Master of Science / Food Science Institute - Animal Sciences and Industry / J. Scott Smith / The popularity of convenience foods and consumer awareness have indirectly increased the demand for novel and naturally occurring compounds that can delay oxidative deterioration and maintain nutritional quality of foods. Natural antioxidants from certain herbs and spices such as rosmarinic acid from rosemary, thymol from oregano, eugenol from clove, curcumin from turmeric are rich in polyphenolic compounds that provide long term oxidative stability as well as offer additional health benefits. High antioxidative capacity of herbs and spices phenolics could potentially substitute synthetic antioxidants such as butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), propyl gallate (PG), octyl gallate, and tert-butylated hydroquinone (TBHQ) in the food system. Synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are thermally unstable and decompose at higher temperatures. However, widely used cooking methods such as baking, frying, boiling, and roasting use high thermal temperature that can chemically degrade herbs and spices and diminish their antioxidative capacity, but they have been little studied. In this context, this review deals with the need of natural antioxidants, spices and herbs as natural antioxidants, their origin, chemical composition, pharmacological, and antioxidant properties. Moreover, the impact of temperature on total antioxidant capacity (TAC) of various herbs and spices such as cinnamon, clove, nutmeg, mace, oregano, rosemary, sage, and turmeric is highlighted. Different antioxidant assays are also studied and this approach revealed that there is a clear correlation between total phenolic content (TPC) and TAC of herbs and spices and specific phenolic compounds are responsible for the antioxidative capacity of particular herb and spice. These findings identified the optimum cooking temperature-time combination which results in the highest retention of antioxidative capacity and assures higher quality of food for the maintenance of human health.

Master of Science / School of Family Studies and Human Services / Farrell J. Webb / The Food Sufficiency Status Model is a conceptual model that was devised to help explain why some individuals are at an increased risk of becoming food insufficient. This model proposes that there are four factors that can influence an individual’s food status they are—demographics, family status/household size, food risk factors, and depression. This study uses data from the National Health and Nutrition Examination Survey (NHANES, 2007-2008)—Flexible Consumer Behavior Survey Module (n = 3,413), collected by the Centers for Disease Control and Prevention (CDC). The overall results generally supported the Food Sufficiency model and explained 22% (R[superscript]2adj = 0.215) of the variance in food sufficiency in the study’s population.

Master of Science / Department of Grain Science and Industry / Jon Faubion / Whole wheat flour has become a popular ingredient in baked goods. Consumers are seeking the added benefits of consuming healthy phytochemicals and bioactive compounds. As the demand for wholemeal flour increases it is important to understand the factors contributing to changes in whole wheat flour breadmaking quality as a function of both wheat and flour age. In wholemeal flour, the lipid composition appears to be a factor causing variable baking quality. Changes that occur in both freshly harvested wheat and milled flour can cause variations in baking quality. Bakers’ attempts to adjust formulations and processes are often unsuccessful. The objective of this study was to determine the effects of aging both new crop wheat and freshly milled flour at 2 different temperatures on baking quality and glycolipid composition. This study aged freshly harvested Overley hard red winter wheat at RT (23˚C) and FZ (-26˚C) for 8, 50, and 91 days before milling. Whole wheat flour baking and lipid extraction studies were performed incrementally over 31 days of flour storage after each milling. Glycolipid structure and amounts were measured using automated electrospray ionization-tandem mass spectrometry. The glycolipids analyzed in this study were DGDG (digalactosyldiglycerol), MGDG (monogalactosylmonoglycerol), MGMG (monogalactosylmonoglycerol), and DGMG (digalactosylmonoglycerol). Both the wheat and flour stored at -26˚C produced larger mean loaf volumes than did the 23˚C treatment for all 3 wheat ages. The FZ and RT DGDG:MGDG ratios were similar over both wheat and flour age so changes to the glycolipid fraction did not appear to be the cause of the significant difference between volumes of bread baked from samples stored at RT and FZ. There was limited change in mean volume over flour age except for an increase at the FZ 91 day point. The DGDG:MGDG ratios were generally unchanged over flour age. Loaf volumes were the same over wheat age except for an unexpected drop during the 50 day wheat study. The corresponding DGDG:MGDG ratios did not show any significant differences over wheat age. The FZ storage temperature might be inhibiting some biochemical change not affecting the glycolipids, leading to higher volumes than the RT storage treatment.

Master of Science / Department of Hospitality Management and Dietetics / Kevin R. Roberts / The Centers for Disease Control and Prevention estimated that one in six Americans become ill,128,000 are hospitalized, and 3,000 die each year due to foodborne illness. Children are at a higher risk of acquiring foodborne illness than adults for several reasons, including: an immune system that has yet to fully develop, limiting their ability to fight infections; a lack of control over the food they consume because their meals are usually provided by others; and the lack of awareness of food safety risks. Thus, it is critical to ensure that childcare center employees practice safe food handling. The purpose of this study was to explore the food safety knowledge, practices, and barriers to safe food handling practices of childcare center employees. Observations were conducted in 10 childcare centers in Manhattan, Kansas. Each childcare center was observed for two days during lunch preparation and service. Observations of foodservice employees were conducted in the kitchen using a structured observation form. Teacher observations were conducted in the classroom using detailed notes. A questionnaire was used to collect demographic, food safety training, and food safety knowledge information. SPSS (v. 20.0) was used to analyze data. Childcare center employees had high average scores on the safety knowledge assessment. The majority of employees received some type of food safety training. Time pressures, availability of equipment, and small food preparation space were found as the main barriers to implementing safe food handling. Childcare center foodservice workers and teachers were knowledgeable about handwashing and time/temperature control, but failed to utilize on the job. Results of this study will help childcare educators to develop materials to improve food safety practices and encourage owners/managers of childcare centers to enhance their food safety behaviors.

Master of Science / Department of Grain Science and Industry / Sajid Alavi / The objective of the study was to investigate extrusion as an alternative processing method and grain sorghum as a viable substitute for corn in fortified blended foods (FBFs) used in nutrition and food assistance programs around the world. In the first part of this study, sorghum-soy blend (SSB), corn-soy blend (CSB) and whole corn-soy blend (WCSB) were developed using extrusion and compared with traditional CSB13 for physico-chemical and sensory properties. After milling of extrudates, average particle size (PS) ranged between 341-447 microns, with 78-85% below 600 microns. In general, Bostwick flow rates (VB=12-23 cm/min) of rehydrated blends (11.75% solids) were within standard specifications but higher than CSB13. Descriptive sensory analysis indicated that the sorghum-based rehydrated blends were significantly less lumpy and had a more uniform texture as compared to corn-based blends and CSB13. In the second part, the impact of decortication level and process conditions was investigated with respect to sorghum-based extruded blends. Degree of gelatinization of the whole sorghum-soy blend (WSSB) and decorticated sorghum-soy blend (DSSB) extrudates ranged from 93-97%. Expansion ratio (ER=3.6-6.1) was correlated with specific mechanical energy input (SME=145-415 kJ/kg; r=0.99) and average particle size after milling (PS=336-474 microns; r= -0.75). Rehydrated blends at 20% solids concentration provided recommended energy density (0.8 kcal/g) for FBFs. Bostwick flow rates had high correlation (r = -0.91) with pasting data (final viscosity) obtained using rapid visco analyzer (RVA). Addition of oil (5.5%) prior to extrusion was also studied, and resulted in process instabilities and also lower shelf-life as determined via descriptive sensory analysis (rancid and painty attributes) and gas chromatography-mass spectroscopy (hexanal, heptenal and octanal concentrations). In conclusion, extruded sorghum-soy blends met standard specifications for energy density and consistency (Bostwick flow rate), and were superior in some aspects as compared to extruded corn-soy blends and traditional corn-soy blends (CSB13). Relationships between extrusion mechanical energy input, expansion, particle size after milling and consistency of rehydrated blends were established. Consistency of the rehydrated blends is an extremely important criterion as it affects the ease of ingestion by target consumers (children below 5 years, in this case).

Master of Science / Department of Grain Science and Industry / Sajid Alavi / Texturized vegetable protein (TVP) based foods offer several advantages compared to animal protein, including lower costs and improved health benefits. Wheat gluten is often processed using extrusion to produce TVP. Processing aids, such as reducing agents (example, cysteine and sodium metabisulfite) and pH modifiers (example, tetra potassium phosphate) aid in texturization. Reduction of sulfhydryl groups, cleavage of disulfide bonds, and reformation of bonds between elongated protein molecules results in protein aggregation and texturization. This study focused on development of a fundamental understanding of these mechanisms for texturization using analytical tools such as the phase transition analyzer (PTA), in combination with lab- and pilot-scale extrusion. The abovementioned three chemicals were added to four varieties of gluten. The control treatment had no additives. PTA was used to understand the operative flow properties of gluten in an environment similar to an extrusion system. Addition of sulfite (0.18%) and cysteine (0.18%) lowered the thermal softening (Ts:36.6-44.1 °C) and thermal flow (Tf:79.6-105.6 °C) temperatures of all varieties of gluten as compared to the controls (Ts:38.8-48.2 °C; Tf:91.7-112.2 °C). Phosphate (3%) did not have the same lowering effect on Ts (40.2-47.0 °C) and Tf (96.2-108.2 °C), indicating a different mechanism. Extrusion studies were conducted to gain an understanding of the reformation of disulfide bonds and texturization. Two of the varieties of gluten, a “superior” one that texturizes well and an “inferior” gluten requiring texturizing aids, were processed on a lab-scale extruder. Pilot scale extrusion was used to process the other two glutens (“superior” varieties) to obtain commercial quality products, which were evaluated for degree of texturization (hydration rate, absorption index and integrity). During lab-scale extrusion, texturization was observed only in the case of phosphate and corresponded with an increase in specific mechanical energy (SME) as compared to the control, indicating disulfide bond reformation. Phosphate also led to significantly (p<0.05) better texturization during pilot-scale extrusion, although SME trends were different due to higher in-barrel moisture and a more ideal extrusion system. Fourier Transform Infrared Spectroscopy was used to examine protein structural changes and indicated a loss of α-helix structure in TVP with an increase in β-sheet formation.

Doctor of Philosophy / Food Science / Justin Kastner / Many Chinese aquaculture farmers use unapproved chemicals to treat their fish, many of which are diseased as a result of the country’s poor waste management and environmental practices. During 2006-2007, the United States (U.S.), the European Union, and Japan rejected large amounts of Chinese seafood imports due to the presence of unapproved chemicals or the presence of approved chemicals at concentrations that exceeded permitted levels. This dissertation examines the sources of environmental health and food safety problems in China; it also examines how effective the U.S. and Chinese governments’ regulations are in protecting consumers from hazards in Chinese aquaculture products. The study looks at specific chemical contaminants found in Chinese aquaculture imports, explores their potential toxicity or carcinogenicity, and examines the reasons for their prohibition from human food. The study exploits the available U.S. seafood consumption patterns (courtesy of the National Health and Nutrition Examination Survey—NHANES—database) and then uses probabilistic modeling (courtesy of CREMe Software Limited) to determine the extent to which specific sensitive U.S. consumer subpopulations were exposed to aquaculture chemical contaminants in the food supply in a contrived scenario using real consumption data (from NHANES) and actual contamination data (from the FDA). The study compares exposure between children and adult consumers, and also looks at exposure among women aged 18 years and older and the elderly aged 60 years and older. This study suggests a strong likelihood that NHANES children, as well as female consumers aged 18 years and older and elderly consumers aged 60 years and older, were (in the contrived scenario) all exposed to violative intake levels of chemical contaminants from Chinese aquaculture imports. Children forming the 99.5th and 99.9th percentiles of NHANES seafood consumers were exposed to higher levels of nitrofuran, gentian violet, and malachite green contaminants per kilogram of body weight than were their adult counterparts. Conversely, children were exposed to lower levels of fluoroquinolone contaminants per kilogram of body weight than were their adult counterparts. The 50th, 95th, and 99.9th percentiles of female consumers aged 18 and older and elderly consumers aged 60 years and older were exposed to violative daily intake levels of contaminants in Chinese aquaculture. The study concludes by examining what the U.S. and Chinese governments should do to address aquaculture safety.