Green tea contains high concentrations of polyphenolic compounds known as catechins. Studies in animal models suggest several potential mechanisms for specific metabolic effects at rest and during exercise, including improved glycemic control, altered activity of several glucose transporter proteins and improved endurance capacity. In humans, green tea extract (GTE) supplementation has been associated with improved glycemic control under resting conditions and increased fat oxidation during exercise. This dissertation examined the potential interactive effects of GTE supplementation and exercise on metabolism in humans with a focus on glycemic control. In Study 1, we demonstrated that GTE increased lipolysis and reduced heart rate during steady-state exercise in recreationally active men. Although substrate oxidation was not affected, GTE appeared to lower postprandial glucose under resting conditions. We hypothesized that the effects of GTE on exercise metabolism and glycemic control would be more apparent in humans with reduced exercise tolerance and impaired glucose tolerance. Thus, in Study 2, we examined the effects of GTE in sedentary overweight men. There were no differences in any metabolic or physiological responses during exercise; however, following exercise, GTE supplementation reduced [glucose] and insulinemia in response to an oral glucose load. Based on the findings of Study 2, the aim of Study 3 was to elucidate potential mechanisms for the alterations in glycemic response. Through the use of a dual-glucose tracer method, we demonstrated that GTE did not affect the rate of appearance of glucose in plasma in sedentary men; however, GTE supplementation allowed for the same glucose clearance rate despite a reduced insulinemia. We also observed lower carbohydrate oxidation during exercise with GTE. These findings suggest that GTE has an insulin-sensitizing effect during recovery from exercise, possibly due to enhanced glucose transporter activity; however, this hypothesis warrants further investigation in humans. / Dissertation / Doctor of Science (PhD) / Tea is one of the most popular beverages in the world. Compared to other teas, green tea has a greater abundance of catechins, compounds that have been associated with health benefits particularly related to the metabolism of sugars and fats. This unique property of green tea could partly explain its longstanding medicinal role in some Asian cultures. Extensive research on green tea has increased its popularity over the past three decades. Studies involving both humans and other animals have shown improvements in weight control and glycemic control. In response to these findings green tea is often touted as having “anti-obesity” and anti-diabetic” properties. This dissertation examined the interaction between green tea extract supplementation and exercise on metabolism with a particular focus on blood sugar control. We observed that supplementation with green tea extract improved the response to sugar ingested after exercise. This finding has important implications for improving the control of ingested sugar in humans.

Vine tea (Ampelopsis grossedentata) is a Chinese herbal tea, rich in the natural antioxidant dihydromyricetin, that has multiple health properties and potential food and beverage applications. However, there is little information available on vine tea aroma, color and sensory characteristics. In this study, volatile components of vine tea infusions were identified by headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Commercial vine teas samples were brewed with distilled water and Blacksburg (VA, USA) tap water and analyzed in triplicate. Vine tea infusions had acidic pH values and dark, reddish-yellow color. Type of water and vine tea sample both affected the overall volatile chemical composition of vine tea infusions. A total of fifty-six volatile components were identified in vine tea infusions. However, only seven aldehydes (hexanal, (E)-2-hexenal, (Z)-4-heptenal, nonanal, (E,Z)-2,4-heptadienal, (E,E)-2,4-heptadienal, and β-cyclocitral), two ketones (6-methyl-5-hepten-2-one and β-ionone), and one alcohol (1-penten-3-ol) were identified in more than 90% of all vine tea infusions (n=54). Results of this study may help further investigations in chemical and sensorial characteristics of vine tea, and the development of new healthy products. / Master of Science in Life Sciences

Emotional processing and characterization of internal and external stimuli is believed to play an integral role in consumer acceptance or rejection of food products. In this research three experiments were completed with the ultimate goal of adding to the growing body of research pertaining to food, emotions and acceptance using traditional affective sensory methods in combination with implicit (uncontrollable) and explicit (cognitive) emotional measures. Sweetness equivalence of several artificial (acesulfame potassium, saccharin and sucralose) and natural (42% high fructose corn syrup and honey) sweeteners were established to a 5% sucrose solution. Differences in consumer acceptability and emotional response to sucrose (control) and four equi-sweet alternatives (acesulfame potassium, high fructose corn syrup, honey, and sucralose) in tea were evaluated using a 9-point hedonic scale, check-all-that-apply (CATA) emotion term questionnaire (explicit), and automated facial expression analysis (AFEA) (implicit). Facial expression responses and emotion term categorization based on selection frequencies were able to adequately discern differences in emotional response as it related to hedonic liking between sweetener categories (artificial; natural). The potential influence of varying product information on consumer acceptance and emotional responses was then evaluated in relation to three sweeteners (sucrose, ace-k, HFCS) in tea solutions. Observed differences in liking and emotional term characterizations based on the validity of product information for sweeteners were attributed to cognitive dissonance. False informational cues had an observed dampening effect on the implicit emotional response to alternative sweeteners. Significant moderate correlations between liking and several basic emotions supported the belief that implicit emotions are contextually specific. Limitations pertaining to AFEA data collection and emotional interpretations to sweeteners include high panelist variability (within and across), calibration techniques, video quality, software sensitivity, and a general lack of consistency concerning methods of analysis. When used in conjunction with traditional affective methodology and cognitive emotional characterization, AFEA provides an additional layer of valued information about the consumer food experience. / Master of Science in Life Sciences

Tea is the world's oldest and currently most popular beverage in the world. Tea drinking has long been an important aspect of Chinese culture and has evolved as an art form called the "tea ceremony". With the growing interest in Asian culture, ethnic food, and the health benefits of tea, the tea market in the United States has increased dramatically. These developments, along with the recent growth in coffeehouses/shops, indicate a potential for similar success for teashops. The purpose of this study was to design a contemporary teashop deriving design inspiration from traditional Chinese culture and teahouse design. An existing site in a university town was selected for the study. Historical factors were identified through review literature and visual records of historic teahouses and architecture. Photos of contemporary Chinese teahouses provided information on teahouse operation and layout of functional areas. Observation of four local coffee shops was completed to collect data on function and design. Data were used to determine the workable solutions for a teashop designed for an American market. Based on the data collected, a design concept and programming requirements were developed. Design solutions that were found to be suitable and advantageous to enhance the concept were incorporated into the proposed design. Interior space layout, teashop logo, lighting fixtures, and façade design were developed. The design solutions were presented through plans, elevations, detail drawings, and perspective drawings. / Master of Science

Architecture is a structured relationship of physical elements in which use, experience and memory are integral to its sense of shelter. Beginning with the drawn and built conceptions of the House at Yellow Sulfur Springs, structural fragments of the project included cast concrete studies, a desired relationship between surface, physical structure and light, an indirect path of entry and pre-existing qualities of the site. These fragments coalesced as a house with varying degrees of enclosure, a structure defined by material distinctions and assembly details, and a sensual path between inside and outside. Throughout the project, memory of the Japanese Tea Ceremony, thoughts about the nature of shelter and the ratifying logic of geometry served as additional guides. / Master of Architecture

In the first experiment, effects of brewing time, chlorine, chloramine, iron, copper, pH and water hardness were investigated for their effects on extraction of epigallocatechine gallate (EGCG) and caffeine in green tea and oolong tea aqueous infusions. The extraction of EGCG and caffeine were lower when green tea was brewed in hard water compared to distilled water. Brewing green tea and Oolong tea in tap water resulted in higher extraction of caffeine but had no effect on EGCG compared to distilled water. The extraction of EGCG and caffeine were significantly increased (P<0.05) when green tea and Oolong tea were brewed in the chlorinated water at 4.0 mg free chlorine per liter. The purpose of the second experiment was to optimize SDE conditions (solvent and time) and to compare SDE with SPME for the isolation of flavor compounds in Jin Xuan oolong tea using Gas Chromatography- Mass Spectrometry (GC-MS) and Gas Chromatography- Olfactrometry (GC-O). The concentration of volatile compounds isolated with diethyl ether was higher (P<0.05) than for dichloromethane and concentration was higher at 40 min (P<0.05) than 20 or 60 minutes. For SDE, 128 volatiles were identified using GC-MS and 45 aroma active compounds using GC-O. The number of volatiles identified using GC-MS was lower in SPME than SDE. For SPME, 59 volatiles and 41 aroma active compounds were identified. The composition of the volatiles isolated by the two methods differed considerably but provided complementary information. The goal of the third experiment was to determine effects of panning on flavor volatile compositions of oolong using GC-MS and GC-O. Simultaneous Distillation and Extraction (SDE) and Solid Phase Microextraction (SPME) techniques were applied for extraction of volatiles in panned and unpanned teas. A total of 190 volatiles were identified from SDE and SPME extractions using GC-MS and GC-O. Trans-nerolidol, 2- hexenal, benzaldehyde, indole, gernaiol, and benzenacetaldehyde contents were significantly decreased (P<0.05) by panning; however, panning increased (P<0.05) contents of linalool oxide, cis jasmone, methyl salicylate in oolong tea. Overall, panning significantly changes the volatile compositions of the tea and created new aroma active compounds. / Ph. D.

Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Aspalathus linearis is a leguminous shrub native to the Cedarberg Mountains in the Western Cape, of which the leaves and stems are used for the preparation of rooibos tea. Over the past few decades, rooibos tea and other related products have gained popularity due to their health promoting properties. These beneficial properties can partly be ascribed to the phenolic constituents that are trapped within the cellulolytic plant material of the tea leaves as glycoconjugated aroma and phenolic compounds. Although many fungal species are known for their efficient hydrolysis of plant material, fungal enzymes have not been evaluated for the bioprocessing of rooibos tea to improve its commercial value. It was the objective of this study to identify a specific cocktail of microbial enzymes to enhance the maceration of the rooibos plant material, while retaining the antioxidant content. During this study, 11 fungal species known for the production of hydrolytic enzymes, as well as 12 species isolated from rooibos tea products, were screened for their potential to improve aroma development and/or increased extraction of soluble matter and/or antioxidants from rooibos tea material. After culturing in Potato Dextrose medium, the crude enzyme extracts of the 23 isolates were evaluated on spent rooibos tea for enhanced extraction of soluble solids (SS) and/or total polyphenols (TP). Nine strains increased the yield in SS (improvement varying from 3% to 42%), while 14 strains yielded higher levels of TP (increase varying from 1% to 36%). Little improvement in colour development from green (unfermented) rooibos tea was observed, but the enzyme extracts from Pleurotus ostreatus var. florida, Lentinula edodes, Aspergillus oryzae, Aspergillus tubingensis, Paecilomyces variotti and Trichoderma reesei improved the aroma development from green tea to some extent. Ten-fold concentrated enzyme extracts from four of these isolates were able to release at least an additional 10% in SS from the green tea. The crude enzyme extracts prepared from three food-grade strains, i.e. Aspergillus oryzae, Lentinula edodes and Pleurotus ostreatus var.florida, contained relatively high levels of endoglucanase, xylanase and pectinase activities. Eight different culture media were evaluated for optimal hydrolase and laecase production by these food-grade fungi. MYPG proved to be the best growth medium, while 1% spent grain, 1% wheat straw and 1% pineapple peel gave the best induction of xylanase, cellulase, pectinase and laecase activities for L. edodes. When cultured in the Yeast Peptone (YP) medium + 1% wheat straw, the L. edodes enzyme cocktail showed the best improvement in both the aroma and colour development of green tea and may be considered for shortening of the fermentation time required for green tea processing. Traditional open-air fermentation of rooibos tea can take up to -1-6hours, which results in a significant loss in antioxidants and therefore also in its pharmaceutical and nutraceutical value. The Rhizopus oryzae cocktail prepared in YP + 1% wheat straw showed potential for the development of a quick-draw fermented tea made by infusion, where there is improved colour release and more than 20% improved extraction of soluble solids without a loss in the TP content. When cultured in Potato Dextrose medium, the L. edodes cocktail can be used for aroma and colour development from green tea, while the R. oryzae cocktail can be used for increasing the antioxidant content in rooibos extracts from green or fermented tea. This was confirmed with small-scale industrial treatments of fermented tea where the L. edodes YP + wheat straw cocktail improved the release in SS by more than 10% and the R. oryzae yP + wheat straw cocktail increased the yield in SS by more than 30% and the TP by more than 20%. / AFRIKAANSE OPSOMMING: Aspalathus linearis is 'n fynbosplant inheems aan die Sederberge in die Wes-Kaap, waarvan die blare en stingels vir die voorbereiding van rooibostee gebruik word. Die afgelope paar dekades het die gewildheid van rooibostee en verwante produkte aansienlik toegeneem weens die gesondheidsvoordele wat dit inhou. Hierdie voordelige eienskappe kan toegeskryf word aan die fenoliese komponente wat binne die sellulolitiese plantweefsel van die teeblare as gekonjugeerde geur- en fenoliese verbindings vasgevang is. Alhoewel verskeie swamspesies vir hul doeltreffende degradering van plantmateriaal bekend is, is fungale ensieme nog nie geëvalueer vir die prosessering van rooibostee om die kommersiële waarde daarvan te verbeter nie. Die doelwit van hierdie studie was om 'n spesifieke kombinasie van mikrobiese hidrolitiese ensieme te identifiseer wat die maserasie van rooibos plantmateriaal sal verhoog met behoud van die anti-oksidant inhoud. Tydens hierdie studie is 11 swamspesies wat bekend is vir die produksie van hidrolitiese ensieme, asook 12 swamspecies wat vanaf rooibostee produkte geïsoleer is, geëvalueer vir hul potensiaalom geurontwikkeling en/of ekstraksie van oplosbare stowwe en/of anti-oksidante vanuit rooibostee materiaal te verbeter. Die kru ensiemekstrakte van die 23 isolate, wat ID Aartappel-Dextrose medium opgegroei is, is op oorskot rooibostee geëvalueer vir verhoogde ekstraksie van oplosbare vastestowwe (SS) en/of totale polifenole (TP). Nege rasse het die opbrengs van oplosbare vastestowwe verhoog (verbetering tussen 3% en 42%), terwyl 14 rasse die totale polifenoliese vlakke laat toeneem het (tot so hoog as 36%). Baie min verbetering in kleurontwikkeling van groen (ongefermenteerde) rooibostee is waargeneem, maar ensiemekstrakte van Pleurotus ostreatus var. florida, Lentinula edodes, Aspergillus oryzae, Aspergillus tubingensis, Paecilomyces variotti en Trichoderma reesei, het wel die aroma ontwikkeling vanaf groen tee tot 'n mate verbeter. Tienvoudig gekonsentereerde ekstrakte van vier van hierdie isolate het 'n verbetering van meer as 10% in die ekstraksie van opgeloste vastestowwe uit groen tee tot gevolg gehad. Die ensiemekstrakte van drie swarnme bekend vir hul gebruik in die voedselindustrie, nl. A. oryzae, L. edodes and P. ostreatus var. florida, het relatief hoë vlakke van endoglukanase, xylanase en pektinase aktiwiteit getoon. Agt verskillende kultuur-media is vir die optimale produksie van hidrolitiese and lakkase ensieme vanaf hierdie voedsel-graad swarnme geëvalueer. MYPG was die beste groeimedium vir L. edodes, -terwyl 1% koringstrooi, 1% oorskot graan en 1% pynappelskil die beste induksie van xylanase, pektinase, endoglukanase en lakkase aktiwiteite vir hierdie organisme getoon het. Lentinula edodes opgegroei in YP medium + 1% koringstrooi, het die beste verbetering in aroma en kleur getoon vanaf groen tee getoon. Hierdie ekstrak kan dus moontlik gebruik word vir die verkorting van die fermentasietyd wat vir groen tee benodig word. Ope-lug fermentasie van groen tee duur gewoonlik tot 16 uur en lei tot 'n aansienlike verlies in antioksidant-inhoud. Die R. oryzae ekstrak het die beste potensiaal vir die vervaardiging van 'n "quick-draw" tee getoon met 'n goeie kleurvrystelling sonder enige verlies in SS en TP opbrengs. Wanneer die swamme in Aartappel-Dextrose medium opggegroei word, kan die L. edodes ensiemekstrak vir aroma en kleurontwikkeling van groen tee aangewend word, terwyl die R. oryzae ensiemekstrak vir die verhoging van die antioksidant-inhoud in rooibos ekstrakte van groen tee of gefermenteerde tee gebruik kan word. Dit is bevestig met die kleinskaalse behandeling van gefermenteerde tee waar die L. edodes YP + 1% koringstrooi ensiemekstrak die vrystelling van SS met meer as 30% en die TP met meer as 20% verbeter het.

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. / Honeybush (Cyclopia spp.) is indigenous to South Africa and consists of more than 20 species of which only a few are used to make a herbal tea with a unique aroma and sweet taste. The aroma of unfermented and fermented honeybush tea differs considerably, indicating that changes take place in the chemical composition of the aroma during the fermentation process. Using a sample enrichment probe (SEP) and gas chromatography-mass spectrometry (GC-MS), the chemical composition of the aroma of unfermented and fermented C. genistoides, was analyzed and the resulting aroma profiles were compared. A total of 74 compounds were identified in the unfermented honeybush aroma, comprising, inter alia, a large number of saturated and unsaturated alcohols, aldehydes and methyl ketones that were found to be either absent, or present in lower relative concentrations, in the aroma of fermented honeybush. Most of these compounds, including 6-methyl-5-hepten-2-one, identified as one of the major constituents of unfermented honeybush, are probably responsible for its grassy, hay-like aroma. In the aroma of fermented honeybush 70 compounds were identified, of which 36 were found to be terpenoids. These compounds are probably responsible for the pleasant sweet aroma of the fermented honeybush. For instance, the major aroma constituent in the fermented honeybush, α-terpineol, is known to have a delicately floral and sweet odour. Other terpenoids occuring in significant quantities in the fermented honeybush, are linalool, cis and trans linalool oxide, nerol, geraniol, 2,6-dimethyl-1,7-octadien-3,6-diol, hexahydrofarnecyl acetone and phytol. These terpenoids are known to have sweet, sweet-woody en floral odours that probably contribute to the overall sweet aroma of the fermented honeybush. In the aroma of the unfermented honeybush a total of 25 terpenoids was identified, of which geranyl acetone, β-ionone, and dihydroactinidiolide are the most significant, since they are present in higher relative concentrations compared to the same terpenoids in the fermented honeybush. These three terpenoids have overall woody and even slightly green odours which contribute to the typical aroma of the unfermented honeybush. The terpenoids present in the aroma of unfermented and fermented honeybush belong to the following compound classes: • Terpenes • Terpene alcohols • Terpene aldehydes • Ketoterpenes • Terpene ethers • Terpene lactones Apart from the terpenoids present in the aroma of unfermented and fermented honeybush, the following classes of compounds are also present: • Aliphatic hydrocarbons (saturated) • Aliphatic alcohols (saturated and unsaturated) • Phenols • Aliphatic aldehydes (saturated and unsaturated) • Aliphatic ketones (saturated and unsaturated) • Aliphatic carboxylic acids (saturated) • Esters (methyl esters, ethyl and higher esters and aromatic esters) • Furane compounds • Lactones The present research was done to compare the chemical composition of the aroma of unfermented and fermented honeybush of one particular species, namely C. genistoides, to obtain an understanding of the evolution and/or disappearance of volatile compounds during fermentation that ultimately could help to identify compounds or compound types and their precursors responsible for its unique sweet aroma.

Xu Jinze. / "August 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 165-182). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Hypoxia and reperfusion can result in many pathological complications in the fetus including retinopathy, ischemic encephalopathy and even stillbirth. The adverse effects are due to excess production of free radicals that attack vital bio-molecules such as DNA and enzymes. Antioxidant treatment may be a way to alleviate oxidative stress. Green tea is a source of antioxidants. It contains polyphenols mainly catechins, that possess high reducing power and low toxicity. Major catechin compounds in green tea are (+)-catechin (C), (-)-epicatechin (EC, (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-catechin gallate (CG), (-)-epicatechin gallate (ECG), (-)-gallocatechin gallate (GCG) and (-)-epigallocatechin gallate (EGCG). Accordingly, catechins may be ideal agents for antioxidant treatment of the fetus exposed to hypoxia during pregnancy. / In the animal experiments, rat mothers, at the 15.5th gestation day, were intragastrically administrated a single dose of green tea extract. The pharmacokinetic profiles of catechins in maternal plasma, whole embryos and embryonic organs were investigated. The catechins GC, ECG, C, EC, were found to exhibit non-linear capacity limited pharmacokinetic behaviour implying their metabolism or absorption was saturated. Catechin gallates, EGCG and ECG, appeared to exhibit enterohepatic re-circulation behaviour. Peak time was about 1 hour for both groups of catechins; the half life of the catechin group was about 1 hour while that of EGCG and ECG was about 3.7 hours. EC, EGC and EGCG were the dominant compounds present in plasma. All catechins exhibited a consecutive one-compartment model in the embryo, where EGCG, ECG, EGC and EC were dominant compounds and ECG had the highest penetrability. (Abstract shortened by UMI.) / In this study, pregnant rat dams were fed green tea extract in an attempt to raise catechin levels in the rat embryo in order to scavenge free radicals. To test this hypothetical application, we first established analytical methods to evaluate oxidative stress and catechins levels of the fetus in vivo. The methodologies included assaying F2-isoprostanes in cord blood and determining catechin levels in biological fluids and tissues. We further utilized these new sensitive analytical methods to investigate the pharmacokinetics of the catechins in maternal rat plasma, whole embryos and embryonic organs. Since no data has been previously reported on the toxic effects of catechins on embryos, we also tested the toxic effects of various concentrations of catechins on the developing embryonic features in embryo culture. / Chu Kai On. / "April 2005." / Advisers: Michael Scott Rogers; Chi Pui Pang. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0244. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 208-241). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.