Browsing by Author "Bunning, Marisa, committee member"
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Item Open Access A case study evaluation of edible plants curriculum implemented in an elementary school(Colorado State University. Libraries, 2014) Graves, Leila, author; Hughes, Harrison, advisor; Balgopal, Meena, advisor; Bunning, Marisa, committee member; Krishnan, Sarada, committee memberThe main purpose of this study was to describe elementary teachers' attitudes and perceptions toward plant science. The secondary purpose was to create an edible plant curriculum as a vehicle for integrating STEM and 21st Century skills into Common Core Content. Results indicate that teachers and STEM coordinators did find the curriculum to be effective in teaching the interdisciplinary standard-based and inquiry based content and skills targeted. Additionally, the curriculum development process produced a hybrid design framework that facilitated the creation of life science content as a vehicle for integrating STEM into common core content. However, several significant barriers will need to be overcome with regard to the teachers', STEM coordinators' and administrators' perception that plant science and nutrition literacy are "special" content activities versus important STEM content.Item Open Access Comparative analysis of antioxidant properties, quality attributes and yield of organically and conventionally grown melons (Cucumis melo L.) and tomatoes (Solanum lycopersicum L.)(Colorado State University. Libraries, 2008) Salandanan, Karen A., author; Stushnoff, Cecil, advisor; Bunning, Marisa, committee member; Wallner, Stephen J., committee memberFresh fruits and vegetables including melons and tomatoes have gained considerable prominence in the American diet due to increasing awareness of their potential health and nutrition benefits. Consumers are starting to take a closer look not only at organoleptic qualities but also at nutritional value of the produce. This new trend of consumer preference for healthier food choices is one of the driving forces of the organic industry. Organically grown fruits and vegetables are perceived to be more nutritious than those that are produced under conventional production system. Comparison studies on selected fruit and vegetable crops have been carried out to examine this claim. However, verifiable results from well-designed experiments were very limited in many crops, including tomatoes and melons. This research assessed the difference in the antioxidant properties, quality attributes, and yield of organically and conventionally grown tomatoes and melons. Nutritionally superior cultivars were also identified which could be beneficial for small and medium sized farmers. Ten commercial cultivars of tomatoes were grown in 2005 and 2006, under certified organic and conventional production systems at the Horticulture Field Research Center, Colorado State University, Colorado USA. Melon and tomato cultivars were analyzed for their ascorbic acid, total phenolic content, Trolox equivalent antioxidant capacity (TEAC), percent dry matter, soluble solids content, and yield. A 3 to 6 fold difference in ascorbic acid, total phenolic content, and antioxidant activity was observed both in melon and tomato cultivars. Melons grown organically had significantly higher ascorbic acid when both years were combined while total phenolic content was significant only in the first year. In tomatoes, higher antioxidant activity was observed in organically grown tomatoes while yield and soluble solids concentration was higher under the conventional production system. Lower yield was observed in melon and tomato cultivars with higher antioxidant content and activity suggesting a possible trade- off between yield and nutrients. Compared to genotype, production system had less influence on antioxidant properties and fruit quality attributes. A significant interaction between cultivar and production system would likewise imply that some cultivars when grown organically or conventionally could have higher antioxidant content and activity. Thus, choice of cultivar was the most important contributor to high antioxidant properties. Based on the antioxidant index that we have developed as a tool to rank the cultivars in terms of antioxidant content and activity, the top melon cultivars, regard less of year or production system, are the following: 'Savor', 'Sweetie#6', 'Early Queen', 'Edonis' and 'Rayan'; while ' Jet Star', 'New Girl', 'Fanstastic', 'First Lady', and 'Celebrity' were determined to be nutritionally superior tomatoes. These nutritionally superior cultivars with high antioxidant levels may provide a competitive marketing and supply niche for small fam1 producers. Future initiatives could involve screening of tomato and melon cultivars for higher antioxidant content that could be utilized in breeding programs.Item Open Access Comparison and acceptabilty of gluten-free yeast breads made with quinoa flour(Colorado State University. Libraries, 2014) Chase, Caraline Bianchetto, author; Stone, Martha, advisor; Bunning, Marisa, committee member; Timpson, William, committee memberQuinoa (Chenopodium quinoa Willd) is a plant that is native to South America and is grown in the Andean mountains. The quinoa plant is resistant to harsh weather conditions and drought. It is a gluten free (GF) grain and has significance in making a GF yeast bread for people who cannot safely consume gluten proteins due to celiac disease, gluten allergies, or other issues. Most GF yeast breads on the market are made with a large portion of white or brown rice flour, which is neutral in taste, easily digestible, but low in vitamins and nutrients compared to quinoa flour. Quinoa flour is more expensive than rice flour and can impart negative aftertastes. The objectives of this study were to develop GF yeast bread formulas incorporating quinoa flour for rice flour and potato starch at 0, 36, 72, or 100% and obtain sensory and instrumental data on the breads. Specific gravity was calculated on the batter before baking with significant (p<0.05) differences existing among all batters. The 100% GF quinoa yeast bread was (p<0.05) smaller in volume than the other breads. The GF bread made with 100% rice flour and potato starch was significantly (p<0.05) softer (less hardness or firmness values) than the GF breads containing quinoa flour, while the 100% GF quinoa flour bread was firmest and least tender. Crust and crumb color did not (p>0.05) differ among any of the breads. The 100% GF quinoa yeast bread had the lowest water activity (p<0.05). Sensory analysis showed that for tenderness, flavor, and overall acceptability the 100% GF quinoa yeast bread was liked less (p<0.05) compared to the other breads. Based on the instrumental and sensory data collected, both the 36 and 72% QF yeast breads are acceptable GF yeast bread options containing QF.Item Open Access Edible mealworms: can fermentation improve consumer acceptability and nutritional value?(Colorado State University. Libraries, 2023) Wilson, John W., author; Weir, Tiffany, advisor; Bunning, Marisa, committee member; Stull, Valerie, committee member; Nair, Mahesh, committee memberAs the global population increases, the demand for animal-based protein is also on the rise. To meet this demand, it is important to identify sustainable sources of animal protein that have a smaller environmental impact than conventional animal protein production. One potential solution to this challenge is the development of consumer-acceptable insect-based protein products utilizing the larva and pupae of Tenebrio molitor, a type of darkling beetle whose larval and pupal states are edible. These beetles can be reared in small spaces, do not require direct sources of fresh water, and convert feed into protein more efficiently than conventional meat production. In addition, their waste (frass) is dry, making it easier to contain than waste from conventional animal rearing operations, reducing the risk of contaminating the surrounding environment. In addition, the larvae and pupae can be eaten in their entirety, eliminating potential waste streams of byproducts associated with conventional meat processing. With less space, less water usage, more efficient feed conversion ratios, and nearly zero waste, the development of an edible mealworm industry in the global West would help relieve some of the pressures on the current animal protein systems and improve global food security. To accomplish this, it is necessary to generate a consistent demand in the global West for insect protein. Currently, in the United States, edible insects are largely relegated to ground powders designed to "hide" the insects or are placed in novelty products like chocolates and lollipops to confront people's notion of disgust. To introduce mealworm protein into the mainstream, it must be in a form that is accessible to the average American consumer, be safe to eat, and have comparable nutritional attributes as other protein-based products on the market. Tempeh fermentation techniques may be an appropriate approach to accomplish these goals. Tempeh fermentation uses Rhizopus oligosporus mycelium to knit together legumes into a solid cohesive substrate. The product can then be utilized in a variety of ways that are familiar to American consumers including stir frys, burgers, nuggets, and crumbles. This project seeks to utilize tempeh fermentation techniques to develop an insect-based product that is both consumer-friendly but also capitalizes on the known and emerging nutritional and environmental benefits of edible insects. In Chapter 1, I examine the safety of tempeh produced with various life stages of the Tenebrio molitor beetle. Samples were assessed for water activity (aw), and pH to determine the shelf stability of the products. Pathogenic risk was assessed through testing for coliforms, Salmonella and Listeria, and samples were analyzed for heavy meatal content via utilized Inductively Coupled Plasma and Mass Spectrometry (ICP-MS). This exploration allows us to determine best storing and cooking methods and helps identify critical control points in production to help minimize the risk to the consumer. In this chapter, I was able to demonstrate that tempeh made with Tenebrio molitor was just as safe as conventional soy-based tempeh and requires similar storage and cooking precautions to minimize the risks of consumption. In Chapter 2 we conducted a nutritional analysis of the insect-based tempeh products in comparison to traditional soy-based tempeh. We utilized ICP-MS to quantify the presence of micronutrients within each example. Samples were also analyzed for vitamins, macronutrients, and amino acid profile. We then calculated the protein digestibility using the Protein Digestibility-Corrected Amino Acid Score (PDCAAS). Comparison of results with traditional soy-tempeh products helps us to determine if the products provide comparable nutrition to products already on the market. It also helps to determine if the novel products will fill the nutritional space of more conventional sources of protein. This chapter found that the tempeh products made with the Tenebrio molitor had nutritional attributes comparable to conventional soy tempeh. Chapter 3 examines the bioavailability of iron within the sample set and compare the results to conventional bee samples, current on-the-market plant-based meat alternatives, and traditional soy-based tempeh. ICP-MS was utilized to quantify the amounts of iron present in each chemically digested sample. Then, digestates were added to Caco-2 human colonic cells to allow absorption of available iron. Iron absorption rates were then determined by using a human ferritin Eliza kit. This assessment helps us determine if the presence of insect protein improves the bioavailability of iron in a traditionally plant-based food and allows us to compare the availability of the iron in the novel products to conventional beef and current plant-based meat products. The bioavailability of iron in the novel products exceeded that of the conventional beef and the plant-based meat alternative. In Chapter 4, we conducted a consumer acceptability study to analyze the potential for consumer acceptance of a tempeh product made with 50% mealworms and 50% soybeans when compared to a commercial soy-based tempeh. An online survey was conducted to assess the public's attitudes to entomophagy, their current level of exposure to the practice, and the willingness to consume insects. Next, the mealworm soybean tempeh was evaluated by a trained sensory panel to develop a lexicon that describes the organoleptic attributes of the product. Finally, a blind in-person sensory evaluation was conducted to assess the overall acceptability of the product. During the in-person evaluation, participants were provided with different prompts to determine if details around the environmental impact of insect eating versus conventional meat production would affect the favorability of the product. Participants in this study rated the flavor equal to that of the commercial soy tempeh and majority of participants indicated they were equally or more likely to consume insect-based products again. The final chapter explores the need for research around branding and availability on insect-based food products to increase acceptance of entomophagy in Western society. This dissertation aims to determine the safety of utilizing edible insects in tempeh fermentation, examine the nutritional attributes of tempeh products made with various life stages of the Tenebrio molitor beetle, determine how effective these products are in filling their intended nutritional niches, and assess the potential for consumer acceptance of insect-based tempeh products. This dissertation provides a strong foundation for the understanding of the safety, nutrition, and acceptability of utilizing T. molitor-based tempeh as an alternative source of protein.Item Open Access Effect of genotype, storage and processing on the polyphenolic content, composition, in vitro anti-cancer activity and sensory attributes of colored-flesh potatoes(Colorado State University. Libraries, 2012) Madiwale, Gaurav, author; Vanamala, Jairam, advisor; Stone, Martha, advisor; Reddivari, Lavanya, committee member; Bunning, Marisa, committee member; Holm, David, committee memberThe potato (Solanum tuberosum L.) is the world's third largest food crop with per capita consumption of ~126 lbs. annually in the US. The 2010 US Potato Board Report revealed that over the past ten years, while consumption of traditional potatoes (mashed, baked, fried, steamed, boiled and french fries) declined, specialty/colored potato consumption increased by 17%, possibly due to their putative health benefits. Specialty/colored potatoes, which are rich in anti-proliferative and pro-apoptotic anthocyanins and/or carotenoids, can be an attractive "delivery system" for these bioactive compounds in humans. However, colored potatoes can undergo 3-6 months of storage before processing/consumption and the effect of storage and processing on their anti-cancer properties remains unknown. We hypothesized that potatoes retain polyphenolic content (TP), antioxidant activity (AA) and chemopreventive properties against early stage (HCT-116) and advanced stage (HT-29) human colon cancer cells even after 3 months of storage and processing (baking and chipping). To test this hypothesis, we utilized white-, yellow- and purple-fleshed potato clones and tested their phenolic (Folin-Ciocalteu) and anthocyanin (pH-differential) content, antioxidant activity (ABTS and DPPH), metabolite profile (UPLC-MS), anti-cancer properties (cell proliferation via cell counting and BrdU assays, and apoptosis via Caspase-Glo 3/7 assay), and sensory attributes (9-point hedonic scale). Purple-fleshed potatoes had higher phenolic content and antioxidant activity as compared to their white- and yellow-fleshed counterparts. The antioxidant activity of all clones increased with storage; however, an increase in total phenolic content was observed only in purple-fleshed clones. Baking caused minimal losses while chipping reduced the phenolic and anthocyanin content, and antioxidant activity of the potatoes. With storage, total phenolic and anthocyanin content, and antioxidant activity increased in baked samples while in the chipped samples, they remained constant. Principal component analysis of approximately 1600 peaks obtained by UPLC-MS analysis revealed that storage caused a shift in the metabolite profiles of potato clones. In general, ethanol extracts of uncooked, baked and chipped samples suppressed proliferation and elevated apoptosis (p < 0.05) in human colon cancer cell lines (HCT-116, HT-29). However, chipped samples did not have any effect on HT-29 cell lines. Anti-proliferative and pro-apoptotic properties of baked potatoes were similar to that of raw potatoes while chipping caused a significant reduction in the biological activity. Storage generally negatively affected the anti-cancer properties of the potato extracts. Sensory analysis revealed comparable acceptance of purple-fleshed baked and chipped potatoes when compared with traditional cultivars. Consumers were willing to pay a premium for colored-flesh potatoes if they were educated on their potential health benefits. Phenolic content and antioxidant activity of purple-fleshed potatoes, after baking, were comparable with those of anthocyanin-rich berries. Hence, locally grown purple-fleshed potatoes can be a healthier choice as they possess greater levels of bioactive compounds and in vitro anti-cancer properties even after processing as compared to their white- and yellow-fleshed counterparts.Item Open Access Effects of organic, biological and conventional production methods on apple antioxidant levels, sensory qualities and human glycemic response(Colorado State University. Libraries, 2009) Bogs, Jana Dee, author; Stushnoff, Cecil, advisor; Wallner, Stephen, committee member; Bunning, Marisa, committee member; Kendall, Patricia A. (Patricia Ann), 1947-, committee memberDifferent cultivation systems of fruit trees may influence fruit nutrient and phytochemical content, and consequently, human responses. This experiment compared two cultivars of apples (Malus domestica Mill.) each under differing cultivation systems. These were evaluated for antioxidant activity, human glycemic response, soluble solids content, shelf life and consumer acceptability by human sensory panels. In addition, soil and leaf tissue tests were performed and correlated to the above results. 'Braeburn' (M. domestica) apples grown in Washington state under biologically-enhanced organic and conventional methods were evaluated in 2007. Treatments were split to include apples from the outside and inside of the tree canopies. There were no differences (P > 0.05) in ABTS or DPPH antioxidant activity between organic and conventional 'Braeburn' apples. Organic 'Braeburn' apples had a higher level (P = 0.003) of total phenolics (TP) than the conventional apples. Outside-canopy apples had higher TP, ABTS and DPPH antioxidant activity levels (P < 0.01) than inside-canopy apples. Organically-grown 'Braeburn' apples from both outside and inside the canopies had higher soluble solids levels (P < 0.001) than those conventionally-grown. Fruit soluble solids content was higher (P = 0.002) in 'Braeburn' apples from outside the canopies than from inside the canopies. There was no difference in shelf life between organic and conventional ‘Braeburn’ apples (P = 0.366), nor between outside-canopy and inside-canopy apples (P = 0.286). The 'Braeburn' overall acceptability sensory ratings for organic apples were significantly higher (P < 0.001), than conventional fruits, and outside-canopy fruits surpassed inside-canopy fruits (P < 0.001). 'Crimson Gala' (M. domestica) apples from Washington state orchards grown under biologically-enhanced conventional management and typical conventional management were evaluated in 2008. The biological apples had higher ABTS antioxidant activity than the conventional (P = 0.0498). The conventional 'Gala' apples had higher DPPH antioxidant activity (P = 0.002) than the biological. There was no difference (P = 0.681) between the biological and conventional 'Gala' apple total phenolics (TP) levels. None of the values used to compare human glycemic response were statistically different (P > 0.05). The conventionally-grown 'Gala' apples had higher soluble solids levels (P = 0.005), greater shelf life (P = 0.035), and a higher overall sensory rating (P = 0.014) than the biologically-grown fruit. The above measured values were also correlated with soil, leaf, and fruit tissue values. It should be noted that the biological 'Gala' orchard had a soil with a cation exchange capacity (CEC) of 7.1 meq/100g compared to the conventional control orchard's CEC of 11.3 meq/100g, which may have negatively affected the quality of the biological apples. Understanding how cultivation practices affect consumer acceptance will encourage growers to further improve production practices.Item Open Access Efficacy of antimicrobial compounds against Salmonella spp., Escherichia coli O157:H7, non-O157 Escherichia coli, and non-pathogenic Escherichia coli on beef and poultry(Colorado State University. Libraries, 2015) Scott, Brittney R., author; Delmore, Robert J., advisor; Belk, Keith E., advisor; Woerner, Dale R., committee member; Bunning, Marisa, committee memberTo view the abstract, please see the full text of the document.Item Open Access Evaluation of risk factors and detection of selected foodborne pathogens associated with fresh produce(Colorado State University. Libraries, 2015) Coleman, Shannon M., author; Goodridge, Lawrence, advisor; Bunning, Marisa, committee member; Woerner, Dale, committee member; Newman, Steven, committee memberThe Economic Research Service (ERS) of the United States Department of Agriculture (USDA) has reported increases of greater than 40 pounds per capita in yearly fresh produce consumption over the last 30 years. Outbreaks associated with fresh produce have also increased with an estimated 46% of foodborne outbreaks attributed to the consumption of various types of fresh produce from 1998 to 2008. One of the foodborne pathogens of concern is Salmonella spp., the leading cause of foodborne illness hospitalizations and deaths in the United States (US). Salmonella species are ubiquitous microorganisms necessitating increased need for proper surveillance. Testing for major pathogens such as Salmonella spp. and Escherichia coli O157:H7 in produce is impractical due to large retail volume, variability of contamination, and low sensitivity of current platforms. Irrigation, wash waters, and other agricultural sources offer greater probability for pathogen detection when combined with appropriate sample preparation. One food commodity commonly linked to Salmonella spp. outbreaks is tomato. Greenhouse/hydroponic production currently accounts for a large share of tomato production and has had a significant impact on the U.S. fresh-tomato market. There is little known about the possibility of contamination and internalization of foodborne pathogens via greenhouse/hydroponic commercial production since these operations are usually considered relatively sanitary due to the closed environment. I evaluated the risk factors associated with fresh produce contamination such as contaminated irrigation water and agricultural sources using simple sample preparation, subtyping techniques, and rapid molecular testing. This research is comprised of three study topics: development of an irrigation water concentration method with subsequent detection of Salmonella spp. and E. coli O157:H7 using Vitek Immuno Diagnostic Assay (VIDAS) technology, comparison of molecular serotyping methods to conventional serotyping methods for Salmonella enterica subsp. enterica isolates from food and agricultural sources, and evaluation of contaminated irrigation water as a risk factor for contamination of hydroponically grown tomatoes. Novel molecular methods were used in the three studies, including VIDAS UP® technology, Automated RiboPrinter, Luminex® xMAP Salmonella serotyping assay, and pulsed-field gel electrophoresis to detect foodborne pathogens. Results showed that a novel concentration method was effective in concentration of Salmonella spp. and E. coli O157:H7 with subsequent detection via mini VIDAS® technology. Molecular serotype methods were unable to serotype isolates obtained from agricultural sources. However, molecular methods allowed us to identify serovars associated with food and clinical sources. Salmonella Typhimurium did not survive well in the nutrient solution of a conventional hydroponic system used in tomato production. We also discovered that continuous contamination with S. Typhimurium might lead to contamination of the root systems but not contamination of the leaves and fruit. This work illustrates the continuing need to evaluate production methods and pathogen detection techniques to improve the safety of fresh produce.Item Open Access Evaluation of the effectiveness of supplemental lights vs no supplemental lights on hydroponically grown lettuce(Colorado State University. Libraries, 2017) Al-Houti, Fatima, author; Newman, Steven, advisor; Heuberger, Adam, committee member; Bunning, Marisa, committee memberThe purpose of the study was to examine the literature from the past 20 years regarding the evaluation of the Effectiveness of Supplemental lights vs No supplemental lights on Organic and Synthetic lettuce production via hydroponically growing lettuce in a greenhouse. The two types of lettuce are 1) green salad bowl and 2) gourmet blend mix. This research was conducted in the Colorado State University, Ft. Collins (CSUFC). The Researcher used quantitative research design with basic agricultural, horticultural, quantitative, and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) quantitative statistical calculations. This research method addressed agricultural horticulture research findings from agriculturalists, farmers, horticulturalists, policy makers, researchers, scientists, universities, and/or other key stakeholders in the agriculture, farming, greenhouse, and horticulture industry. The student researched the historical and current literature and the effects of altering the Supplemental lights for the maximum growth and development of healthy mineral rich lettuce. Twenty-three minerals were tracked and measured using the ICP-MS after production via Supplemental light vs. No Supplemental light using parts per million (ppm) converted from mg, (ng/g), and other amounts. This Thesis contains five chapters including: (1) Introduction, (2) Literature review, (3) Material and Methods, (4) Results and Discussion and (5) Conclusion. Finally, research recommendations are made for future replications and studies to accentuate and increase the validity and reliability of this study.Item Open Access Influence of preharvest factors on peach fruit quality and metabolism(Colorado State University. Libraries, 2021) Anthony, Brendon, author; Minas, Ioannis, advisor; Musacchi, Stefano, committee member; Prenni, Jessica, committee member; Bunning, Marisa, committee memberWorldwide peach consumption has been in steady decline throughout the past few decades due to poor fruit quality and consumer experiences. Fruit quality is developed in the orchard by optimizing preharvest factors and orchard practices. Several studies have been conducted to understand how these factors influence peach internal quality, but fail to control for confounding variables. One particular confounding variable that is influenced by preharvest factors and directly impacts fruit quality is maturation. Pomological experiments investigating the impact of preharvest factors on internal fruit quality must control for maturity. Historically, maturity control through destructive and subjective methods was not feasible nor efficient. The development of new technologies, such as visual radiation and near-infrared spectroscopy allowed the development of novel maturity indices (index of absorbance difference) that can be used for maturity control and quality assessment simultaneously in a single scan. The following literature review and experiments investigate three critical preharvest factors: training systems, canopy position and crop load (i.e., carbon supply), for their true impact on peach fruit quality development and metabolism, while controlling for maturity. The training system review demonstrates the progression of orchard design from three-dimensional, low-planting densities to planar, high-density plantings through the application of size-controlling rootstocks and vigor diffusion architecture. The canopy position trial revealed that the fruit's light environment is more influential in quality development and metabolic shifts than genotype or position alone. Canopies with uniform light distribution generate fruit of uniform quality and metabolite profiles across distinct positions. Fruit under sufficient carbon supply (i.e., thinned fruit) will exhibit superior quality and phenotype when compared to carbon-starved fruits at harvest, even when assessed at equal maturity. Primary metabolite profile differences between distinct carbon supply conditions are minimal at harvest due to experimental maturity control and metabolic processes being heavily regulated by development and maturation. While differences in secondary metabolite profiles are more distinct at harvest between carbon supply treatments. Although, both the primary and secondary metabolism demonstrate vast profile differences between carbon supply treatments early, and may prime the quality phenotype at harvest. Flavonoids are consistently elevated in carbon sufficient fruit throughout development. Phenylpropanoids, such as catechin, along with benzenoids, sucrose and sorbitol demonstrate strong relationships with high-quality fruit throughout experiments, while lipids, amino acids, monosaccharides and organic acids showcase relationships with inferior quality fruit. Overall, maturity control is necessary in pomological experiments assessing the true impact of preharvest factors on fruit quality and metabolism.Item Open Access Investigation of niche adaptation in Listeria monocytogenes subpopulations and small molecule inhibitors of Escherichia coli O157:H7(Colorado State University. Libraries, 2010) Corron, Jessica Lee, author; Nightingale, Kendra, advisor; Bunning, Marisa, committee member; Sofos, John, committee memberListeriosis is a severe and often fatal disease caused by the foodborne pathogen Listeria monocytogenes. At least two distinct subpopulations of this pathogen have been observed, including (i.) Epidemic clone (EC) strains, which have been responsible for numerous outbreaks worldwide, as well as the majority of sporadic listeriosis cases in the U.S., and (ii.) strains carrying a premature stop codon mutation (PMSC) in a key virulence gene inlA, leading to natural virulence attenuation. The latter population is prevalent in foods, with strains harboring an inlA PMSC comprising approximately 50 percent of food isolates. We thus hypothesized that these two distinct subpopulations have undergone niche adaptation, where EC strains have become adapted to a human host niche while inlA PMSC strains have become adapted to a food niche and additionally alternative mammalian hosts (e.g. mice, rats, etc.). In order to test this hypothesis we assembled a strain set of eight strains, four EC strains and four in/A PMSC strains, and subjected these strains to various assays, which mimic a host or food environment. Specifically we performed intracellular growth assays and cytotoxicity assays in macrophage like-cells. Additionally we performed invasion assays in mouse L929 fibroblast cells to determine the ability of these cells to invade cells other than human cells. InlA, a surface protein, binds to the receptor E-cadherin and mice possess a different isoform which does not allow for efficient InlA binding; therefore, these assays should provide insight on invasion of cells with different non-human isoforms of E-cadherin. Lastly, we performed cold growth assays in BEII broth at 7°C as well as a growth study on deli turkey in order to evaluate growth in food-like or food conditions. Overall, we found that although all strains grew similarly in all broth cold growth conditions; EC and inlA PMSC strains showed differences in terms of virulence phenotype as well as the ability to grow in RTE deli turkey. Although all strains grew similarly at all time points during intracellular growth experiments, differences between EC and inlA PMSC strains were observed at later time points in the cytotoxicity assays. Specifically, the inlA PMSC strains exhibited higher cytotoxicity 9, and 12 hours following inoculation {P = 0.0028, and P < 0.0001 respectively). All inlA PMSC strains invaded mouse L929 cells better than a standard laboratory control strain, in comparison to only one EC strain which showed the same trend (P<0.05). Lastly, inlA PMSC strains had higher exponential phase growth rates (P = 0.0243) when compared to EC strains when grown on deli turkey for 28 days. These data support the conclusion that EC strains are better adapted for pathogenesis in a human host while inlA PMSC strains are better adapted to survival in foods as well as in non-human hosts where inlA mediated invasion is not necessary for internalization. Escherichia coli 0157:H7 causes an estimated 73,480 cases of illness each year, a small percentage of these cases progress to a potentially fatal disease called hemolytic uremic syndrome or HUS, sometimes leading to kidney failure or even death in serious cases. The majority of E. coli 0157;H7 cases are food related, and cattle are implicated as the major reservoir host for this pathogen. Antibiotics are not recommended for the treatment of E. coli 0157:H7 infections, thus treatment options are limited. Therefore, it is critical to minimize the load of E. coli 0157:H7 that reaches the consumer. In order to identify compounds to be used for the control and treatment of this deadly pathogen, we designed a high throughput, small molecule, turbidometric growth assay for the identification of bactericidal or bacteriostatic compounds. Through this screening we investigated the potential of nearly 65,000 compounds, which were assayed in duplicate, and identified 43 which inhibited E. coli 0157:H7 growth. Of the 43 compounds, 38 were known bioactive compounds, while the other five were from libraries of commercially available chemical compounds. Many of the known bioactive compounds were known antibiotics, specifically cephalosporins (n=13), fluorquinolones (n=12), and tetracyclines (n=9), as well as one carbapenem and two other antibiotics. Additionally, an antiviral agent, an inhibitor of the tricarboxylic acid cycle, as well as two structurally related disinfectants, which are used in a number of non-clinical applications, were also discovered. Specifically, the non-clinical disinfectants show promise for spray-wash and dip type treatments to be implemented in the food supply, due to their antimicrobial activities against E. coli 0157;H7, and their cytotoxicity, which is similar to other widely used disinfectants.Item Open Access Listeria control and safe food training for dietary managers(Colorado State University. Libraries, 2010) Thigeel, Hanaa Abid, author; Kendall, Patricia A. (Patricia Ann), 1947-, advisor; Sofos, John Nikolaos, committee member; Bunning, Marisa, committee memberElderly individuals are a growing sector in the U.S. population. With that increase, the need for long-term care facilities (LTCF) is growing as well. It is estimated that 5% of individuals age 65 or older and 20% of individuals age 85 or older live in long-term care facilities. Due to aging, the immune system of the elderly becomes weak, which increases the vulnerability to foodborne illnesses. Other factors associated with aging like chronic disease, dementia, lack of physical activity and entering nursing homes, can also contribute to the increased susceptibility to foodborne diseases. For these reasons, caregivers of the elderly, including dietary managers who serve food to the elderly, should be aware of factors that can increase the likelihood of contracting infection. Listeria monocytogenes is a particularly important foodborne pathogen that can cause severe illnesses or even deaths in populations at higher risk for foodborne illness, including the elderly. "Listeria Control and Safe Food Training for Dietary Manager" was an on-line course developed to provide important information about this pathogen and suggested control measures. The training module targeted Dietary Managers and Registered Dietitians who work in LTCF. The module consisted of three segments and was 47 minutes long. The module included PowerPoint® slides, recorded audio, written scripts and reference links. Pre and post questionnaires were used to measure the course outcomes along with course evaluation items. Multiple-choice knowledge questions were developed and evaluated for reliability, content validity and difficulty by module developers. Of 20 questions initially developed from the course content and tested for reliability, 13 questions were selected as final questions. Participant recruitment for the module pilot testing was conducted through winter 2010. Participants were recruited via state Dietary Manager Associations and state associations for Registered Dietitians and Dietetic Technicians. Emails and advertisement fliers were used for recruiting efforts. Of 211 participants who showed interest in the module, 143 participants were able to complete both the pre and post knowledge questionnaires. Participants who completed the course received one continuing education credit from their professional organization. The module knowledge scores achieved significant increase (P<0.0001) from pre to post-questionnaire. The knowledge score overall increased from 65.7% correct pre to 88.7% post. The course evaluation showed that more than 90% agreed or strongly agreed that they gained new and useful information from the course and planned to use the information in training others. They also found the web module a convenient way to earn continuing education credits. Feedback gained from course pilot test and evaluation will be considered as a helpful tool in making improvements to future on-line courses.Item Open Access Molecular ecology of foodborne pathogens in primary production agriculture environments in northern Colorado and investigations in internalin A diversity in Listeria monocytogenes DUP-1039C strains(Colorado State University. Libraries, 2011) Manuel, Clyde Simmons, author; Nightingale, Kendra, advisor; Goodridge, Lawrence, committee member; Avens, John, committee member; Bunning, Marisa, committee memberListeria monocytogenes, Salmonella, and Shiga toxin-producing Escherichia coli (STEC) represent clinically important human foodborne pathogens. The presence, transmission, and molecular epidemiology of these pathogens in primary agricultural environments (i.e., grazing pastures and produce farms) is understudied and represents a significant knowledge gap. We conducted a two year longitudinal sampling study in Northern Colorado to assess the presence, genetic diversity, and potential transmission patterns of these pathogens in production agriculture environments. Five produce farms and five grazing pastures in Northern Colorado were selected and sampled during the spring, summer, and fall in 2009 and 2010. Microbiological analysis was performed on composite soil (228 samples), composite fecal (105 samples), composite water (80 samples), and individual drag swabs (227 samples) to detect Listeria (i.e., L. monocytogenes and other Listeria spp.), Salmonella, E. coli O157:H7, and non-O157 STEC. Samples were evaluated to detect each target organism using modified versions of the U.S. Food and Drug Administration Bacteriological Analytical Manual and presumptive colonies for each target organism were confirmed by PCR. Overall, eight (1.25%), eleven (1.7%), and 22 (3.4%) of samples tested positive for L. monocytogenes, Salmonella, and STEC, respectively. Thirty-one samples contained Listeria spp. other than L. monocytogenes, the majority of which were determined to be Listeria innocua by sigB allelic typing. Additionally, 20 samples were positive for a proposed novel Listeria spp. that displayed unique phenotypic traits, i.e., non-motility and impaired growth at 37oC. Pulse field gel electrophoresis analysis indicated isolates obtained in this study to exhibit significant genetic diversity. These results demonstrate a rare presence of foodborne pathogens in agricultural environments in Northern Colorado. Prevalence and molecular subtyping data generated by this study provides important insight into the molecular epidemiology of these pathogens in the pre-harvest agriculture environment. Listeria monocytogenes uses the key virulence factor internalin A (InlA; encoded by inlA) to traverse host cell barriers during establishment of a systemic infection. Multiple naturally occurring mutations leading to a premature stop codon (PMSC) in inlA have been reported worldwide, and these mutations have been shown to be virulence attenuating in guinea pig infection models. Ribotype DUP-1039C is a broadly distributed molecular subtype within L. monocytogenes that has been commonly isolated along the food continuum. Ribotyope DUP-1039C isolates have been shown to carry three distinct PMSC mutations in inlA, including a frameshift mutation in a 5' homopolymeric tract of adenine restudies (PMSC4), a C to T substitution leading to a PMSC at aa 562 (PMSC 7), and a G to A substitution leading to a PMSC at aa 684 (PMSC 12). Additionally, DUP-1039C isolates carry one of three allelic types of a 5' hypermutable region of inlA, which may have a role in phase variation. A selection of DUP-1039C isolates available from the PathogenTracker database (n=368) were screened for known inlA PMSCs and the allelic type of the 5' hypermutable region by two multiplex single nucleotide polymorphism (SNP) genotyping assays. SNP genotyping assays included (i) a previously described single nucleotide extension assay and (ii) a newly developed probe-based assay, which uses differentially labeled probes to differentiate between wild type (WT; AAAAAAA), frameshift (FS; AAAAAA), and interrupted HT (IHT; AAGAAAA) 5' allelic types of inlA. DUP-1039C isolates carrying a PMSC in inlA were not uniformly distributed among isolation sources. inlA PMSC type 4 (n=19) and PMSC type 7 (n=25) were associated (P < 0.05) with isolation from food and food environments, while WT isolates encoding a full-length InlA (n=184) were associated (P < 0.05) with non-food environments and mammalian hosts. Interestingly, all DUP-1039C isolates carrying inlA PMSC7 also had the IHT inlA allele in the hypermutable 5' region, and these isolates persisted within a single NY state seafood processing plant. The 5' IHT allelic type was frequently encountered among isolates from diverse sources, though at lower frequencies as compared to the WT allele. Together, the results may help to explain the underlying mechanisms behind the ability of lineage II L. monocytogenes isolates to adapt to both human and environmental niches.Item Open Access Rebuilding local food systems: marketing and economic implications for communities(Colorado State University. Libraries, 2011) Gunter, Allison Lynn, author; Thilmany, Dawn, advisor; Bunning, Marisa, committee member; Pritchett, James, committee memberThe research community has identified value chains as one of the most successful ways for small and mid-scale distributors, focused on providing locally sources foods to structure their businesses. The concept of value chains is still relatively new, so by conducting case studies of successful value chains this thesis provides insight into the best practices for new value chains, organized based on the value chain's main customer. After conducting case studies, the next step was to address one of the claims made by local food proponents: that increased local food consumption has a positive impact on the economy of a community. The local school food procurement program studied in this paper provides evidence that yes, the direct impact on the local economy is positive when there is an increase in local food purchasing. But that impact is quite small and may or may not cover the cost of investment necessary to build the necessary infrastructure. Moreover, that positive impact is dependent on some important linkages between the new food distribution enterprise and other economic actors (workers, owners) in the community.Item Open Access Salmonella contamination in poultry – are we missing a potential reservoir?(Colorado State University. Libraries, 2017) Sexton, Ty L., author; Martin, Jennifer N., advisor; Geornaras, Ifigenia, committee member; Belk, Keith E., committee member; Bunning, Marisa, committee memberThe objective of this study was to assess presence and characteristics of Salmonella enterica found in synovial fluid of broiler carcasses. Synovial fluid of three individual joints from 500 broiler carcasses was individually sampled (1,500 total samples) from five broiler processing facilities located in the Southeast and Western U.S. The external surface of broiler carcass was decontaminated prior to sampling of the shoulder, coxofemoral, and tibiofemoral joints. Individual samples were enriched, composited, and subjected to rapid PCR-based detection of Salmonella. Individual samples from any positive composites were also enriched before determination of Salmonella presence in the same manner. Positive individual samples were subjected to secondary enrichment before plating onto selective agar for isolation of Salmonella. Salmonella isolates were serotyped before determination of antimicrobial susceptibility. Overall, 1.00% (5 out of the 500 broiler carcasses) of composite samples, and 0.47% (7 out of 1,500 samples) of individual samples were positive for Salmonella. Five of the seven isolates were susceptible to all drugs and determined to be Salmonella Enteritidis. The remaining two isolates, identified as Salmonella Typhimurium, were resistant to streptomycin. To our knowledge, no previous assessments of Salmonella in synovial fluid of broilers has been reported; however, results of the present study suggested that Salmonella may be present in synovial fluid of broilers. Although low prevalence, this information provides valuable insight into potential poultry contamination pathways and warrants further exploration.Item Open Access Sensory quality of cheddar cheese made with bulk starter and direct to vat starter culture(Colorado State University. Libraries, 2024) Musetti, James, author; Stone, Martha, advisor; Bunning, Marisa, committee member; Narayanan Nair, Mahesh, committee member; Miller, Jeff, committee member; Romero, Dennis, committee memberThe production of cheese in the world consumes around 35% of the total milk production and has increased on average by 4% per year over the past 30 years (Fox et al., 2017). Cheddar consumption had modestly and steadily increased in the past several years in the United States and has increased 2.22% from 9.87 pounds per capita to 10.09 pounds per capita (USDA ERS Dairy Data, n.d.). Over the past several decades modernization of cheddar production in the United States has enabled producers to increase throughput with fewer resources resulting in more efficient production and consistent quality. This includes the common practice of standardizing cheese making procedures on a strict timing basis and using reliable and consistent rate and extent of acidification through culture selection and dosage. One such advancement was the development of defined starter cultures produced in a frozen or lyophilized state to be applied directly to the vat as a direct to vat inoculant (DVI) by the cheesemaker. Previously lactic acid bacterial cultures, defined or natural, were propagated by the cheesemaker prior to cheese production by a preceding fermentation of milk or whey and used to inoculate the milk for cheddar production. The current research investigated if any differences in cheddar cheese biochemical and sensory characteristics exist among cheeses made with bulk starter and DVI technologies. Cheeses were produced using bulk starter culture technology, DVI technology, and DVI technology with pre-acidification then ripened for 90 days. The rate and extent of acidification in the process was analyzed with cheese composition, extent of the catabolism of protein and fat during ripening, and sensory characteristics of the cheese analyzed. MANOVA model analysis reported that the treatments had a significant effect on the cheesemaking process (p=0.00381). Coagulation time was the only response found to be statistically significant (p=0.00081) from the process, biochemical, and sensory responses after mixed model analysis was completed. The make data or milk batch was found to have a significant effect on the cheese production process (p=0.00036), biochemistry (p=0.04391), and sensory characteristics (p=0.00002) of the cheeses. Therefore, it can be concluded that there was no difference in cheddar proteolysis, lipolysis, and sensory characteristics in cheeses manufactured with bulk starter and DVI, and there was no difference in cheddar proteolysis, lipolysis, and sensory characteristics in cheeses manufactured with bulk starter and DVI culture preparations with recipe adjustment for coagulation. The null hypotheses cannot be rejected.Item Embargo Survival and persistence of Salmonella enterica in dry bulb onion production practices; a risk assessment approach(Colorado State University. Libraries, 2023) Carpenter, Griffin, author; Gutierrez-Rodriguez, Eduardo, advisor; Prenni, Jessica, advisor; Bunning, Marisa, committee member; Uchanski, Mark, committee memberThe first chapter of this research thesis focuses on onion production practices and the potential risks associated with contamination of dry bulb (DB) onions along the cropping cycle with human enteric pathogens. Dry bulb onions are a widely consumed vegetable globally that has been previously thought to be safe from human pathogen contamination. This literature review summarizes the history of outbreak-related information, the biology of etiologies of interest, the body of literature associated with microbial risks and onions, and pre-and post-harvest production practices with respect to the risk of contamination with human pathogens. The information discussed in this review is useful for portraying the complex interactions of the microorganisms of interest and for industry professionals, producers, and consumers with respect to management and applicable risk mitigation efforts in the future for DB onions. The second chapter of this research thesis focuses on determining the microbial risk factors associated with pre-and post-harvest commercial DB onion production practices. In the past 30 years DB onions have not been involved in foodborne illness outbreaks in the United States. However, two major multi-state foodborne outbreaks linked to Salmonella spp. (Sal) in 2020 and 2021 have altered the perception of producers and consumers about the microbial safety of this crop. Despite significant efforts to identify the source and route of contamination, little knowledge exists regarding the risk factors associated with enteric pathogen contamination along the DB onion cropping cycle. Thus, the goal of this research was to develop risk assessment profiles of DB onion production practices capable of identifying and reducing Sal contamination in pre-and post-harvest activities. DB onion cultivars grown in the state of Colorado were used to determine the ability of these onions to potentially inhibit Sal. This was achieved by testing the minimum inhibitory concentration (MIC) with a cocktail of attenuated and pathogenic Sal at 3,600 mg/L of onion slurry. All evaluations indicated that there was no significant inhibition of Sal irrespective of the type of strain or DB onion cultivar. Pre- and post-harvest risk quantification was determined based on field inoculations of a 2-strain attenuated Salmonella (attSal) cocktail. Survival and persistence of attSal was assessed at multiple production stages including at the 3 leaf stage, lifting, topping, curing, harvest, transport, and packing house environments. From these evaluations, results indicate that attSal is capable of surviving in both DB onions and soil for over a period of 64 days across the entire cropping cycle including harvest. Cultivar, agronomic practice, and UV index had no significant impact in our ability to recover attSal and in the survival of these strains along the cropping cycle in soil or DB onion. At harvest, the population of attSal on DB onion was 3.4 MPN/g at the three-leaf stage development (3LS), log 2.07 cfu/g at topping and log 1.87 cfu/g at lifting irrespective of DB onion cultivar. During interstate transport, the population of attSal further decreased to undetectable levels (< 3.0 MPN/g of DB onion). This scenario was considered a low-risk event for packinghouse purposes. Commercially grown DB onions were also included in all packinghouse evaluations. These onions were free from naturally occurring Sal and were inoculated with chalk containing attSal to mimic soil dust contamination. This chalk had an initial attSal population of log 5.5 cfu/g DB onion and for packinghouse purposes, it was considered a high-risk contamination event. A total of 14 locations within the packing line were selected to test the potential transfer of attSal from inoculated DB onions to control treatments and food contact surfaces. Additionally, DB onions from both high and low-risk contamination events were collected during sorting and packing. In both high and low -risk packing line contamination events, attSal was not recovered from any food contact surface or DB onions (Totl N= 897) over the course of 4 days of processing. A dry sanitation event was implemented in the packing line to assess whether such approaches could reduce contamination from attSal or any other residues left by the crop or by previous activities at the packing line. Our dry sanitation cleaning protocol involved the cleaning of the crop contact surface with a dry brush-single use paper towel, followed by sanitation with a food grade alcohol wipe, followed by a spray of an ethanol alcohol solution (food grade) at 75%, followed by a final removal of alcohol residues with a dry single-use paper towel. This approach proved to be effective in reducing packing line residues Adenosine triphosphate (ATP) measurements and the population of two indicator organisms Enterobacteriaceae (EB) and Escherichia coli (EC). However, the effectiveness varied with the type of surface. Plastic and camel hair bristles were not cleanable. There was no correlation between the population of EB and EC and the presence of attSal from high and low-risk contamination events. Dry sanitation events clearly indicated that it is a viable and useful practice that could be implemented on DB onion packing lines. The absence of cleaning and sanitation will be conducive to significant accumulation of DB onion debris and for the potential proliferation of indicator and pathogenic organisms. These findings are important to industry professionals, producers, and consumers regarding developing risk profiles and application of risk mitigation strategies to improve the microbial safety of DB onions.Item Open Access The effect of CSA membership on fruit and vegetable intake(Colorado State University. Libraries, 2011) Hedden, Jessica L., author; Auld, Garry, advisor; Bunning, Marisa, committee member; Stonaker, Frank, committee memberObjective: Increased fruit and vegetable intake has been associated with decreased BMI and disease rates (Ford & Mokdad, 2001; Lin & Morrison, 2002; Liu, 2000; Newby, et al., 2003; Riboli & Norat, 2003). Multiple barriers inhibit fruit and vegetable consumption, including the availability in the U.S. (Pollard, et al., 2002). Currently, there are many forms of alternative food networks (AFNs) such as farmers markets, community gardens and community supported agriculture (CSAs) providing local, seasonal produce to consumers, attempting to address availability and provide other outlets for fresh produce. This study examines the influences that CSA membership may have on fruit and vegetable intake. Methods and Materials: Sixty-one participants were recruited from an average-sized CSA (<100 members; CSU), a large CSA (>2000 members; GFF), and non-CSA members (NON- as a control group). Three, 24-hour dietary recalls were collected by phone to estimate the produce components of each participant's diet over 6 months during the 2010 CSA season. Each diet was quantified based on the amount and variety of fruit, vegetables, total fruit and vegetables, and leafy greens. Results: The groups were very similar in fruit and vegetable consumption at baseline. At the peak of CSA season (T2), GFF participants were consuming more vegetables (2.96 [0.26]) and more total fruits and vegetables (4.45 [0.40]) than NON participants (2.16 [0.29], p<0.1; 3.38 [0.45] p<0.1, respectively). Both CSU and GFF participants had an increased variety of vegetables over NON participants (p<0.01 and p<0.001, respectively) and participants from both CSAs had higher total variety (p<0.01) at Time 2. Conclusions/Implications: From this study, variety was the major dietary difference in produce intake between both CSA groups and the control group. Demographic characteristics of participants were similar, indicating that the observed changes were likely a true relationship. A diet with increased variety of fruits and vegetables has been associated with increased health benefits, having the potential to reduce disease rates (Wirt & Collins, 2009). More studies need to be conducted examining larger study populations, the potential effect CSAs may have on low-income populations, and other forms of alternative food networks, such as farmers markets or community gardens.Item Embargo The impact of rootstock on peach tree vigor, light environment, fruit quality, and metabolism(Colorado State University. Libraries, 2024) Pieper, Jeffrey Ross, author; Minas, Ioannis, advisor; Bunning, Marisa, committee member; Caspari, Horst, committee member; Prenni, Jessica, committee memberThe key to Colorado's successful peach industry is superb fruit quality. The fruit quality growers achieve allows for the highest premium 'farm-gate' price per pound in the nation. Fruit quality is created in the orchard via the interaction of several pre-harvest factors. One critical pre-harvest factor that has several knock-on effects for orchard management decisions is rootstock selection. Rootstock selection has the potential to impact the longevity, productivity, efficiency, and profitability of an orchard, and is dependent on climatic and edaphic environments as well as the soil microbiome. Rootstock selection may also allow growers to augment orchard design through vigor manipulation. In Colorado, growers are faced with relatively short growing seasons, sudden fall and spring frost events, and calcareous soils which limit the availability of certain nutrients. The unique growing environments coupled with the need for high quality fruit production makes rootstock selection limited. Identifying rootstocks suitable for production in Colorado and determining how they impact fruit quality is paramount. While previous studies have evaluated rootstocks for their performance and relationship to fruit quality, few have limited confounding factors such as crop load, canopy position, and or physiological maturity when assessing fruit. The following experiments evaluated twenty-one genetically diverse rootstocks for their phenotypic and agronomic performance and potential use in Colorado production systems. The nine-year performance review, in chapter one, details the productivity and suitability of seventeen genetically diverse peach rootstocks in Colorado growing conditions. The trial determined rootstock vigor strongly correlates with cumulative yield. However, vigor also showed an inverse relationship with internal fruit quality development measured as dry matter content (DMC) and soluble solids concentration (SSC). The trial showed interspecific peach and non-peach hybrids outperformed peach seedling rootstocks. One interspecific peach rootstock in particular, 'Krymsk® 86', performed exceptionally well and has since been widely adopted by industry. By controlling for several confounding factors, the rootstock vigor trial, chapter two, demonstrated the true impact of vigor and light availability on fruit quality enhancement and primary metabolite profiles. Fruit developing in reduced vigor canopy of the dwarfing rootstock 'Krymsk® 1' had increased light availability and enhanced internal fruit quality parameters (DMC and SSC) at harvest. Mesocarp metabolites relating to internal quality showed they are up and down accumulated by rootstock vigor and the light environment. Several metabolite classes including soluble sugars, cyclitols, flavanols, and chlorogenic acids were associated with 'Krymsk® 1', a low vigor rootstock that had high light availability and enhanced fruit quality profiles. 'Atlas™' and 'Bright's Hybrid® 5', both vigorous rootstocks, showed low light availability and reduced fruit quality. The vigorous rootstocks also showed an increase of amino and fatty acids compared to the standard and dwarfing rootstocks. The six-year physiological and agronomic performance of modern semi-dwarfing rootstocks trial, chapter three, reiterated the impact of vigor on yield, light availability, and fruit quality development. Furthermore, the trial showed increased vigor was related to an increase of gummosis incidence and severity. Also, intra-specific Prunus hybrids had increased rates of proleptic shoot formation, however, some showed they were susceptible to iron chlorosis. Overall, the rootstock trials identify key parameters of performance and suitability in Colorado production systems. The outcomes indicate that rootstocks with increased vigor resulted in higher yields per tree, however, lower light availability in the canopy decreased DMC and SSC. While rootstock genotype and vigor are influencing peach fruit development and quality, their effect on light availability may play a more significant role in achieving optimal yield and fruit quality and augmented metabolite profiles. Additionally, this work demonstrates the importance of controlling for confounding variables when evaluating preharvest factors for their impact on internal fruit quality and metabolite profiles.