Insects have been proposed as a sustainable alternative to livestock to help feed the growing population. Edible insects such as mealworms require less land and resources and can utilize food by-products to grow. While insects are consumed by over 2 billion people worldwide, they are not widely accepted in developed countries like the United States because of their unfamiliarity and the perception of disgust associated with entomophagy. The objectives of this research are to 1) grow mealworms using carrot pomace and determine an optimum diet for growth and nutritional composition, 2) identify and classify early adopters of insects, and propose a product form, and 3) assess the acceptability of frozen, ready-to-cook mealworms with early adopters. A response surface design was used to evaluate the use of carrot pomace in various percentages in the substrate and as the moisture source in a mealworm growing system. Mealworms were grown under controlled conditions in a climate chamber until they began to pupate, and statistical models were fitted to predict mealworm mortality, weight, days to pupation, protein content, fat content, and moisture content. An algorithm in Design Expert was used to optimize mealworm growth based on maximizing mealworm weight and minimizing mortality and days to pupation, and the optimum diet was found to be 36% carrot pomace in the substrate with carrot pomace as the moisture source. Early adopters of insects were identified through a survey using Red Jade Sensory Software. Participants were segmented using partitioning around medoids clustering algorithm based on responses to questions on willingness to consume insects in a variety of forms. Four segments were identified: No-thank-you’s, Hideaways, Daredevils, and Peekaboo’s. Daredevils, Peekaboo’s, and Hideaways are early adopters of insects in the nonvisible form, and Daredevils and Peekaboo’s are also early adopters of insects in the visible form. Based on these insights, frozen, ready-to-cook mealworms were selected to target Daredevils and Peekaboo’s as a product to serve as a sustainable alternative to traditional livestock protein. Participants from each of the four segments were shown a video of mealworm cooking and asked their willingness to buy the product and the motivation behind their response. The majority of respondents were unwilling to buy this product, driven by unfamiliarity and the perception of disgust. However, over half of Daredevils were willing to buy the product, driven by the novelty and ease of preparation. Marketing a product towards this group may be a feasible route for entry into the market and increase the familiarity of edible insects, thereby contributing to long-term acceptability.

The food industry is increasingly concerned with operational sustainability and food waste reduction. In the United States, the tomato industry was worth $1 billion in 2020, and tomatoes are currently ranked second as the most consumed vegetable after potatoes. Tomato processors have striven to valorize pomace by-products, which contain seeds with valuable compounds such as 45% fiber, 30% oil, and 26% protein. The U.S. peach industry, which was worth $599 million in 2017, is also looking for alternative ways to utilize their seeds, made up of 52% oil. Both tomato and peach seeds are rich in bioactive compounds such as carotenoids and polyphenols, respectively. Meanwhile, global edible oil production is forecasted to reach 632 million tons in 2022, and there is increasing interest to produce specialty oils. Organic solvent extractions are commonly used to extract oils from various commodities in the food industry, but this method comes with some environmental concerns, such as toxicity and flammability. Enzyme-assisted aqueous extractions (EAEP) have been proposed as a green alternative to solvent extractions of oilseeds. However, research on the economic feasibility of this process has been limited. There is a need for a better understanding of the potential of EAEP and performing such analysis on peach and tomato seeds would be valuable based on the importance of these commodities in California and in the U.S. in general. To determine whether applying such a process to tomato and peach seeds would be valuable, data on oil yields from EAEP, quality of the extracted oils, and economics associated with EAEP is needed. The U.S. snack food industry was worth approximately $42 billion as of 2019, and this market continues to grow as an increasing number of people eat snacks as meal replacements. There is also growing consumer demand for natural and functional foods, which offer health benefits beyond basic nutritional value, such as reducing risk of disease. Therefore, this consumer landscape provides excellent opportunities for by-products from vegetable and fruit processing to be transformed into functional ingredients. With these key ideas in mind, the objectives of this research were 1) to determine the impact of various extraction factors on oil yields from EAEP of tomato and peach seeds; 2) to evaluate the effect of aqueous extractions on oil quality; 3) study whether these processing steps are economically feasible for industrial commercialization and 4) identify another potential use for tomato pomace as a functional ingredient in snack food application. Tomato and peach seeds were each isolated and ground into a flour, then analyzed for fiber, fat, protein, moisture, and ash content. The effects of pH (set to 3, 9, and sequential adjustment of 3 followed by 9), time (2–8 h), and addition of cellulase, protease, and 1:1 enzymatic cocktail at a concentration of 4% were evaluated during aqueous extractions of tomato oils. Peach oil extractions were evaluated for the same parameters except for time which was fixed at 2 h. The impact of the pH of aqueous extractions on the oxidative stability and nutritional composition of tomato and peach oils were also determined. Techno-economic analyses were conducted using Superpro software to estimate operational costs and profits from this process. To assess the value of tomato by-product as a functional ingredient, pomace flour was added to crisp snacks at usage levels of 0 and 7% (w/w flour basis). Crisp snacks were stored at ambient room temperature and frozen temperatures (-23 °C) for ten weeks. Proximate analyses on the crisp snacks were conducted. Sensory evaluation was performed over time using hedonic scoring surveys. For tomato seeds, the highest oil yield (41%) was obtained during 2 h extractions at pH 9, which were 68% higher than from 2 h extractions performed at pH 3. Enzyme addition was only beneficial during 8 h extractions of tomato seeds using 4% cellulase at pH 3, which led to 53% higher oil yield compared to the control performed in the same conditions without enzymes. Increasing incubation time from 2 to 8 h improved oil yields by 63% for cellulase extractions at pH 3 and 69% for protease extractions at pH 9. Peach oil yield of the controls at pH 9 (53%) and the yield obtained with protease extractions at pH 9 (45%) were approximately eight times higher than all extractions set to pH 3. Once extracted, some properties of the tomato and peach oils were determined. The pH of the aqueous extractions did not have a significant effect on quality parameters on both tomato and peach oils, except for polyphenol content, DPPH production, peroxide and TBARS values. Overall, both tomato and peach oils had peroxide and free fatty acid values comparable to other specialty oils, such as sunflower and sesame oils. From a techno-economic point of view, tomato oil production at flow rate of 1,752,000 kg pomace/yr garnered $13 million in profit (equivalent to $7.42/kg pomace) after a payback time of 1.6 years, which was more profitable than the industry’s current pomace disposal practice. Peach oil processing became profitable once the production scale reached 65,700,000 kg pits/yr, which led to $15.5 million in profit ($0.24/kg pits). Overall, production of tomato oil was more profitable than peach oil. When tomato pomace was added into crisp snacks at 7% concentration, fiber increased by 35.2% compared to the control. Moisture content and water activity for the control and pomace crisp snacks remained constant during room temperature and frozen storage for ten weeks. However, the addition of tomato pomace led to a bitter aftertaste of the crisp snacks and reduced overall liking scores by panelists compared to scores for the control crisp snacks. Overall, this research took multiple, innovative approaches to valorize tomato and peach seeds, while also studying the economic, environmental, and industrial implications of such approaches. It highlighted alternative, sustainable strategies of how tomato and peach by-products could be repurposed to reduce waste and make value-added food products.

String cheese, a Mozzarella cheese, has the unique ability to string in fibrous strands when pulled apart. Graders judge string cheese by its stringy texture; samples with copious amounts of string are awarded high ratings. But just as the texture of natural cheeses softens with time, the stringy texture of string cheese can diminish with age too. Age related softening in cheese is due primarily to an important biochemical event known as proteolysis, which is attributed to inherent milk proteinases, residual coagulant activity, and enzymes from the lysis of starter culture microorganisms. It is hypothesized that a post manufacture heat treatment of string cheese could inactivate these proteolytic enzymes and slow or eliminate proteolysis during storage. Therefore, the main objective of this study was to determine the effects of a post manufacture thermal dip treatment on proteolytic activity in packaged, commercial string cheese. Proteolysis was examined qualitatively by Urea-PAGE electrophoresis, quantitatively by measuring percentage of water-soluble nitrogen (%WSN), and by using a scoring method to analyze stringy texture during refrigerated storage. Fresh, commercial string cheese was sourced on two separate occasions and treated six days after manufacture. Treatment consisted of dipping the packaged cheese sticks in water baths at 55°C, 75°C, and 95°C for 30 and 60 seconds. String cheese that did not undergo treatment served as the control. Treated and control cheeses were stored at 4°C until sampling for Urea-PAGE, WSN extraction, and texture analysis on days 1, 11, 22, 29, 49, 91, and 172 after treatment. The degree of β-CN breakdown was not observed to be different between all treatment levels throughout the storage period. This was not expected since Mozzarella cheese exposed to a higher temperature should have more plasmin activity than that of cheese exposed to a lower temperature. There was a trend of slightly more intact αs1-CN in the most severely treated string cheese (95°C for 60s) when compared to the control at the final time point of the study. This suggests the possibility of successful inactivation of residual coagulant, intracellular enzymes, or other proteolytic enzymes in the string cheese at this treatment. However, only storage time had a significant effect on %WSN (p The research completed in this study provides insight of the proteolytic effects from a thermal treatment process applied post string cheese manufacture. Though relationships between the treatments to the extent of secondary proteolysis and stringy texture were not significant, it was still found that there was more intact αs1-CN due to one of the treatments. These results suggest that it is possible that the use of other heat treatment parameters, longer storage period, or a combination of the two could show a significant relationship between thermal treatment and proteolysis. These results also suggest that further work to improve shelf life of string cheese or other cheese varieties through the concept of a post manufacture heat treatment may be promising.

Adjuvants can enhance the performance of the pesticide active ingredients in many ways including decreasing surface tension and reducing evaporation. Understanding how adjuvants effect pesticide behavior (e.g., surface persistence) is crucial for developing effective pesticide formulations, as well as facilitating the development of effective approaches to reduce pesticide residues from the surface of fresh produce post-harvest. The objective of this study is to investigate the effect of a non-ionic surfactant, Surf-Ac 910, on the persistence of two model pesticides, thiabendazole and phosmet on apple surfaces. The result shows that the addition of Surf-Ac 910 increased both the maximum wetted area and evaporation rate of thiabendazole, a systemic pesticide, and phosmet, a non-systemic pesticide. Utilizing surface-enhanced Raman spectroscopy to explore the surface and penetrative behaviors of thiabendazole and phosmet revealed that the addition of Surf-Ac 910 influenced the Raman signal of pesticides as well. The addition of Surf-Ac 910 decreased the Raman signal intensity when added to phosmet but did not affect the Raman signal intensity when added to thiabendazole. In terms of penetration, the addition of Surf-Ac 910 did not affect the penetration depth of phosmet but slightly increased the penetration depth of thiabendazole. These findings were true for both short-term, 40 minutes, and long-term, 3 days, exposure. Next, the effects of adjuvants on the removal of pesticide residues were investigated. Common household materials, such as baking soda, were effective at removing surface pesticide residues. After testing a variety of baking soda concentrations and starch granules, 2% baking soda and 2% corn starch were found to be the most effective baking soda concentration and starch granule respectively. 2% corn starch was the most effective removal method overall, with 99% of pesticide with/without adjuvant removed in just 5 minutes of wash time. Overall, this study demonstrated that although adjuvant Surf-Ac 910 could affect the surface persistence of pesticides, washing with common household materials such as 2% corn starch can be used as an effective, safe, and economic way to reduce pesticide exposure through fresh produce.

Blueberry juice and pomace, enzyme pretreated (PT) or not, were extracted (EM) by steam and hot press methods. The pomace was further dried by convection oven (OD) or freeze-dried (FD). Juice yield was not affected by PT but was greater for steam extract (SE), due to water uptake. Carbohydrate and protein concentration were greater for hot-pressed (HP) pomace. Anthocyanins were not affected by PT or EM whereas phenolics were greater HP juice when subjected to enzymes. Dehydration method did not affect total phenolics when pomace was from HP but were higher in OD SE pomace. Enzymatic pretreatment had little influence on pomace quality, but HP pomace resulted in higher nutrients probably due to dilution. Oven drying resulted in slight degradation of pomace anthocyanins but not total phenolics. The dried pomace was shown to possess good nutrient quality and elevated functional components and can be used for value-added products.

<p dir="ltr">Baked goods are one of the primary sources of added sugar in the American diet. Excessive consumption of added sugar can lead to diseases such as obesity, heart disease, and diabetes. As information pertaining to the link between health and diet becomes more available to consumers, the demand for products with lower calories, fat, and sugar continues to rise. The obstacle in formulating baked goods with alternative sweeteners is that these sweeteners have different effects on the physicochemical properties of the starch in the products than that of sucrose, leading to differences in texture, color (browning), texture, and flavor between the sucrose-containing products consumers are accustomed to and the new reduced sugar products. Previous studies done by the Mauer lab have found that interactions between the sweeteners that enter the amorphous region of the starch granule alter physicochemical properties of the starch, including the gelatinization temperature (T_gel) and pasting properties of the starch. The purpose of this project was to investigate how the presence of oligosaccharides (OS) used as sucrose replacers in starch-containing products alters the functionality of the starch through modification of its thermal and physicochemical properties. Different botanical sources of starch were preconditioned in solutions containing different concentrations of select OS, varying temperature during preconditioning. The preconditioned starches were then analyzed by differential scanning calorimetry (DSC), rapid visco analysis (RVA), and x-ray diffraction (XRD). Results demonstrated that several OS are less effective plasticizers of starch (all botanical sources) than sucrose, meaning T_gel is higher in the presence of these OS and less pasting occurs. This is advantageous for formulating low moisture baked goods that rely on inhibition of starch gelatinization for desirable product quality.</p>

This study examined the effects of electrical stimulation on water-soluble flavor compounds in beef semimembranosus muscle, collected immediately after exsanguination (PRE), immediately after stimulation (POST), and 24 h postmortem (H24) from both stimulated (ES) and non-stimulated (CON) carcasses. Short-chained peptides were greater in ES at H24 (P = 0.007). Glutamic acid concentration was above its taste threshold (0.044 mmol/kg) and was less in ES at PRE and POST by 0.030 mmol/kg (P ≤ 0.028) but was similar in both ES and CON by H24 (P = 0.142). Lysine, a Strecker amino acid, was greater in ES at H24 by 0.138 mmol/kg (P = 0.002). Adenosine triphosphate and adenosine 5’-monophosphate were greater in CON at both POST and H24 (P < 0.001). Inosine 5’-monophosphate was greater at H24 in CON (P < 0.001) than in ES. Electrical stimulation may negatively impact beef flavor by increasing bitter peptides and decreasing umami-enhancing nucleotides.

A two-year study was conducted to assess the effects of cofermentation on red wine varietals. During the winemaking process, wines can be made from two or more varieties by picking, crushing and fermenting them together, a practice known as cofermentation. They can also be blended either after the completion of alcoholic fermentation or after malolactic fermentation. In the first year of the study, two grape varieties, Merlot (Mer), and Malbec (Mal) were cofermented. On the second year, a third varietal, Petite Sirah (PS) was also studied. Cofermented wines containing every possible binomial combination of the varietals was made and one trinomial on 2019. The cofermented wines were compared to monovarietal wines and also to wines that were produced by blending either after alcoholic fermentation or after malolactic fermentation. The phenolic profile of the wines was followed from the onset of fermentation up to 36 months of bottle aging for the 2018 vintage and in the case of the 2019 vintage, up until 250 days after crushing. In 2018, cofermented wines and wines that were blended after malolactic fermentation had an anthocyanin profile that was more similar to Malbec than to Merlot, while the tannin profile was more resemblant of Merlot. In 2019 cofermentation improved the anthocyanin content when compared to post alcoholic and post malolactic blend only when the three varietals were cofermented. A sensory analysis with 10 trained individuals was conducted on the 2018 vintage. It was demonstrated that Malbec wines had a higher amount of red fruit aromas while Merlot wines were perceived as being more astringent. Cofermented and post malolactic fermentation blended wines were indistinguishable to panelists and blending after alcoholic fermentation produced wines that highlighted the individual varietal character.

<p> The inter/intramolecular interactions and associations between constituents determine the microstructure of food and its response to mechanical deformation and flow. The characterization of food rheology enables the design of efficient processing equipment, production of high-quality, stable end products, prediction of textural and sensorial attributes, and assurance of consumer acceptability. Foods are subjected to rapid and large deformations during processing operations and consumption. Dynamic oscillatory shear tests are carried out by subjecting food to a sinusoidal deformation (or stress) and probing the mechanical stress (or strain) and recording the response as a function of time. In the SAOS region, the mechanical response is in the form of a perfect sinusoidal curve and interpretation is straightforward as expected from a linear model. On the other hand, LAOS response requires complex mathematical relations to extract meaningful rheological parameters. In this dissertation, Fourier Transform-Chebyshev Decomposition (FTC) and Sequence of Physical Processes (SPP) methods were utilized to quantify the LAOS response of selected food materials. The objective of this study is to gain new insights into the nonlinear rheology and structural architecture of food materials. To offer insights into the microstructure–rheology relations, rheological measurements were accompanied by various techniques probing chemical interactions (FTIR), imaging (Cryo-SEM, SEM), quantitative network analysis, and molecular size (SDS-PAGE). This dissertation showed that LAOS rheology is highly correlated with the network structure of food shown by the quantitative network analysis utilizing SEM images. It is a powerful tool to detect the effect of small molecules on the nonlinear rheology of food (HMW-LMW glutenin ratio, gliadin for dough, fat content in yogurt, and amylopectin/amylose ratio of starch in a suspension). Nonlinear parameters were sensitive to structural changes occurring in dough structure during processing conditions including aging at room and elevated temperatures. Lastly, the SPP method enabling time-resolved interpretation of nonlinear rheology provided detailed transient microstructural interpretations whereas the FTC method gave static measures at specific strains in an oscillation cycle. Thus, nonlinear rheology of doughs with various gluten subfractions in MAOS and LAOS regions as well as shear thickening characteristic of starch suspensions with changing amylopectin/amylose ratio interpreted by the SPP method gave more sensitive results than the FTC method. The application of fundamental knowledge from this work can be a guide to evaluating the architecture and nonlinear rheology of food for the assurance of consumer acceptancy and the fabrication of efficient machinery by building more accurate mechanical models of complex food systems. </p>

<p>  </p> <p>The research in this dissertation explored the impact of different sugar reducing agents [SRAs: sugars, sugar alcohols, oligosaccharides (OS), and polymers] on the thermal properties of starch (gelatinization, pasting, and retrogradation) and the baking performance of a model baked goods system (wire-cut cookies). The overconsumption of added sugar and underconsumption of dietary fiber have been linked to increased developmental risks for obesity and related diseases, including cardiovascular disease, diabetes, and colorectal cancer. Some SRAs, such as non-digestible oligosaccharides (OS), are considered soluble dietary fiber and could help offset the health detriments from excess sugar and low fiber intake, while also providing similar functionality (texture and structure) to that of sucrose in baked goods systems that rely on the control of phase and state changes in starch. The gelatinization temperature (Tgel) of wheat starch in the presence of SRA solutions at various concentrations (10% to 60% w/w) was measured using differential scanning calorimetry (DSC), and was best explained by SRA plasticization properties [solvent effective volume fraction (<em>feff,w</em>)], solution viscosity, and size (based on the previously proposed starch granule size limit of 1,000 g/mol). The paste viscosity parameters of starch in SRA solutions were measured with a routine rapid visco analyzer (RVA); and were increased in monosaccharide solutions and decreased in 6-carbon sugar alcohol and OS solutions as solution concentration was increased. Differences in starch paste response variables were explained by SRAs either promoting or restricting amylose leaching during heating. The recrystallization of amylopectin over time was promoted in monosaccharide solutions (glucose, fructose, allulose) and in many OS solutions, and was explained in terms of SRA hydrogen bonding interactions with water and/or starch chains. The appearance attributes of wire-cut cookies containing OS were similar to a sucrose control formulation; however, differences were found in cookie texture attributes which were linked to OS effects on solution viscosity and moisture retention during baking. Cookies made with allulose and erythritol were the least similar to the sucrose control across all quality attributes, and therefore these two SRAs would not be recommended as sugar replacers in low-moisture baked goods. The findings from this dissertation could be helpful to food researchers and product developers seeking to reduce or replace added sugars in starch-containing food systems with healthier alternatives.</p>