<p>The farming of insects has been shown to require less land, feed, and water compared to traditional livestock maintenance, while proven to be a source of high-quality protein. The aversion of the Western culture towards edible insects is the major hurdle into their incorporation in the market, unveiling the challenge of integrating them into an existing familiar product. However, studies have shown that merely pulverizing insects into edible “flours” possesses difficulties on itself such as low solubility; severely altering the structural and sensory characteristics of food products upon their addition. Alternatively, scientists have turned to chemical protein isolation techniques to create insect flours with improved functionality. Furthermore, enzymatic proteolysis has shown to aid in extracting the protein bound to insoluble chitin and enhancing techno-functional properties. While this promising technique may open a range of possibilities, no research has been done regarding the incorporation of insect hydrolysates into a food matrix. The purpose of this work was to explore the production of insect hydrolysates with improved techno-functional properties and their impact in the physicochemical, structural, and sensory characteristics on a chosen model matrix: corn tortillas. Crickets (<i>Acheta domesticus</i>) were chosen due to their current relevance in the Western market. </p> <p>Hydrolysates were produced with low (5%), medium (8%), and high (15%) degrees of hydrolysis (DH) either with Alcalase (AL) or Flavourzyme (FL). Alcalase cricket protein hydrolysates (CPH) resulted in higher fat content, which was suspected of possessing surface-activity. Overall, AL peptides displayed significantly (p < 0.05) higher emulsion and foam capacity and stability, suggesting stronger amphiphilic activity. On the other hand, FL peptides were more soluble and had a lower mean molecular weight, demonstrated by their lower glass transition temperatures. Both of these developments may be explained by Alcalase endopeptidase activity and Flavourzyme primarily exopeptidase activity. Treatments resulted in AL-peptides with large and medium size molecular weights that included hydrophobic terminal ends, while FL peptides were smaller and likely contained free amino acids. The difference in molecular weights were seen upon their addition in the raw corn masa, where AL-CPH increased elastic and viscous behavior compared to control, whereas the smaller FL-CPH lowered them due to the plasticizing capability of hydrophilic small peptides. The ability of FL-CPH to interact with corn macromolecules was observed upon thermal treatment, resulting in FL-tortillas with superior strength and extensibility compared to AL-tortillas. In fact, AL-tortillas fragility was seen by the rollability test, showing a complete disintegration of the tortilla structure. Raman spectroscopy further showed the heat-induced intermolecular interactions of FL-peptides with the corn macromolecules. Raman bands at 1049 cm^-1 in FL-tortillas allude to protein-starch complexes and the <i>gauche-gauche</i> region confirmed the presence of disulfide bridges in FL-tortillas, both of these developments were absent in AL-tortillas. Lastly, the formulation of corn chips with these CPH proved to be globally accepted by a population with diverse neophobia levels, confirming theories that consumers are willing to eat insects in an “invisible” format. Flavor and aroma profiles of the chips, quantified by a descriptive analysis study, revealed no commonalities between the two sets of chips. AL-chips were characterized as having corn, shrimp, and roasted peanut notes, while FL-chips were characterized as having tomato, ketchup, and French fry notes. Overall, enzymatic proteolysis was shown to generate cricket peptides with different characteristics, both able to be utilize as a functional ingredient for palatable food products. </p>

<p>  </p> <p>  The effects of science have remarkably changed our world and we should learn how to live effectively in a consistently evolving world. Scientific thinking is believed to be the key factor in developing the ability to use scientific knowledge in problem-solving (Norris & Philips, 2003; Zimmerman, 2000). Therefore, increasing adults’ ability to think scientifically would help them apply better problem-solving strategies in everyday routines. Unfortunately, not a lot has been done on advancing scientific thinking education among adults in formal and nonformal educational settings in the U.S. (Osborn, 2013). Hence, this study used case study approach, a qualitative research method, to explore Purdue Extension Master Gardener volunteers’ scientific thinking in the context of problem-solving through inquiry. The purpose of this study was to explore Purdue Extension Master Gardener volunteers’ scientific thinking throughout a home hydroponics inquiry-based project and to describe their experiences to complete the learning module. This study took over nine weeks of a virtual inquiry-based learning program with four Purdue Extension Master Gardener volunteers. Data collection included pre- and post-interview, project worksheets and exit notecards at the end of each online lesson.</p> <p>  </p> <p>There were three major findings. First, participants demonstrated scientific thinking skills by conducting experiments and acknowledging the effectiveness of scientific inquiry in problem-solving. Second, participants’ learning experiences were positive following the integration of adult learning theory assumptions into the learning module. Third, participants expressed intent to continue using scientific experiments to solve their gardening problems as a new skill they learned and found effective in helping them understand and solve problems. The findings of this study suggest that both domain-specific (prior knowledge and everyday life experience) and domain-general (scientific methods and reasoning processes) strategies are important to conduct scientific reasoning. In addition, motivation is a critical factor that drives the direction of inquiry, hypothesis, and helps in persisting to finish up the experiments. The findings also suggested that adults learn best when they have independence and self-direction in working on topics that align with the real-world problem-solving directly linked to their everyday life. </p> <p>  </p> <p>The findings of this study suggest that developing scientific thinking increases the ability of adults to appreciate valuable information, evaluate data source, and increase informed citizenry in general. Also, for teaching adults, instructors and instructional designers should concentrate on topics that have direct impact on adults’ life, mainly focusing on real-world problem-solving. Future studies could consider exploring scientific thinking using a different context than problem-solving used in this study. Future studies also should consider using larger populations with a variety of backgrounds to assess the role of prior knowledge in scientific thinking development. </p>

<div><div><div><p>Interfacial rheology describes the functional relationship between the deformation of an interface, the stresses exerted in and on it, and the resulting flows in the adjacent fluid phases. These interfacial properties are purported to influence emulsion stability. Protein emulsifiers tend to adsorb to the interface of immiscible phases, reduce interfacial tension as well as generate repulsive interactions. A magnetic interfacial shear rheometer was used to characterize the surface pressure-area isotherms as well as interfacial rheological properties of two proteins- sodium caseinate and b-lactoglobulin. Then, sodium caseinate was used as a carrier for b-carotene encapsulation.</p><p>b-carotene is a carotenoid that exhibits pro-vitamin A activity, antioxidant capacity and is widely used as a food colorant. It is however, highly hydrophobic and sensitive to heat, oxygen and light exposure. Thus b-carotene as food ingredient is mainly available as purified crystals or as oil-in-water emulsions. In this study, b-carotene stability, and solubility in water for application as a natural colorant was improved by preparation of a sodium caseinate/ b-carotene powder using high pressure homogenization, solvent evaporation and spray drying. The powders thus prepared showed good solubility in water and yielded an orange coloration from b-carotene. The effect of medium chain triglyceride concentration (1%, 10%) and incorporation of a natural antioxidant (Duralox, Kalsec) on powder stability was studied as a function of storage time and temperature.b-carotene stability was reduced at higher storage temperature (4oC> 21oC> 50oC) over 60 days and followed first order degradation kinetics at all temperatures. Incorporation of natural antioxidant improved b-carotene stability and resulted in a second first order degradation period at 50oC. As b-carotene content decreased, Hunter Lab color values denoting lightness increased, while those for redness and yellowness of the powder decreased. This sodium caseinate based b-carotene powder could be used as a food ingredient to deliver natural b-carotene to primarily aqueous food formulations.</p><div><div><div><p>In the last part of this work, an engagement workshop was developed as a means to educate young consumers about the function of emulsifiers in foods. Food additives are important for food product development, however to consumers, a discord between their objective purpose and subjective quality has led to confusion. Food emulsifiers, in particular, are associated with lower healthiness perception due to their unfamiliar names. In collaboration with the 4H Academy at Purdue, a workshop high school student was conducted to develop an increased understanding of emulsions and emulsifiers. A survey was conducted with the participants who self-evaluated their gain in knowledge and tendency to perform certain behaviors with regards to food ingredient labels. The participants reported a gain in knowledge in response to four key questions on emulsions and emulsifiers, as well as an increased likelihood to read ingredients on a food label and look up information on unfamiliar ingredients.</p></div></div></div></div></div></div>

<div>The House Cricket (Acheta domesticus) is a promising alternative to traditional protein sources, as these insects produce over 12 times the mass of protein for a given mass of food/water when compared to cattle, while also producing lower amounts of greenhouse gases and NH3 emissions (Kim et al. 2017, Hanboonsong, Jamjanya and Durst 2013, Van Huis 2013). Additionally, previous studies have demonstrated significant emulsification and gelling properties of insect flours, such as from cricket, which has been attributed to the functional properties of the protein (Kim et al. 2017). Ground cricket flours contain significant quantities of both protein and fibrous polysaccharides, particularly chitin. Since chitin particles are also capable of preparing emulsions as a Pickering stabilizer, there remains a question on the relative role of the protein and chitin components in crickets for stabilizing emulsion products. Relative contributions of each component was identified by first isolating the water-soluble protein and water-insoluble chitin fractions from ground cricket flour and then determining their interfacial properties and stability of prepared oil-in-water emulsions. Dynamic interfacial tension measurements indicated significant surface activity of the protein fraction, while there was minimal evidence of significant surface pressure development in the presence of 5-10 μm chitin particles. 10 % (w/w) canola oil-in-water emulsions were prepared with 0.5-2% (w/w) of the water-soluble protein fraction and 5.29% (w/w) canola oil-in-water emulsions were prepared with 0.688% of the chitin fraction. Stability of the emulsions against creaming was between 75% and 90% for emulsions stabilized by the protein fraction over three weeks of storage and between 93% and 96% for emulsions stabilized by chitin over 24 hours of storage. Significant fractions of precipitate- and oil-layers found in chitin-stabilized dispersions was attributed to the presence of large chitin particles (79 μm volume weighted mean diameter) and inefficient adsorption to droplet interfaces during homogenization, respectively. Volume-weighted mean diameter of emulsified oil droplets remained at 17-24 μm among protein-stabilized (>1.5 wt%) emulsions over three weeks of storage but only 60 μm over 24 hours among chitin-stabilized emulsions. Light micrographs of emulsion droplets showed successful adsorption of chitin fractions to oil droplets in the emulsion layer, verifying their potential as Pickering stabilizers. These findings demonstrated that both water-soluble protein and chitin particles obtained from ground cricket flours are legitimate emulsion stabilizers, yet the chitin fraction is much less effective without a more intensive approach to reduce their particle size.</div>

<div>Zein is major nitrogen storage protein that accounts for nearly half of the protein content of the corn grain. As a byproduct of starch and ethanol processing, it is generally recognized as safe (GRAS) and soluble in up to 70% ethanol. Historically, zein has been used for films and coatings. However, usage of the corn protein has diminished in recent years. New advances in food nanotechnology has renewed interest in zein. By forming the protein into stable nanoparticles capable of being dispersed in aqueous solution, zein can be used in many applications ranging from improving stability and digestion of functional ingredients or active biodegradable packaging. Developing novel applications for this protein would then add value to a waste product during the processing of corn.</div><div><br></div><div>The formation of hydrophobic zein nanoparticles (ZNPs) would allow for easier dispersion in aqueous systems without further modification to increase hydrophilicity. However, their dispersibility and subsequent stability in aqueous systems is important for its functionality in food. Addition of sufficient ι-carrageenan (ι-CGN) prevented aggregation in the pH range of 5.25 to 6.75 and limited aggregation at pH 7.0. Enhanced stability was attributed to the adhesion of ι-CGN to the nanoparticle surface, as the ZNPs surface charge became significantly negative with introduction of ι-CGN. These particles remained stable for up to 30 days with significantly lower turbidity and greater resistance to gravitational separation when compared to ZNPs alone.</div><div><br></div><div>Lutein was encapsulated in zein nanoparticles, and the bioaccessibility was determined by quantifying lutein content after exposure to in vitro gastric and intestinal conditions. It was found that ZNPs provided a protective environment for lutein in aqueous dispersions and would release the carotenoid into the small intestine by rapid breakdown of ZNP structure during intestinal digestion. However, the process or residual components must have limited uptake of lutein into mixed micelles. ZNPs can be a promising encapsulating agent to improve the digestive stability of lutein.</div><div><br></div><div>Composite films composed of methylcellulose (MC) and zein nanoparticles (ZNPs) were prepared as a potential biodegradable alternative for synthetic packaging. The effects of ZNP aggregation on mechanical and moisture barrier properties as affected by drying temperature, pH, and stabilizers were tested. The phase separation of composite films was determined to be detrimental to both its mechanical and moisture barrier properties. The drying temperature, pH, and composition of the solvent casting solution all affected the distribution of ZNPs dispersed in MC films. Drying films at 23°C or setting the pH to 6.5 resulted in ZNP aggregation and weaker, brittle films that were poor moisture barriers. The presence of CGN was able to provide stability to ZNPs at both pH 4 and 6.5, thus improving its mechanical and moisture barrier properties.</div>

Fruit and vegetable derived polyphenols have been linked with many health benefits. In light of this, many consumers are seeking to increase their intake of polyphenols, with many turning to dietary supplements that contain concentrated doses of purified polyphenols. However, the safety of this consumption modality is not known, nor are the dose-dependent metabolic changes that may be present, especially when considering colonically generated phenolic metabolites. Using blueberry polyphenols as a model, we explored these phenomena in a rat model. Animals were dosed with blueberry polyphenols at levels up to 20 times what would be consumed in 1-2 servings of whole blueberries in an adult human. In the first study, animals were acutely dosed with blueberry polyphenols and urine and plasma pharmacokinetics measured. In the second study, animals were repeatedly dosed for 90d, with urinary metabolites monitored throughout the study and a complete necropsy performed following standard guidelines. In both studies, metabolite excretion patterns were similar: cinnamic acids accounted for a majority of the observed metabolites, followed by hippuric acids and then phenylpropionic acids (PPA). A dose-dependent shift in metabolite production was observed; as the dose increased, the relative amounts of PPA increased while hippuric acids decreased. No adverse or toxic effects were found, and, though there were several statistically significant differences in toxicological endpoints, all measured parameters remained in the normal range for these animals and thus were not deemed biologically significant. These results indicate that high doses of blueberry polyphenols, as may be present in dietary supplements, are safe for consumption. These results also demonstrate dose-dependent shifts in metabolism that may impact gut function and affect the health benefits derived from blueberry polyphenols.<br>

<p>In this study, structural specificity of flavonoids was investigated toselectively inhibit starch digestive enzymes to stimulate the ileal-brake by triggering glucagon-like peptide-1 (GLP-1) through distal small intestine starch digestion which can regulate food intake and appetite. The double bond between C2 and C3 on flavonoid’s chemical structure plays a critical role to inhibit human pancreatic α-amylase, leading to π-staking interaction. Meanwhile, the hydroxyl group at C3 on the backbone benzopyran ring is intimately related to inhibition of the mucosal α-glucosidases. This selective inhibition is likely the result of fundamental differences in the protein structures of α-amylase and α-glucosidases, as they belong to different glycosyl hydrolase Families 13 and 31 (GH13 and GH31). α-Amylase has the catalytic active siteslocated in wide and shallow grooves on the protein structure, while α-glucosidases possess the narrow and deep catalytic pocket. In an acute study done on mice, luteolin, which had thehigher degree of selectivity toward α-amylase, showed a slow and sustained postprandial glycemic response with a reduced blood glucose peak and extended high glucose profile, compared to 3’,4’-dihydroxylflavonol as the selective α-glucosidases specific inhibitor. Quercetin was inhibitory of both α-amylase and α-glucosidases.Glycemic profiles in mice confirmed in vitro analysis of the inhibitory selectivity of the flavonoids tested. Additionally, the extended glycemic response with luteolin was accompaniedthe higher secretion of GLP-1 at extended postprandial times by delivering more starch portion into the distal small intestine where the ileal-brake and gut-brain axis activation takes place. Overall, selective inhibition of α-amylase by flavonoids potentially could be considered as a key approach to control glucose release from starch with slow and extended, but still complete, digestion for improved glycemic response and minimized adverse side effects that result from severely restricting or even shutting down starch digestion by pharmaceutical grade inhibitors.<br></p>

<p>Moderating glycemic response to foods is important for the potential to control or prevent hyperglycemia-related diseases, such as diabetes and cardiovascular disease. The importance of slowly digestible carbohydrates (SDC) lies in their health effects: moderated blood glucose response, and a potential for increased satiety and reduced intake, and weight management. The research presented is on structural properties of novel, mostly soluble, a-glucans (glucose-containing oligomers and polymers with different linkage types and combinations) that are required for slow yet full digestion, and how they behave in food systems. Up to this point, little has been known regarding what structural properties of glucose-containing carbohydrates result in slow digestion, although starch structure has been well investigated and it is known that raw starch has a slowly digestible property. In addition to the structure-function aspect of the thesis work, this research contributes information about how a-glucan SDCs can be incorporated into food products that undergo heat treatment in the presence of moisture. The a-glucans maintain their SDC property while raw starch is gelatinized and becomes rapidly digestible. The rate of hydrolysis of a large number of novel a-glucans was studied using a simulated upper gastrointestinal in vitro digestion utilizing porcine pancreatic α-amylase and α-glucosidases from the rat intestine, and a subset was then evaluated in a crossover design clinical trial with blood glucose monitoring. Linkage and molecular weight analysis using gas chromatography of partially methylated alditol acetates and multi-angle light scattering and refractive index (MALS-RI) detection at time points during in vitro digestion were used to elucidate the relative rate of digestion of different linkage types in new and known a-glucan carbohydrates. Rheological, turbidity, and SLS and DLS analyses were used to examine ingredient interaction between novel, enzymatically-modified α-glucans with slow digesting properties found most promising for inclusion in food products. A model nutritional beverage system was utilized containing proteins and salts. It was found that solvent and ion concentration of solutions were important for dictating aggregation formation with highly branched alternans and oligosaccharides in solution alone, or in the presence of soluble protein aggregates. Further, salts in solution proved to influence rheological and turbidity measures of all four α-glucans examined in the model system, indicating they may affect aggregation and structural conformation of such large carbohydrates. However, only tapioca maltodextrins showed in vitro rate of digestion affected by aggregation.</p><p></p> <p>These results show the chemical and molecular properties of modified carbohydrates that contribute to slow digestion rate, which is informative to develop improved or new SDCs, as well as how these novel SDCs interact with other ingredients within a model beverage system, informing applications for the food industry.</p>

<p>Findings presented in this dissertation show that polyunsaturated fatty acids of soybean oil effectively reacted with high voltage atmospheric cold plasma gas species of various gases including hydrogen, nitrogen, and oxygen at room temperature without a catalyst. Hydrogenation, nitration, and epoxidation reactions were observed along with polymerization. Unexpectedly, hydrogen gas was not the primary source of atomic hydrogen observed under these experimental conditions. Rather, it is suggested that water vapor, present as an impurity, supplied hydrogen ions to the hydrogenation reactions. Nitrogen gas modified atmosphere is an electron-rich medium that catalyze reactions. Further investigation is suggested for optimizing the process of oil hydrogenation, as well as for exploring the potential to produce bio-based gels, lubricants, and greases.</p>

<p>High-school-aged youths have limited food safety knowledge and lack safe food-handling skills. However, these youths will prepare food for themselves and are frequently employed in the food service industry, where their food-handling practices can directly impact public health. Youths’ beliefs about safe food-handling behaviors are affected by Key Influencers in their lives such as peers, classroom instructors, parents, and celebrities including popular web-content authors or video hosts. Societal changes have prompted the elimination of Family and Consumer Science courses from many schools and the reduction of food-handler role models at home, while increasing access to unregulated sources of food-handling information such as information published on web-based platforms. These societal changes largely remove peers, classroom instructors, and parents from influencing youths’ food-handling behaviors. </p> <p>The purpose of this study was to (1) evaluate the effectiveness of a researcher-developed food safety educational intervention at changing students’ food-handling behaviors specifically focusing on the role of subjective norms in generating behavior change and (2) conduct an exploratory content analysis of food safety messages delivered by blog authors and video hosts of popular web-content. </p> <p>The researcher-developed curriculum was evaluated for adherence to academic standards and overall usability in the classroom using the Delphi Technique by a panel of secondary educators who were considered experts in the education field. The curriculum was evaluated for effectiveness at changing high school students’ food-handling behaviors through self-reported surveys and observation using GoPro head mounted and stationary cameras. Finally, content analysis was performed on food safety messages disseminated by authors and video hosts of popular blogs and YouTube videos, respectively. </p> Findings from the study demonstrated that youths’ food-handling behaviors are affected by Key Influencers including their peers and classroom instructor. However, post-intervention, a role-reversal was observed and reported as students became influencers who sought to improve their Key Influencers’ food-handling behaviors. Differences in influencing power within these relationships could impact the sustainability of youths’ safe food-handling behaviors. In particular, imbalances in influencing power of celebrities in the absence of other Key Influencers could leave students vulnerable to adopting unsafe food-handling practices.