Master of Science / Department of Grain Science and Industry / Subramanyam Bhadriraju / Heat treatment of food-processing facilities involves using elevated temperatures (46 to 60°C for 24 h) for management of stored-product insects. Heat treatment is a viable alternative to the fumigant methyl bromide, which is phased out in the United States as of 2005 because of its adverse effects on the stratospheric ozone. However, very little is known about responses of the cigarette beetle, Lasioderma serricorne (F.), a pest associated with food-processing facilities, to elevated temperatures. The main objective of my research was to evaluate stage-specific susceptibility of L. serricorne to elevated temperatures to identify the most heat tolerant stage. In the laboratory, I found L. serricorne was able to develop on ground, pelleted feed at 28°C and 65% RH; however, there is no data on the biology of this species on this diet. Therefore, several life history parameters of L. serricorne were studied on ground, pelleted feed at 28°C and 65% RH, to facilitate harvesting stages of specific ages in large numbers for assays with elevated temperatures. The mean duration for eggs was 8.1 d, and the mean egg survivorship was 92.0%. There were four discrete instars, and the mean durations of first, second, third, and fourth instars were 4.7, 4.5, 4.7, 11.8 d, respectively. The survivorship of first through third instars was about 99%, whereas that of fourth instars was 85%. The mean pupal duration was 4.6 d, and pupal survivorship was 98%. Newly eclosed unmated female adults lived 5 d longer than unmated males (29 d), whereas, mated males lived 6 d longer than mated females (17 d). Mated females started laying eggs on the third day after emergence and continued this activity for an additional six to eight days. Females, on average, laid 105 eggs with a mean daily output of 12 eggs. The data reported here provide new information on the biology of L. serricorne on ground, pelleted feed, which appears to be an optimal diet for mass rearing this species. Exposure of eggs, young larvae (3 to 4- July 2007 did not clearly show which of the life stages was heat- tolerant. However, exposure of all life stages to fixed times at 46, 50 and 54°C and 25% RH in the laboratory indicated eggs to be the most heat-tolerant stage. Time-mortality responses, at each of these three d old), old larvae (20 to 21-d old), and adults during heat treatment of a food-processing facility in 20-22 temperatures, showed that the time for 99% mortality (LT99) based on egg hatchability and egg-to-adult emergence was not significantly different at each temperature. The LT99 based on egg hatchability at 46°C was 605 min and it decreased to 190 min at 50°C and 39 min at 54°C. Therefore, during structural heat treatments eggs should be used in bioassays for gauging heat treatment effectiveness, because treatments aimed at controlling the egg stage should control all other life stages of L. serricorne.

Master of Science / Food Science Institute / Karen A. Schmidt / The demand for ultra high temperature processed and aseptically packaged dairy foods is growing throughout the U.S. The technology provides value-added food preservation for many foods including flavored milks, puddings, custards, creams, ice-cream mixes, whey-based drinks, sports drinks, and yogurt. Ultra high temperature nonfat milk, milk, light cream, and 18% cream are used throughout the U.S. by the restaurant and food service industries. There are several advantages to aseptic processing and packaging over traditional pasteurization. Advantages include extended shelf life, lower energy costs, and the elimination of required refrigeration during storage and distribution. Challenges are present in all aspects of dairy processing. Major challenges associated with ultra high temperature processing and aseptic packaging of dairy foods include product quality loss, such as age gelation, fat separation, and flavor loss, as well as manufacturing issues such as limited production capacity, potential contamination, slow packaging speeds, and limited shelf life knowledge. This report reviews the history of aseptic processing, principles of ultra high temperature processing, principles of aseptic filling, quality control of UHT dairy foods, and regulations for dairy processors.

Master of Science / Food Science Institute / J. Scott Smith / In the past 50 years or so dietary fiber has become an increasingly significant area of nutritional focus, debate, and research. Advances in food production practices have resulted in more and more refined foods being available and consumed throughout the world and particularly in developed nations such as the United States. While refined foods are typically more palatable to consumers, the content of dietary fiber is greatly reduced. Currently many diseases are believed to be associated with a lack of dietary fiber intake, and furthermore significant health benefits are thought possible via increased consumption of many dietary fibers. These issues are discussed in Chapter 2- Dietary Fiber and Disease. There is not a well accepted definition for dietary fiber, but most reference the human inability to fully digest fibers, fibers being made up of various monomer units of variable length, and some mention plant origin. In many ways the definition of dietary fiber is connected to the analytical methods used to quantify it, which there are many, several of which are detailed in Chapter 5- Analytical Techniques for Dietary Fiber. Newer ingredients that are not quantified by typical fiber analysis methods have created the need for additional assays. Dietary fiber is subject to all sorts of labeling regulations and a few nutritional claims. This has resulted in many manufacturers taking an interest in increasing the fiber content of their products while maintaining product quality and label friendliness. There are many raw materials/ingredients that can increase the fiber content in foods, each with its own set of functional and sensory characteristics. These are detailed in Chapter 7 and include acacia gum, beta glucan, cellulose, chitin/chitosan, corn bran, corn fiber, inulin, oat Bran/oat fiber, pea fiber, pectin, polydextrose, psyllium, resistant starch, rice bran, soy fibers, wheat bran, and wheat fiber. These fibers are unique in their functional capability and effect on flavor and texture. Discussion of the product development considerations includes these functional characteristics as well as cost, ingredient labeling requirements, usage levels, other sensory characteristics, storage stability, and effect on water activity.

Master of Science / Food Science Institute-Animal Science & Industry / Daniel Y.C. Fung / Three experiments were conducted to study the antimicrobial effectiveness of persimmon puree and phenolic compounds commonly found in the persimmon and plum. The objectives in experiment 1 were to evaluate the antimicrobial effects of persimmon puree on BioballTM Listeria monocytogenes and Escherichia coli O157 in a liquid medium. Persimmon puree was added at 1, 3, 5, and 10% wt./vol concentrations to brain heart infusion broth and inoculated with BioballTM Listeria monoctogenes and BioballTM Escherichia coli 0157. Microbial growth was evaluated at 0, 24, 36 and 72 h. Results indicated that at 24 h, persimmon puree at all concentrations suppressed (P<0.05) growth of L. monocytogenes compared to the control. Suppressed (P<0.05) growth of L. monocytogenes continued through 36 and 72 h for all concentrations of persimmon puree tested. However, due to non-pathogenic background Gram-negative micoflora, inhibition of E. coli O157 could not be ascertained. The objectives of experiment 2 were to evaluate the antimicrobial effectiveness of selected phenolic compounds (benzoic acid, gallic acid, vanillic acid, chlorogenic acid, and quercetin on E. coli O157:H7, Salmonella Typhimurium, Bacillus cereus, Yersinia enterocolitica, L. monocytogenes, and Staphylococcus aureus. Quercetin, vanillic, and chlorogenic acids were effective against selected pathogens at varying levels, but not as potent as Benzoic or Gallic acid. Results indicated that benzoic acid had the most effect against E. coli O157:H7, S. Typhimurium and B. cereus at concentrations of 452.98, 239.63 and 518.79 µg/ml, respectively. Gallic acid was the most effective against Y. enterocolitica, L. monocytogenes, and S. aureus at concentrations of 11.01, 29.06 and 22.45 µg/ml, respectively. The objective of experiment 3 were to evaluate the antimicrobial effectiveness of persimmon puree at concentrations of 0, 3, 5 and 10% wt./wt on a five strain cocktail of L. monocytogenes in ground beef. There was no suppression of growth at any concentration at 0, 1, 3 or 5 d. However, there was an increase (P<0.05) on 5 d for concentrations 5 and 10% persimmon puree when compared to the control. These series of experiments suggest that benzoic and gallic acids may have potential to suppress microbial growth. Persimmon puree appears to be an effective antimicrobial agent against Gram-positive bacteria in a liquid medium. However, incorporation of persimmon puree into ground beef did not yield an antimicrobial effect. Therefore, more research needs to be conducted to validate the effectiveness of phenolic compounds and persimmon puree as antimicrobial agents in food substances.

Master of Science / Food Science Institute - Grain Science & Industry / Thomas J. Herald / Donghai Wang / The number of people diagnosed with celiac disease has increased and subsequently the market for gluten-free products is rising. Sorghum has been identified to be a safe grain to use as a wheat alternative for the celiac community. There are many sorghum hybrids that are commercial available for use in food and feed. Noodles are selected for the growing market in the US and the lack of research and availability for sorghum noodles. Viscoelastic properties are crucial for making acceptable noodles which makes this research more challengeable. The research hypothesis is that sorghum can be used in making gluten-free noodles and there are end product quality differences that exist among the hybrids in production of gluten-free noodles. A series of chemical and physical analyses were conducted to compare four sorghum hybrids (Orbit, NE #8, F-525, NE #4) in a gluten-free noodle system. The noodles were formulated with 100% sorghum flour and the other functional ingredients including dried whole eggs, egg whites, xanthan gum and corn starch. Sorghum noodles were significantly different in color, texture and cooking quality among hybrids. The starch properties were found to have more effect than protein content on sorghum noodle qualities. Sorghum flour with fine particle size and low ash content was crucial for making acceptable sorghum noodles. Noodles made from sorghum F-525 exhibited some properties significantly closer to the commercial wheat flour noodles.

Master of Science / Food Science Institute / Fadi M. Aramouni / Jeffrey A. Gwirtz / In order to improve the quality of products available for consumers who require a gluten-free diet, this study examined the effects of sorghum flour composition and particle size on functionality in gluten-free batter bread. White, food-grade sorghum was milled to flour of varying extraction rates (60%, 80%, 100%), and was subsequently pin-milled at different speeds (no pin-milling, low- speed, and high-speed) to create flours of both variable composition and particle size. Two commercially-milled sorghum flour samples (AF and TV) were included in the study and subjected to the same pin-milling treatments. Characterization of each flour included measurements of flour composition, total starch content, particle size distribution, damaged starch, and water absorption. Bread characterization included measurement of specific volume, crumb properties, and crumb firmness through the use of digital imaging and texture profile analysis. Significant differences were found (p<0.05) in the composition of sorghum flours of varying extraction rate, most notably for fiber and total starch contents. Flour particle size and starch damage were significantly impacted by extraction rate and speed of pin milling (p<0.05). With the exception of the commercial flour samples, water absorption increased significantly with increasing extraction rate and speed of pin-milling speed (p<0.05). Within all treatments, breads produced from 60% extraction flour had significantly higher specific volumes, better crumb properties, and lower crumb firmness when compared to all other extractions and flour types. These measured bread characteristics were significantly impacted by flour properties, specifically particle size, starch damage, and fiber content (p<0.0001). The commercial flours studied produced breads of low specific volume, poor crumb properties, and dense textures. These results can assist millers and product developers in advancing the quality of sorghum-based gluten-free foods for the consumers that require them. Further research is necessary to better understand the extent to which particle size, and therefore starch damage, can improve sorghum-based gluten-free breads.

Master of Science / Food Science Institute, Human Ecology / Koushik Adhikari / The potential health benefits of spices, used as flavor enhancers since ancient times, are being explored more and more by researchers in animal and in vitro models. The application of mood and emotion constructs to understand the consumer psyche is a relatively new area of study in food science. The main objective of our study was to determine if spices (a blend of cinnamon, ginger, nutmeg, and cloves) that have high antioxidant properties evoke/change emotions in consumers. The carrier food, an extruded apple-based cereal-like product, was selected because cereals are convenient and consumed by many. Three cereal-like products containing 0, 4, or a 5% spice blend were extruded at Kansas State University. Four consumer tests, one day of hedonic and just-about-right evaluations (n= 100), followed by three days of emotion testing were carried out. For the emotion tests, 25 consumers saw the control sample three times, 25 consumers saw the 4% blend sample three times, 25 consumers saw the 5% blend sample three times, and 25 consumers saw all three samples once. In a clinical trial (n=10), total antioxidant capacity and blood glucose levels were determined from two samples (control and the 4% blend). The data were subjected to analysis of variance and principal components analysis to determine significant effects and trends in the data, respectively. ‘Calm’ was the only emotion that was significantly different in all three samples, which decreased over time (pre-consumption to 1-hour post consumption). The emotion ‘Satisfied’ increased significantly in the 5% blend showing that there might have been an effect because of the higher spice content. The PCAs showed that for the 4% and 5% blends, the movement of the consumers was towards emotions such as active, energetic, and enthusiastic. There were no trends for the control. For the clinical trial, the 4% blend was significantly higher (P < 0.05) in total antioxidant capacity than the baseline, although the differences in absolute terms are debatable. Blood glucose levels were not significantly different. Future research needs to be done to better understand how individual emotions affect overall liking and product acceptance.

Master of Science / Department of Grain Science and Industry / Subramanyam Bhadriraju / Stored-grain insects were managed traditionally with grain protectants and the fumigant phosphine. Protectant use leads to undesirable pesticide residues on grain. Many stored-grain insects are resistant to grain protectants and phosphine. Therefore, novel technologies are needed in the future to replace traditionally used methods. Preliminary laboratory and pilot scale field trials have shown catalytic infrared radiation of 2.8 to 7 μm wavelength to be effective in killing insects associated with stored wheat. The effectiveness of catalytic infrared radiation in killing life stages of three economically-important stored-grain insects in hard red winter wheat were evaluated. Wheat (113.5 or 227.0 g) infested with eggs, various ages of larvae, pupae, and adults were exposed for 45 or 60 sec at a distance of 8.0 or 12.7 cm from the catalytic infrared emitter. Infested wheat samples unexposed to infrared radiation served as the control treatment. Temperatures attained by the wheat samples during infrared exposure were monitored continuously using a non-contact infrared thermometer. The three insect species tested were the lesser grain borer, Rhyzopertha dominica (F.); rice weevil, Sitophilus oryzae L.; and red flour beetle, Tribolium castaneum (Herbst). The life stages of R. dominica and S. oryzae developing within wheat kernels were age-graded using radiographic techniques. The mean temperatures attained by wheat at the various treatment combinations ranged from 80[degrees] to 114[degrees]C. Both the time-dependent temperature profiles and mean wheat temperatures were greater in 113.5 g of wheat, exposed at a distance of 8.0 cm from the infrared emitter for 60 sec. The most heat tolerant stage in R. dominica was the older larvae, whereas in S. oryzae it was the egg, and in T. castaneum it was the pupa. In general, older larvae of all three species were less susceptible to infrared radiation than young larvae. The differences in susceptibility among life stages of all species to infrared radiation decreased with an increase in the mean temperature attained, and temperatures ≥105[degrees]C were needed to obtain 98 to 100% mortality of all life stages. Exposure to catalytic infrared radiation at the temperatures used to disinfest wheat did not adversely affect wheat, flour, and baking quality.

Master of Science / Department of Grain Science and Industry / Jon M. Faubion / Charles E. Walker / Shortening is a major ingredient used in high-ratio layer cakes. Plastic shortenings are most commonly used by the U.S. baking industry, but high levels of trans- or saturated fats cause health concerns. Compared to plastic shortenings, liquid shortenings could significantly reduce the dependence on high melting point fats and the emulsifiers used would enhance the shortening’s functionality. The objective of this research was to compare the influence of different types of fats on the texture and shelf-life of high-ratio layer cakes. Cakes were baked with soybean oil to evaluate the function of three emulsifiers (PGMS, GMS, and Lecithin) on layer cake quality, including volume, cake score, interior visual texture (C-Cell), and firmness (Voland-Stevens). An optimum emulsifier combination was chosen (PGMS 1.8%, GMS 1.0% and Lecithin 0.8%) for addition to the liquid oil. Four groups of layer cakes were baked using: plastic shortening, liquid shortening, liquid oil, or liquid oil plus emulsifier combination. Cake performance and firming over-time were evaluated. The liquid shortening provided the best fresh cake characteristics and cake firmness performance. Liquid oil combined with a combination of added emulsifiers performed very similar in terms of firmness, as did the liquid shortening. This indicated that emulsifiers played an important role on the improvement of cake firmness shelf-life.

Master of Science / Food Science Institute -- Human Nutrition / Delores H. Chambers / This research aimed to determine the sensory characteristics of commercially-available plain yogurts and examine how three "more sustainable" prototypes compared. Three experimental non-fat set-style yogurts were provided – one control and two samples that differed in fermentation time. These shortened fermentation times could result in energy reductions and potentially substantiate a “sustainable” marketing claim, a concept gaining traction with consumers. Twenty-six commercially-available yogurts varying in percent milk fat, milk type (organic or conventional), and processing (set-style, stirred, or strained/Greek-style) were also included. Using descriptive sensory analysis, a six-person highly-trained panel scored the intensity of 25 flavor, six texture, four mouth feel, and two mouth coating attributes on a 15-point numerical scale. Three replications were conducted, and all samples were tested at least 10 days prior to the end of their shelf-lives. The samples differed for 19 flavor and all texture, mouth feel, and mouth coating attributes. Cluster analysis indicated approximately seven flavor and five texture (texture, mouth feel, and mouth coating combined) clusters, resulting in 15 unique combinations of flavor and texture. Although no legal definitions exist for “sustainable,” the prototypes’ sensory characteristics were comparable to those of top-selling yogurts indicating potential market viability. This research also demonstrated potential growth opportunities. Despite the current diversity, several combinations of flavor and texture were not represented.