<p>Cardiovascular diseases (CVD) and their risk factors remain the leading cause of morbidity and mortality in North America. Food-derived bioactive peptides (BAP) have been shown to play a role in regulating physiological pathways of CVD risk factors including hypertension, diabetes, and chronic inflammation. Common sources of BAP include dairy and plant proteins. In addition to being an alternative protein source, it is now accepted that edible insect proteins can also confer health benefits beyond nutrition. However, as with any novel protein source, allergenicity remains a major concern surrounding edible insect consumption. </p> <p>This dissertation aimed to: 1) Evaluate the bioactive potential of peptides from an edible cricket species and; 2) determine the effects of BAP production methods on immunoreactivity. First, peptide-rich extracts were generated from farmed food-grade crickets via enzymatic hydrolysis techniques with the commercial protease Alcalase™. To measure the <i>in vitro</i> bioavailability, cricket peptides were also subject to simulated gastrointestinal digestion (SGD). Peptides and their digests were tested for relevant bioactivities and active groups were further fractionated by chromatographic methods to identify the major peptides responsible for the bioactivity. When tested for <i>in vitro</i> antihypertensive and anti-glycemic properties, cricket peptides were found to inhibit the activities of angiotensin converting enzyme, dipeptidyl peptidase-4, α-amylase, and α-glucosidase. The anti-inflammatory potential was expounded using RAW-264.7 macrophages and human umbilical vein endothelial cells (HUVEC). Cricket peptides (after SGD) effectively lowered NF-κB, MCP-1, and IL-6 production in cells without affecting their viability. Proteomic analyses identified 18 sequences from the enriched cationic peptide fraction that showed the highest activity. Three novel peptides were identified via molecular docking, as potent ACE-inhibitors and binding was similar to that of the commercial drug captopril. Key binding characteristics included interaction with hydrophobic amino acids (Phe, Pro, Leu) near the C-terminal position and coordination with Zn (II) ions near the ACE active site.</p> <p>Immunological reactivity was measured by IgE-binding from shrimp-allergenic patient sera to antigens present within cricket peptides. Our studies demonstrate that immunoreactivity was impacted by enzymatic hydrolysis, depending on the conditions and heating source used. Tropomyosin (a major shrimp allergen) was extracted from both untreated crickets and protein hydrolysates, and verified as the major reactive protein. Tropomyosin reactivity decreased (under both partial and extensive hydrolysis) or retained (under conditions which prevented epitope cleavage). However, using microwave-assisted enzymatic hydrolysis was effective at decreasing tropomyosin reactivity in all immunoassays tested (IgG and IgE). Proteomic and immunoinformatic analyses revealed prominent allergen binding regions of cricket tropomyosin available for cleavage during enzymatic hydrolysis. Conserved antigen regions showed greater homology with other crustacean species, but not with other well studied allergenic insect proteins (i.e., cockroach). Lastly, LC-MS/MS and FT-Raman spectrometry suggests that reactivity was affected due to distinct epitope cleavage within the protein instead of decreased antigen extractability/solubility. </p> <p>The findings of this dissertation support that edible cricket proteins are a potential source of bioactive peptides for functional food or nutraceutical development. Additionally, using protein extraction methods such as microwave-assisted hydrolysis seems a promising tool for minimizing the immunoreactivity of the allergen present in this edible cricket species.</p>

<p>When starch granules are gelatinized, many complex structural changes occur as a result of large quantity of water being absorbed. The enlargement of granule sizes and the leaching out water-soluble macromolecules contribute to the viscoelasticity. Starch pasting behavior greatly influences the texture of a variety of food products such as canned soup, sauces, baby foods, batter mixes etc. It is important to characterize the relationship between the structure, composition and architecture of the starch granules with its pasting behavior in order to arrive at a rational methodology to design modified starch of desirable digestion rate and texture. Five types of starch used in this study were waxy maize starch (WMS), normal maize starch (NMS), waxy rice starch (WRS), normal rice starch (NRS) and STMP cross linked normal maize starch. Evolution of volume fraction φ and pasting of 8% w/w starch suspension when heated at 60, 65, 70, 75, 80, 85 and 90 °C were characterized by particle size distribution and G’, G” in the frequency range of 0.01 to 10 Hz respectively. As expected, granule swelling was more pronounced at higher temperatures. At a fixed temperature, most of the swelling occurred within the first 5 min of heating. The pastes exhibited elastic behavior with G’ being much greater than G”. G’ increased with time for waxy maize and rice starch at all times. G’ and G’’ were found to correlated only to the temperature of pasting and not change much with the rate of heating. For WMS, WRS and STMP crosslinked NMS, G’ approached a limiting value for long heating times (30 min and above) especially at heating temperatures of 85°C and above. This behavior is believed to be due to the predominant effect of swelling at small times. For normal maize and rice starch, however, G’ reached a maximum and decreased at longer times for temperatures above 80 °C due to softening of granules as evidenced by peak force measurements. For each starch sample, the experimental data of G’ at different heating temperatures and times could be collapsed into a single curve. The limiting value of G’ at high volume fraction was related to granule size and granule interfacial energy using a foam rheology model. The interfacial free energy of granules were obtained from contact angle measurements and was employed to evaluate the limiting G’. The experimental data of G’ for all starches when subjected to different heating temperatures and times were normalized with respect to the limiting value at high volume fractions. The master curve for normalized G’ was employed to predict the evolution of G’ with time for different starches which was found to agree well with experimental data of storage modulus. A mechanistic model for starch swelling that is based on Flory Huggins polymer swelling theory was employed to predict the evolution of volume fraction of swollen granules. The model accounts for the structure and composition of different types of starches through starch-solvent interaction as quantified by static light scattering, gelatinization temperature and enthalpy of gelatinization, porosity and its variation with swelling and crosslinking of starch molecules within the granule from equilibrium swelling. Consequently, one could predict the evolution of texture of these starch suspension from the knowledge of their swelling behavior. Expressing the limiting storage modulus of complete swelling (volume fraction approaching unity) of starch suspension in terms of foam rheology, we were able to normalize the storage modulus of different types of starches with respect to its limiting value which is found to fall into a master curve. This master curve when employed along with the swelling model resulted in the successful prediction of development of texture for different types of starches. The above methodology can quantify the effects of structure and composition of starch on its pasting behavior and would therefore provide a rational guideline for modification and processing of starch-based material to obtain desirable texture and rheological properties.</p> <p> </p>

<p>Behavior change is not a product of knowledge alone but by the other constructs within the Theory of Planned Behavior (TPB). This includes attitude, subjective norms, and perceived behavioral control. In order to ensure positive change in food safety behavior, researchers should explore the current situation before providing the necessary resources for consumers. This can be done through consumer needs assessments which explore practices, perceptions, demographics, and more. Along with that, major health events like the COVID-19 pandemic can increase risk perceptions of consumers which may lead them to follow safe (washing hands with soap and water) and unsafe food handling behaviors (washing fruits and vegetables with soap). Information spreads quicker during this digital age and this can cause consumers to follow certain behaviors. To assess information being spread, chapter 2 includes a study assessing COVID-19-related food safety information on YouTube early on in the pandemic. Chapter 3 and 4 contain longitudinal studies that used surveys and focus groups to assess consumer food handling practices and risk perceptions throughout the pandemic. Another factor is the type of food being handled. Consumers are not aware that certain foods like pet food (Ch. 5) and raw wheat flour (Ch. 6) can cause foodborne illness. Thus, they may not be handling these types of products as carefully. It is important to communicate that these foods can also cause foodborne illness. In the case of raw wheat flour, while commercial brands provide food safety messages on the packaging, consumers have a hard time finding and understanding the messages. All the studies within this dissertation explored multiple elements that can fall under the different constructs of the TPB in the context of the different factors that affect food safety behaviors. For example, previous studies have found that risk perception may fall under the construct of attitude because human perceptions can influence how a person feels about the situation. The objective of this dissertation is to explore different consumer food safety needs and explore how the elements within the needs assessments feeds into the TPB. With this information, researchers can advance the use of the TPB and researchers and food safety educators can ensure positive behavior change through the TPB.</p>

The practice of gleaning began as a way for the poor to provide sustenance for themselves and their families. Changes in societal ideas about private property as well as a shift toward a neoliberal style of governance have caused gleaning to become what it is today: a practice primarily undertaken by charitable organizations, nonprofits, and church groups who then donate their bounty to local food banks, providing fresh produce to the food insecure. In modern society, gleaning is often held up as a single solution to the problems of food insecurity, poor nutrition, and food waste. This thesis complicates that discourse by analyzing the websites of five different San Francisco Bay Area gleaning groups to investigate how they present themselves as fitting into the larger conversation surrounding food charity, health, and food waste. This thesis uses qualitative and quantitative textual analysis to show how the language used on each organization’s website illustrates the organization’s relationship with those three values. Each organization presents itself as fitting into contemporary food recovery discourse in a different way: one focuses primarily on community building; one is looking to expand its model as far as possible; one seeks to be a solution to poor nutrition, food insecurity, and food waste in its community; one provides myriad resources to anyone looking; and one actively embraces the food insecure. The differences among these organizations show the one-dimensionality of the current discourse surrounding gleaning as a single solution to food insecurity, poor nutrition, and food waste. While gleaning can, and does, have value, its focus on the individual’s role in solving food insecurity, poor nutrition, and food waste, as well as its inability to provide long-term solutions, complicates its role in contemporary food recovery.

<p>  </p> <p>     As industrial hemp acreage throughout the United States has grown, there is an increasing need for research-based information towards effective pest management in this crop. A key pest group is insects, which may attack hemp and cause reductions in production and yield. However, knowledge of regional insect communities found on outdoor hemp is still limited. A critical initial step in growing our understanding is to identify potential pests, predatory (beneficial) insects, and likely visiting insects that occur in hemp systems throughout the production season. To address this knowledge gap, we conducted weekly and biweekly visual scouting of outdoor-grown CBD hemp plants over two summer production seasons at three sites in Indiana to characterize the identity and seasonality of potential pest, predatory, and visiting insects observed on plants. </p> <p><br></p> <p>     Across all of our sites, we made 1493 insect observations consisting of 60 taxonomic families across 13 orders. The most common potential pests observed were aphids, whiteflies, and leafhoppers, while the most common predators were long-legged flies, spiders, and hover flies, respectively. Other herbivorous insects such as red-headed flea beetles and tarnished plant bugs were observed feeding on hemp plants. However, many others, such as Japanese beetles and brown marmorated stink bugs, were not. Based on these results, we recommend that hemp growers in our region scout for insects on a twice-weekly basis, beginning at germination or 1 week following transplant.</p> <p><br></p> <p>     These findings will help inform growers about the timing of scouting for insects on outdoor grown CBD hemp, as well as when key potential pests and beneficial insects are likely to be present so management decisions can be focused accordingly. This work further serves as a foundation for future examinations of insect pest management in hemp, including predator-prey interactions that may be leveraged for biological control strategies in indoor production.</p>

<p> There has been substantial growth in recent decades in the variety and popularity of roles for dogs assisting humans in professional therapeutic partnerships. Simultaneously, increasingly rigorous research has repeatedly demonstrated the effects of professional human-canine partnerships in remedying important issues of public health among several at-risk populations. Yet, despite these areas of growth, mechanisms of action and predictors of efficacy in the field of human-animal interaction (HAI) remain poorly understood, and the role of human diversity has been rarely discussed. Thus, the present dissertation examines potential mechanisms and diverse predictors in two distinct samples of professional human-canine partnerships, while building the impetus to explore diversity in the HAI field as a whole. For the first three studies (Chapters 2-4), the selected samples of professional human-canine partnerships include military veterans working with psychiatric service dogs to mediate their symptoms of PTSD and healthcare professionals in pediatric hospitals working with facility dogs to benefit their patients. Following the introduction in Chapter 1, the objective of Chapters 2-3 was to examine primary human outcomes in the selected professional canine partnerships. In a crosssectional study of N=198 military veterans with PTSD, Chapter 2 compared PTSD symptom severity between n=112 veterans with service dogs and n=86 veterans on the waitlist to receive service dogs in the future. Next, in a cross-sectional study of N=130 healthcare professionals in pediatric hospitals, Chapter 3 compared job-related well-being and mental health of n=65 professionals working with facility dogs to n=65 working without. Findings suggested benefits to the mental health and well-being of both military veterans with PTSD and pediatric healthcare professionals, which were significantly associated with their professional canine partnerships. Subsequently, the objective of Chapter 4 was to explore how variances within a specific professional canine partnership may suggest predictors and potential mechanisms for the observed human outcomes. Thus, in a longitudinal study of N=82 veterans with PTSD and their service dogs, Chapter 4 explored associations of veterans’ outcomes with veteran-service dog demographics and interactions. Results suggested components of the human-canine partnership which might explain observed human outcomes, including social connections, a calming influence, and strong humananimal bonds. </p>

<p>  </p> <p>Glucocorticoids (GC) play a critical role in regulating the physiological response to stress. Disruptions to baseline levels due to stress can have negative implications on a variety of factors including growth and development, physical body conditions, metabolism, immune functions, and expression of normal behaviors, although this list is not exhaustive. When birds are unable to adapt to the stressor and return to homeostasis, the energy expenditure associated with the failed attempt at coping can lead to significant declines in the overall health, welfare, production, and performance of the bird. This can go on to impact producers and consumers as well, indicating the extensive repercussions of stress. Recently, scientists have been investigating thorough and efficient methods of quantifying stress in birds, such as measuring heterophil-to-lymphocyte ratio (HLR) or detecting glucocorticoid levels through enzyme-linked immunoassays (ELISA). However, the precise mechanism behind HLR increase during stress is unknown and ELISAs may not provide accurate results depending on when the blood is being measured. </p> <p><br></p> <p>GC are differentially released and exert their effects in a manner that is dependent on sex, age, and time. However, before investigating this, it was critical to validate the GC kits to ensure that they were measuring cortisol and corticosterone separately along with zero cross reactions with other precursors. Chapter 2 had 4 experiments carried out. The objective of experiment 1 was to validate ELISAs to ensure that they were measuring the GC accurately and separately since both cortisol and corticosterone were being measured. To do this, duck serum was pooled and charcoal-stripped to remove the presence of steroids. 3 standard curves were run to confirm that there was no cross reactivity. The objective of experiment 2 was to further validate the ELISA kits with mass spectrometry by checking for both glucocorticoids in the pooled samples. Once the validation process was complete, experiment 3 was carried out to look at the effect of ACTH stimulation on GC release. 16-week-old drakes and hens were given either intramuscular (IM) injections of cosyntropin (0.06 mg/kg) or saline as control. The cosyntropin dose was chosen according to previous studies reporting relatively high physiological responses, therefore, we wanted to replicate this. N was 10/sex/treatment. Blood was then collected at 0, 1, and 2 hours after injections and serum was analyzed by ELISAs. Lastly for experiment 4, 14-week-old developer drakes and hens at Maple Leaf Farms were assessed for a transportation stress experiment. Blood from 10 ducks/sex/time/barn were collected at 24 hours before transport to the breeder barn, immediately after a 1-hour transport, 24 hours after, and 1 week after transport. The results from experiment 1 yielded that both cortisol and corticosterone can be measured without the presence of unwanted contaminants or other products. Experiment 2 identified the greater sensitivity of mass spectrometry when reading GC levels, although the differences were linear. Experiment 3 showed that serum corticosterone levels were significantly increased at 1 hour after ACTH injections in both drakes and hens, with levels continuing to increase for the drakes. Serum cortisol levels were significantly increased at 1 hour after ACTH injections in both sexes, however, the hens had greater levels compared to the drakes. Serum cortisol levels returned to levels similar to that of saline-injected ducks at the 2-hour mark. Lastly, the transportation stress portion showed that cortisol was released at about 1/3 of corticosterone levels in both sexes. Hens showed increased levels of serum corticosterone compared to drakes at all time points except for 1 week after transport, and also had significantly increased serum cortisol levels at all time points. In conclusion, the ELISA kits were verified for future use when measuring GC as well as mass spectrometry. GC were detected in the ACTH and transportation stress experiments with hens displaying a greater sensitivity to GC release due to increased circulating levels compared to drakes. Although it was nonsignificant, there was a trend for GC to increase in response to transport. </p> <p><br></p> <p>There are sex differences in GC release and HLR for Pekin ducks and various challenges from the studies support this. With hens showing increased sensitivity to stress and drakes with more transient and gradual levels, we have consistently seen that both GC have differential roles in the stress response and not only is it critical to study both hormones, the timing of when measurements are taken are important as well to get a clear understanding of when the stress response is initiated. </p> <p><br></p> <p>Chapter 3 went further to understand the response of GC and HLR. The objective was to  investigate the release of cortisol and corticosterone in response to an ACTH dose response challenge. In Chapter 2, only one dose of cosyntropin was used and sample collection times only went to 2 hours after injections. In this study, 2 additional doses and an extra hour of sample collection were added to obtain more information. Pekin ducks were either given IM cosyntropin injections or saline for control, with an N of 10/sex/treatment. There were 3 treatment doses: High (0.06 mg/kg), medium (0.03 mg/kg), and low (0.015 mg/kg). All injections were given promptly at 0730 hours. Blood was collected at 0, 1, 2 and 3 hours after injections from the tibia veins to obtain serum for ELISAs. Blood smears were done to analyze HLR and sent to an independent lab to obtain values. The results indicated that both GC had significant sex x dose x time interactions. The low dose injection had no effect on corticosterone in hens with a slight increase for drakes at the first hour. The high dose for hens led to a spike in corticosterone levels at the first hour with a gradual decrease, and drakes had an increase that lasted for 2 hours until they returned to baseline at the last hour. The high dose in drakes stimulated cortisol release during the first 2 hours after injection with a similar effect in hens. However, hens had elevated levels compared to drakes. Finally, there was no dose response effect for HLR, although interestingly, the low dose injection elevated HLR even though there was no effect in GC. There were sex differences in the HLR response where the drakes given the high dose had levels that plateaued by the third hour, while the hens still had elevated levels. In conclusion, the ACTH dose-response test identified that ACTH has a dose-dependent effect in both GC and sex differences in their release. HLR also showed sex differences that did not depend on the dose given.</p> <p><br></p> <p>Chapter 4 observed acute exposure of GC in ducks. Pekin ducks were assigned 10/sex/treatment to receive either IM control, cortisol, or corticosterone injections. In addition, a low-dose cortisol treatment was given to represent the endogenous levels of cortisol compared to corticosterone. The control injections contained safflower oil, which was chosen as vehicle due to the low levels of genistein present. This is important as genistein is a plant estrogen and this could interact with the GC and alter the results. Blood was collected at 0, 1, 2, and 3 hours after injections for serum analysis with ELISAs, and blood smears were collected for complete blood count (CBC) differentials. Significant sex x treatment x time interactions were notable in both GC. Hens had significant increases at the first hour after injections in all treatments compared to controls, and drakes had increases at 2 hours after injections in all treatments except the low-dose cortisol. </p> <p><br></p> <p>After observing the effect of acute stress in ducks, the next step was to investigate the effects of chronic stress in chapter 5. Adult breeder Pekin ducks were randomly distributed into 3 groups: corticosterone, cortisol, or control treatments. The GC were in crystalline steroid form distributed through 2 capsules that were subcutaneously implanted on the backs of the neck. The ducks in the control group were given empty capsules. Blood smears, blood draws for serum, egg collection, body weights, and organ samples were collected over a period of 2 weeks. For the results, the corticosterone implants elevated corticosterone levels in both sexes. Interestingly, cortisol levels were elevated in both GC treatments in both sexes. Cortisol elevated HLR in drakes 1 day after implants with no effect from corticosterone. Hens had elevated HLR from both GC at all timepoints throughout the experiment. There were no significant differences in morphometrics in either sex. Corticosterone was not present in eggs, but cortisol was elevated in the albumen on day 7 and 14 of the experiment. Overall, there were sex differences in HLR where hens had greater levels in both GC treatments.</p>

<p>The attached document contains the dissertation of Clare Jensen, including descriptions of all procedures used in the associated research studies.</p>

<p dir="ltr">The impacts of processing on protein structure are of broad interest to the food science community including ingredient producers, product developers, and researchers. Processing and isolation steps induce protein structural changes which occur due to temperature based, shear, and chemical inputs, leading to denatured protein with different functionalities. However, exploration of the protein folding landscape as a way to intentionally modify protein conformation is not widely understood in food science. This particularly applies to cold denaturation, which is the structural changes in protein as the result of low temperature treatments.</p><p dir="ltr">This work has two primary goals. The first was to develop understanding of protein conformations resulting from cold denaturation and its implications for food textural properties. Pea protein was selected for this work since it is a source of plant-based protein that has recently grown in popularity and contains many hydrophobic amino acids that would make is susceptible to cold denaturation. Cold denaturation was studied using physicochemical techniques including differential scanning calorimetry, Fourier transform infrared spectroscopy, zeta potential, fluorescence spectroscopy, dynamic light scattering, and rheology. These techniques are used to characterize untreated pea protein, and proteins that have been modified using different combinations of ethanol, shear forces, acidic conditions, extrusion, and temperatures below 0°C. Significant physicochemical differences are found as the result of low temperatures, driven by an increase in surface hydrophobicity and electrostatic interactions. These differences led to protein gelation through hydrophobic forces, changing the nature of gels. Similarly, the increase in protein hydrophobicity leads to more stable emulsions from these products and unique fatty extrudates.</p><p dir="ltr">A second aim of this work developed bioinformatic models to interpret physiochemical data and provide mechanistic understanding of the process, as well as predict functional properties based on protein models. Strong correlations are found for the zeta potential, secondary structure, hydrogen bonds, and surface hydrophobicity. These models are used to convert data into physicochemical energy and used to provide reasonable estimates of mechanical properties of pea protein in extrusion, gelation, and emulsification. Together, this work shows that cold denaturation may be a useful tool for food product developers creating fatty and creamy textures. It also suggests bioinformatic modeling as a tool to estimate protein functionality, which could lead to tremendous time savings in process and product design.</p>

<p dir="ltr">Global food demand increases rapidly as a result of continuously growing population has raised severe concerns with food security. To overcome this critical challenge, food systems must be transformed to produce food with not only higher yield but also better nutritional quality. Therefore, food processing, as a critical step in food production chain that turn agricultural products into food, needs to be innovated through applications of cutting-edge technologies.</p><p dir="ltr">Microbubbles (MBs) are tiny gas-filled bubbles with distinctive physicochemical characteristics, including slow rising speed and long lifetime in liquid, large surface area per unit of gas volume, high internal pressure, high gas dissolution rate, hydrophobic and negatively charged surface and production of reactive oxygen species. Additionally, MB dispersion can enhance the heat and mass transfer properties of liquid. These features have led MBs to numerous applications in the fields of disease treatment, anaerobic digestion, and wastewater treatment, however, their applications in food processing have not thoroughly explored.</p><p dir="ltr">In this dissertation, MB technology was applied to different unit operations of food processing, including freezing, concentration and extraction, and the effects of MBs on process efficiency and food product quality were comprehensively studied. In the first study, MB-infused freezing medium was used for grape tomato immersion freezing. MBs markedly reduced the drip loss of tomato by 13.7–17.0% and improved its firmness, which were correlated to the accelerated nucleation process and formation of small ice crystals during freezing. The impact of MBs on water evaporation during apple juice concentration was investigated in the second study. MBs dramatically enhanced water evaporation, and concentration at bubble gas temperature of 40 °C and juice temperature of 70 °C showed the largest increase in the evaporation rate, by 104%. Moreover, although air-MBs showed an oxidation effect on both frozen tomato and concentrated juice, N₂-MBs were found to be an ideal alternative which much better preserved the nutritional values of processed foods. Lastly, MBs and cold plasma-MBs were incorporated into citric acid solution for extracting pectin from apple pomace. MBs present in extracting solvent increased the extraction yield by 18–21%, and extraction with plasma-MBs showed even higher yields by up to 30%. Additionally, MB and cold plasma-assisted extraction were found more effective in extracting complex RG-I pectin.</p><p dir="ltr">This dissertation develops various approaches to incorporating MBs into conventional unit operations and enhancing their performance. With these novel applications explored, MB technology will not only increase the productivity but also reduce the energy, water and chemical use of food processing. Ultimately, MB-assisted processes are expected to play an important role in improving the sustainability of the food industry.</p>