest has developed in functional foods and their therapeutic effects as well as the use of nutraceuticals in food product development and food fortification. Tea and its polyphenols, due to the antioxidant properties, is a potentially viable option for nutraceutical and functional food use. Rooibos and honeybush herbal teas, native to South Africa, can be potential nutraceutical sources to increase antioxidant levels of food due to their unique polyphenol content. The objective of the study was to increase the total antioxidant capacity (TAC) of a basic food item consumed regularly by most South Africans, such as brown bread through fluid manipulation using rooibos, honeybush and black teas respectively, as the replacement fluid for water in a standardised bread recipe formulation. The TAC of these experimental breads were compared to the TAC of the bread produced with no fluid manipulation (control bread) and a commercially processed bread (reference bread). The experimental breads were prepared using 2% weight per volume (w/v) and 5% (w/v) concentration levels for rooibos, honeybush and black tea respectively. To ascertain the TAC of the experimental breads, the fluorescein(FL)-based oxygen radical absorbance capacity (ORACFL) method was used. The hydrophilic (H)-ORACFL assay was used as the teas contain polyphenols which favour a water environment. The results indicated that the H-ORACFL of the control bread using water as the fluid and the commercial reference bread was significantly different (p < 0.05 for each) to all the experimental bread formulations besides for the 2% (w/v) honeybush experimental bread formulation. The 2% (w/v) honeybush experimental bread formulation was therefore not considered for the consumer acceptance testing. There was no significant difference (p > 0.05) in the H-ORACFL of the 2% (w/v) rooibos and black tea experimental bread formulations, but the H-ORACFL of the 5% (w/v) black tea experimental bread formulation was significantly (p < 0.05) higher than that of the 5% (w/v) rooibos experimental bread formulation. This particular experimental bread formulation had a “golden-orange” colour with a pungent smell due to the increase in rooibos concentration. The 5% (w/v) black tea experimental bread formulation, however, had noted negative sensory attributes of being densely textured with a very dark colour and a pungent and overpowering taste of black tea. These sensory attributes and TAC results lead to the rooibos experimental breads containing 5% (w/v) (as bread A) and 2% (w/v) (as bread B) chosen for the consumer acceptance testing and rooibos being a proudly South African product. The participants (n = 85) of the consumer acceptance testing participated voluntarily and were regular bread consumers. The sample was mostly female (57.6%), in the age group of 18 to 24 years (54.1%), with an education level of between three to four years post-matric/-grade 12 (71.7%) and single, living on their own without children (76.4%). They also represented a sample which had characteristics of a healthy lifestyle. Most participants perceived themselves as being of an optimal body weight (55.2%) and the majority was non-smokers (74.1%), physically active (63.5%), having no family history of chronic disease (69.4%) and not consuming dietary supplements (70.5%). Three sensory attributes of the experimental breads were rated for the acceptance testing and included appearance/colour, flavour/taste and texture/mouthfeel. Both the experimental bread formulations was accepted favourably regarding the above-mentioned sensory attributes. The three liking acceptance categories, ‘neither like nor dislike’ (neutral response), ‘like’ and ‘like very much’ were the most commonly indicated by the participants which also resulted in the experimental breads being rated as fair, good and very good according to the development scores. Although both breads were very similarly scored, there was a trend for bread A to be rated slightly higher regarding the above-mentioned sensory attributes. The acceptance category, ‘like’/good was scored the highest for bread A according to the sensory attributes of appearance/colour (56.5%), flavour/taste (55.3%) and texture/mouthfeel (50.6%). There was no significant association/difference (p > 0.05 for each) between the participants’ demographic characteristics and their overall acceptance of the experimental breads. Most of the participant biographic characteristics also had no significant (p > 0.05 for each) impact on the sensory attribute acceptance of the experimental breads. Although the majority (75%) of the participants consumed rooibos, there was no significant (p > 0.05) association/difference between the participants’ tea consumption and their acceptance of the experimental breads. Although most participants (64%) had no awareness of functional foods, most indicated willingness to purchase foods with added health benefits (93%) and to pay more for foods with added health benefits (73%). These results indicated a general acceptance of bread with functional food characteristics and the possibility of purchasing such products with added health benefits and even at a higher price premium.

Thesis (M. Sc.(Agric))(Horticulture)-University of Pretoria, 2005. / Includes bibliographical references. Available on the Internet via the World Wide Web.

University of Macau / Institute of Chinese Medical Sciences

Bush tea (Athrixia phylicoides DC.) is a herbal beverage and medicinal plant indigenous to South Africa. A trial was conducted to determine the effect of micronutrients on the plant growth and quality of bush tea. The trial was laid out in a completely randomized block design with five replicates. Treatments consisted of single applications of Zinc (Zn), Copper (Cu), Boron (Bo), Iron (Fe) and Magnesium (Mg) at three levels (50ml/l, 100ml/l and 150ml/l) and a combination of all micronutrients. A control treatment with no spray was also included. Leaf analysis was conducted using Varian Liberty series II instrument. Total polyphenols were determined using the Folin Ciocalteau method and tannins were determined using Vanillin HCl method. Bush tea samples (one leaf per sample) were analysed using head space solid phase micro-extraction gas chromatography (HS-SPME-GC-MS). Results of this study demonstrated that application of micronutrients increased the total polyphenols, tannins and total flavonoids in bush tea, with most of the increase in total polyphenols (77.5-93.7 mg/g) occurring in combination B + Zn + Fe + Cu + Mg treatment, increase in tannins (87.3-99.5 mg/g) occurring in copper treatment and increase in total flavonoids (164.6-176.6 mg/g) occurring in mixture (B + Zn + Fe + Cu + Mg) treatment. Results also show a significant increase in the quality and plant growth of bush tea. Five major compounds were identified (>80% identification probability) namely alpha-pinene, beta-pinene, myrcene, beta-caryophyllene and caryophyllene oxide. Linear relationship between percentage leaf tissues and treatments levels of micronutrients in bush tea was also observed. Boron and copper treatments showed strong linear correlation with a positive relationship between treatments levels and leaf percentage. Therefore, for improved total polyphenols content in bush tea leaves, a combination of (B + Zn + Fe + Cu + Mg) is recommended. Tannin content in bush tea leaves were significantly increased at Cu50 ml/l, Cu100 ml/l and Cu150 ml/l. For improved total flavonoids content in bush tea leaves, a combination of foliar spray of (B + Zn + Fe + Cu + Mg) is recommended. The LC-MS observations from the study showed no significant qualitative difference between control and micronutrient treatments with these treatments showing similar number of peaks. There was a significant quantitative difference between control and where magnesium peaks applied at adequate rates at (50 ml/l and 100 ml/l) and combination of (B + Zn + Fe + Cu + Mg) applied at (10 ml/l and 20 ml/l) / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Chronic inflammation is suggested to contribute to cancer development and therefore a potential target for chemoprevention. In the skin, keratinocytes and macrophages play an integral part in acute and chronic inflammation, with interleukin 1-α (IL-1α) and tumor necrosis factor α (TNF-α) as key cytokines governing this process. Green tea (Camellia sinensis) and the South African herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) displayed antiinflammatory effects in mouse and human skin. To further investigate the antiinflammatory properties of green tea and the herbal teas, rooibos and honeybush (C. subternata and C. maculata) herbal teas, suitable cell culture models were developed and validated utilising human keratinocytes (HaCaT) and monocyte (THP- 1) derived macrophages. Aqueous extracts of the green tea and unfermented herbal teas were prepared and their chemical composition determined by high performance liquid chromatography (HPLC) and the antioxidant activity characterised utilising different antioxidant assays. Green tea and rooibos exhibited similar antioxidant activities while C. maculata displayed the lowest overall antioxidant activity of all the extracts, despite possessing the highest mangiferin level, the major polyphenol in honeybush. The modulation of cytokine release was studied in (i) an UVB-induced pre-exposure HaCaT model monitoring the accumulation of IL-1α and (ii) a LPS stimulated THP-1 macrophage model monitoring the TNF-α release, utilising both a pre-exposure and co-exposure extract regimens. In the pre-exposure HaCaT inflammatory model the UVB-induced IL-1α was decreased by the green tea extract while a far weaker response was obtained with the rooibos extract. Both the honeybush extracts displayed a significant effect in the reduction of IL-1α with C. subternata exhibiting a slight increased protection at a lower extract concentration. In the pre-exposure THP-1 derived macrophage model, green tea and the herbal tea extracts inhibited TNF-α release in a dose dependent manner in the absence of an overt loss in cell viability and apoptosis at lower extract concentrations, suggesting a typical anti-inflammatory effect. In the co-exposure model, the different extracts also exhibited an anti-inflammatory effect at the lowest concentrations in the absence of apoptosis while at higher extract concentrations the effect was masked by a decrease in cell viability and increased apoptosis. C. maculata exhibit differential effects when considering the inhibition of cytokine production and, depending on the cell model, either exhibited a weaker or stronger effect when compared to C. subternata and rooibos. Phenolic diversity of the different teas is likely to explain the differential effects in the antioxidant assays and cell culture models with respect to the regulation of the production of the inflammatory markers. Proposed mechanism for the anti-inflammatory effects include the modulation of oxidative stress via various pathways and the subsequent down regulation of nuclear factor kappa β (NFκB) and activated protein-1 (AP-1) which are key regulators of cytokine production governing the inflammatory response. / AFRIKAANSE OPSOMMING: Kroniese inflammasie van die vel kan bydra tot die ontwikkeling van kanker en is dus ’n potensiële area om te teiken in die voorkoming van velkanker. Keratinosiete en makrofage speel ’n integrale rol in akute en chroniese inflammasie van die vel en TNF-α en IL-1α is die belangrikste sitokiene wat hierdie proses inisieer. Dit is bekend dat ekstrakte van groen tee (Camellia sinensis) en die Suid-Afrikaanse kruietees, rooibos (Aspalathus linearis) en heuningbos (Cyclopia spp.) ‘n anti-inflammatoriese effek op die vel van muise en mense het. Om die anti-inflammatoriese aktiwitieit van groen tee, rooibos en 2 heuningbos kruietees (C. subternata en C. maculata) verder te ondersoek en te definieer is geskikte selkultuurmodelle ontwikkel en gevalideer deur gebruik te maak van menslike keratinosiete (HaCaT) en monosiet (THP-1) afgeleide makrofage. Water ekstrakte van groen tee en ongefermenteerde kruietees is voorberei en die chemiese samestelling deur hoë druk vloeistof chromatografie (HDLC) bepaal. ‘n Verskeidenheid van antioksidant bepalingstoetse is gebruik om die antioksidant aktiwiteit van die ekstrakte te meet. Groen tee en rooibos het soortgelyke antioksidant aktiwiteite getoon, terwyl C. maculata die swakste algehele aktiwiteit getooon het, ten spyte van die teenwoordigheid van hoёr vlakke van mangiferin, die belangrikste polifenoliese verbinding in heuningbos. Modulasie van sitokiene is verder bestudeer in (i) ’n UVB-geïnduseerde vooraf-blootstelling HaCaT model, waartydens akkumulering van IL-1α gemonitor is en (ii) ‘n lipopolisakkaried (LPS)-gestimuleerde THP-1 makrofaag model, waar die vrystelling van TNF-α gemonitor is. Vir die THP-1 model is beide die voor en gelyktydige blootstelling benaderings vir die ekstrakte met LPS gebruik. In die keratinosiet model, waar die selle aan ekstrakte blootgestel is voor UVB bestraing, is IL-1α beduidend verlaag deur die groen tee ekstrak, terwyl ’n swakker reaksie gesien is met rooibos. Beide heuningbos ekstrakte het ’n beduidende invloed in die vermindering van IL-1α getoon, waar C. subternata ’n effense verhoogde beskerming teen selsterfte by ‘n laer ekstrakkonsentrasie toon. Blootstelling van die makrofage aan al vier ekstrakte voor LPS stimulasie (vooraf-blootstelling), het gelei tot inhibisie van TNF-α vrystelling op ’n dosis afhanklike wyse en die afwesigheid van apoptose en selsterftes by lae ekstrak konsentrasievlakke. Hierdie waarnemings dui op ’n tipiese antiinflammatoriese effek. In die gelyktydige-blootstelling model verlaag al die ekstrakte TNF-α vrystelling teen die laagste ekstrak konsentrasievlakke, in die afwesigheid van apoptose en met geen effek op seldood nie. Hoёr ekstrak konsentrasievlakke het sitotoksisiteit en verhoogde apoptose getoon, dus was die anti-inflammatoriese effek gemaskeer. C. maculata toon ‘n variërende effek met betrekking tot antioksidant aktiwiteit en die bekamping van sitokien produksie, afhangend van die model wat bestudeer is. Die verskeidenheid fenoliese verbindings teenwoordig in die verskillende tee ekstrakte is waarskynlik die rede vir die effekte wat waargeneem is tydens antioksidant toetsing en selkultuurmodelle. Die anti-inflammatoriese meganismes wat deur hierdie studie voorgestel word sluit die modulasie van oksidatiewe stres via verskeie metaboliese paaie in. Modulasie van oksidatiewe stres lei tot af-regulering van kernfaktor-kappaB (NF-κB) en aktiveerderproteïen- 1(AP-1), wat sleutel reguleerders van sitokien produksie tydens inflammatoriese respons is.