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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.
31

The View from the Table: An Analysis of Participant Reactions to Community-Based Dialogues on Food and Justice

Turner, Jennifer 30 July 2013 (has links)
While Portland, Oregon's sustainable food movement wins accolades for explicitly situating itself in opposition to the industrialized global food system, it often fails to address systems of oppression that are reproduced within the alternative agri-food movement itself. This demonstrated aversion towards the messy, complex, contingent nature of the social world reflects larger processes of "de-politicization" of the overall sustainability agenda, which leads to the favoring of technological and/or spatial solutions that may undermine the social equity and justice dimensions of the "triple bottom line." This thesis focuses on an action research project involving a series of community dialogues that provided participants with a common language and understanding necessary to interrogate issues of race and class in Portland's sustainable food movement while developing visions for possible futures. Dialogue participants may find new ways to communicate, learn, identify common goals and best practices, and potentially network, collaborate and/or co-produce transformative anti-oppression strategies that integrate into the sustainable food movement. By asking those vested in the sustainable food movement to interrogate dimensions of anti-oppression consciousness, the movement becomes fortified with voices better equipped to envision sustainability within a more political and contingent reality that recognizes conflicts of power, and less resembling an idyllic, utopian, and ultimately impossible sustainability. This thesis delivers some preliminary outcomes following the dialogue series by describing and reflecting on the series' implementation and processes, and reflecting on its impact on participants' anti-oppression consciousness in the context of food and sustainability, while discussing possibilities for future scholarship.
32

Inosine 5’- monophosphate derived umami flavor intensity of beef determination by electrochemistry and chromatography

To, Kezia Virellia 09 August 2022 (has links) (PDF)
The umami sensation contributes to beef flavor and acceptability. Inosine 5’- monophosphate (IMP) was the most abundant nucleotide in meat known to impart umami taste which thus far had been overlooked in meat flavor studies. The objectives of this study were to determine the umami taste threshold of inosine 5'-monophosphate (IMP), the effects of spiking IMP on the sensory descriptive attributes of various USDA graded beef strip steaks, and to differentiate beef by IMP content using electrochemistry. USDA Prime, Choice, and Select steaks were spiked with 0.3 and 0.6 mM IMP and analyzed chemically and organoleptically. Liquid chromatography-mass spectrometry and descriptive sensory analysis showed no changes in IMP content and the perceived sensory attributes of steaks. The electrochemical approach successfully differentiated IMP concentrations in aqueous solutions when present at 0.5 mM or above and was able to recognize the presence of nucleotides in the meat extract.
33

Saponin Removal from Quinoa by Abrasion Processing

Lundberg, Luke 01 June 2019 (has links) (PDF)
Quinoa is coated with a thin layer of saponins, glycosylated triterpenoids, that produce a bitter flavor when consumed. The average saponin content in commercial varietals from Bolivia average around 2.7% saponins and organoleptic testing shows the threshold for noticing a bitter flavor is below 0.12% (Medina-Meza et al., 2016). Current industrial processing methods use a combination of abrasion and turbulent water flow to remove saponin. This study will address the following research question: How will grain-to-grain and grain-to-surface abrasion affect the processing time to remove saponin from quinoa? In particular, can effective saponin removal be achieved in less than 10 minutes without washing with water? Three different laboratory scale systems for generating grain-to-grain abrasion alone and in combination with grain-to-surface abrasion were constructed. Preliminary studies using mass balance and visual observation found the tubular system removed 4.45% of the quinoa mass in saponin containing fractions compared to the conical system (1.33%) and fluidized bed (0.62%). After preliminary studies, a saponin estimation method was adapted and the conditions of the tubular system were determined. A randomized experiment was carried out in triplicate at three levels of time (5, 10, and 15 minutes) and mass (200, 300, and 400 grams). The effect of surface roughness in the tubular system was also evaluated. The samples were collected and saponin content in each sample was quantified using the adapted method. The saponin levels were compared to commercially processed quinoa in the market. The processing conditions of 15 minutes at an input mass of 300 grams yielded the lowest saponin level of 0.19%. The four processing conditions of (10 minutes/200 grams, 10 minutes/400 grams, 15 minutes/200 grams and 15 minutes/300 grams) were statistically different (p The tubular system showed promise for reducing process time and saponin content in commercially processed quinoa without washing. However, further experimentation is needed for industrial implementation. The system would provide the industry with a sustainable process with better saponin removal capacity.
34

Modifying the Mineral Profile of Crickets (<i>Acheta Domesticus</i>) Using a Supplemented Diet

Maxwell, Rhianne Morgan Le 01 August 2018 (has links) (PDF)
Captive insectivores may consume invertebrates as all, or part of their overall diet. The challenge with feeding captive insectivores involves the limited number of invertebrate species that are commercially available, and the lack of key nutrients provided by these insects. Among these insects, a naturally occurring low concentration of calcium and an inverse calcium to phosphorus ratio may put insectivores at the risk of developing hypocalcemia. A strategy to correct this nutrient imbalance involves supplementing the insect diet with high concentrations of targeted nutrients – a term referred to as gut-loading. Current industry guidelines recommend feeding a supplemented diet for 48 to 72 h before offering the insect to an insectivore. In the present study, the mineral profile of adult crickets (Acheta domesticus) offered a maintenance diet (1.58% Ca, DMB) are compared to crickets offered a supplemented diet (11.32% Ca, DMB) over 120 h. The supplemented diet produced a cricket with significantly higher calcium concentration compared to the maintenance diet. The calcium concentration of crickets offered the supplemented diet was highest at 48 h (0.63%), but did not achieve a 1:1 Ca:P ratio nor meet the lowest reported nutrient requirements of carnivorous reptiles, omnivorous reptiles, or an insectivorous bird at various life stages. Although the supplemented diet improved the whole body calcium concentration in feeder crickets, the crickets do not provide adequate calcium, iron, or manganese to meet the requirement of insectivores. As evidenced by the current study, the supplemented crickets are not recommended to serve as the sole source of nutrition for an insectivore.
35

Latent Variable Methods: Case Studies in the Food Industry

Nichols, Emily 10 1900 (has links)
<p>Accommodating changing consumer tastes, nutritional targets, competitive pressures and government regulations is an ongoing task in the food industry. Product development projects tend to have competing goals and more potential solutions than can be examined efficiently. However, existing databases or spreadsheets containing formulas, ingredient properties, and product characteristics can be exploited using latent variable methods to confront difficult formulation issues. Using these methods, a product developer can target specific final product properties and systematically determine new recipes that will best meet the development objectives.</p> <p>Latent variable methods in reformulation are demonstrated for a product line of frozen muffin batters used in the food service industry. A particular attribute is to be minimized while maintaining the taste, texture, and appearance of the original products, but the minimization is difficult because the attribute in question is not well understood. Initially, existing data is used to develop a partial least squares (PLS) model, which identifies areas for further testing. Design of experiments (DOE) in the latent variable space generates new data that is used to augment the model. An optimization algorithm makes use of the updated model to produce recipes for four different products, and a significant reduction of the target attribute is achieved in all cases.</p> <p>Latent variable methods are also applied to a difficult classification problem in oat milling. Process monitoring involves manually classifying and counting the oats and hulls in the product streams of groats; a task that is time-consuming and therefore infrequent. A solution based on near infrared (NIR) imaging and PLS-discriminant analysis (PLS-DA) is investigated and found to be feasible. The PLS-DA model, built using mixed-cultivar samples, effectively separates the oats and groats into two classes. The model is validated using samples of three pure cultivars with varying moistures and growing conditions.</p> / Master of Applied Science (MASc)
36

CAN NUTRITIONAL GEOMETRY MODULATE THE EFFECTS OF DIETARY RESTRICTION IN ACHETA DOMESTICUS?

LeBlanc, Zillon K. 10 1900 (has links)
<p>This study was performed to better understand the physiological responses of the cricket <em>Acheta domesticus</em> to dietary restriction and nutritional geometry (relative nutritional balance). Dietary restriction in crickets decreases the growth rate, survivorship, maturation mass and delays maturation, but it has the benefit of increasing their maximum longevity. Measurements of maturation mass, maturation age and longevity were obtained and used to calculate adult duration, growth rate and survivorship. This experiment combined both dietary restriction and nutritional geometry. Treatments were dietary restricted and provided with one of three macronutrients: lipid, carbohydrate or protein. The macronutrients were predicted to modulate the effects of dietary restriction while still producing an increase in maximum longevity. The lifetime restricted males and females obtained the highest maximum longevity of all treatments. The females of the carbohydrate treatment experienced significant increases in survivorship when compared to the lifetime restricted treatment. The males of the carbohydrate treatment achieved the second highest maximum longevity as well as a significant increase in longevity when compared to the lipid and protein males. A significantly earlier maturation age was obtained by the carbohydrate males when compared to the lifetime restricted treatment. The protein females had a significantly higher maximum longevity than the control treatment. The lipid treatment had an extremely low survivorship, a decreased adult duration as well as a low maturation mass. In summary, carbohydrates decreased the maturation age and increased the survivorship of the female crickets and increased the longevity of the male crickets. The protein treatment did not obtain the expected increases in growth rates or maturation mass associated with high protein diets. Therefore, different high protein diets should be tested in conjunction with the carbohydrate diet, in order to offset the negative effects of dietary restriction.</p> / Master of Science (MSc)
37

Vitamin D Levels and Risk of Dyslipidemia among Us Children with Diabetes and Obesity

Hagan, Elsina E. 01 January 2011 (has links) (PDF)
Dyslipidemia is increasing among U.S. children, and the prevalence is highest among children with diabetes and obesity. Recently, vitamin D deficiency has been suggested as a possible dietary risk factor for dyslipidemia. Despite the high prevalence of vitamin D deficiency amongst children, virtually no studies have evaluated the association between vitamin D and dyslipidemia among children. We evaluated the vitamin D and dyslipidemia relationship among 240 children and adolescents aged 2 through 21 years who were outpatients of a pediatric endocrinology unit at a large tertiary care facility in Western Massachusetts from April 2008 to April 2010. Eligible children were those with either obesity and/or type 1 or 2 diabetes mellitus. A total of 17.4% of children had severe (<15.0 ng/ml) vitamin D deficiency, 19.2% had moderate (15.0-19.9 ng/ml) deficiency, 36.3% were insufficient (20.0-29.9 ng/ml), and 27.1% had normal (≥30.0 ng/ml) levels. A total of 28.8% of children had high total cholesterol (TC ≥180 mg/dL), 19.6% had high triglycerides (TG; <10years: ≥110 mg/dL, ≥10years: ≥130 mg/dL), 21.3% had low high density lipoprotein (HDL <40 mg/dL), and 6.7% had high low density lipoprotein (LDL ≥130 mg/dL). Moderate vitamin D deficiency was associated with increased risk of high TC (adjusted odds ratio [OR adj] = 2.9, 95% confidence interval (CI): 1.0, 8.8) compared to children with normal vitamin D levels. Severe vitamin D deficiency was associated with an increased risk of low HDL (OR adj = 3.5, 95% CI: 1.0-12.3) and high TG (OR adj = 11.7, 95% CI: 1.9, 70.3) compared to children with normal vitamin D levels. Children with moderate vitamin D deficiency had approximately 3-fold increased risk of high TC compared to children with normal vitamin D levels. In comparison to children with normal vitamin D levels, severe vitamin D deficiency was associated with a strong and significant increased risk of low HDL and high TG; with a significant dose-response relationship. Additionally, in linear regression analyses, we found that an increase in vitamin D deficiency was associated with a significant mean increase in all four measures of dyslipidemia. Vitamin D adequacy may reduce the risk of dyslipidemia in children.
38

Seasonal Variation of Milk in Central Valley California and the Association of Milk Variation with the Composition and Texture of Low Mositure Part Skim Mozzarella

Jai, Vaideki 01 December 2014 (has links) (PDF)
The chemical composition of milk (specifically casein, fat, and calcium) is known to affect the quality and functional properties of Mozzarella cheese. Therefore, concentrations of total nitrogen, casein nitrogen, non-casein nitrogen, non-protein nitrogen, true nitrogen, casein nitrogen to total nitrogen ratio, casein nitrogen to true nitrogen ratio, fat, total calcium, total solids, somatic cells, and pH were measured in silo milk samples collected weekly over 18-months from a large dairy plant in Central Valley, California from July 2008 to December 2009 to verify changes and correlate to low moisture part skim Mozzarella (LMPS) characteristics. LMPS mozzarella cheese from the same plant was also collected biweekly during the same period and analyzed five days post manufacture for total nitrogen, water soluble nitrogen, total calcium, water soluble calcium, salt, pH, fat in dry matter and total solids and texture properties (i.e., hardness (g), cohesiveness, springiness, chewiness (g), aggregation index (AGI), and percentage cheese loss during shredding). Significant seasonal variations of total nitrogen, non-protein nitrogen, casein nitrogen, casein nitrogen to total nitrogen ratio, casein nitrogen to true nitrogen ratio, and total calcium in milk were explained using a linear model equivalent to a basic single cosinor model with sine and cosine of week (converted into radians) as predictors. Correlation studies were done between milk composition and cheese composition, milk composition and cheese textural characteristics as well as cheese composition and cheese texture, showing that concentration of total calcium and nitrogen fractions in cheese milk significantly affected the texture and composition of LMPS mozzarella. Also, the cheese total nitrogen, total calcium and water soluble calcium affected the cheese texture. The LMPS Mozzarella that was firmer and more cohesive had less loss during shredding and aggregated to a lesser extent. The milk total nitrogen, non-protein nitrogen, casein nitrogen, casein to total protein ratio, casein to true protein ratio, and total calcium had positive correlation with each other. However, the milk non-casein nitrogen did not significantly correlate with other nitrogen fractions and total calcium of milk. In addition, there was a significant increase of water soluble nitrogen, percent loss in shredding and aggregation index, and a significant decrease of hardness, and chewiness of LMPS Mozzarella ripened at 8.90 C in comparison to the cheese ripened at 3.30 C for 21 days.
39

San Antonio High School Food Justice Program: A Handbook and Evaluation of Edible Education

Tenneson, Katherine B 12 May 2012 (has links)
This senior environmental studies thesis explains and analyzes edible education through a food and gardening program at a continuation high school in Claremont, California. The first chapter situates the program-specific analysis by providing background information of the edible education movement, a history of the Edible Schoolyard in Berkeley, California, and an explanation of why food is a powerful teaching tool. The second chapter delineates the program by describing all of its components and compiling essential resources and teaching documents. The third chapter is based on interviews with 9 of 12 involved students and 7 teachers, and thoroughly explains the outcomes of the program for students, the high school at large, and the overall Claremont community. Overall, this work demonstrates the successes of edible education, the power of school gardening programs, and provides a useful resource for the continuation of the program.
40

A Multidisciplinary Approach to Food Safety Evaluation: Hummus Spoilage and Microbial Analysis of Kitchen Surfaces in Residential Child Care Institutions (rcci) in Massachusetts, U.S.A.

Hagan, Elsina E. 01 January 2011 (has links) (PDF)
Food borne illnesses continues to be a public health challenge in the United States (U.S.); an estimated 9.4 million incident cases occurred in 2011. In view of this challenge we conducted two food safety studies; 1) related to product formulation (hummus spoilage challenge study) and 2) evaluating the microbial safety of domestic kitchen surfaces in Residential Child Care Institutions (RCCI pilot study). Hummus is of Mediterranean origin but is currently eaten globally. This challenge study evaluates a variety of industrial hummus formulations (four in total, differing in pH and/or addition of a preservative (natamycin). Two batches were setup: batch 1; aseptically inoculated hummus with 100 CFU/g fungal isolates and batch 2; uninoculated hummus. Samples of both hummus batches were stored at both 20oC (10 days accelerated testing) and 4oC (84 days recommended temperature testing). Inoculated samples were analyzed for fungus, whiles both fungi and bacteria (standard plate count (SPC) and Lactococci) counts were done for uninoculated samples. Results indicate that accelerated testing inaccurately predicts fungal growth at 4oC in hummus, also fungal growth inhibition requires a pH ≤ 4.0 ± 0.2 and refrigeration. Limited studies have specifically evaluated the prevalence of pathogenic bacteria in domestic kitchens in the U.S, for this reason we assessed the microbial safety of 6 RCCI locations in MA. Fifteen key food contact surfaces and dish washing sponges, if available at each RCCI facility were assessed for SPC, yeast and molds, total coliform and E. coli, Listeria sp and Salmonella sp. Microbiological assessments were conducted preceding and after a hazard analysis and critical control point (HACCP) food safety training and implementation at each location. Microbial growth varied by surface for each type of microorganism, wet surfaces had higher most probable number (MPN) counts. Compared to dry surfaces, wet surfaces had significantly higher mean total coliform counts. For both E. coli and total coliform, microbial load differed significantly by surfaces sampled (P = 0.0323 and 0.014) respectively. The surface and training interaction effect was highly significant for only E. coli (P = 0.0089). Training overall had no significant effect on reducing the microbial load on kitchen surfaces.

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