Master of Science / Department of Grain Science and Industry / Sajid Alavi / Foods with high fiber can reduce calorie uptake and provide health benefits related to chronic ailments like obesity, diabetes, cancer and cardiovascular disease. However, inclusion of fiber diminishes the final product quality and consumer acceptability of cereal products. The overall objective of this project was to produce fiber-enriched, pre-cooked wheat flours using extrusion processing in order to enhance their nutritional value, while maintaining functional and sensory properties in baked products such as cookies and tortillas. In the first part of this study, extrusion processing was utilized to pre-cook wheat flours substituted with 0, 10, 20 and 30 % wheat bran in order to enhance their rheological properties and functionality with regards to cookies and tortillas. Two extrusion conditions, low-temperature-low-shear (LTLS) and high-temperature-high-shear (HTHS) were studied for pre-cooking the flours. Results showed that for all flours, as % bran increased, RVA peak viscosity (PV), and mixograph peak time (PTM) and peak height (PH) decreased. At all bran levels, PV and PH were significantly lower for pre-cooked flours as compared to uncooked. As the percent bran increased, the quality of cookies (weight and spread factor) and tortillas (specific volume, rollability and extensibility) deteriorated for both uncooked and pre-cooked wheat flours. In the second part of this study, effect of extrusion pre-cooking on the dietary fiber profile of wheat flour substituted with 0, 10, 20 and 30 % wheat bran was evaluated. Pre-cooking by extrusion significantly increased SDF in flours (by 22 to 59 %), although in most cases it also led to a significant decrease in TDF. Cookies and tortillas, produced from uncooked and pre-cooked flours with 0 and 20% substituted bran, were evaluated for consumer acceptability using a 9-point hedonic scale. Organoleptic properties of cookies from uncooked flour did not change significantly with increase in bran substitution from 0 to 20%. However, consumer ratings for tortillas did decrease slightly but significantly with increase in bran level. To summarize, pre-cooking of the flours using extrusion did not improve the sensory properties of cookies and tortillas, although the products were still found acceptable by consumers and also contained higher soluble fiber.

Master of Science / Department of Grain Science and Industry / Jon M. Faubion / Charles E. Walker / In commercial bakeries, the baker expects to get the same bread loaf, including weight and size, after sheeting the same size dough piece. Doughs made from different flours have different elastic recoveries to a great extent, which has an effect on the dough’s size and density. Products made from differently elastic doughs can’t have the same shape and height. Weight may also be affected. The dough rheological behaviors of five flours and their blends having different chemical and physical properties were measured as were changes in thickness and snapback (thickness of the machined dough sheet relative to the roll gap) immediately following sheeting. Dough snapback was determined to be a function of both processing parameters, reduction ratio, and dough rest time, as well as different flour properties. The predication equation for dough snapback is based on multiple flour properties and sheeting conditions. Among the variables, Mixograph work, reduction ratio, and dough rest time were the main factors affecting the elastic characteristics of the doughs. Minimum snapback occurred with the weakest flour experiencing the longest rest time and the smallest reduction ratio. A 7-factor equation was found to be robust to predict the snapback of several flours, by combining Mixograph work, reduction ratio, dough rest time, Mixograph peak height and mixing time, Alveograph P/L, and protein content.

Doctor of Philosophy / Department of Animal Sciences and Industry / John A. Unruh / Sixty cows were utilized to investigate the use of zilpaterol, implanting, and concentrate feeding on performance, carcass traits, subprimal yield, steak retail display, and meat palatability of cows fed for 70 d. The 5 treatments were: 1) grass-fed on pasture (Grass); 2) concentrate-fed (C); 3) concentrate-fed and implanted (CI) with a trenbolone acetate/estradiol implant, DE); 4) concentrate-fed and fed zilpaterol beginning on d 38 of the feeding period (CZ); and 5) concentrate-fed, implanted and fed zilpaterol (CIZ). Hot carcass weights and dressing percentages were higher (P < 0.05) for all concentrate-fed cows than grass-fed cows. The CIZ cows had the largest and grass-fed cows the smallest longissimus muscle (LM) areas. Total subprimal weights were lightest for cuts from the grass-fed cows; and CIZ cows had greater weights than those from C cows. Sensory panelists found LM steaks from C and grass-fed cows were more tender than steaks from CZ and CIZ cows; and steaks from CI cows were more tender than steaks from CIZ cows. However, no tenderness differences were observed among treatments for knuckle (KN) steaks. In another study, carcasses from 31 fed cows and 24 fed steers were used to investigate the effects of aging (7 or 28 d) on LM retail display; aging and enhancement (blade tenderization and enhancement solution injection) on LM tenderness; and aging on enhanced KN, top blade, and top sirloin steaks. Steaks (LM) aged 7 d had less discoloration and were more color stable than steaks aged for 28 d. A sensory panel found enhanced-cow LM steaks were more tender than non-enhanced steaks; and aging for 28 d improved tenderness compared to 7 d aging for non-enhanced steaks only. Aging for 28 d compared to 7 d improved Warner-Bratzler shear (more tender) for enhanced cow top sirloin, steer top sirloin, and steer top blade steaks. Feeding cull cows a concentrate diet improved lean meat yields. When feeding a concentrate diet a combination of an implant and feeding zilpaterol can further increase lean meat yields. Enhancement provides an opportunity to improve tenderness of steaks from fed cows and steers.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Edward E. Carey / With acceptance and utilization of chemical pesticides declining, some vegetable producers are turning to alternative methods to manage plant health issues. Compost tea (CT) has provided control of some foliar pathogens and may provide benefits beyond disease suppression. Despite an increasing body of popular and scientific literature focusing on CT as a biological control option for growers, information on the efficacy of CT is still lacking for many pathosystems. In this study, field trials were conducted to evaluate the efficacy of CT on Septoria lycopersici, causal agent of Septoria leaf spot on tomato, in Kansas, in 2006 and 2007. Previous research done at KSU with a similar CT showed adequate control of this pathogen in field and greenhouse studies conducted. Additional work to develop a rapid screening method for efficacy of CT formulations was carried out in the greenhouse at Manhattan, KS. CT sprayed weekly on tomato plants prior to and after disease onset led to no significant difference in control of the pathogen compared to untreated controls. A contact fungicide (chlorothalonil) provided significant control of the pathogen in 2007, but not in 2006. These results contrast with those obtained in previous K-State research. It is difficult to assess why such striking differences were obtained, but the variation in these results point to the need to identify optimal recipes of CT for this pathosystem. Preliminary investigations standardized plant age, inoculum concentration, incubation conditions, and incubation interval for measurable Septoria leaf spot disease development on young tomato plants in the greenhouse. Ingredients of the field-tested CT were used to make a variety of CTs to test using the greenhouse-screening assay. Further work on identifying effective CT recipes is needed to substantiate the validity of this screening protocol and to evaluate the correlation of this method with disease suppression in the field.

Master of Science / Department of Human Nutrition / Koushik Adhikari / The cosmetic industry is growing rapidly, and one popular category is lip products. Women consider lip products a necessity and many would not leave home without it. Though the bigger cosmetic companies may have internal cosmetic lexicons, they are not available in the public domain. The purpose of this study was to develop a lexicon for descriptive sensory testing of lip products. Lip balms, lip glosses, and lipsticks were tested in this study. In part 1 (EXPERIMENT 1), two focus groups were conducted to understand women's perceptions of lip products, and also to elicit desirable and undesirable characteristics in the products. The women's idea of a perfect lip product was: clear/sheer/neutral color, smooth, not sticky, moisturizing and flavorless/tasteless. In part 2 (EXPERIMENT 2), a lexicon was developed for the lip products. Attributes were categorized under "Initial Texture", "Initial Appearance", "After Appearance" and "After Texture." In part 3 (EXPERIMENT 3) of the study, the lexicon was validated by testing various lip products using lexicon developed in part 2. The analysis of variance (ANOVA) results by product type indicated that the lexicon was able to differentiate among the lipsticks, lip balms and lip glosses. The lexicon was further able to show similarities and differences within a product type. Principal component analysis and cluster analysis, which are both multivariate techniques, validated the inferences from the univariate analysis (ANOVA). The two panelist groups (three panelists from the lexicon development panel – group 1, and three new panelists – group 2) showed no differences (P > 0.05) in attribute evaluations for all the samples tested. The lexicon developed in this study could be used to identify similarities and differences in other lip products such as lip plumper, lip liners and multi-use products. The authors hope that this research is extrapolated to other aspects of the personal care industry, such as hair care and skin care, and can aid in product development, product optimization, and claim substantiation.

Master of Science / Department of Human Nutrition / Delores H. Chambers / Ultra-high temperature (UHT) milk is marketed as a convenience product in the United States (U.S.) and as the most common form of milk in many other parts of the world. Two studies were conducted to get a better understanding of sensory properties and consumer acceptability in UHT milk. First study compared the differences in flavor and texture of commercial UHT milk from different countries (France, Italy, Japan, Korea, Peru, Thailand, and the U.S.). A total of 37 UHT and sterilized milk samples including whole, 2% reduced-fat, and low-fat milk were evaluated. Five highly trained panelists used flavor and texture profiling to describe the sensory properties of each milk sample. Higher levels of processed, chalky, brown, and cooked flavor notes generally corresponded to lower levels of fresh dairy flavor characteristics. In general, samples did not vary consistently within a country. Interestingly, fat content did not correlate with dairy fat flavor or with viscosity. This research suggests that companies' manufacturing processes may have more impact than country or fat content in determining quality of UHT milk. Second study compared UHT milk acceptability by U.S. milk consumers unused to UHT milk and Thai consumers who typically drank UHT milk. Preference mapping technique was used to study sensory characteristics of UHT milk that drive overall liking from each of those consumer groups. Consumer studies were conducted in Bangkok, Thailand and in Manhattan, Kansas with one hundred consumers participating in each location. Both groups of consumers evaluated five commercial UHT whole milks that represented a range of UHT milk properties. U.S. consumers thought that the UHT milks had more off-flavor and liked them overall less than did Thai consumers. Results from the external preference map showed that both groups of consumers liked UHT milk with more dairy characteristics and higher fat feel. However, there was a separate group of Thai consumers who liked UHT milk with processed, cooked, and brown flavors. Lack of freshness, butyric acid, and sour aromatics were undesirable sensory attributes in UHT milk, regardless of consumer population. Off-flavors in the UHT milks in this study may be described with those attributes.

Master of Science / Food Science Institute / J. Scott Smith / Food irradiation is one of the most important food processing methods utilized to reduce microbial load and extend shelf life. In 1995 the World Health Organization (WHO) declared irradiated foods to be safe from a nutritional and toxicological point of view. Various methods have been applied to detect irradiated foods. Detection of 2-alkylcyclobutanones has been found to be a useful method in identifying irradiated foods. The solvent extraction method utilizes a Soxhlet apparatus for lipid extraction followed by clean up with Florisil. However, this method is very time consuming. The other methods available to detect 2-alkylcyclobutanone include supercritical fluid extraction (SFE), and accelerated solvent extraction method using a Dionex ASE 200 instrument. The SFE is a fast method to detected 2-alkylcyclobutanone. All the above mentioned methods involve costly equipment. The aim of this study was to eliminate the requirement of costly extraction equipment for lipid extraction before clean up or direct isolation of 2-alkylcyclobutanone as in case of SFE instrument using Florisil cartridges. In this study, the manual solvent extraction method was applied to isolate alkylcylcobutanone followed by clean up with 2 g silica cartridge. The clean up extract was injected to gas chromatography-flame ionization detector (GC-FID) for detection of 2-dodecylcyclobutanone (2-DCB). Gas chromatography-mass spectrometry (GC-MS) was used to confirm that the compound detected was 2-dodecylcyclobutanone. The ions m/z 98 and 112 were selected for 2-DCB for monitoring in selected ion monitoring (SIM) mode of GC-MS. The results showed that this method was able to detect 2-DCB from irradiated ground beef. The manual method does not require costly equipment such as supercritical fluid extractor, Dionex, or Soxlet apparatus for extraction process.

Master of Science / Department of Grain Science and Industry / David L. Wetzel / Fourier transform infrared microspectroscopy was used to determine protein secondary structure in hard wheat breeding lines in situ, providing a molecular means to rank endosperm hardness for the selection of wheat cultivars for a specific end-use. Mapping with a single masked spot size diameter of 4.5 [Mu]m or confocal 5 [Mu]μm on beamlines U10B and U2B, respectively, produced spectra from the subaleurone layer within each wheat kernel using the high spatial resolution available with synchrotron infrared microspectroscopy. This procedure was used for the first four crop years. A focal plane array instrument was adapted for use for the remaining two crop years with a slight reduction of spatial resolution. Deconvolution and curve fitting were applied to the amide I region of spectra selected from the interstitial protein between the starch granules, and the relative amount of [Alpha]-helix to other protein secondary structures was revealed. Over six crop years, the [Alpha]-helix to [Beta]-sheet ratio of experimental wheat varieties were compared to those of released varieties in 143 mapping experiments. The highest measurable value was 2.50 while the lowest was 1.11, a range consistent with hard wheat secondary structure determination found in previous studies (13, 16). The determination of protein secondary structure provides a means of ranking experimental breeding lines for selection in specific end-use applications. FT-IR microspectroscopic imaging was used to develop a method, using myoglobin as the model protein, to study the effects of thermal processing to 100 [degrees]C on protein secondary structure. Films cast onto highly polished stainless steel plates allowed the study of the exact same film before and after heating. Analyzing the shift in the amide I peak maxima of reflection absorption spectra for 280 pixels from myoglobin films revealed the depletion of [Alpha]-helix at the expense of other protein secondary structures. Deconvolution and curve fitting techniques were applied to the amide I region of each spectral average to model protein secondary structure components found within the region. The method developed was applied to another animal source, gelatin, and a plant source, wheat gluten.

Master of Science / Food Science Institute / Fadi M. Aramouni / With an increasing number of people with celiac disease, the need for gluten-free products is inevitable. Sorghum is a grain safe for celiac patients. Therefore, the purpose of this work was to characterize four sorghum hybrids in terms of their grain and flour; then utilize the hybrids in a wheat-free product and test for physical, chemical, textural, and sensory differences. Flour tortillas were chosen for their current popularity and the lack of research and availability for gluten-free flour tortillas. Grain characterization included diameter, weight, and hardness as measured by the Single Kernel Characterization System and Tangential Abrasive Dehulling Device. Flour characterization included flour and starch particle size distributions, total starch, amylose content, starch pasting properties, moisture, crude protein, and ash content. Significant differences were found (p<0.05) among hybrids for each test except total starch. Gluten-free flour tortillas were made from the four sorghum hybrids in addition to a commercial sorghum flour. Tortilla weight, diameter, thickness, color, pH, Aw, and moisture content were measured along with extensibility and stretchability. A descriptive panel was trained and used to analyze the five samples. Significant differences were found (p<0.05) among samples for color, pH, Aw, and moisture content. Significant differences were also found (p<0.05) among samples for extensibility and stretchability. Extensibility was a more effective test in studying quality. The sensory panel found significant differences (p<0.05) for grain specks, angle of bend, rancidity, sweetness, springiness, hardness, and grittiness. The commercial flour had the highest score for angle bend and springiness and was, therefore, utilized in a consumer study. When compared to a gluten-free wrap already in the market, the sorghum flour tortilla made from this study scored significantly higher in all attributes, including overall acceptability. The commercial flour is thought to have preformed better than the other four samples due to its smaller particle size and greater starch damage allowing an increase in water absorption.

Master of Science / Food Science Institute, Agriculture / Katherine A. Tilley / Michael Tilley / The wheat tortilla is a chemically leavened circular light colored flat bread. Desirable characteristics for good quality tortilla include large diameter, softness, flexibility and long shelf stability. Important components influencing quality are wheat flour properties, which have not been optimized for tortilla industrial production thus far. The studies presented here investigated the effects of high molecular weight glutenin subunits (HMW-GS) on tortilla quality. Two approaches were employed: biotypes derived from Centurk and OK102 cultivars expressing defined HMW-GS compositions and transgenic wheat lines over-expressing HMW-GS 10. Analysis of protein expression and protein extractability were conducted to characterize wheat flours and suitable assays carried out to determine the respective dough properties. Tortillas were prepared by the hot-press method and quality parameters were measured at days 0, 2, 4, 7 and 14. Tortillas derived from Centurk biotypes possessing HMW-GS 2*, 7+9, 2+12, 2*, 7+8, 5+10 and 2*, 7+9, 5+10 exhibited superior texture profiles over time, but smaller diameters than the biotype 2*, 7+8, 2+12. Tortillas containing HMW-GS 7+9 and 2+12 revealed a texture profile similar to tortillas containing 5+10. Tortillas from the OK biotype 2*, 7+9, 3+12 exhibited larger diameter and texture profiles equivalent to tortillas containing 5+10. Therefore, this biotype showed the best quality within this cultivar. Tortillas derived from transgenic flours over-expressing HMW-GS 10 exhibited an undesirable rough appearance with decreased diameter, greater thickness, lower rollability scores, lower stretchability and greater rupture force over time. Over-expression of HMW-GS 10 in a wheat line containing 1RS-translocation did not promote the same deleterious effects in tortilla quality as it did in transgenic lines without 1RS translocation.