Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Spoilage, be it due to microbial actions, chemical reactions or both, poses a serious threat to the food and beverage industries. Not only can spoilage lead to great economic losses, but it can also cause industries to lose their competitive edge in the economic and consumer market. Considering all the modern technologies and the range of preservation techniques that are available, it is surprising that spoilage is still an economic problem. Wine spoilage due to unpalatable bitterness, and the role of lactic acid bacteria (LAB) in causing this bitterness, have received much attention over the years, but no definite understanding has yet emerged. The first objective of this study was to isolate, enumerate and identify the LAB from three red grape varieties, viz. Pinotage, Merlot and Cabernet Sauvignon. The LAB populations on the grapes of all three varieties ranged from 102 to 104 cfu/ml during the 2001 and 2002 harvest seasons. The Cabernet Sauvignon grapes had slightly higher numbers than the Pinotage and Merlot. The LAB population in the Cabernet Sauvignon, Pinotage and Merlot wines after completion of the alcoholic fermentation ranged from 102 to 105 cfu/ml, while during 2002 the numbers in wine undergoing malolactic fermentation (MLF) ranged from 104 to 108 cfu/ml. The isolated LAB were divided into the three metabolic groups, with 59% belonging to the facultatively heterofermentative group, 26% to the obligately heterofermentative group and 15% to the obligately homofermentative group. The isolates were identified by means of species-specific primers as Leuconostoc mesenteroides (4), Oenococcus oeni (28), Lactobacillus brevis (15), Lb. hilgardii (15), Lb. plantarum (98), Lb. pentosus (12), Lb. paraplantarum (3), Lb. paracasei (28), Pediococcus acidilactici (2) and Pediococcus spp. (35). The most predominant species isolated was Lb. plantarum, followed by Pediococcus spp. The results suggest that Pinotage carries a more diverse LAB population in comparison to Merlot and Cabernet Sauvignon. The second objective of this study was to determine the presence of the glycerol dehydratase gene in the LAB strains by using the G01 and G02 primers. Twenty-six strains tested positive, namely Lb. plantarum (15), Lb. pentosus (1), Lb. hilgardii (5), Lb. paracasei (2), Lb. brevis (2) and a Pediococcus spp. (1). Interestingly, 62% of these strains were isolated from Pinotage. The strains all had the ability to degrade glycerol by more than 90%, and no significant differences were observed between the species. The GO-possessing strains exhibited varying degrees of inhibition towards Gram-positive and Gram-negative bacteria, and the results suggest that this inhibition activity may be similar to that of reuterin, which is produced by Lb. reuteri. This study can form the foundation for unravelling the causes of bitterness in red wines. Combining the results of this study with analytical, sensory and molecular data may very well provide the industry with valuable tools with which to combat the occurrence of bitterness. / AFRIKAANSE OPSOMMING: Bederf as gevolg van mikrobiese aksies, chemiese reaksies of beide, hou 'n groot bedreiging vir die voedsel- en drankbedrywe in. Nie net kan bederf lei tot groot ekonomiese verliese nie, maar dit kan ook veroorsaak dat bedrywe hul kompeterende voordeel in die ekonomiese en verbruikersmarkte verloor. As die moderne tegnologie en die reeks preserveringstegnieke wat beskikbaar is, in ag geneem word, is dit verbasend dat bederf steeds 'n ekonomiese probleem is. Wynbederf as gevolg van oormatige bitterheid en die rol van melksuurbakterieë (MSB) in die ontwikkeling van hierdie bitterheid het oor die jare heen baie aandag geniet, maar geen definitiewe verklaring is nog daarvoor gevind nie. Die eerste doelwit van hierdie studie was om MSB vanaf drie rooidruifvariëteite, nl. Pinotage, Merlot en Cabernet Sauvignon, te isoleer, te kwantifiseer en te identifiseer. Die MSB-populasies op die druiwe van al drie variëteite het gedurende die 2001- en 2002-parsseisoene tussen 102 en 104 kvu/ml gevarieer. Die Cabernet Sauvignon-druiwe het effens hoër getalle as die Pinotage- en Merlot-druiwe gehad. Die MSB-populasies in die Cabernet Sauvignon-, Pinotage- en Merlot-wyne aan die einde van die alkoholiese fermentasie het tussen 102 en 1055 kvu/ml gevarieer. Gedurende 2002 het die MSB-getalle in die wyne waarin appelmelksuurgisting (AMG) aan die gang was tussen 104 en 108 kvu/ml gevarieer. Die geïsoleerde MSB was onderverdeel in die drie metaboliese groepe, met 59% wat behoort aan die fakultatiewe, heterofermentatiewe groep, 26% aan die obligate, heterofermentatiewe groep en 15% aan die obligate, homofermentatiewe groep. Die isolate is geïdentifiseer as Leuconostoc mesenteroides (4), Oenococcus oeni (28), Lactobacillus brevis (15), Lactobacillus hi/gardii (15, Lactobacillus p/antarum (98), Lactobacillus pentosus (12), Lactobacillus parap/antarum (3), Lactobacillus paracasei (28), Pediococcus acidi/actici (2) en Pediococcus spp. (35) deur middel van spes iespesifieke inleiers. Die mees algemeen geïsoleerde spesies was Lb. p/antarum, gevolg deur Pediococcus spp. Die resultate impliseer dat Pinotage 'n meer uiteenlopende MSB-populasie in vergelyking met Merlot en Cabernet Sauvignon dra. Die tweede doelwit van hierdie studie was om die teenwoordigheid van die gliseroldehidratase-geen in die MSB-isolate deur middel van die GD1- en GD2- inleiers te bepaal. Ses-en-twintig isolate was positief, nl. Lb. p/antarum (15), Lb. pentosus (1), Lb. hi/gard;; (5), Lb. paracasei (2), Lb. brevis (2) en 'n Pediococcus spp. (1). 'n Interessante resultaat was dat 62% van hierdie isolate vanaf Pinotage geïsoleer is. Die isolate was almal in staat om meer as 90% van die gliserol te gebruik en geen noemenswaardige verskille is tussen die isolate waargeneem nie. Die GD-bevattende isolate het verskillende grade van inhibisie teenoor Grampositiewe en Gram-negatiewe bakterieë getoon, en die resultate impliseer dat hierdie inhiberende aktiwiteit dieselfde is as dié van reuterin wat deur Lb. reuteri geproduseer word. Hierdie studie kan dus die basis vorm vir die ontrafeling van die oorsake van bitterheid in rooiwyne. Deur die resultate van hierdie studie met analitiese, sensoriese en molekulêre data te kombineer, kan die wynbedryf voorsien word van waardevolle metodes om die voorkoms van bitterheid mee te bekamp.

published_or_final_version / Business Administration / Master / Master of Business Administration

Objectives. This study aimed to provide data on water intake from food and beverages of free-living adults in their natural environment, and investigate how this is affected by physiological, psychological, social and environmental factors. A further aim was to monitor the hydration status of free-living adults and relate this data to water intake. Methods The consumption of all food and beverages was recorded in a diary over three consecutive days by 80 healthy adults (40 males, 40 females), aged 18 to 65 years, who were instructed to continue their normal eating and drinking habits and lifestyles throughout the study. The data was analysed to determine total daily water intake and how this was affected by time of day, day of the week, presence of others, location of consumption, age and subjects mood. A further 20 healthy subjects (10 males, 10 females) repeated these procedures but also had blood samples taken for monitoring of blood indices (haemoglobin concentration, haematocrit, sodium concentration, and potassium concentration) and provided urine samples for the measurement of urine indices (volume, colour, specific gravity, osmolality and sodium, potassium, chloride, and creatinine concentrations). Results The total volume of water consumed by the 80 subjects was 2229  882 ml/day (mean  standard deviation). Females tended to consume more water than males (2402  827 ml/day vs 2056  911 ml/day, P = 0.079). Similar volumes were consumed by the additional 20 subjects in the hydration status study. Females appeared euhydrated; males appeared mild dehydrated, having a higher morning and 24-hour urine specific gravity and osmolality than females (P < 0.05, respectively). Conclusions The mean daily total volume of water consumed by females in this study was greater than the adequate intake value set by the European Food Safety Authority; for males it was lower. Females were euhydrated during the study but males tended to be mild dehydrated, reflecting their comparative water intakes.

Beyond the expected DBP exposure from drinking water, dermal from bathing, and inhalation, occurrence in food and beverage items can provide an additional occurrence pathway. Synthetic dyes are often added to beverages for aesthetic purposes and many are in the form of a reactive azo (-N=N-) dye or triarylmethane dye, both with a characteristic aromatic ring. The presence of dyes in beverages that are reconstituted with disinfected tap water pose the risk of reactions with the residual chlorine in the drinking water resulting in decolorization, and of greater concern, disinfection byproduct formation. Additionally, oral over-the-counter (OTC) medications contain chemical constituents that when reconstituted with tap water present a risk of DBP formation. Several studies were performed to evaluate the kinetic decay rates of the dyes and drugs in disinfectants, and the effects of water quality conditions on DBP formation. Commercial beverage products and OTC medications were evaluated for the DBPs that were detected in the free chlorine-treated precursor samples. The dye and drugs precursors followed second order kinetics, with the fastest rates for brilliant blue and phenylephrine in chlorinated water. The effects of water properties on precursor degradation and DBP formation was complex due to the influence of characteristics of precursor molecules. The cytotoxic and anti-estrogenic responses were measured in the dye and drug precursors and their respective beverages and OTC medications, to determine potential links. Mio Energy showed estrogenic character and Alka Seltzer induced an anti-estrogenic and cytotoxic response, however there were no clear linkages between the beverage/ medication and their respective dye and drug precursors.

A research report submitted to Wits Business School, Faculty of Commerce, Law and Management, University of the Witwatersrand, Johannesburg, in partial fulfilment of the Degree of Master of Management in Strategic Marketing November 2015 / Building, maintaining and measuring consumption frequency over a specific period of time has become the primary driver of success for nonalcoholic beverage organisations; however, there is limited research on youth consumption frequency within South Africa. Using the Theory of Planned Behaviour, the study aimed to investigate the impact of brand association, flavour variety, peer influence and perceived value on consumption frequency intention in the sparkling soft drink (SSD) category amongst youth in South Africa. A quantitative research design was followed and data collected from 300 research participants aged between 16 and 24 years in Soweto, Gauteng Province in South Africa. The collected data was analyzed using SPSS 22 and AMOS 21 statistical packages for structural equation modelling. All four hypotheses are supported, with results indicating a positive relationship between brand association, flavour variety, peer influence, perceived value and consumption frequency intention. Peer influence and perceived value have a significantly stronger influence on consumption frequency intention. The results also indicate that flavour variety “ambiguous SSD flavour names” scored higher amongst 16 to 18 years olds. Ambiguous flavour naming strategies have proven to be successful in other beverage categories. Quantity-frequency (QF), a consumption frequency measurement instrument has been used, with consumption skewed towards “sharing” with friends or family. This study contributes significant new knowledge to the existing body of marketing literature in Africa and consumer behaviour in emerging markets. This study has implications for practitioners, academicians and public policy makers. / MT2017

Embora os fatores de risco ao consumo de drogas sejam bastante conhecidos, ainda pouco se sabe sobre a dinâmica e a organização das famílias de adolescentes que consomem álcool, assim como suas interrelações com a comunidade. Buscando compreendê-las, esta pesquisa objetivou analisar e interpretar a influência da família no consumo de álcool por adolescentes, a partir dos referenciais teóricos do interacionismo simbólico e da perspectiva sistêmica de família. Para tanto, adotou-se como campo de estudo a Unidade de Saúde da Família Emocy Krause, localizada no Distrito Sanitário IV, da cidade do Recife, Pernambuco, Brasil. Os participantes do estudo foram 22 membros de dez famílias, dentre os quais estavam onze adolescentes, de ambos os sexos, na faixa etária de quatorze a dezenove anos, e que consumiam álcool. As técnicas utilizadas para coleta de dados foram: observação e entrevista em profundidade, baseada modelo Calgary de Avaliação da Família, para obtenção de informações que permitissem a avaliação dos componentes estrutural, de desenvolvimento e funcional das famílias, além da construção do genograma e do ecomapa familiar. A análise dos dados foi realizada empregando-se a análise temática do tipo indutiva. Foram elaborados três temas: na internalidade da família: fragilidade e conflitos; entre nós: limites, responsabilidades e esperança; e decisão pela bebida: diversão permeada por riscos. O primeiro tema aborda as fragilidades das famílias, como as relações interpessoais conflituosas, o padrão de comunicação intrafamiliar, a experiência de separação e as perdas, e os conflitos vividos entre seus componentes. O segundo tema trata da interação entre os componentes da família, caracterizada pela desestruturação, envolvendo o consumo abusivo de bebidas alcoólicas pelos familiares e desrespeito, marcando os limites de atuação da família que contribuíram para que os adolescentes se aproximassem das bebidas alcoólicas. Mesmo assim, a família não se eximiu de sua responsabilidade para com seus membros, bem como manteve a esperança, nutrida pelas aspirações e religião dos seus membros. Por fim, a decisão pela bebida retrata o contexto do consumo de álcool e as motivações para esse consumo. Os adolescentes apontaram como motivos o prazer e a diversão, sem ignorar os prejuízos do uso abusivo da bebida alcoólica. A diversão associou-se a músicas que se aproximavam do contexto de vida dos adolescentes, incentivando o consumo de bebidas e funcionando como escape dos problemas familiares. Concluiu-se que, tanto a família quanto o contexto sociocultural de inserção dos adolescentes podem influenciar, ao mesmo tempo, de forma positiva e negativa o uso e o abuso de álcool. A estrutura e composição da família, o padrão de interação familiar, a comunicação entre seus membros, a religião e a esperança são componentes que ser articulam diretamente com a prática do consumo de álcool pelos adolescentes e podem ser alvo de intervenção na enfermagem. / Although the risk factors for drugs consumption are well known, little is known so far about the dynamics and organization of families of adolescents who consume alcohol, as well as about their interrelations with the community. In the attempt to understand them, this research aimed to analyze and interpret the influence of the family on alcohol consumption by adolescents, based on the theoretical frameworks of symbolic interactionism and the systemic family perspective. Therefore, the place of study was the Family Health Unit Emocy Krause, located in Health District IV in Recife, Pernambuco, Brazil. The study subjects were 22 members of ten families, including eleven male and female adolescents between 14 and 19 years old who consumed alcohol and were considered index cases. The following data collection techniques were used: observation and in-depth interview, based on the Calgary Model of Family Assessment, to obtain information to assess the structural, development and functional components of the families, besides the construction of the genogram and the family ecomap. Inductive thematic analysis was used to analyze the data. Three themes were elaborated: in the familys internality: weakness and conflicts; among us: limits, responsibilities and hope and desire for the drink: diversion permeated by risks. The first theme addresses the families weaknesses, including conflicting interpersonal relations, the intra-family communication standard, the separation experience and losses, and conflicts experienced among family members. The second theme refers to the interaction among family members, characterizes by loss of structure, involving alcohol abuse by family members and disrespect, outlining family activities that contributed for adolescents to approach alcoholic beverages. Nevertheless, the family did not refuse the responsibility towards its members and kept up hope, nourished by aspirations and members religion. Finally, the decision to drink pictures the consumption context and the motivations to consume alcohol. The adolescents appointed pleasure and fun as motives, without ignoring the harm of alcohol abuse. Fun was associated with songs that approached the adolescents life context, encouraging drinking and functioning as an escape from family problems. It was concluded that both the family and the adolescents sociocultural context can influence alcohol use and abuse positively and negatively at the same time. The family structure and composition, the family interaction standard, communication among family members, religion and hope are components that directly articulate with adolescents alcohol consumption and can be targets of nursing intervention.

Objetivo: Este estudo avaliou a influência de bebidas e escovação na estabilidade de cor, rugosidade superficial e microdureza em profundidade de uma resina composta. Materiais e Método: 120 discos (10mm de diâmetro X 2mm de espessura) de resina composta (Filtek- Z250) foram preparados e polidos após 24 horas. A cor inicial e a rugosidade superficial inicial foram mensuradas e os espécimes foram divididos aleatoriamente em quatro grupos (vinho tinto, refrigerante, aguardente, ou saliva artificial controle) e três subgrupos (sem escovação; escovação com Colgate, ou escovação com Close Up Whitening). Os espécimes foram imersos na sua respectiva solução, 5x ao dia, por 5 minutos, durante 30 dias, sendo dois subgrupos escovados ao final de cada dia (120 movimentos/dia). A cor foi mensurada no 15º e no 30º dia de imersão; a rugosidade superficial final foi medida no 30º dia. Após o período de imersão, os espécimes foram armazenados em saliva artificial por 7 dias, quando a superfície dos mesmos foi polida e imediatamente realizou-se uma mensuração de cor. A alteração de cor foi mensurada com um espectrocolorímetro e analisada pelos valores de &Delta;E, &Delta;L, &Delta;a, e &Delta;b. Os valores de rugosidade (Ra-&mu;m) foram medidos com um rugosímetro. Com relação à microdureza, os espécimes primeiramente foram incluídos em resina de poliéster e seccionados no sentido transversal. Após o polimento destas superfícies, foram realizadas mensurações nas profundidades de 30&mu;m, 60&mu;m, 90&mu;m, 120&mu;m e 250&mu;m, empregando os parâmetros 25gf/40s de microdureza Knoop. Os dados foram submetidos à ANOVA e teste de Fisher\'s (&alpha;=5%). Resultados: Os valores de alteração de cor foram estatisticamente diferentes após a imersão nas bebidas; o vinho tinto promoveu a maior alteração, seguido pelo refrigerante e aguardente, que foram similares entre si e diferentes da saliva artificial. Nenhuma diferença foi observada com ou sem escovação, independentemente do dentifrício utilizado. Ao 30º dia, os espécimes apresentaram uma mudança de cor mais intensa do que ao 15º dia, após o repolimento, a cor dos espécimes foi similar à cor do 15º dia. As bebidas e a escovação influenciaram negativamente na rugosidade da superfície. Em relação à microdureza, não houve diferença significativa entre os grupos, independentemente da profundidade analisada. Conclusões: A mudança de cor da resina composta foi influenciada apenas pelas bebidas; a escovação não afetou a propriedade analisada. O repolimento não foi suficiente para promover o retorno da cor dos espécimes aos valores iniciais. A rugosidade superficial foi influenciada negativamente tanto pelas bebidas quanto pela escovação. Para a microdureza, a resina composta apresentou resultados similares independentemente das bebidas utilizadas e da presença ou ausência de escovação nos espécimes avaliados. / Objective: This study evaluated the influence of beverages and brushing on the color change, surface roughness and microhardness in depth of a composite resin. Methods: 120 composite resin disks (10mm-øX2mm-thickness; Filtek-Z250) were prepared and polished after 24h. Initials color and surface roughness were measured and specimens were randomly assigned into four groups (red wine, soft drink, sugar cane spirit, or artificial saliva control) and three subgroups (without brushing; brushing with Colgate, or brushing with Close Up Xtra Whitening). Specimens were immersed in the beverage 5x/day, for 5 minutes, over 30 days, being two subgroups brushed at the end of every day (120 moving/day). Color was measured at the 15th and 30th days of immersion; final surface roughness was measured at the 30th day. After the immersion period, specimens were stored in artificial saliva for 7 days, when their surfaces were repolished and immediately assessed by color. Color change was measured with a spectrocolorimeter and analyzed by &Delta;E, &Delta;L, &Delta;a, and &Delta;b values. The values of roughness (Ra - &mu;m) were measured with a rugosimeter. As regard microhardness, the specimens were firstly included in polyester resin and sectioned in the transverse direction. After polishing these surfaces, measurements were realized at depths of 30&mu;m, 60&mu;m, 90&mu;m, 120&mu;m and 250&mu;m, employing the parameters 25gf/40s of microhardness Knoop. Data were submitted to ANOVA and Fisher\'s tests (&alpha;=5%). Results: Color change values were statistically different after immersion in the beverages; red wine promoted the highest alteration, followed by soft drink and sugar cane spirit, which presented similar results among them and different from saliva. No difference was observed with or without brushing independently of the toothpaste used. At 30th day, specimens exhibited a color change higher than 15th day; after repolishing, the color of the specimens was similar to 15th day. Beverages and brushing negatively influenced the surface roughness. In relation to microhardness, there was no significant difference among groups, regardless of the depth examined. Conclusions: Color change of the composite resin was influenced only by the beverages and brushing did not affect the analyzed property. The repolishing was not sufficient to promote the return of the specimens color to their initial values. The surface roughness was negatively influenced both by the beverage as brushing. For microhardness, the composite resin showed similar results regardless of the beverages used and the presence or absence of brushing in the specimens tested.

A embalagem desempenha uma função crucial na estabilidade dos alimentos. Neste estudo avaliou-se a estabilidade microbiológica de néctar de jabuticaba e caldo de cana pasteurizados (85 ºC/30 s), acondicionados assepticamente em garrafa de polietileno de alta densidade (PEAD) incorporada com agentes inorgânicos microestruturados com Ag/ZnO. Os lotes processados foram estocados a 5 ºC na ausência de luz. Testes físico-químicos, microbiológicos e sensoriais foram conduzidos para avaliar a estabilidade e estimar o tempo de vida útil das bebidas. Médias de notas superiores a 5 (na escala hedônica de 9 pontos) e percentagens de aceitação superiores a 60% foram estabelecidas para estimar o tempo de vida de prateleira das bebidas. Os resultados dos testes físico-químicos para o néctar de jabuticaba variaram de 3,40 a 3,76 para o pH, de 11,0 a 12,5 ºBrix para sólidos solúveis totais, e de 0,52 a 0,76% (m/m) de ácido cítrico para acidez total titulável. Para o caldo de cana, os valores de pH, sólidos solúveis totais e acidez total titulável variaram de 5,10 a 5,37; 14,3 a 24,0 ºBrix e de 0,05 a 0,13%(m/m) ácido cítrico, respectivamente, durante o período do estudo. Para o néctar de jabuticaba, as contagens de mesófilos, psicrotróficos e bolores e leveduras variaram de 1 a 1,5; &lt; 1est a 1; &lt; 1est a 1,3 logUFC/mL respectivamente, durante o período de estocagem. Para o caldo de cana as contagens variaram de &lt; 1est a 4,5 1est a 4,4; 1est a 4,0 logUFC/mL. O néctar de jabuticaba alcançou maior estabilidade microbiológica que o caldo de cana. As médias de notas para sabor, aparência e impressão global obtidas nos testes de escala hedônica variaram entre 6 a 7,1 para o néctar de jabuticaba e 5 e 7,7 para o caldo de cana. O néctar de jabuticaba e caldo de cana permaneceram microbiologicamente estáveis por um período de 120 e 50 dias, respectivamente. Os agentes inorgânicos microestruturados com Ag/ZnO não exerceram influência na estabilidade microbiológica dos dois produtos. / Packaging plays a crucial role in food stability. In this study, the microbiological stability of pasteurized (85 ºC/30 s) jabuticaba nectar and cane juice, aseptically packaged in high density polyethylene (HDPE) bottle treated with silver and zinc oxide (Ag/ZnO), was evaluated. All processed batches were stored at 5 ºC in the dark. Physicochemical, microbiological and sensory tests were conducted to evaluate the stability and estimate the beverage´s shelf life. Average scores greater than 5 (in the 9-point hedonic scale) and percentage of approval greater than 60% were both used as threshold values for estimating the product´s shelf life. As for the nectar, the pH ranged from 3.40 to 3.76; soluble solids from 11.0 to 12.5 ºBrix and titratable total acidity from 0.52 to 0.76% (w/w) citric acid. The pH values, total soluble solids and titratable acidity of cane juice varied from 5.10 to 5.37; 14.3 to 24.0 ºBrix and 0.05 to 0.13%(w/w) citric acid, respectively, during the storage. For nectar, counts of mesophiles, psychrotrophs and molds and yeasts ranged from 1 to 1.5; &lt; 1est to 1; &lt; 1est to 1.3 logCFU/mL, respectively, during the storage period. For the cane juice the counts ranged from &lt; 1est to 4.5; &lt;1est to 4.4; &lt;1est to 4.0 logCFU/mL. Jabuticaba nectar achieved longer microbiological stability than cane juice. The mean scores for flavor, appearance and overall impression obtained in the nine-point hedonic scale tests ranged from 6 to 7.1 for jabuticaba nectar and 5 and 7.7 for cane juice. Nectar and cane juice remained microbiologically stable for 120 and 50 days, respectively. The Ag/ZnO microstructured inorganic agents had no influence on the microbiological stability of both products.

O presente trabalho teve como objetivo estudar o comportamento de três linhagens de leveduras, sendo duas da espécie S. cerevisiae, (Y-904 e CAT) e uma da espécie S. bayanus, (EC) em duas temperaturas de fermentação 20 e 32 °C, usando dois meios, YEPD (meio controle) e caldo de cana-de-açúcar clarificado. As fermentações foram realizadas em câmara de BOD, estático, em frascos de erlenmeyer, com 200 mL de meio e 1 g de fermento seco. A concentração de açúcar foi padronizada para 150,0 g L-1 de ART (açúcares redutores totais) e 15,2 °brix, nos ensaios que se utilizou o caldo de cana como substrato. As fermentações que se utilizou apenas o caldo de cana foram realizadas em balões de cinco litros, em ambas as temperaturas, nas quais as três linhagens de levedura foram avaliadas, através da análise cromatográfica do destilado. Para a obtenção dos destilados foi montado em laboratório um destilador feito totalmente de vidro. Nos ensaios que se utilizou o meio controle e o caldo de cana nas duas temperaturas de fermentação, as leveduras foram avaliadas quanto ao crescimento celular, o açúcar residual e o teor alcoólico. As amostras dos destilados provenientes das fermentações que utilizaram apenas o caldo de cana como mosto, foram avaliadas quanto: ésteres, aldeídos, acidez volátil, álcoois superiores, álcool metílico, furfural, carbamato de etila, acroleína e cobre. As três linhagens ensaiadas apresentaram diferenças estatísticas entre si e entre os meios utilizados. O objetivo não foi a comparação entre as duas temperaturas e sim avaliar o comportamento das linhagens e verificar a possibilidade de se efetuar fermentações a 20 e a 32 °C. Pela análise cromatográfica alguns componentes voláteis como ésteres, aldeídos, acidez volátil, álcoois superiores e álcool metílico, apresentaram diferenças estatísticas, isto é, a formação desses compostos foi influenciada pela temperatura e pelas linhagens utilizadas. O teor de ésteres aumentou com o decréscimo da temperatura para S. bayanus. A acidez volátil aumentou com o acréscimo da temperatura, assim como ocorreu com a formação de álcoois superiores e de álcool metílico que foi mais elevada a 32 °C do que a 20 °C. Enquanto que outros componentes como: furfural, carbamato de etila, acroleína e cobre não apresentaram diferenças em relação a variação da temperatura ou pelas leveduras utilizadas. / The present work had the aim of studying the behavior of three yeast strains, considering two from Saccharomyces cerevisiae species (Y-904 and CAT) and one from Saccharomyces bayanus species (EC), in two fermentation temperatures, 20 and 32 C, utilizing two mediums, YEPD (control medium) and clarified sugarcane juice. The fermentations were carried out in stable BOD chambers, in bottles of Erlenmeyer, with 200 mL of each medium and 1 g of dried yeast. The sugarcane concentration was standardized to 150g/L of ART (total reductor sugar) and to 15,2 °brix in the essay that was used the sugarcane juice as medium. The fermentations that were used only the sugarcane juice were carried out into 5 liters balloons capacity, in both temperatures, where the three yeasts strains were evaluated through chromatography analysis of the distillates. In order to obtain the distillates, it was built a all-glass distillation apparatus. The yeasts were analyzed as the cell growth, the residual sugar and the alcoholic concentration at the essays which were used the control medium and the sugar cane juice in both temperatures. It was evaluated esters, aldehydes, acidity, higher alcohols, methyl alcohol, furfural, acrolein and copper in the distillates samples which came from the fermentations that used only the sugarcane juice as wort. The three yeast strains showed differences between each other and between the mediums. The aim of this study was not to compare the results between the temperatures, but it was to evaluate the behavior of the strains and find out the possibility of making fermentations at 20 and 32°C. The chromatography analysis showed statistical differences from volatile compounds as: esters, aldehydes, acidity, higher alcohols and methyl alcohol. These results show that the formation of these compounds was influenced by temperature and by the yeats strains used. The content of esters increased when temperature decreased for S. bayanus. The acidity increased when the temperature also increased, the same occurred with higher alcohol formation and methyl alcohol formation. The methyl alcohol formation was higher at 32 C than 20 °C. The others compounds as: furfural, ethyl carbamate, acrolein and copper did not show differences related to the temperature variation and the yeasts strains used.

Os benefícios à saúde oferecidos pelos leites fermentados probióticos podem ser ampliados pela adição de polpa de frutas vermelhas uma vez que estas apresentam reconhecidas propriedades funcionais. Ácido elágico e elagitaninos presentes nas frutas apresentam função fisiológica e metabólica na alimentação. Porém, a estabilidade destes compostos bioativos em produtos probióticos durante armazenamento refrigerado ainda não foi estudada. Sendo assim, este projeto tem por finalidade investigar o comportamento do ácido elágico em bebidas lácteas simbióticas suplementadas com L-triptofano e polpa de frutas vermelhas durante armazenamento refrigerado. O estudo foi realizado através de um delineamento experimental do tipo simplex centróide para modelagem de misturas. Foram preparadas 16 bebidas lácteas divididas em duas diferentes matrizes de ensaios segundo: (i) enriquecimento ou não da bebida láctea com triptofano e (ii) composição em frutas vermelhas do preparado de frutas. As amostras de bebida láctea foram avaliadas quanto as suas características físico-químicas (pH, reologia e atributos de cor), microbiológicas, microestrutura e quanto ao teor de ácido elágico. As bebidas lácteas apresentaram reduzidas pós-acidificação sem variações significativas para as bebidas contendo triptofano. As mesmas bebidas apresentaram melhora significativa na viabilidade da bactéria probiótica Lactobacillus acidophilus ao longo do período estudado. Os parâmetros de cor se mostraram estáveis nas bebidas lácteas durante o armazenamento refrigerado. O comportamento reológico das bebidas lácteas foi semelhante e adição de polpa de fruta proporcionou um efeito benéfico na consistência e viscosidade dos produtos. Foi possível estimar o conteúdo ótimo de ácido elágico nas bebidas lácteas simbióticas pela metodologia de superfície de resposta. As bebidas lácteas adicionadas de polpa de morango apresentaram maiores teores de ácido elágico, principalmente nas bebidas contendo triptofano. As fotos micrografias obtidas através da microscopia eletrônica de varredura permitiram avaliar a interação dos componentes da matriz das bebidas lácteas simbióticas de forma satisfatória. / The health benefits provided by probiotic fermented milk can be enhanced by the addition of native fruit pulp as they have recognized functional properties. Ellagic acid and ellagitannins present in fruis show physiological and metabolic function. Identification of these bioactive compounds in the formulation of symbiotic fermented beverages supplemented with L-tryptophan and red fruit pulp is innovative. Therefore, this project aimed to investigate the behaviour of ellagic acid in symbiotic lactic beverages supplemented with L-tryptophan and red pulp fruits during cold storage. Through an experimental simplex centroid design for mixtures modelling 16 beverages were prepared divided into four different matrices according to : (i) enrichment or not with L-tryptophan and (ii) composition of the prepared fruit pulp. The responses to be evaluated will be defined between the physical-chemical (pH, rheology and colour attributes), microbiological, microstructure and the amounts of ellagic acid. Lactic beverages have shown low post-acidification without significant variations for beverages containing tryptophan. The improvement in the viability of the probiotic bacteria Lactobacillus acidophilus throughout the study period was achieved. The colour parameters were stable during cold storage. The rheological behaviour was similar and the addition of red fruit pulps provided a beneficial effect on the consistency and viscosity of the products. It was possible to estimate the optimum amount of ellagic acid throughout response surface methodology. Lactic beverages added with strawberry pulp have had higher amounts of ellagic acid, particularly when L-tryptophan was supplemented. The photomicrographs obtained by scanning electron microscopy allowed adequate assessing the interaction of the matrix components of symbiotic lactic beverages.