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The multibillion dollar agricultural industry is an important part of the United States economy, and the management of factors that affect crop and human health is imperative to maintaining this economic sector. The fungi Botrytis cinerea, Fusarium pallidoroseum, and Fusarium moniliforme are the causative agents of several plant diseases and can cause significant crop loss both before and after harvest in commodities such as strawberries, lettuce, citrus, and grains. Fungicides are employed to control these phytopathogens, but the use of these chemicals has led to an increase in fungicide resistance and may negatively affect the environment and human health. In addition to plant pathogens, foodborne pathogens also have a substantial impact on the agricultural industry. Foodborne disease outbreaks involving Listeria monocytogenes, Salmonella, and Escherichia coli O157:H7 not only cause considerable economic losses, but can also result in devastating health problems for consumers. The increase in fungicide resistance and number of produce-related foodborne disease outbreaks warrants investigation into additional methods of microbial control for use in the agricultural industry. Many bacterial species, including Lactic Acid Bacteria (LAB) and Bacillus species, produce antifungal and antimicrobial compounds, thus the use of biological control agents pre- and postharvest could augment current methods of pathogen management. The purpose of this study was to screen 22 bacterial isolates for inhibitory activity against the fungal phytopathogens Botrytis cinerea, Fusarium pallidoroseum, and Fusarium moniliforme and the foodborne pathogens Listeria monocytogenes, Salmonella, and Escherichia coli O157:H7 in vitro, then evaluate antimicrobial efficacy of select isolates against the foodborne pathogens on fresh produce. To evaluate antifungal activity, the bacterial isolates were individually spot-inoculated onto Tryptic Soy Agar, Potato Dextrose Agar, or MRS agar, depending on isolate growth requirements and then a plug of fungal-colonized agar was placed onto the center of the isolate-inoculated plate. Plates were incubated at 24°C for 10 days; fungal growth was evaluated daily, beginning on Day 3. Nine of the 22 isolates screened inhibited all three fungi; inhibition by these isolates ranged from 51-62% for B. cinerea, 60-68% for F. pallidoroseum, and 40-61% for F. moniliforme. Isolates were also screened for biosurfactant activity using the drop-collapse test. Biosurfactant production was detected in seven of the nine isolates. Bacillus megaterium, Bacillus coagulans, Bacillus thuringiensis BT2 and three Bacillus amyloliquefaciens isolates demonstrated strong biosurfactant activity and suppression of all three fungi, and therefore are recommended for further study. Antimicrobial activity of the isolates was assessed using two methods: LAB isolates were screened using a seeded-overlay method and all other isolates were evaluated by spot inoculating the isolate on pathogen-seeded TSA. Three LAB isolates and six Bacillus isolates suppressed L. monocytogenes, Salmonella, and E. coli O157:H7 in vitro. Based on the results of the screening, three LAB isolates—Lactobacillus plantarum, Pediococcus acidilactici, and Pediococcus pentosaceus—were selected for further evaluation and use in challenge studies on fresh produce. The role of organic acids in pathogen inhibition was evaluated by incubating L. monocytogenes, Salmonella, and E. coli O157:H7 cultures in the cell-free supernatant (CFS; pH 3.81-4.27) or the neutralized cell-free supernatant (pH adjusted to 6.5 -7.0) of each isolate. When neutralized, the antimicrobial activity of the CFS of the three LAB isolates was greatly diminished, illustrating the role of lactic acid in the inhibition of pathogen growth. To assess antimicrobial efficacy on Iceberg lettuce, a cocktail of the three LAB isolates (7-8 log CFU/g) was sprayed onto lettuce spot-inoculated with L. monocytogenes (2-3 log CFU/g); lettuce was incubated at 10°C for 14 d. L. monocytogenes levels were 1.84 log lower on LAB-treated lettuce than on untreated lettuce at the end of incubation. Because the LAB cocktail suppressed the growth of L. monocytogenes on lettuce, testing on fresh produce continued using DF1, which was a powdered product comprised of the three LAB isolates and media components. Because DF1 caused substantial browning of Iceberg lettuce after 2 d, Gala apples were chosen to evaluate the antimicrobial activity of DF1 against L. monocytogenes, Salmonella, and E. coli O157:H7. The effect of DF1 on L. monocytogenes, Salmonella, and E. coli O157:H7 on Gala apples was determined by spraying a Gala apple spot-inoculated with pathogen (6-7 log CFU/plug) with approximately 3 mL of a 20% DF1 solution, then incubating at 20°C for 5 d. After 5 d incubation, L. monocytogenes, Salmonella, and E. coli O157:H7 levels on DF1-treated apples were approximately 4, 2, and 2 log higher than the control, respectively. Based on the results of these experiments, DF1 is not the optimal formulation for the biocontrol of foodborne pathogens on fresh produce. This study identified several bacterial isolates with potential for use in the biocontrol of plant and foodborne pathogens. Further investigation is required to assess possible use in the agricultural industry, including characterization of bioactive compounds, optimization of biocontrol product formulation, and evaluation of the commercial viability of the biocontrol product

Food security is essential amongst households as it enables consumers to live a healthy and productive life. Determining factors for households to be classified as food secure is the availability, accessibility and utilisation of food in a sustainable manner as food availability and accessibility alone are not enough for households to be food secure. The food utilisation aspect of food security, which includes the type of food consumed, food knowledge and food handling practices, should therefore also be considered as it determines the quantity, quality and safety of food. High percentages of the population in the Northern Cape province of South Africa has inadequate access to food, is unemployed, poorly educated, and living below the poverty line. All these aspects contribute to food insecure households. A specific community within the Northern Cape was chosen to do research regarding households‟ food security status, namely the employees of the Vaalharts Irrigation Scheme (VIS). The VIS was approached as consumers at the Vaalharts region indicated a need to improve their awareness regarding hygiene and the consumption of adequate and a variety of food. Objective: The aim of the study was to explore employees of the VIS‟ food security status. The focus of the study was therefore on consumers who earn a stable income. As food access and utilisation are fundamental aspects in determining household food security, self-production activities, food knowledge, and consumption were investigated. Methodology: A quantitative method was used to explore the study population‟s food security status with the use of a purposive sample and interviewer-administered questionnaires (n=162). The study was conducted at the premises of VIS over a period of three weeks. Data analysis was performed by Statistical Consultation Services of the North-West University using the Statistical Program for Social Sciences. Results: Nearly one third (29.6%) of respondents‟ households were classified as food secure while almost half (48.8%) of households were at risk of being food insecure and 21.6% were food insecure. Only a few respondents were engaged in self-production activities with limited space being the main problem. Good basic food knowledge was identified amongst respondents and food secure respondents had better food knowledge than food insecure respondents. Food insecure respondents mainly consumed monotonous diets consisting of maize meal, chicken and milk. There was a tendency that at risk respondents consumed a larger variety of food high in protein which is also more expensive. Overall food secure respondents consumed a larger variety of food groups. There was an additional problem identified. Respondents at risk as well as food insecure respondents either do not use their income effectively or do not use resources bought, such as food optimally. Conclusions: Although all of the respondents were employed, and earned an income, only a small percentage were food secure. According to the findings, basic food knowledge, food consumption practices and income have an influence on respondents‟ food security status. These aspects which had an influence on respondents‟ food security status should be addressed especially amongst at risk and food insecure respondents through food related healthcare information. Food related healthcare information should be made available to the community via several sources (schools, clinics, churches) to improve consumers‟ awareness regarding aspects which negatively influence their food security status as well as how to improve it. / Master of Consumer Sciences, North-West University, Potchefstroom Campus, 2015

Food security is essential amongst households as it enables consumers to live a healthy and productive life. Determining factors for households to be classified as food secure is the availability, accessibility and utilisation of food in a sustainable manner as food availability and accessibility alone are not enough for households to be food secure. The food utilisation aspect of food security, which includes the type of food consumed, food knowledge and food handling practices, should therefore also be considered as it determines the quantity, quality and safety of food. High percentages of the population in the Northern Cape province of South Africa has inadequate access to food, is unemployed, poorly educated, and living below the poverty line. All these aspects contribute to food insecure households. A specific community within the Northern Cape was chosen to do research regarding households‟ food security status, namely the employees of the Vaalharts Irrigation Scheme (VIS). The VIS was approached as consumers at the Vaalharts region indicated a need to improve their awareness regarding hygiene and the consumption of adequate and a variety of food. Objective: The aim of the study was to explore employees of the VIS‟ food security status. The focus of the study was therefore on consumers who earn a stable income. As food access and utilisation are fundamental aspects in determining household food security, self-production activities, food knowledge, and consumption were investigated. Methodology: A quantitative method was used to explore the study population‟s food security status with the use of a purposive sample and interviewer-administered questionnaires (n=162). The study was conducted at the premises of VIS over a period of three weeks. Data analysis was performed by Statistical Consultation Services of the North-West University using the Statistical Program for Social Sciences. Results: Nearly one third (29.6%) of respondents‟ households were classified as food secure while almost half (48.8%) of households were at risk of being food insecure and 21.6% were food insecure. Only a few respondents were engaged in self-production activities with limited space being the main problem. Good basic food knowledge was identified amongst respondents and food secure respondents had better food knowledge than food insecure respondents. Food insecure respondents mainly consumed monotonous diets consisting of maize meal, chicken and milk. There was a tendency that at risk respondents consumed a larger variety of food high in protein which is also more expensive. Overall food secure respondents consumed a larger variety of food groups. There was an additional problem identified. Respondents at risk as well as food insecure respondents either do not use their income effectively or do not use resources bought, such as food optimally. Conclusions: Although all of the respondents were employed, and earned an income, only a small percentage were food secure. According to the findings, basic food knowledge, food consumption practices and income have an influence on respondents‟ food security status. These aspects which had an influence on respondents‟ food security status should be addressed especially amongst at risk and food insecure respondents through food related healthcare information. Food related healthcare information should be made available to the community via several sources (schools, clinics, churches) to improve consumers‟ awareness regarding aspects which negatively influence their food security status as well as how to improve it. / Master of Consumer Sciences, North-West University, Potchefstroom Campus, 2015

Thesis (M.P.P.A.)--University of Massachusetts Amherst, 2008. / Includes bibliographical references (p. 56-59).

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 209-219). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 209-219). Also available on the Internet.

Animal foraging behavior is shaped by patterns and processes that operate on several temporal and spatial scales. In chapter 1, I briefly review the meaning and importance of temporal and spatial scales. In chapter 2, I examine the foraging behavior of the Long Jawed spider (Tetragnatha elongata). In North Carolina, the spider exhibits the counter intuitive behavior of relocating its web daily in rich habitats, but rebuilding its web on the same site for many days in a row in poor habitats. I test a risk-sensitive foraging model of this behavior, but its predictions were not met. I develop an alternative hypothesis to explain the behavior of Long Jawed spiders: that the higher density of spiders in rich habitats results in more frequent interactions between spiders, and that these interactions provoke spiders to relocate more often in rich habitats. I report the results of density-reduction experiments, which corroborate my hypothesis. In chapter 3, I examine the foraging and storing strategy of the Eastern Gray Squirrel (Sciurus carolinensis). The squirrels ate most of the white oak (WO) acorns, and buried most of the red oak (RO) acorns, confirming my prediction. I also present the results of an experiment designed to reveal whether squirrels used tannin and/or fat content of acorns to distinguish between acorns of different species. The results of this experiment were inconclusive. In another experiment, I buried a large number of acorns, and assessed samples of acorns retrieved at intervals through the fall/winter season. I found that tannin levels in RO acorns did not decline during their interment, rendering an alternative hypothesis untenable. Further, I confirmed an earlier assumption: stored WO acorns do suffer more insect damage than RO acorns. I hypothesize that the storing and foraging strategy of squirrels may affect the distribution of oaks, and review evidence from the literature that supports this hypothesis. Finally, I argue that Clark's Nutcracker (Columbiana nucifraga) may employ the same strategy as it forages for pine seeds, and again review evidence from the literature to support this hypothesis. (Abstract shortened by UMI.)

MA RESEARCH REPORT Prepared for the Department of Development Studies, University of the Witwatersrand, Johannesburg June 2016 / This research argues that food sovereignty offers a plausible alternative to the current unjust, unsafe and unsustainable food system in South Africa. In addition, it argues that food sovereignty provides important solutions to hunger and the brutalities of the food system which current policies and interventions fail to address. Food sovereignty is an ideal that originated amongst a peasant movement in the global South. This ideal and framework to address hunger has since evolved and spread to international movements, and is making great strides in advocating for change in the current broken food system. Food sovereignty has lately been adapted in South Africa as a grassroots led initiative promoted by the nascent South African Food Sovereignty Campaign (SAFSC). This research uses the SAFSC as a case study to explore food sovereignty alternatives in South Africa. It does this by using in-depth interviews and participant observation in the campaign to draw out understandings of food sovereignty particular to South African activists. It further assesses tactics and strategies the SAFSC uses, and compares these to current state, business and civil society organisations’ solutions to show how a more grassroots-led approach, using the food sovereignty framework, has the potential to address the roots of hunger. These roots of hunger are shown to be at the corporate food regime level, as has been indicated by the literature and confirmed in this research. As food sovereignty is pursued by various actors in South Africa it provides important examples of approaches by which power in the food system can be reclaimed to benefit the majority instead of a few elites, as is currently the case.

Thesis (Masters Diploma (Food Technology)) -- Cape Technikon, Cape Town, 1992 / Kakamas peaches and Bulida apricots were heat processed in transparent and aluminium laminated plastic bags and compared with fruit heat processed in standard cans. Heat processing conditions were optimized to produce acceptable processed products. Appropriate chemical and microbiological properties of all treatments as well as sensory quality of peaches were investigated. Although rectifiable disadvantages such as texture softening and fading of colour appeared during storage, peaches and apricots were successfully heat processed in aluminium laminated pouches. Heat processed peaches had a maximum storage life of 12 months and apricots 6 months when stored at ambient temperature in aluminium laminated pouches.