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Starch Structures And Properties Affected By Genetics And By Environment, Hanyu Yangcheng Jan 2016

Starch Structures And Properties Affected By Genetics And By Environment, Hanyu Yangcheng

Graduate Theses and Dissertations

Functionalities of starch for food and non-food applications are dependent on the starch structures and properties, which are affected by both the genetics and the growing conditions of the crop. Objectives of this dissertation research were to 1) Understand the unique properties of Tibetan hull-less barley starches, their structures, and the impacts of growing conditions; and 2) Understand dosage effects of waxy gene on the contents and structures of amylose and amylopectin and properties of corn starch; and 3) Understand the starch physicochemical properties of Apios mother and child tuber and the mechanism of starch development.

Tibetan hull-less barley varieties ...


Evaluating The Microbial Safety Status Of Products From Sustainable Organic Agriculture, Sai Deepikaa Elumalai Jan 2016

Evaluating The Microbial Safety Status Of Products From Sustainable Organic Agriculture, Sai Deepikaa Elumalai

Graduate Theses and Dissertations

There has been a steady increase in the demand for organic and sustainable agricultural products. Consumers increasingly prefer non – GMO products grown without pesticides and antibiotics. In order to satisfy the increasing demand, several agricultural producers have opted for use of different types of modern agricultural practices which are more efficient and sustainable than conventional methods. My research focuses on two such modern agricultural practices. Because the products from these methods do not have many food safety interventions applied to them, it is important to make sure that they are free of pathogens and are safe for human consumption. My ...


Reducing Risk Of Foodborne Illness In Older Adults: Interventions Targeting At-Home And Foodservice Handling Behaviors, Amber Lynn Roy Jan 2016

Reducing Risk Of Foodborne Illness In Older Adults: Interventions Targeting At-Home And Foodservice Handling Behaviors, Amber Lynn Roy

Graduate Theses and Dissertations

The United States population is aging, creating a higher number of people and proportion of the population at increased risk for foodborne illness. OA awareness and behavior when purchasing and preparing foods inside the home affects food safety risk in this population. A national trend in eating outside the home also places foodservice workers in a key role for interventions focused on foodborne disease prevention in OA. By targeting both OAs and foodservice workers, both projects in this thesis intend to reduce food safety risk in OAs by increasing familiarity and knowledge about food safety and food handling.

For the ...


Modified Milk Protein Concentrates In High-Protein Nutrition Bars, Justin Charles Banach Jan 2016

Modified Milk Protein Concentrates In High-Protein Nutrition Bars, Justin Charles Banach

Graduate Theses and Dissertations

This dissertation research focuses on studying time-dependent texture changes in high-protein nutrition (HPN) bars and their underlying mechanisms to possibly prevent or reduce change when formulated with high-protein (≥ 80% protein w/w) milk protein concentrate (MPC). HPN bars (20-50% protein w/w) are a target application for these nutritious and flavorless powder ingredients. However, high-protein MPCs produce HPN bars with undesirable texture that harden and lose cohesion during storage. The overall goal of this work is to improve the performance of MPCs for use in HPN bars by modifying their physicochemical properties to impart softness, cohesion, and textural stability. Twin-screw ...


Development Of An Online Food Safety Training And Pilot Study For Employees Of University Farms And School Gardens, John Michael Dzubak Jan 2015

Development Of An Online Food Safety Training And Pilot Study For Employees Of University Farms And School Gardens, John Michael Dzubak

Graduate Theses and Dissertations

Two one-hour on farm food safety online module were developed to inform k-12 students and university farm workers on food safety hazards associated with production and harvesting of fresh produce. Module content was developed through a review of the current Good Agricultural Practices (GAPs) Program, current research available, and updated regulations in produce food safety. Quizzes for students and a user manual were created for facilitators and instructors to support the online modules. After developing the course materials, a pilot study was conducted at two k-12 school districts in Iowa, two land grant universities, with a six member expert steering ...


Analysis Of Co-Crystallized Free Phytosterols With Triacylglycerols As A Functional Food Ingredient, Danielle Franchetti Jan 2015

Analysis Of Co-Crystallized Free Phytosterols With Triacylglycerols As A Functional Food Ingredient, Danielle Franchetti

Graduate Theses and Dissertations

Free phytosterols (FPS) have been utilized in recent research compared to their esterified or soluble counterparts in order to reduce costs and inconvenience associated with esterified phytosterols during processing. Furthermore, bans on trans fats have led to the need for substitutes that can mimic their desirable properties. This research focuses on the analysis of FPS co-crystallized with fully hydrogenated soybean oil (FHSO) and soybean oil (SO) as a zero-trans substitute for puff pastry shortening and various other types of shortenings. Differential interference contrast microscopy and wide angle x-ray diffraction demonstrated co-crystallization of FPS with FHSO and SO. Polymorphic forms were ...


Natural And Value-Added Approaches For Pathogen Control, Zongyu Zhang Jan 2015

Natural And Value-Added Approaches For Pathogen Control, Zongyu Zhang

Graduate Theses and Dissertations

Infectious diseases caused by established foodborne pathogens, multidrug-resistant bacteria and opportunistic fungal pathogens pose serious threats to both public health and the economy. The aim of this work was to provide new approaches based on natural or value-added agricultural materials to address these important threats. Chapter 1 of this thesis provides a general introduction and description of how the work is organized. Chapter 2 reviews the literature related to our topics of research and Chapter 8 provides general conclusions. The remaining chapters report on the various projects that were conducted on the topics of natural and value-added approaches for pathogen ...


Supplementation Of Laying-Hen Feed With Annatto Tocotrienols And Impact Of Α-Tocopherol On Tocotrienol Transfer To Egg Yolk And Tocopherol And Annatto Tocotrienol Distribution Analysis In Laying-Hen Body, Hannah Elisabeth Hansen Jan 2015

Supplementation Of Laying-Hen Feed With Annatto Tocotrienols And Impact Of Α-Tocopherol On Tocotrienol Transfer To Egg Yolk And Tocopherol And Annatto Tocotrienol Distribution Analysis In Laying-Hen Body, Hannah Elisabeth Hansen

Graduate Theses and Dissertations

Laying-hens efficiently transfer nutrients from their feed to the resulting eggs, and nutrients from feed are distributed in many organs and tissues for various uses. Annatto is the only known source of tocotrienols (T3s) (gamma-T3 ~10% and delta-T3 ~90%) without alpha-tocopherol present. The T3s have many health benefits including lowering cholesterol. The objective of this research was to study the effect of alpha-tocopherol on the transfer of T3s to eggs and various organs and tissues in the body of the laying-hen. To do so, laying-hens were fed treatment diets for 7 weeks supplemented with annatto T3s in the presence and ...


Analysis And Characterization Of Oleogel Consisting Of Beta-Sistosterol And Gamma-Oryzanol In Soybean Oil, Zoey Quynh Nguyen Jan 2015

Analysis And Characterization Of Oleogel Consisting Of Beta-Sistosterol And Gamma-Oryzanol In Soybean Oil, Zoey Quynh Nguyen

Graduate Theses and Dissertations

Unsaturated and trans fatty acids have been proven to contribute to negative health effects such as cardiovascular diseases. There is a demand for healthier alternatives that mimic similar properties in bakery applications. Oleogels, composed of beta-sitosterol (BS) and gamma-oryzanol (GO) in vegetable oil, have recently been studied as a healthy alternative. Previous research focused on the development of a gel consisting of low concentrations of sterol mixtures. The goal of this research was to characterize the physical properties of phytosterol oleogels (POs) composed of high concentrations of sterol mixtures (10-20%) in liquid soybean oil. Samples with different BS:GO ratios ...


Determination Of The Gelation Mechanism Of Freeze-Thawed Hen Egg Yolk, Carmen Au Jan 2015

Determination Of The Gelation Mechanism Of Freeze-Thawed Hen Egg Yolk, Carmen Au

Graduate Theses and Dissertations

Gelation, the irreversible loss of fluidity in freeze-thawed hen egg yolk, is undesirable to food processors because of reduced yolk dispersibility and functionality. The mechanism of gelation has not yet been fully elucidated. The objective of this research was to determine the gelation mechanism by studying the gel mechanical properties, particle size distribution, protein characteristics, free water content, matrix mobility, and microstructural arrangement of fresh vs gelled yolk in a long-term frozen storage study. A separate investigation was conducted for the development of a sensitive and robust proton nuclear magnetic resonance (1H NMR) spectroscopic technique to study matrix mobility in ...


Impact Of Ddgs Feeding On The Composition Of Milk And Baby Swiss Cheese, Vaishnavi Manimanna Sankarlal Jan 2015

Impact Of Ddgs Feeding On The Composition Of Milk And Baby Swiss Cheese, Vaishnavi Manimanna Sankarlal

Graduate Theses and Dissertations

Late blowing in Swiss cheese, a result of unwanted gas production during ripening, is unacceptable to consumers, and causes economic loss to manufacturers. Cheese processors have raised concerns that feeding dried distillers' grains with soluble (DDGS) to cows leads to this defect, in part, because of Clostridial spores. Apart from that, in order to minimize bacterial contamination, antibiotics are being used in industrial ethanol fermentations. Residual antibiotics in DDGS could lead to inadvertent feeding of antibiotics to animals is also of concern. In this study, the effect of feeding DDGS to lactating dairy cows on composition and quality of milk ...


Modification Of Egg Albumen To Improve Thermal Stability, Charlwit Kulchaiyawat Jan 2015

Modification Of Egg Albumen To Improve Thermal Stability, Charlwit Kulchaiyawat

Graduate Theses and Dissertations

Eggs are an excellent source of high quality protein for consumers that can be economically produced. This dissertation focuses on improving the thermal stability of egg albumen or egg white protein. As consumers are demanding more protein in their diets, egg white proteins can provide the supply to meet those needs. A major barrier of egg white protein's use as a mainstream protein in beverages, further food processing, or other consumer food is its sensitivity to heat (precipitating out of solution when heated). If this functional property can be resolved, it would not only add value to the egg ...


Sonic Boom Or Bust?: Application Of High-Power Ultrasound For Fluid Milk Processing, Lily Claire Benner Jan 2015

Sonic Boom Or Bust?: Application Of High-Power Ultrasound For Fluid Milk Processing, Lily Claire Benner

Graduate Theses and Dissertations

Ultrasonication has potential application in the dairy industry for extending milk shelf life by killing bacteria and spores that survive pasteurization. However, ultrasound treatment may result in off-aromas or undesirable milk quality consequences, which increase as treatment time and intensity increase. The primary objective of this research was to determine whether short treatments of acoustic energy, in conjunction with pasteurization, increase refrigerated shelf life while producing no adverse aroma effect. Shelf life was determined by performing total aerobic counts (TAC) on skim milk that had been inoculated with Paenibacillus amylolyticus, a spore-forming, thermotolerant and psychrophilic milk contamination bacterium. Pasteurized control ...


Antimicrobial Efficacy Of Commercial Produce Sanitizers Against Artificially Inoculated Foodborne Pathogens And Natural Fungal Contaminants On The Surface Of Whole Melons, Amanda Lyn Svoboda Jan 2015

Antimicrobial Efficacy Of Commercial Produce Sanitizers Against Artificially Inoculated Foodborne Pathogens And Natural Fungal Contaminants On The Surface Of Whole Melons, Amanda Lyn Svoboda

Graduate Theses and Dissertations

Foodborne disease outbreaks linked to enteric pathogens on cantaloupe and watermelon over the past few years has raised concern in the melon industry. As a result, new formulations of antimicrobial treatments have been developed, creating more choices for melon producers to utilize in attempts to improve microbial safety of their product. Previous research has indicated that the use of these strong post-harvest sanitizers may have detrimental quality effects on produce. The overall objective of this research was to evaluate the broad spectrum antimicrobial activity of commercially available produce sanitizers marketed towards the melon industry.

Sanitizers selected represented various chemical categories ...


Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan Jul 2014

Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan

Open Access Theses

There are five major mechanisms of water-solid interactions. The primary focus of this thesis was on two of these: deliquescence and hydrate formation. Many crystalline food ingredients are deliquescent compounds (e.g., NaCl, sucrose, and ascorbic acid) and some are both deliquescent and hydrate formers (e.g., glucose, thiamine HCl, citric acid). Deliquescence is the first order phase transformation of a crystalline solid to a solution above a critical relative humidity (RH) known as the deliquescence point (RH0). A crystalline hydrate is a pseudo-polymorph in which water is incorporated into the crystal structure, altering the molecular formula and the physical ...


Crystallization Inhibitor Properties Of Polymers And Effects On The Chemical And Physical Stability Of L-Ascorbic Acid During Preparation And Storage, Belinda Christina Jul 2014

Crystallization Inhibitor Properties Of Polymers And Effects On The Chemical And Physical Stability Of L-Ascorbic Acid During Preparation And Storage, Belinda Christina

Open Access Theses

Crystalline L-ascorbic acid (VitC) is an essential nutrient solid that is widely used in food applications for fortification, antioxidant, and label claim purposes. VitC is known as one of the most unstable vitamins, and its content must be declared on food labels. Interest has been increasing in creating amorphous solid structures for improving the solubility and/or dissolution rates of crystalline compounds. One of the most promising methods studied to prevent the crystallization of an amorphous solid is the use of polymers in dispersions, although the specific polymer properties that lead to the best physical stability for a particular type ...


Mechanisms Of Nutrition Bar Hardening: Effect Of Hydrolyzed Whey Protein And Carbohydrate Source, Shaun P. Adams Dec 2008

Mechanisms Of Nutrition Bar Hardening: Effect Of Hydrolyzed Whey Protein And Carbohydrate Source, Shaun P. Adams

All Graduate Theses and Dissertations

The influence of increasing hydrolyzed protein content on the microstructure and hardness of high protein nutrition bars was investigated to determine the mechanism of hardening during storage. Bars with various hydrolyzed protein levels were manufactured using differing ratios of 0, 25, 50, 75, 100% (wt. /wt.) of partially hydrolyzed whey protein isolate (HWPI) to an intact (non-hydrolyzed) whey protein isolate (WPI) which made up approximately 38% of the total bar composition. High fructose corn syrup (HFCS) (42%) and vegetable shortening (20%) constituted the rest of the ingredients. Accelerated aging was performed by storing bars at 32 ºC for 36 d ...


Soybean Quality Loss During Constant Storage Conditions , Ibni Hajar Rukunudin Jan 1997

Soybean Quality Loss During Constant Storage Conditions , Ibni Hajar Rukunudin

Retrospective Theses and Dissertations

A modified method for determining free fatty acid (FFA) in crude and refined soybean oils from 0.3 to 6.0 g oil sample size was developed. Good correlation between the modified and official methods was established for crude and refined soybean oils with R2 of 0.9995 and 0.997, respectively. The slopes were 1.01 and 0.99 for the crude and refined oil, respectively.;The number of days soybean lost 0.5 and 1.0% dry matter, for low and high harvest moisture content (MC) soybeans both mechanically and manually harvested, were determined. Soybeans manually harvested at ...


Effect Of Postmortem Storage On Degradation Of The Recently Discovered Myofibrillar Protein Titin In Bovine Longissimus Muscle, Mary Lee Gragg Lusby Jan 1983

Effect Of Postmortem Storage On Degradation Of The Recently Discovered Myofibrillar Protein Titin In Bovine Longissimus Muscle, Mary Lee Gragg Lusby

Retrospective Theses and Dissertations

The high molecular weight (M(,r) (TURN) 1 x 10('6)) protein titin was isolated from purified bovine longissimus muscle myofibrils by gel filtration column chromatography in the presence of sodium dodecyl sulfate (SDS). Purified bovine, rabbit and chicken skeletal muscle titins were closely related or homologous in that they yielded similar column elution profiles and had similar amino acid compositions. Titin purified from rabbit and bovine skeletal muscles also comigrated in SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and cross-reacted with antibodies specific for titin. Indirect immunofluorescence localization demonstrated that titin is preferentially localized in the A-I junctional area with some diffuse ...


Bound And Free Water Relationships In Soy Proteins As Measured By Differential Scanning Calorimetry, Dorothy J. Muffett Jan 1979

Bound And Free Water Relationships In Soy Proteins As Measured By Differential Scanning Calorimetry, Dorothy J. Muffett

Retrospective Theses and Dissertations

No abstract provided.


Evaluation Of Heat Processing On Soy Proteins Using A Ph Stat To Monitor Tryptic Hydrolysis, Carol Thomasson Stinson Jan 1979

Evaluation Of Heat Processing On Soy Proteins Using A Ph Stat To Monitor Tryptic Hydrolysis, Carol Thomasson Stinson

Retrospective Theses and Dissertations

No abstract provided.


Flavor And Composition Of Soymilk As Influenced By Ethanolic Soaking, Heating And Ph Control, Hae-Ran Lee Ashraf Jan 1979

Flavor And Composition Of Soymilk As Influenced By Ethanolic Soaking, Heating And Ph Control, Hae-Ran Lee Ashraf

Retrospective Theses and Dissertations

No abstract provided.


Thermal Inactivation Of Staphylococcal Enterotoxin B With Changing Ph, Protein Concentration, And Ionic Strength , Sister Evamonica Mercedita Jamlang S.Sp.S. Jan 1970

Thermal Inactivation Of Staphylococcal Enterotoxin B With Changing Ph, Protein Concentration, And Ionic Strength , Sister Evamonica Mercedita Jamlang S.Sp.S.

Retrospective Theses and Dissertations

No abstract provided.


Preparation Of "Natural" Cow-Milk Fat Globules: Preliminary Investigation Of Materials Adsorbed At Their Surfaces , Eugene Harry Sander Jan 1962

Preparation Of "Natural" Cow-Milk Fat Globules: Preliminary Investigation Of Materials Adsorbed At Their Surfaces , Eugene Harry Sander

Retrospective Theses and Dissertations

No abstract provided.


Water Content Changes Of Poultry Held In Frozen Storage As Related To Palatibility, Helen Virginia Johnson Jan 1946

Water Content Changes Of Poultry Held In Frozen Storage As Related To Palatibility, Helen Virginia Johnson

Retrospective Theses and Dissertations

No abstract provided.


The Relationships Of A Lipolytic Organism To Rancidity Of Butter, Ralph Victor Hussong Jan 1932

The Relationships Of A Lipolytic Organism To Rancidity Of Butter, Ralph Victor Hussong

Retrospective Theses and Dissertations

No abstract provided.


Problems Related To The Commercial Production Of Levulose, Jack Waldo Eichinger Jr. Jan 1931

Problems Related To The Commercial Production Of Levulose, Jack Waldo Eichinger Jr.

Retrospective Theses and Dissertations

The factors controlling the conversion reaction have been determined.;The decomposition of levulose under conditions of high acidity and, temperature has been studied, and the limiting conditions have been determined.;Conversion experiments under varying conditions of concentration and acidity have been run, and the data are presented in the form of tables and graphs.;Normality-pH data for different concentrations of juice treated with varying, quantities of sulfuric and hydrochloric acids have been determined.;A table has been prepared which shows the amount of sulfuric or hydrochloric acid required to convert a juice of any concentration from 4 to 40% total ...