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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Application of innovative beverage fermentation technology to plums and selected berries

Williams, Gareth January 2016 (has links)
Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2016. / This study focused on alcoholic fermented fruit beverages that were produced from various types of fruit, value addition and thus potentially increasing the diversity of commercially available fruit wines. Non-grape alcoholic fermented fruit beverages is a complex mixture of water, alcohol, and other components, that are either initially present in the fruit, or are formed during the fermentation process. The evaluation of wine and similar fermented products quality is important for manufacturers and consumers. The routine analysis of alcoholic fermented fruit beverages acts as an important tool that is useful for wine classification, quality control and sensory evaluation. Therefore, the aims of this study were (1) to measure methanol, ethanol, titratable acidity, objective colour, total soluble solids and sensory profile as a function of yeast strain and percentage pulp in order to adapt existing technologies toward producing new fermented fruit beverage products using plums, an under-utilized agricultural produce; and (2) to measure methanol, ethanol, titratable acidity, objective colour, total soluble solids and sensory profile as a function of yeast strain, pulp percentage and sugar levels in order to adapt existing technologies toward producing new fermented fruit beverages based on red and white wine styles, while applying the technology developed in the first part of the study using red-fleshed plums, blueberries and blackberries. The independent variables (ID) were yeast strains (1) Saccharomyces cerevisiae VIN13, (2) Saccharomyces cerevisiae NT116, and (3) Saccharomyces bayanus N96, with formulations containing percentage pulp concentrations at (40%, 50% and 60%). The dependent variables (DV) constituted key quality parameters for white and red wine style, namely methanol, ethanol, titratable acidity, objective colour, total soluble solids, pH and sensory profile were measured. The optimal combination of independent variables was ascertained and in terms of the overall consumer response, for the red-fleshed plum beverage sample treatment N 96, 60% pulp showed the highest preference amongst consumers. In terms of the other dependent variables, namely methanol, ethanol, titratable acidity, objective colour, total soluble solids, pH and sensory profiles of alcoholic fermented fruit beverages based on white and red wine styles. The processing conditions developed and applied in this study towards the development of alcoholic fermented beverages utilizing plums and selected berries demonstrated ways of improving the utilization of fruit commodities by developing niche products. Hence, the development of alcoholic fermented beverages utilizing (plums and selected berries) showed potential for micro agro-industries, as well as the impact on its potential role in employment creation and income generation.
2

Soft drink consumption among grade 11 and grade 12 learners at a secondary school in Gauteng, South Africa

Rajan, Amy January 2012 (has links)
Thesis (MPH) -- University of Limpopo, 2012. / Background: Over the last few decades, soft drink consumption has been steadily increasing especially at an alarming rate among adolescents. Soft drinks have been associated with positive energy intake. An unhealthy diet along with a lack of physical activity is a major risk factor for health problems like overweight and obesity, cardiovascular diseases and diabetes. Children and adolescents are becoming very susceptible to the development of NCDs due to an increase in consumption of heavily processed and highly caloric foods, leading to early onset of morbidity. Aim of the study: To investigate soft drink consumption among grade 11 and 12 learners at a secondary school in Gauteng, South Africa Methods: A quantitative descriptive survey was conducted among 382 learners (grade 11 and 12) of Liverpool secondary school. A self-administered questionnaire was used to collect data. STATA version 10 was used for data entry and analysis. Results: All learners who participated in the survey reported that they consumed soft drinks over the past 12 months. Out of the 382 learners, only 55 (14.4%) were non-frequent consumers. Carbonated drinks were the most commonly consumed (73.6%). Factors such as frequent snacking (p=0.042), frequent fast food consumption (p=0.001) and easy availability of soft drinks (p=0.00) positively influenced the consumption of soft drinks. Over 55% of the learners had very poor knowledge about the health effects caused by increased consumption of soft drinks. Conclusion: In line with the high consumption of soft drinks, the level of awareness of the health effects of these unhealthy dietary practices among the learners in this study is very poor. Interventions to improve good or healthy dietary habits have to be started both at the home and school level.
3

Pre-meal beverage consumption affects hunger, satiety and energy intake

Welcher, Robin M. January 2009 (has links) (PDF)
Thesis PlanA (M.S.)--University of Wisconsin--Stout, 2009. / Includes bibliographical references.
4

Development of methods for direct and simultaneous determination of alcohol and extract content of wines, cordials, and beers utilizing an ultrasonic principle

Aulik, David James, January 1971 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
5

Young children's knowledge and attitudes toward alcohol and two other commonly consumed beverages

Raycher, Jayne Marie. January 1993 (has links)
Thesis (M.S.)--University of Wisconsin-Madison, 1993. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 44-48).
6

Alcohol and emotions potential dose effects and mechanisms of neuromuscular control /

Donohue, Keith F. Lang, Alan R. January 2003 (has links)
Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Alan R. Lang, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Oct. 1, 2003). Includes bibliographical references.
7

Microencapsulation and supply of Bifidobacterium lactis DSM 10140 in fermented traditional African beverages

Kokott, Shaun January 2004 (has links)
Thesis (MTech (Food Technology))--Cape Technikon, 2004 / Probiotic foods are intended to supply selected viable microorganisms, for example Lactobacillus acidophilus and Bifidobacterium, to consumers. These organisms, when consumed at the daily intake of 108 , provide benefits beyond basic nutrition. Probiotic (AB) foods generally include fermented dairy products such as yoghurts and cheeses, targeted at the upmarket consumer. However, due to technical problems associated with the foods and the organism, viable Bifidobacterium rarely occur in AB foods. The principle aims of this study were to develop a suitable delivery system for Bifidobacterium to the consumer, and to supply these living organisms in the affordable traditional fermented African beverages, amasi and mahewu. This would provide the benefits of probiotics to the rural African consumer, where malnutrition and gastrointestinal diseases occur. The organism selected for this study was Bifidobacterium lactis DSM 10140, commonly associated with AB starter cultures for yoghurts. The delivery system selected was microencapsulation of B. lactis using a mixture of the generally recognised as safe (GRAS) edible gums, gellan and xanthan. Supply vehicles for the microcapsules to the consumer were amasi and mahewu. Prior to microencapsulation, rheological studies were undertaken to determine whether the gellan-xanthan gum mix would provide a suitable support matrix for microencapsulated B. lactis. This was done using a Paar Physica MGR 300 rotational rheometer with a cone plate 50-2 measuring system. Results indicated that the hydrated gellan-xanthan gum mix behaved as a non-Newtonian material, and the flow curve fitted well to the Herschel-Bulkley model. This demonstrated that the gel was a relatively viscous material with solid properties. The average yield stress of the gel was 1.515 Pa, indicating that the gel was stable, and at lower stresses would behave as a solid. The gel mix would be disrupted by shear stresses associated with mastication and peristalsis. The minimum viscosity of the gel was constant at temperatures between 46°C - 61°C. It was concluded from these data that the gel was suitable for microencapsulation and that microcapsules should only be included in soft foods, which do not require chewing. Temperatures associated with microencapsulation, at minimum gel viscosities, were not lethal to B. lactis. Bifidobacterium lactis cells were incubated under anaerobic conditions (4% H2, 10% CO2, and 86% N2) at 37°C overnight in 250 ml Tryptone-Yeast-Glucose (TYG) broth, and grown to an 00600 0.9 - 1.1. Cells were harvested and washed for microencapsulation using centrifugation. Microencapsulation of the organism was done using a mono-axial extrusion technique together with a superposed airflow, by manually extruding the aqueous gum I cell mix through a 27.5 G bevelled needle, fitted on to a 10 ml syringe. The resultant microdroplets were hardened by free fall into 0.1 M CaCI2 solution. Microcapsules were separated from the CaCI2 solution by filtration through Whatman No.1 filter paper. All procedures were carried out in a laminar flow hood. Results indicated that the method of microencapsulation used in this study was successful. Using a concentrated inoculum of B. lactis, high numbers (lOglO 11-12 etu.g-1 ) of bacteria were incorporated into the microcapsules. Therefore the daily intake would be provided by 0.1 g microcapsules. The diameter and size distribution of microcapsules were determined by laser diffractometry. This showed a maximum microcapsule diameter of 2.22 mm with 50% (w/v) of the microcapsules having a diameter of < 0.637 mm. Although this represents a considerable size variation, this would not adversely affect mouthfeel of the beverages, as only 0.1 g microcapsules would be required to obtain at least 108 B. lactis in any volume of amasi or mahewu. To enumerate immobilised viable B. lactis, two techniques were compared. These involved the use of either a pestle and mortar, or high power ultrasound (HPUS) (20 kHz, 750 W). Results showed that HPUS was superior to the pestle and mortar technique. A short exposure (15 s) to HPUS disrupted the matrix releasing all entrapped etus, whereas when using the pestle and mortar xiii technique, cells remained partially entrapped in the gel. Therefore the pestle and mortar technique yielded lower cfu values than expected. The survival of microencapsulated B. lactis, in 1 M sodium phosphate buffer, was studied as a possible means of supply of microcapsules to industry for incorporation into foods. Microcapsules were stored in the buffer for 21 days at either 4°C or 22°C. Results showed that cell viability was not significantly reduced (p>0.05) at either temperature after 21 days. Hence this form of storage could be used to deliver viable immobilised B. lactis to the food industry. In order to assess the survival of immobilised B. lactis in the GIT, the microcapsules were incubated at 37°C over a period of 240 min in simulated gastric juice (SGJ) (pH 1.5). Viable counts were performed by sampling at regular intervals. A similar study was done in simulated bile and pancreatic juices (BPJ) (pH 6.5). In SGJ, it was demonstrated that there was a significant reduction (3 log cycles) (p<0.05) of free cells after 240 min. However, this trend was not noted for microencapsulated B. lactis. Therefore, the gellanxanthan gel matrix protected B. lactis from the lethal effect of SGJ. In BPJ, no significant difference (p>0.05) was noted for surviving fractions of both immobilised and free B. lactis. Commercial pasteurised amasi (pH 4.4) and mahewu (pH 3.5) were selected as the supply vehicles for the microencapsulated B. lactis. Known numbers of viable microencapsulated and free B. lactis cells were added to both beverages. For most samples, incubation was at either 4°C or 22°C for 21 days in the presence of atmospheric oxygen. In addition, free cells were incubated anaerobically at 22°C. As oxygen is limiting in the microcapsules, these were not incubated under anaerobic conditions. The survival I shelf-life studies of commercial amasi indicated no significant difference (p>0.05) in survival rate between immobilised and free B. lactis cells. The reduction noted for viable counts of immobilised or free B. lactis cells was approximately 1.5 log cycles. Even so, after 21 days viable immobilised B. lactis (1010 0.1 g'l microcapsules) remained in excess of the daily intake 108 , whereas in the free B. lactis cells, the viable count declined to 106 mr1 . Statistical analyses showed that temperature or oxygen presence had little effect on the survival of both immobilised or free B. lactis cells (p>O.05). In mahewu, decline in viability of cells was observed for most samples. However microencapsulation enhanced cell survival at both 4°C and 22°C when compared to free cells. The decrease in viable B. lactis free cells occurred more rapidly (3 log cycles) in mahewu, than in amasi, at both 4°C and 22°C. Throughout the shelf-life studies it was apparent that viable B. lactis cell numbers did not increase. This was advantageous as metabolites associated with B. lactis growth would have adversely altered the taste of both amasi and mahewu. Sensory evaluation of the traditional fermented African beverages, enriched with either viable immobilised or free B. lactis, was done in order to determine consumer response to the product. An analytically trained 12-member taste panel analysed the beverages for colour, texture, and taste. The triangle taste test procedure was used. No differences were detected with regard to texture, and colour of the fermented beverages containing immobilised B. lactis. However, in the fermented beverages containing free cells, a change in viscosity was noted. There was a significant difference (p<O.05) recorded in flavour for both amasi and mahewu containing free B. lactis cells. In the two fermented beverages enriched with immobilised cells, significant (p<O.05) flavour differences were detected in mahewu. However, this was not observed in the amasi samples containing immobilised B. lactis. Therefore, in order to retain the sensory properties of amasi, B. lactis should be supplied in microcapsules. In mahewu, although flavour differences noted were not unpleasant to the panellists, results from this study indicate that the use of commercial flavoured mahewu should be considered as a supply vehicle for microencapsulated B. lactis. Overall, this study demonstrated that immobilisation of B. lactis in gellan-xanthan gum is possible. Microcapsules produced contained high numbers of viable B. lactis, and were suitable for incorporation into soft foods. The gel matrix significantly protected viable cells from harsh conditions associated with SGJ. Although the surviving fraction of immobilised cells, when compared to free cells, was not improved in amasi samples, it is recommended that for technological reasons associated with production of amasi, microencapsulation should be used. In mahewu, microencapsulation enhanced B. lactis survival at both 4°C and 22°C. Therefore immobilisation of B. lactis in mahewu is necessary in order to maintain the daily intake. Immobilised B. lactis should be incorporated into both beverages after fermentation, and pasteurisation.
8

A comparative analysis of the advertising objectives and strategies used by major brands of soft drinks in the Hong Kong market by Lam Man-Fai.

January 1972 (has links)
Summary in Chinese on endpapers. / Thesis (M.B.A.)--The Chinese University of Hong Kong. / Bibliography: l. 106-108.
9

An in vitro study on the immunotoxicity of South African beer.

Neethling, Michelle. January 2008 (has links)
<p>&quot / Traditionally brewed beers are of cultural and economic importance to many African nations. The presence of mycotoxins in African beer is a topic that needs to be addressed, since most African countries have a climate of high humidity and temperature that favours the growth of moulds. Mycotoxins challenge not only the health of animals and humans, but also the economy, especially in underdeveloped countries where contamination is most likely. Literature proves that mycotoxins depict various effects on the immune system including immunotoxicity. Beer analysis is therefore of utmost importance in order to evaluate organoleptic characteristics, quality, nutritional value as well as safety. The aims of this study involve the analysis and comparison of traditional and commercial beer in terms of physical characteristics, mycotoxin concentrations as well as effects on specific immune pathway biomarkers in order to elucidate possible immunotoxicity...&quot / </p>
10

The study of corrosion behaviour of Al, Cu and Zn in some commercial beverages by chemical and electrochemical

Wang, Xiaonan January 2012 (has links)
The corrosion behaviour of pure copper, zinc and aluminum in selected commercial beverages was studied. Experiments were also conducted in the presence of citric and phosphoric acid to investigate their role in the corrosion process in these beverages. Two experimental approaches were used to investigate the corrosion behavior: a chemical method in which the dissolved metal concentration was measured after immersion of a sample in a beverage and an electrochemical method using the Tafel extrapolation technique. The metal surfaces were also examined by SEM/EDX after the immersion tests and electrochemical polarization. Among the important conclusions from this research are that the order in which the various beverages affect the corrosion rate as evaluated by Tafel extrapolation of the polarization curves did not agree with the order based on measurement of the dissolved metal concentration as determined by the immersion tests except when a 1- day immersion test was used for Al. The dissolved Al, Zn and Cu concentrations obtained from short-term immersion tests differed from those measured in long-term tests, although the same ranking of the corrosiveness of the seven soft drinks was obtained after 1- and 3- day immersion tests. These discrepancies likely stem from the complicated dynamics of the corrosion of these metals and the various physical, chemical and electrochemical processes that take place in these beverages. No simple correlation was found between the beverage properties and composition and the dissolved copper, zinc and aluminum concentrations after immersion, whether based on short-term or long-term tests. However, the corrosion rate of copper in the 7 soft drinks as determined by the Tafel extrapolation method was found to depend on the pH. Uniform corrosion was observed in all iv cases except for Al immersed in Gatorade. Pitting cavities were observed on the surface of Al after both the 5-day immersion test and Tafel polarization measurements. Of the beverages considered in this study, Gatorade was consistently found to be the most corrosive for the three test metals.

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