Thesis (Ph.D.)(Plant production)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

published_or_final_version / Chinese / Master / Master of Arts

Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2015. / Rooibos iced tea (RIT), as one of the products of Rooibos is fast becoming very popular as a beverage in society due to the benefits of the phenolic compounds that are associated with this herbal tea. Some of the commercially available products have been found to contain, if any, lower contents of the major phenolic compounds, namely aspalathin and its oxidation products, iso-orientin and orientin. Their presence is considered as indicators of a good quality product. The purpose of this study was to investigate the effect of ultraviolet-C (UV-C) light as an alternative treatment to heat treatment on the shelf life, pH, phenolic composition, colour and microorganisms associated with Rooibos. Two formulations of RIT were used in order to determine the efficacy of the UV-C on the shelf life whilst three formulations were used for the physicochemical analysis. Only one formulation was used for inoculation with three spoilage bacteria, yeast and mould spoilage microorganisms namely; Escherichia coli K12, Staphylococcus aureus, Salmonella sp., Saccharomyces cerevisiae and Cladosporium sp. The UV-C dosages of 0, 918, 1 836, 2 754 and 3 672 J.l -1 were used to treat the RIT using a pilot-scale UV-C system with a turbulent flow at a constant flow rate of 4000 l.hr-1 . A log count of 4 log10 was considered the limit for the spoilage growth since it is the average log10 afternormal pasteurisation. The use of UV-C treatment was found to have significantly (p1) effect on the overall colour difference of the RIT in formulations A, B, and C. All the spoilage microorganisms were significantly reduced by UV-C dosage to less than 4 log10 except the Cladosporium sp. The S. cerevisiae was the most sensitive microorganism whilst Cladosporium sp. was the most resistant. The effect of UV-C on the spoilage microorganism followed the sequence: S. cerevisiae>Salmonella sp.>S. aureus>E. coli K12>Cladosporium sp. This study indicated that microbiological reduction was achieved as a function of increasing UV-C dosage. In order to achieve the highest log10 reduction, the highest UV-C dosage of 3 672 J.l-1 may be used. However, the dosage may need to be increased in order to achieve the desired results in the treatment of Cladosporium sp. It can thus be concluded from the above investigations that UV-C dosage treatment of 3 672 J.l-1 is optimum in the non-thermal treatment of RIT / South African Association for Food Science & Technology Cape Peninsula University of Technology Bursary

Several beneficial effects of green tea polyphenols (GTPs) have been shown in both in vitro and animal studies. This pilot study tested their effects on relief of dry mouth and quality of life (QoL) in Sjögren’s syndrome (SS) patients. After one month of green tea consumption in 18 SS patients, and three months in 7 patients, there was an improvement in the patients’ oral health and QoL. In addition there was an increase in the unstimulated salivary flow rate and a decrease in the viscosity of stimulated saliva, although not statistically significant. Furthermore, 83% of the patients reported that they would continue to drink green tea. Although the mechanism of action of the GTPs is unknown in this patient population, we have shown that regular green tea consumption by SS patients is a simple yet effective and enjoyable means of dry mouth relief.

Several beneficial effects of green tea polyphenols (GTPs) have been shown in both in vitro and animal studies. This pilot study tested their effects on relief of dry mouth and quality of life (QoL) in Sjögren’s syndrome (SS) patients. After one month of green tea consumption in 18 SS patients, and three months in 7 patients, there was an improvement in the patients’ oral health and QoL. In addition there was an increase in the unstimulated salivary flow rate and a decrease in the viscosity of stimulated saliva, although not statistically significant. Furthermore, 83% of the patients reported that they would continue to drink green tea. Although the mechanism of action of the GTPs is unknown in this patient population, we have shown that regular green tea consumption by SS patients is a simple yet effective and enjoyable means of dry mouth relief.

Thesis (MSc)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Thesis (M. Med. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 42-53).

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Food Science." Includes bibliographical references (p. 103-117).

Breast cancer is the second leading cause of mortality among women in the US. A contributing factor to such dire statistics is that conventional therapies are all too often compromised due to tumor relapse. Clearly there is an urgent need for agents that can circumvent resistance when combined with conventional therapies. RRR-α-tocopherol ether-linked acetic acid analog (α-TEA), a small bioactive lipid, exhibits in vitro and in vivo anticancer actions in a variety of cancers, including breast, prostate, and ovarian with little or no effect on normal cells and tissues, which potentially makes it an ideal chemotherapeutic agent. My studies investigated the anticancer actions of α-TEA alone and in combination with therapeutic agents using human breast cancer cell lines. Data show that: (i) Endoplasmic reticulum (ER) stress plays an important role in α-TEA induced apoptosis by enhancing DR5/caspase-8 pro-apoptotic signaling and suppressing anti-apoptotic factors c-FLIP and Bcl-2 via ER stress mediated JNK/CHOP/DR5/caspase-8 signaling, (ii) α-TEA plus tamoxifen act cooperatively to circumvent acquired and de novo tamoxifen resistance, resulting in cancer cell death by apoptosis. Mechanistically, the circumvention of tamoxifen resistance involved induction of DR5/caspase-8 pro-apoptotic mediators and suppression of anti-apoptotic factors c-FLIP and Bcl-2 via ER stress mediated JNK/CHOP/DR5/caspase-8 signaling. (iii) α-TEA alone or with tamoxifen circumvents tamoxifen resistance via disruption of membrane cholesterol rich lipid raft microdomains. Cholesterol blocked the ability of α-TEA + tamoxifen to circumvent tamoxifen resistance. (iv) α-TEA in combination with PI3K, MEK or mTOR inhibitors acted cooperatively to induce apoptosis, by down-regulation of IRS-1/PI3K mediators via JNK. (v) α-TEA plus doxorubicin or cisplatin enhanced apoptosis in p53 mutant human breast cancer cells via targeting p53-inducible genes in a p73-dependent manner; namely, via up-regulation of death receptor-5 (DR5), CD95/APO-1 (Fas), Bax and Noxa, as well as down-regulation of anti-apoptotic mediator Bcl-2. Data showed that p73 responses were downstream of c-Abl, JNK and Yap. (vi) FASN inhibitor alone or with Tamoxifen or α-TEA circumvents tamoxifen resistance, thereby, providing novel strategies for restoring tamoxifen sensitivity to tamoxifen resistant cancers. In summary data show, α-TEA alone and in combination with multiple clinically-relevant anticancer agents is a promising anticancer agent. / text

Thearubigins are polyphenolic oligmers which contribute to the quality of black tea: it is necessary to learn more of their origin and structure in order to understand their function, and to utilise opportunities to influence their development during processing to meet market demand. Tea samples were manufactured under controlled conditions, by methods parallel to commercial production in Malawi. Leaf handling, withering, fermentation and drying were manipulated. Conditions selected could be used in current commercial tea factories with only minor modifications. Non-volatile water-soluble components of black tea were analysed in an attempt to identify the critical points in the process. Solvent partition, adsorption chromatography or caffeine precipitation followed by size..exclusion HPLC were used to further separate the thearubigins and estimate molecular mass. Reverse-phase HPLC was also used; both methods were monitored by UV-VIS spectroscopy. Eluate was collected and portions challenged with chemical probes to identify functional groups within the oligmers. Theafulvin was shown to be heterogeneous in both chemical composition and mass. Prolonged fennentation in the presence of air promoted the development of theafulvin, caffeine-precipitable thearubigin, and hump unresolved by reverse-phase HPLC. This is the first evidence that theafulvin is a product of fermentation rather than a plant artefact. Leaf handling and fermentation conditions have a greater impact on liquor colour and perceived quality than withering or well-controlled drying. Modified dryer operating conditions preserved product composition and quality. Opportunities to manipulate product composition to meet market demand were identified.