College of Agriculture & Natural Resources
Permanent URI for this communityhttp://hdl.handle.net/1903/1598
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item Assessment of Petroleum-Based Plastic and Bioplastics Degradation Using Anaerobic Digestion(MDPI, 2021-12-01) Nachod, Benjamin; Keller, Emily; Hassanein, Amro; Lansing, StephanieBioplastics have emerged as a viable alternative to traditional petroleum-based plastic (PET). Three of the most common bioplastic polymers are polyhydroxybutyrate-valerate (PHBV), polylactide (PLA), and cellulose-based bioplastic (CBB). This study assessed biodegradation through anaerobic digestion (AD) of these three bioplastics and PET digested with food waste (FW) at mesophilic (35 °C) and thermophilic (55 °C) temperatures. The four plastic types were digested with FW in triplicate batch reactors. Additionally, two blank treatments (inoculum-only) and two PHBV treatments (with FW + inoculum and inoculum-only) were digested at 35 and 55 °C. The PHBV treatment without FW at 35 °C (PHBV-35) produced the most methane (CH4) normalized by the volatile solids (VS) of the bioplastics over the 104-day experimental period (271 mL CH4/g VS). Most bioplastics had more CH4 production than PET when normalized by digester volume or gram substrate added, with the PLA-FW-55 (5.80 m3 CH4/m3), PHBV-FW-55 (2.29 m3 CH4/m3), and PHBV-55 (4.05 m3 CH4/m3) having 848,275 and 561%, respectively, more CH4 production than the PET treatment. The scanning electron microscopy (SEM) showed full degradation of PHBV pellets after AD. The results show that when PHBV is used as bioplastic, it can be degraded with energy production through AD.Item EXPLORATION OF THE FOOD WASTE ENVIRONMENT IN THE UNIVERSITY SETTING AND ITS IMPLICATIONS TOWARD A SUSTAINABLE FOOD SYSTEM(2020) Pavone, Lauren; Song, Hee-Jung; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Americans are throwing away an alarmingly high amount of food. As highlighted in this thesis project, a multitude of factors account for why food waste occurs, but also a significant potential exists for food waste reduction. The purpose of this research was to investigate the food waste environment in the university setting to better understand where to focus food waste reduction strategies. The volume of student plate waste was quantified, and the nutritional and environmental value of this plate waste was calculated. Further, a behavioral survey guided by the Theory of Planned Behavior helped to identify the key factors influencing food waste behaviors in this setting. Plate waste was found to be 5%-14% of all food served in the dining hall facility. The top three food groups that were most frequently discarded included starch and added sugars, fruits and vegetables and whole grains. Food waste related behaviors were found to be strongly influenced by having the confidence and skills for proper food management, feeling guilty about throwing food away, and having financial concerns related to food waste. The results of this research suggest that student plate waste is a significant problem with enormous potential for food waste reduction.Item DESIGN, IMPLEMENTATION, AND EVALUATION OF A MINDFULNESS FOCUSED NUTRITION PROMOTION PROGRAM TO BALANCE USDA SCHOOL NUTRITION GOALS WITH FOOD WASTE REDUCTION IN ELEMENTARY SCHOOLS(2019) Schachtner-Appel, Amy Elizabeth; Song, Hee-Jung; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Healthy school meals offer numerous benefits for elementary school students, but low produce intake and high rates of waste prevent students from experiencing these benefits. This research aimed to create a mindful and sustainable eating intervention to encourage reduced waste and increased produce intake during lunch. The study was conducted using a mixed-methods triangulation approach for formative research, creation of a behavioral model to design a theory based intervention, and pilot test of the resulting program using a quasi-experimental controlled design. Formative findings, gathered from 50 3rd-5th grade focus group participants, 15 in-depth interviews with school staff, and 9 cafeteria observations supported the use of social cognitive theory (SCT) to explain eating behaviors and emphasized the importance of involving student leaders and creating environmental reinforcements. Pilot intervention approaches included delivery of an education curriculum, dissemination of messages by student leaders, cafeteria environment changes, and creation of a food recovery program. Measurements included observation of kindergarten – 5th grade lunches at baseline and follow-up (n = 162) to estimate foods selected, consumed, and wasted, survey of 3rd – 5th grade students at baseline and follow-up (n = 169) to measure psychosocial changes related to mindful and sustainable eating, and periodic food waste audits (n = 8) to monitor school-level plate waste. Baseline results showed students consumed only 36-42% of vegetables selected and 64-67% of fruit selected. At follow-up, intervention students selected more produce than controls (1.09 vs. 0.64 servings of vegetables; 1.32 vs. 1.06 servings of fruit). Similarly, they consumed more produce (0.51 vs. 0.33 servings of vegetables; 0.94 vs. 0.70 servings of fruit) than controls. Intervention students trended toward reduced vegetable waste while maintaining selection, whereas controls decreased selection substantially. Intervention students experienced significant increase in self-efficacy to base lunch choices on body cues. Higher produce consumption and lower waste were predicted by improved intentions to eat healthfully. Overall, the program successfully improved intake and trends indicate potential to reduce waste. Findings support expansion of the program, with potential to improve nutritional status of students and reduce the environmental impact of school meals.