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.

Master of Science / Department of Animal Sciences and Industry / J. Scott Smith / Emulsifiers have been and remain highly functional ingredients in the food industry. Emulsifiers contain both hydrophilic and lipophilic parts, resulting in their ability to be useful in foods at very low levels. However, knowledge of why emulsifiers work and how to use them most effectively is reserved for the few scientists who specialize in the discipline. Therefore, a comparison of current emulsifier theory with known emulsifier usage in the industry is beneficial to all who use these ingredients. Current emulsifier theory effectively describes how emulsifiers behave in food systems. Emulsion theory details how emulsifiers facilitate the formation and stability of emulsions through study of the kinetics of food systems. Emulsion theory further relates the ability of emulsifiers to interact with other substances in a food system. The main interactions concerning emulsifiers are their ability to form mesophases with water, to strengthen or weaken protein interactions, to form complexes with starches, and to promote or subdue fat crystallization. However, industrial applications of emulsifiers indicate areas where exceptions to theory exist. While emulsion theory has been found to effectively describe the individual interactions and functions in food, the simplicity of the models indicates that complex food system models are still needed to truly understand how to maximize the functionality of emulsifiers.

Master of Science / Food Science Institute - Animal Science & Industry / Kelly J. K. Getty / Fats and oils are an important topic in the margarine and spreads industry. The selection of these ingredients can be based on many factors including flavor, functionality, cost, and health aspects. In general, fat is an important component of a healthy diet. Fat or oil provides nine calories per gram of energy, transports essential vitamins, and is necessary in cellular structure. Major shifts in consumption of fats and oils through history have been driven by consumer demand. An example is the decline in animal fat consumption due to consumers’ concern over saturated fats. Also, consumers’ concern over the obesity epidemic and coronary heart disease has driven demand for new, lower calorie, nutrient-rich spreads products. Fats and oils can be separated into many different subgroups. “Fats” generally refer to lipids that are solid at room temperature while “oils” refer to those that are liquid. Fatty acids can be either saturated or unsaturated. If they are unsaturated, they can be either mono-, di-, or poly-unsaturated. Also, unsaturated bonds can be in the cis or trans conformation. A triglyceride, which is three fatty acids esterified to a glycerol backbone, can have any combination of saturated and unsaturated fatty acids. Triglycerides are the primary components of animal and vegetable fats and oils. The ratio of saturated to unsaturated fatty acids in these fats and oils has a great impact on their functionality. Common fats and oils include butterfat, beef tallow, fish oils, soybean oil, rapeseed (canola) oil, corn oil, cottonseed oil, olive oil, sunflower oil, palm oil, palm kernel oil, coconut oil, linseed (flax) oil, and safflower oil. Typical fat and oil modification techniques include hydrogenation, interesterification, alternative hydrogenation, fractionation, blending, farm/field practices and genetic modification, and the use of fat replacers. There are many processing techniques that can be utilized in margarine and spreads production. The process can be optimized for each margarine or spreads product. There are many fats and oils in margarine and spreads formulations. Familiarity with commonly used fats and oils in regards to availability, cost, nutrition, chemistry, and functionality are important when creating a cost-effective, functional margarine or spreads product.

Inactivation of bacteriophages MS-2 and PRD1, and poliovirus type 1 were measured in Pima Clay Loam and Brazito Sandy Loam soils amended with anaerobically digested sewage sludge. Inactivation was determined at 15°C, 27°C, and 40°C with soils maintained at 30% moisture, and amended soils exposed to evaporation. No inactivation of PRD1 was observed within 30 days and 16 days at 15°C and 27°C respectively with little inactivation after 7 days at 40°C. Inactivation of MS-2 and poliovirus was approximately 2 fold greater at 27°C compared to 16°C. At 40°C neither virus was recovered 24 hours after sludge amendment. Evaporation to less than 5% soil moisture resulted in rapid loss of titer for all three viruses regardless of temperature. Survival of MS-2 and poliovirus 1 in sludge amended fields (15°C) was longer than comparable laboratory studies. None of the viruses were recovered in fields amended during the summer (33°C) after 7 days. A method was also developed to remove cell culture toxic components from these soils.

The antibacterial effect of electrolytically generated copper and silver separately and combined with free chlorine on Listeria monocytogenes was evaluated in filtered well water (FWW) and autoclaved dairy process water (ADPW). The inactivation rate (k = log10 reduction/minute) was determined. Slow bactericidal effects were observed in both FWW and ADPW after exposure to 400:40 or 800:80 mug/L copper and silver compared to 0.15 mg/L chlorine. At least five hours of exposure was required for a 6 log10 reduction in the bacterial numbers with copper and silver; however, with chlorine, the exposure time was reduced to less than one minute for the FWW. Addition of 0.15 mg/L chlorine to water containing copper and silver resulted in a significantly enhanced inactivation rate as compared to chlorine alone in both FWW and ADPW. In ADPW, chlorine with copper (400, 800 mug/L) resulted in an increased k value compared to chlorine alone and copper alone.

The nutritional and chemical properties of three Chinese pollens, sorghum (Sorghum sp.), rapeseed (Brassica napus) and sunflower (Helianthus annuus), were studied. All three pollens were highly preferred, with sunflower pollen the highest, by young honey bees (Apis mellifera). Rapeseed pollen increased honey bee's longevity the greatest; however, sorghum and sunflower pollens also increased the longevity relative to the no-pollen group. All three pollens had high energy (about 5 kcal/g) and carbohydrate quantities (58%). The protein, fat, and fiber levels were 27%, 7%, and 9% in rapeseed pollen, 26%, 5%, and 13% in sorghum pollen, and 15%, 5%, and 10% in sunflower pollen. alpha-Tocopherol was high in sunflower pollen (61 μg/g), lower in rapeseed (33 μg/g) and sorghum pollen (15 μg/g). K, Ca, Mg, Fe, Cu, and Mn were high in all three pollens. These data suggest that a pollen which is highly preferred by honey bees is not necessarily the most nutritious.