Life Sciences Commons^™

Advancing Agroecological Agroforestry: A Vermont Participatory Storytelling And Story Mapping Project, Sydney Blume

Food Systems Master's Project Reports

Agroforestry is the intentional integration of trees into agricultural landscapes. Advancing agroforestry has the potential to support just food system transition, but it must take direction from traditional approaches (culturally-embedded, millennia-old agroforestry practices in forest ecosystems) and agroecology (the movement, science, and practice for just and sustainable food and agricultural systems). An agroecological approach to agroforestry is essential to avoid agroforestry replicating the logics and harms of industrial agriculture and to encourage learning from traditional agroforestry practices, and likewise, traditional approaches to agroforestry can support a transformative agroecological transition through redesign of agroecosystems and shifting perspectives and ethics. This paper …

Biofilm Sanitizer Tolerance Of Vermont Dairy Listeria Monocytogenes, Emily C. Forauer

Graduate College Dissertations and Theses

Listeria monocytogenes is a foodborne pathogen found in biofilms on surfaces and equipment in the food processing environment. Sodium hypochlorite (SH) and quaternary ammonium compounds (QAC) are readily available and commonly used sanitizers. However, due to the structure and additional organic material produced in a biofilm, killing bacteria within the biofilm may be a challenge for one or both of these sanitizers.

The objective of this work was to determine if immature and mature biofilms from L. monocytogenes isolated from Vermont artisan dairy environments were more tolerant to QAC and SH compared to planktonic cultures’ tolerance. To determine sanitizer minimum …

Assessing Growth And Methods Of Decontamination Of Listeria Monocytogenes In Brushes And Brines Used For Production Of Washed-Rind Cheese, Rosalind Grace Neale

Graduate College Dissertations and Theses

Washed-rind, or smear-ripened, cheeses are considered high-risk for contamination with Listeria monocytogenes due to favorable growth conditions on the cheese rind and multiple points for contamination during post-production cheese care and aging. Foodborne illness outbreaks have implicated wash solutions and washing tools as potential vectors for transmission of L. monocytogenes. In order to evaluate the risk posed by the wash solutions and cheese brushes independently, a three-objective study was developed to investigate the growth potential of L. monocytogenes in cheese washing solutions (Objective I) and the transfer potential of L. monocytogenes between wash solution and cheese brush bristles of three …

Validation Of Two Gluten Elisa Assays Utilizing A Novel Polyclonal Antibody System, Lukas Emerson-Mason

Graduate College Dissertations and Theses

Celiac disease is an autoimmune disorder for which there is no cure, the only treatment being a lifelong abstention from a gluten containing diet. The FDA requires any food in the United States labelled gluten-free to contain less than 20 parts per million gluten as determined by validated analytical methods. The major sources of gluten in the American food stream are wheat, rye, and barley cereal grains, but the currently available methods do not detect gluten from these three grains equally. Bia Diagnostics, LLC has developed novel quantitative and qualitative immunoassays for the detection of gluten in foods, which are …

Physiochemical And Microstructural Properties And Probiotic Survivability Of Symbiotic Almond Yogurt Using Polymerized Whey Protein As A Co-Gelation Agent, Hao Shi

Graduate College Dissertations and Theses

Almond milk-based products are becoming increasingly popular as milk product alternatives. In this study, a symbiotic almond yogurt containing probiotics and inulin as a prebiotic was developed using polymerized whey protein (PWP) as a gelling agent. Plant-based starter cultures YF-L02 (Lactobacillus delbrueckii subsp. bulgaricus, Stepcoccos thermophilus, Lactobacillus acidophilus, Lactobacillus paracasei and Bifidobacterium animalis) were incubated in the almond slurry. The control and fortified (Calcium Citrate and Vitamin D) almond yogurt, were analyzed for chemical compositions, pH and viscosity changes and probiotics survivability for 10-week shelf-life. There were no significant differences between the control and fortified group in the pH, viscosity …

Chemical Properties And Probiotics Survivability Of Symbiotic Coconut Yogurt Using Polymerized Whey Protein As A Gelation Agent, Jinglin Lu

Graduate College Dissertations and Theses

Food products from coconut fruits are delicious and nutritious; the coconut water could be directly used as a sports drink; whereas the meat can be processed to coconut milk, coconut puree and other products that are rich in medium fatty acids that can be burnt quickly to provide energy to the body. In recent years, products that incorporated the probiotics with coconut have been developed, however the texture and nutritional qualities were not satisfied.

The purpose of the study was to create a functional coconut yogurt using polymerized whey protein (PWP) as a gelation agent to achieve a better mouthfeel …

Formulation And Functional Properties Of Whey Protein Based Tissue Adhesive Using Totarol As An Antimicrobial Agent, Yifan Hou

Graduate College Dissertations and Theses

Tissue adhesives have been widely used in surgical procedures. Compared to traditional surgical sutures, tissue adhesives provide fast bonding experiences and full closure of wounds. However, current tissue adhesives are mostly fossil-based synthetic products. Therefore, it is of great significance to explore the use of natural polymers in tissue adhesives. Whey is a low-end byproduct of cheese making. Whey protein consists of a group of small globular proteins. They can exhibit adhesive properties if their structures are modified by physical or chemical means. The objectives of this study were to investigate the formulation and functional properties of whey protein based …

An Environmental Approach To Food Safety Assessment Using Artisan Cheese And Fresh Produce As Model Systems, Marie Limoges

Graduate College Dissertations and Theses

This dissertation examined recently issued regulatory standards using cheese and produce as model systems. FDA's 2015 Domestic and Imported Cheese and Cheese Products Compliance Program Guidelines (CPG) E. coli standards on cheese safety, and the extent to which these standards affect domestic and imported cheese commerce, was assessed. Results from FDA's Domestic and Imported Cheese Compliance Program for samples collected between January 1, 2004 and December 31, 2006 were analyzed. Of 3,007 cheese samples tested for non-toxigenic E. coli, 76% (2,300) of samples exceeded 10/g, FDA's target for regulatory activity. In cheese samples containing E. coli levels of 10/g and …

Comparison Of Methods For Detection Of Listeria On Wooden Shelves Used For Cheese Aging: Challenges Associated With Sampling Porous Surfaces, Gina Christine Frontino

Graduate College Dissertations and Theses

This thesis examined the efficacy of various sampling and detection methods used for environmental monitoring of Listeria species on wooden surfaces used for cheese aging. Government agencies including the Food and Drug Administration (FDA) and United States Department of Agriculture (USDA) recommend enrichment methods coupled with use of environmental sponges and swabs. Our study compared efficacy of sponge swabs manufactured by 3M™ and World Bioproducts. There is a lack of research validating the best performing swab type and enrichment method combination that is sensitive when used on rough, porous surfaces. The sensitivity of these environmental sampling tools and methods are …

Analysis Of Surface Crystals On Soft Washed Rind Cheeses Using Polarized Light Microscopy And Their Effect On The Sensory Perception Of Grittiness, Patrick Polowsky

Graduate College Dissertations and Theses

With the rising popularity of artisanal cheese in the United States, the soft washed rind category has emerged as a fast-growing segment of the marketplace. There is much anecdotal evidence to suggest a common sensorial defect in soft washed rind cheese is a gritty/sandy texture attributed to crystal growth on the rind of these cheeses

A preliminary study was undertaken to develop a set of criteria to visually identify crystals found on soft washed rind cheeses. Single crystal identities were presumptively determined using polarized light microscopy (PLM), and cross-checked using powder x-ray diffractometry (PXRD). Two distinct crystal groupings were determined …

Do Labels Make A Difference: Estimating The Impacts Of Vermont’S Gmo Labeling Law On Perceptions And Prices, Orest V. Pazuniak

Graduate College Dissertations and Theses

Vermont is the first and only state in the US to establish mandatory labels for food containing genetically modified organisms (GMOs). This thesis investigates the impact of the mandatory labeling law as it relates to changes in prices, quantities sold, and opinions of GMOs. First, grocery store scanner data from Vermont and Oregon are compared using triple difference (difference-in-difference-in-difference) models. Next, Vermont, Oregon, and Colorado survey response data are compared using difference-in-difference models. The findings reveal that there is a general price premium for non-GMO goods of $0.05/oz across all states and times, that mandatory labeling laws do not result …

A Study Of Food Hub Buyers In Vermont: Motivation, Marketing, And Strategy, Hannah Harrington

Graduate College Dissertations and Theses

Food hubs have been discussed as a promising option for scaling-up the local food system while maintaining close relationships and shared responsibility amongst producers and consumers. Food hubs have the capacity to share important messages about food safety, origin, and production methods with consumers, however little is known about if, and how, food hubs communicate the value of local food to their buyers. This is crucial when assuring value to the consumer, which is necessary for the long-term sustainability of the food hub model. It is important to know more about these methods and practices because these messages can impact …

Development And Implementation Of Methods To Study Crystallization In Cheese, Gil Fils Tansman

Graduate College Dissertations and Theses

Dissolved compounds and ions, including mineral elements and products of microbial metabolism, are present in many cheeses in relatively high concentrations. These dissolved substances may precipitate from the aqueous phase of cheese to form sparingly soluble crystals that can impart a crunchy, gritty, or sandy texture on the cheese. In the present work, optical and diffractometric methods were optimized for use with cheese samples to identify crystal phases in several cheese varieties. These techniques, which included powder X-ray diffractometry (PXRD), single crystal X-ray diffractometry (SCXRD), and petrographic microscopy (PM) have traditionally been used on geological specimens that are quite different …

Role Of Community Social Capital For Acute Food Security Following An Extreme Weather Event, Alana N. Chriest

Graduate College Dissertations and Theses

Worsening climate changes effects are predicted to increase the severity and frequency of extreme weather events (EWE), which can disrupt food systems, from the local to global level, and compromise community food security. In the rural U.S., food insecurity, poverty, low economic growth, and population loss are prevalent, and rural communities often lack the physical capital to bolster community resiliency to climate change adaptation. In 2011, Tropical Storm Irene (TS Irene) in Vermont was the most damaging EWE the state’s history. Severely damaged roads, infrastructure, homes, and land, rendered many rural towns isolated for up to several days. The levels …

A Pilot Study Of The Effectiveness And Usability Of The Myenergybalance Iphone App And Website, Joanna Graff

Graduate College Dissertations and Theses

The powerful technical capabilities of smartphones offer unprecedented opportunities for collecting dietary information. We have developed an enhanced smartphone application called MyEnergyBalance, which permits imaged-based self-monitoring of all foods consumed, and links to a convenient and user-friendly web-based dietary assessment tool. The primary objective of this pilot study was to determine if the MyEnergyBalance app (with use of images) in combination of the associated website improves dietary recall compared to diet analysis on the MyEnergyBalance website alone. We also generated preliminary data on the usability of the MyEnergyBalance iPhone app and website. This pilot study was a crossover study design …

The Microbial Ecology Of Listeria Monocytogenes As Impacted By Three Environments: A Cheese Microbial Community; A Farm Environment; And A Soil Microbial Community, Panagiotis Lekkas

Graduate College Dissertations and Theses

This dissertation examined the microbial ecology of Listeria monocytogenes in three distinctly different environments: a cheese microbial community; a farm environment; and a soil microbial community.

The aim of the first study was to investigate the effects of L. monocytogenes on the composition of the surface microflora on washed rind soft cheese. Two trials with washed rind cheeses that were inoculated with 100cfu cm⁻² of a L. monocytogenes six strain cocktail were conducted. The first trial had to be terminated early (day 28) as contamination of Pseudomonas spp. from the initial brine did not produce the expected characteristics of the …

Effect Of Radiation On Polymerization, Microstructure, And Microbiological Properties Of Whey Protein In Model System And Whey Protein Based Tissue Adhesive Development, Ning Liu

Graduate College Dissertations and Theses

Whey proteins are mainly a group of small globular proteins. Their structures can be modified by physical, chemical and other means to improve their functionality. The objectives of this study were to investigate the effect of radiation on protein-protein interaction, microstructure, and microbiological properties of whey protein-water solutions. Whey protein isolate (WPI) solutions (27-36% protein) were treated with different dosages (10-35 KGy) of gamma radiation. The protein solutions were analyzed for viscosity, turbidity, soluble nitrogen, total plate count, and yeast and mold counts. The interactions between whey proteins were also analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and …

Chemical Composition, Probiotic Survivability And Shelf Life Studies Of Symbiotic Buttermilk, Dong Zhang

Graduate College Dissertations and Theses

Cultured buttermilk is becoming popular as an ingredient for bakery applications and for direct consumption in the U.S.. The objective of this study was to develop a symbiotic cultured buttermilk, containing inulin as a prebiotic and the probiotics Lactobacillus acidophilus and Bifidobacterium spp. The cultured buttermilk was prepared using a commercial mesophilic starter CHN22 (Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Leuconstoc mesenteorides subsp. cremoris, Lactococcus lactis subsp. lactis biovar diacetylactis) and the probiotics. The control buttermilk was prepared using CHN22 and the symbiotic buttermilk were analyzed for chemical composition, probiotics survivability, mold, yeast …

The Impact Of Engagement With Community Supported Agriculture On Human Attitude Towards The Sustainable Food Movement, Ariana Margarita Cano

Graduate College Dissertations and Theses

With a total of 164 community supported agriculture programs (CSA), Vermont is leading the "locavore" movement in the United States, ranked number one in the country with the most CSAs and Food Hubs per capita. ("Locavore Index," 2013)

CSAs have a large positive impact on reducing carbon emissions, advancing local economic growth, and promoting healthy lifestyles of consumers. The purpose of this study is to explore the overall experience of individuals in comparison to their current social norm, individual attitudes, identity, and intentions of change, and understand any change overtime in their individual attitude and behavior.

Attitude change was measured …

Physicochemical Properties, Microstructure And Probiotic Survivability Of Non-Fat Goat's Milk Yogurt Using Heat Treated Whey Protein Concentrate As A Fat Replacer, James Thomas Mccarthy

Graduate College Dissertations and Theses

Probiotic dairy foods, especially non- and low-fat dairy products, are becoming popular in the US. A non-fat goat's milk yogurt containing probiotics (Lactobacillus acidophilus and Bifidobacterium spp.) was developed using heat-treated whey protein concentrate (HWPC) as a fat replacer and pectin as a thickening agent. Yogurts containing non-heat treated whey protein concentrate (WPC) and pectin as well as one with only pectin were also produced. A fat-free cow's milk yogurt with pectin was also used as a control yogurt. The yogurts were analyzed for chemical composition, water holding capacity (syneresis), microstructure, changes in pH and viscosity, mold, yeast and coliform …

Pasteurization And Its Discontents: Raw Milk, Risk, And The Reshaping Of The Dairy Industry, Andrea M. Suozzo

Graduate College Dissertations and Theses

Milk is something many Americans consume every day, whether over cereal, in coffee or in a cup; as yogurt, cream, cheese or butter. The vast majority of that milk is pasteurized, or heated to the point where much of the bacteria in the milk dies. Pasteurization both slows spoilage of the milk and eliminates potentially harmful bacteria. The fact that we call heat-treated dairy simply "milk" is a testament to pasteurization's widespread proliferation over the past century. Prior to the 1900s, "milk" was raw and unheated, and pasteurized milk was a radically new technology. My research delved into understandings of …

Improved Recovery And Rapid Identification Of Strains, Mixed Strains, Mixed Species, And Various Physiological States Of Foodborne Pathogens Using Infrared Spectroscopy, Esmond Boafo Nyarko

Graduate College Dissertations and Theses

Challenges encountered in pathogen identification and detection include the genetic heterogeneity of strains within species of some foodborne pathogens, isolation of injured cells, mixed strains or mixed species contamination of foods, and differentiation between viable and dead cells. The first objective of this research was to evaluate an isolation medium that was based on time-delayed release (5 to 6 h) of selective agents in tablet format to a modified Listeria recovery enrichment broth (mLRB) medium for enhanced and rapid recovery of injured Listeria. The second objective involved the use of Fourier transform infrared (FT-IR) spectroscopy and chemometric analysis for the …

Functional Properties Of Whey Protein And Its Application In Nanocomposite Materials And Functional Foods, Helen Walsh

Graduate College Dissertations and Theses

Whey is a byproduct of cheese making; whey proteins are globular proteins which can be modified and polymerized to add functional benefits, these benefits can be both nutritional and structural in foods. Modified proteins can be used in non-foods, being of particular interest in polymer films and coatings. Food packaging materials, including plastics, can linings, interior coatings of paper containers, and beverage cap sealing materials, are generally made of synthetic petroleum based compounds. These synthetic materials may pose a potential human health risk due to presence of certain chemicals such as Bisphenol A (BPA). They also add to environmental pollution, …

Exploring The Nature Of Crystals In Cheese Through X-Ray Diffraction, Gil Fils Tansman

Graduate College Dissertations and Theses

The optimization of powder x-ray diffraction (PXRD) for the study of cheese crystals was the focus of this study. A survey was conducted of various manifestations of calcium lactate crystals on the rindless surface and within mechanical openings of Cheddar cheese using PXRD. The diffraction reference card database contained a card that was entitled calcium lactate pentahydrate and corresponded to some of the crystalline material found on the cheeses. Diffractions patterns generated from other samples of crystalline material revealed the existence of an unknown crystal that resembled and behaved similarly to calcium lactate pentahydrate, but did not match the reference …