Browsing by Author "Kendall, Patricia, committee member"
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Item Open Access Control of Escherichia coli O157:H7 and Listeria monocytogenes in meat and poultry products with chemicals and heating treatments(Colorado State University. Libraries, 2010) Shen, Cangliang, author; Sofos, John, advisor; Kendall, Patricia, committee member; Belk, Keith, committee member; Scanga, John A., committee memberObjectives of studies included in this dissertation were to evaluate the effects of chemical antimicrobials, such as cetylpyridinium chloride, lactic acid, hops beta acids, commercial salad dressings, and heat treatments including cooking with various appliances and microwave oven heating to control Escherichia coli 0157:H7 in moisture enhanced noninact beef and Listeria monocytogenes on ready-to-eat (RTE) meat and poultry products. In the first study, the effect of different cooking appliances on thermal inactivation of E. coli 0157:H7 in nonintact beef steaks of different thickness was evaluated. In general, the thicker the steaks, the higher the reduction levels reached, and roasting in a standard kitchen oven showed the best inactivation effect compared to the other cooking appliances. The second study evaluated thermal inactivation of E. coli 0157:H7 in nonintact beef steaks with pan-broiling or roasting appliances set at different temperatures. Results showed that setting the cooking appliances at higher temperatures resulted in higher reduction levels of E. coli 0157:H7 cells in nonintact beef steaks compared to the lower ones. The third study involved comparison of inactivation of different types of stress-adapted or unstressed E. coli 0157:H7 cells, inoculated in moisture enhanced nonintact beef steaks with various brining solutions and cooked by pan-broiling on an electric skillet. It was evident that acid stress-adapted cells were more resistant to heat treatment, while cold or desiccation stress-adapted cells were more Hi sensitive to heat treatment than controls. The lowest pathogen counts survived during cooking of beef steaks moisture enhanced to include cetylpyridinium chloride or lactic acid for all stressed inocula tested, thus, indicating that cetylpyridinium chloride and lactic acid could be considered as potential antimicrobial agents for use in beef brining solutions. An additional study evaluated the antilisterial activity of hops beta acids (HBA) in broth medium. HBA exhibited promising antilisterial activity in culture broth, and its activity was increased with increasing concentrations (0.5 to 5.0 pg/ml), and when combined with potassium lactate (1%), sodium diacetate (0.25%), or acetic acid (0.1%), at 4°C. In a subsequent study, HBA applied as dipping solutions (0.03 to 0.10%) on frankfurters, inoculated with L. monosytogenes, vacuum packaged and stored at 4 or 10°C, inhibited pathogen growth for 30 to 50 (4°C) or 20 to 28 days (10°C). The last two studies were designed to detect the antilisterial effects of commercial salad dressings, oil with vinegar or lemon juice, on artificially inoculated frankfurters, diced ham and turkey breast during simulated home storage, without or with prior microwave heating for 30 s or 45 s. Results indicated that microwave heating followed by immersing in salad dressings, especially oil with vinegar, could potentially contribute to control of L monocytogenes on RTE meat and poultry products in the home environment. The results of all studies in this dissertation indicated that certain chemical antimicrobials and heating treatments could be effectively to control E. coli 0157:H7 and L. monocytogenes in meat and poultry products.Item Open Access Examining the application of the transtheoretical model of change for fruit and vegetable consumption among college students(Colorado State University. Libraries, 2002) de Oliveira, Maria do Carmo Fontes, author; Jennifer Anderson, advisor; Kendall, Patricia, committee member; Auld, Garry, committee member; Morgan, George, committee memberNutrition education messages about the adequate amount of fruits and vegetables in the diet have the potential to disseminate information the optimum level of fruit and vegetable intake to the population. However, this potential will be effective, only if the audience incorporates these messages. To facilitate the acceptance of nutrition education messages, we need to understand the process of behavior change across different behaviors and cultural/ethnic groups. The main purpose of this study was to examine the applicability of the Transtheoretical Model for fruit and vegetable eating behavior in male North American, Latino and Asian college students at Colorado State University. First, a 40-item scale was developed to measure the processes of change. Second, stages of change for eating five fruits and vegetables a day were assessed. Third, the relationship between stages of change and processes of change constructs for fruit and vegetable consumption was examined. Results showed that the developed scale was reliable and valid for the target population. Most of the participants were classified as in the preparation or contemplation stages of change, and the stage classification was significantly related to the participant's cultural/ethnic background. North American and Latino participants were predominantly in preparation while Asian participants were in precontemplation. In addition, the North American and Latino groups used less processes of change (stimulus control, dramatic relief and environment reevaluation) than the Asian group. The relationship between stages of change and processes of change indicated that generally the processes of change scores for fruit and vegetable intake were lower in early stages of change than in later stages of change. The finding that each cognitive/experiential composite score was higher than behavioral composite scores across stages of change did not agree with most studies in smoking, but agreed with some studies on diet and exercise. Although more research needs to focus on the applicability of the stages of change and processes of change constructs, the present study provides partial evidence of the value of the Transtheoretical Model in fruit and vegetable eating behavior in the nutrition education arena.Item Open Access Farm-to-table food safety for Colorado produce crops: a web-based approach for promoting good agricultural and handling practices(Colorado State University. Libraries, 2011) Wall, Gretchen Lynn, author; Bunning, Marisa, advisor; Kendall, Patricia, committee member; Lamm, Dennis, committee memberFresh fruits and vegetables have been increasingly associated with cases of foodborne illness (CDC, 2010; FDA, 1998). Direct links of these outbreaks to farms highlights the need to employ strategies to reduce pathogenic microbial contamination of fresh produce at this stage of the food system (Bihn & Gravani, 2006). One approach to fresh produce safety on the farm involves participation in voluntary audits based on Good Agricultural Practices (GAPs) and Good Handling Practices (GHPs). Currently, only a small percentage of Colorado producers employ this strategy. In response to new regulations and guidelines, changing food consumption patterns, and improved market access, Colorado producers need to have the flexibility to adopt programs that can help them meet the demands of providing a safer food supply (Rejesus, 2009). In response to these issues, Farm to Table Food Safety for Colorado Producers, a series of three web-based GAPs/GHPs trainings, was developed following the guidelines of FDA, USDA, and the National GAPs program. These trainings were implemented and evaluated targeting small farm producers of fresh fruits and vegetables based on an initial needs assessment to identify potential barriers and drivers for adopting these types of programs. In addition, a series of consumer-friendly, down-loadable fact sheets with nutrition, safe food handling, and recommended storage guidelines was developed to help promote ten selected Colorado specialty crops: apples, berries, broccoli, leafy greens, melons, peaches, peppers, potatoes, squash, and tomatoes. The approach of developing technology-based training modules and educational materials allowed for improved accessibility to growers and produce consumers across the state while accommodating their variable time schedules and need for convenient, reliable information. Pre and post questionnaires were used to measure self-assessed knowledge outcomes along with overall course evaluation items. As a result of participating in the webinar series, producers, buyers, and Extension professionals indicated they planned to utilize the information and resources. Specific topics related to GAPs such as irrigation water quality, management of manure and compost, and food safety legislation were of most interest to the participants and had the most significant increases (p<0.001) in self-reported knowledge, pre to post webinar. The course evaluation showed that produce buyers, Extension professionals, and other webinar attendees intend to utilize the material presented in the webinar series directly or indirectly in their professions, with average mean scores on a 5- point Likert scale (1= Very Unlikely and 5= Very Likely), of 4.2, 4.2, and 3.6, respectively. Overall, reviewers rated the produce fact sheets with a mean score of 4.34 for usefulness (1=Not Useful and 5= Extremely Useful). Feedback gained from the webinar and produce fact sheet evaluations will be a helpful tool in making improvements for future web-based on-farm food safety educational materials.Item Open Access Increasing fruit and vegetable consumption in grade-school children(Colorado State University. Libraries, 1997) Ryan, Linda DeBell, author; Jennifer Anderson, advisor; Bechtel, Peter J., advisor; Kendall, Patricia, committee member; Keefe, Thomas, committee member; Jansen, Duane, committee memberDiets rich in fruits and vegetables have many health benefits. Nutrients in fruits and vegetables such as vitamins, minerals, and fiber help protect individuals from certain cancers and cardiovascular disease. Children in our nation are not meeting the national health objectives or recommendations to eat plenty of fruits and vegetables. This research assessed whether the provision of classroom nutrition education on the benefits of eating fruits and vegetables and providing more fresh fruits and fresh vegetables in the school lunch program increased consumption by grade-school children. This research was completed in three parts. The purpose of part one (The Nutrition Education Intervention Study) was to determine if providing nutrition education to grade-school children and the community increased fruit and vegetable consumption. In this study a nutrition education program was given to the grade-school children and community of Holyoke (experimental group). The effects of the nutrition education intervention were compared to the control group (i.e., the grade-school children and community of Haxtun), which received no intervention. A nutrition education program was developed and designed as a hands-on education program for the children and for the community. The intervention included nutrition education materials, demonstrations, and activities on increasing the consumption of fruits and vegetables and good nutrition. Fruit and vegetable consumption was measured by a 24-hour food recall (children only) and a pre- and post-questionnaire for the children and community. The results showed mean fruit and vegetable consumption increased by 1.37 servings per day (from 2.45 to 3.82) among the grade-school children using the 24-hour food recall assessment method and 0.93 (3.93 to 4.86) using a pre/post self-reported questionnaire (both at p[less than or equal to]0.05 ). The community's mean fruit and vegetable intake increased by 0.66 servings per day (3.28 to 3.94) from the pre to post questionnaire (p[less than or equal to]0.05 ). The purpose of part two (The Fresh Fruit and Vegetable Intervention Study) was to determine if providing quality fresh fruits and fresh vegetables increased consumption by grade-school children. In this study the Department of Defense (DOD) provided fresh fruits and vegetables to schools within Colorado. The schools receiving the fresh fruits and vegetables (experimental group) were compared to schools not receiving fresh produce (control group). The children in the experimental group were offered a variety of high quality of fresh fruits and vegetables in the school cafeteria with their school lunches. Fruit and vegetable consumption was measured by subtracting plate waste from the beginning weight for each fruit and vegetable served. The results were as follows: 1. The experimental group took on an average 2. 70 ounces combined fruits and vegetables per child, the control group took 3.14 ounces per child (p[greater than or equal to]0.05). 2. The children in the experimental group consumed a greater percentage (73%) of fruits and vegetables than the control group (61 %) (p[less than or equal to]0.05). 3. The children in both groups consumed more fruits than vegetables. In part three, the results of the two studies were completed. The results showed that there was no difference in the two approaches, both interventions increased consumption of fruits and vegetables in the grade-school children.Item Open Access Longitudinal study of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes in a small and very small fresh meat processing plant environment(Colorado State University. Libraries, 2012) Orellana, Eva Danira Borjas, author; Bunning, Marisa, advisor; Nightingale, Kendra, committee member; Kendall, Patricia, committee memberSmall and very small fresh meat processing facilities have scarce resources to monitor foodborne pathogen contamination patterns and transmission dynamics in their premises. Environmental control of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes, is important to prevent cross-contamination of meat products by pathogens that may persist in a facility. Although Listeria spp. are non-pathogenic, a high prevalence in a meat processing environment indicates failures in the cleaning and sanitation procedures. The purpose of this study was to conduct a six month longitudinal study to monitor Escherichia coli O157:H7, S. enterica, L. monocytogenes and other Listeria spp. contamination patterns, and to identify potential harborage sites in a small and very small fresh meat plant. Additionally, in order to gain insights about the facilities, manufacturing practices, and other relevant practices, managers from the two participating plants were asked to complete a questionnaire. Feedback of the study results was given to plant staff in a bilingual session, along with a basic training in food safety topics. Both plants were sampled during mid-shift operation on a monthly basis. Environmental site (n ≤ 54) and beef carcass composite samples were collected mid-shift. Samples collected included food contact surfaces (e.g., tables, scales, bins), and non-food contact surfaces (e.g., walls, drains, sinks). Overall, 1,979 environmental sponge samples were collected and microbiologically analyzed to detect and isolate S. enterica, E. coli O157:H7 and L. monocytogenes. Further characterization of the recovered pathogen isolates by molecular subtyping (e.g. PFGE, ribotyping) was performed to gain insight in contamination transmission within the facilities. S. enterica was isolated from 15 (4.5%) and 8 (2.4%) samples from Plant 1 and Plant 2, respectively. Characterization by PFGE using XbaI generated 6 different patterns in Plant 1, whereas all isolates from Plant 2 had the same pattern. S. enterica was recovered more than once from two sites in Plant 1, but only 2 isolates recovered from a drain in the slaughter area yielded the same PFGE pattern. E. coli O157:H7 was detected in 1.2% of samples in Plant 1; PFGE using XbaI generated 2 different patterns, and none was recurrently isolated from a single site. E. coli O157:H7 was not isolated from Plant 2. Over the course of the study, roughly 28% and 6% of the samples tested positive for Listeria spp. other than L. monocytogenes, in Plant 1 and 2, respectively. Listeria innocua was the predominant Listeria spp. in both plants. L. innocua allelic type AT-1 was recovered from 15% of samples collected across Plant 1, whereas in Plant 2, type AT-6 was found mostly contained in the slaughter area. L. monocytogenes was isolated from 17% of the samples from Plant 1 and 1.2% of samples from Plant 2. Roughly 97% (54/56) of L. monocytogenes isolates recovered from Plant 1 belonged to ribotype DUP-1042B, which was recovered up to five times from 15 different sampling sites across the facility; the remaining two isolates belonged to ribotype DUP-1057B. Noteworthy, ribotype DUP-1042B belongs to a major human outbreak-associated clonal group known as Epidemic Clone I, posing a high risk for meat product contamination in this facility. Conversely, in Plant 2, L. monocytogenes DUP-1030B was recovered from three samples and only one isolate belonged to DUP-1030A; no single site in Plant 2 repeatedly tested positive for L. monocytogenes. In light of the bacteriological results from this study, good manufacturing practices for the control of environmental contamination practiced by Plant 2 seem to be effective in the prevention of contamination spread and pathogen persistence; e.g. sanitizer dip stations at entry points, use of foam to clean equipment, use of quaternary ammonium compounds (QAC) or chlorine for sanitation of floors and other food contact surfaces, and QAC for sanitation of drains. Some high risk procedures practiced by the cleaning crew in Plant 1 may contribute to contamination spread; e.g., use of high pressure water for daily cleaning of drains, no sanitation step after cleaning drains, and lack of designated cleaning tools for drains. Although economic resources may be limited, microbiological monitoring of the plant environment is useful from a risk assessment standpoint. In this study, the prevalence of L. monocytogenes was high and widespread in Plant 1, and a predominant strain belonging to an Epidemic Clone group was elucidated. This information increases awareness and provides the plant management with valuable information for decision making, and motivates the implementation of new policies and targeted interventions in problematic areas. Our findings suggest that L. monocytogenes and L. innocua have higher prevalence than S. enterica and E. coli O157:H7 in the fresh meat processing plant environments. While L. monocytogenes may persistently contaminate the environment of fresh meat processing plants, E. coli O157:H7 and S. enterica contamination appears to be mostly sporadic.Item Open Access Survival and inactivation of Listeria monocytogenes, shiga toxin-producing Escherichia coli, and multidrug-resistant and susceptible Salmonella serovars exposed to heat and antimicrobials on food contact and food surfaces(Colorado State University. Libraries, 2013) Fouladkhah, Aliyar, author; Sofos, John, advisor; Nightingale, Kendra, advisor; Kendall, Patricia, committee member; Belk, Keith, committee memberTo view the abstract, please see the full text of the document.Item Open Access Survival and persistence of foodborne pathogens in food residues on packaging materials and reduction of Escherichia coli O157:H7 and Salmonella in beef trimmings(Colorado State University. Libraries, 2012) Nunnelly, Matthew Charles, author; Sofos, John N., advisor; Woerner, Dale, committee member; Kendall, Patricia, committee memberFoodborne pathogens continue to cause health problems for modern consumers of meat products despite efforts to control bacteria in food. New approaches to controlling pathogens and identifying sources of contamination are needed. Some of the most important foodborne pathogens that affect modern food supplies are Salmonella serotypes and Escherichia coli O157:H7, both associated with uncooked meat, and Listeria monocytogenes, a problematic organism for ready-to-eat foods. The objective of this thesis is to investigate survival of E. coli O157:H7 and L. monocytogenes on food packaging materials soiled with meat-based residues, and compare differences of behavior when exposed to different packaging materials and storage conditions. In addition to these investigations, a study comparing resistance of multi drug-resistant and susceptible Salmonella serotypes and E. coli O157:H7 on beef trimmings treated with decontaminating antimicrobials provides valuable information concerning the efficacy of current chemical interventions against Salmonella serotypes that are at the forefront of public health concerns. To evaluate pathogen survival on contaminated food packaging materials, meat based homogenate (10% w/w) was inoculated with a multi-strain mixture of either L. monocytogenes or E. coli O157:H7 and spot-inoculated on packaging material samples, placed in a new, empty petri dish, and stored in incubators set at either 4 or 25° C for up to 130 days. Samples were analyzed regularly until the end of the study. There were survivors of the pathogens on several soiled packaging material types even at 123 or 130 days of storage (L. monocytogenes or E. coli O157:H7, respectively). When the decontamination of beef trimmings contaminated with multi drug-resistant and susceptible Salmonella was compared with E. coli O157:H7, there were very few statistically significant differences (P < 0.05) between the reduction of Salmonella and the response of E. coli O157:H7 to acidified sodium chlorite (1000ppm), peroxyacetic acid (200ppm), and sodium metasilicate (40000ppm). In addition, there were only minor differences between the reductions of antibiotic susceptible Salmonella and multi drug- resistant strains. Results of these studies will aid in quantifying risks associated with contamination of food packaging materials as well as beef trimmings.