Life Sciences Commons^™

Strain Hardening And Anisotropy During Tensile Testing Of Sheared Model Mozzarella Cheeses, Prateek Sharma, Peter A. Munro, Tzvetelin T. Dessev, Peter G. Wiles, E. Allen Foegeding

Nutrition, Dietetics, and Food Sciences Faculty Publications

We studied the tensile fracture properties of model Mozzarella cheeses with varying amounts of shear work input (3.3–73.7 kJ/kg). After manufacture, cheeses were elongated by manual rolling at 65°C followed by tensile testing at 21°C on dumbbell-shaped samples cut both parallel and perpendicular to the rolling direction. Strain hardening parameters were estimated from stress–strain curves using 3 different methods. Fracture stress and strain for longitudinal samples did not vary significantly with shear work input up to 26.3 kJ/kg and then decreased dramatically at 58.2 kJ/kg. Longitudinal samples with shear work input <30 kJ/kg demonstrated significant strain hardening by all 3 estimation methods. At shear work inputs <30 kJ/kg, strong anisotropy was observed in both fracture stress and strain. After a shear work input of 58.2 kJ/kg, anisotropy and strain hardening were absent. Perpendicular samples did not show strain hardening at any level of shear work input. Although the distortion of the fat drops in the cheese structure associated with the elongation could account for some of the anisotropy observed, the presence of anisotropy in the elongated nonfat samples reflected that shear work and rolling also aligned the protein structure.

Growth And Gas Formation By Lactobacillus Wasatchensis, A Novel Obligatory Heterofermentative Nonstarter Lactic Acid Bacterium, In Cheddar-Style Cheese Made Using A Streptococcus Thermophilus Starter, Western Dairy Center, Utah State University, Megan Jane Ostler, Jeff Broadbent, Craig J. Oberg, Donald J. Mcmahon

Nutrition, Dietetics, and Food Sciences Faculty Publications

A novel slow-growing, obligatory heterofermentative, nonstarter lactic acid bacterium (NSLAB) Lactobacillus wasatchensis WDC04 was studied for growth and gas production in Cheddar-style cheese made using Streptococcus thermophilus as the starter culture. Cheesemaking trials were conducted using St. thermophilus alone or in combination with Lb. wasatchensis deliberately added to cheese milk at a level of ~10⁴ cfu/ml. Resulting cheeses were ripened at 6 or 12°C. At d 1, starter streptococcal numbers were similar in both cheeses (~10⁹ cfu/g) and fast-growing NSLAB lactobacilli counts were below detectable levels (<10² cfu/g). As expected, Lactobacillus wasatchensis counts were 3 x 10 …

Transcriptome Analysis Of Bifidobacterium Longum Strains That Show A Differential Response To Hydrogen Peroxide Stress, Taylor S. Oberg, Robert E. Ward, James L. Steele, Jeff Broadbent

Nutrition, Dietetics, and Food Sciences Faculty Publications

Consumer and commercial interest in foods containing probiotic bifidobacteria is increasing. However, because bifidobacteria are anaerobic, oxidative stress can diminish cell viability during production and storage of bioactive foods. We previously found Bifidobacterium longum strain NCC2705 had signifi- cantly greater intrinsic and inducible resistance to hydrogen peroxide (H₂O₂) than strain D2957. Here, we explored the basis for these differences by examining the transcriptional responses of both strains to sub-lethal H₂O₂ exposure for 5- or 60-min. Strain NCC2705 had 288 genes that were differentially expressed after the 5-min treatment and 114 differentially expressed genes …

Effect Of Shear Work Input On Steady Shear Rheology And Melt Functionality Of Model Mozzarella Cheeses, Prateek Sharma, Peter A. Munro, Tzvetelin T. Dessev, Peter G. Wiles, Robert J. Buwalda

Nutrition, Dietetics, and Food Sciences Faculty Publications

Model Mozzarella cheeses with varied amounts of shear work input were prepared by working molten cheese mass at 70 °C in a twin screw cooker. Rheology and melt functionality were found to be strongly dependent on total shear work input. A non-linear increase in consistency coefficient (K from power law model) and apparent viscosity and decrease in flow behaviour index (n from power law model) were observed with increasing amounts of accumulated shear work, indicating work thickening behaviour. An exponential work thickening equation is proposed to describe this behaviour. Excessively worked cheese samples exhibited liquid exudation, poor melting and poor …

Effects Of Beef Finishing Diets And Muscle Type On Meat Quality, Fatty Acids And Volatile Compounds, Arkopriya Chail

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumer evaluation, proximate data, Warner-Bratzler shear force (WBSF), fatty acid (FA) composition and volatile compounds were analyzed from the ribeye steaks (LT) finished on conventional feedlot (FL) and forages, including a perennial legume, birdsfoot trefoil (BFT; Lotus corniculatus), and a grass, meadow brome (Bromus riparius Rehmann, Grass). Representative retail forage (USDA Certified Organic Grass-fed, COGF) and conventional beef (USDA Top Choice, TC) were investigated (n = 6) for LT. Additionally, the effects of diet on round (GM) and chuck (TB) muscles FL, BFT and Grass were explored. Forage-finished beef was less liked in most of the affected …

Investigation Of Sugar/Polyols As Weakly Interacting Cosolvents And Their Influence On Hardening Of High-Protein Nutrition Bars, Sami Kadhim Hassan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Western Dairy Center (WDC) at Utah State University demonstrated opportunities to improve the quality of high-protein snack foods that becoming more prevalent in western diets. Previously, such high-protein nutrition bars became too hard during storage and they had a limited shelf life, resulting in disappointment by consumers or loss of product as older products needed to be discarded.

With sponsorship as a doctoral student by the Iraq Ministry of Higher Education and Scientific Research and in conjunction with WDC researchers, an investigation was conducted into the chemistry of high-protein nutrition bars and how the various components (protein, carbohydrate and …

Self-Learning, Dvd-Based Education Versus Traditional Education Approaches To Improve The Safety Of Warfarin Use Among Patients With Atrial Fibrillation, Jessica Oliver Hatch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Atrial fibrillation (AF) is a common cardiac arrhythmia that requires extensive medical and pharmaceutical management. The coagulation antagonist warfarin is commonly prescribed to reduce AF-associated stroke. Although warfarin effectively mediates thromboembolitic risk, its management is complex as many factors influence its therapeutic range including: genetics, diet, medication, and herbal and dietary supplement (HDS) interactions. Lack of patient knowledge regarding these factors contributes to poor patient outcomes. With the emerging epidemic of AF, readily available educational tools are necessary to improve patient outcomes while reducing clinician burden.

The purpose of this study was to develop both a self-learning, DVD-based and one-on-one …

Analysis Of Quality Of Two Different Varieties Of Peaches With Respect To Organic And Conventional Cultivation Techniques, Shruti D. Sawant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The worldwide demand for organic produce has been on the rise in recent years. This is a result of consumer concerns about the environment and chemicals used in food production. In addition, consumers have demonstrated that they are willing to pay premium prices for organic produce based on the general assumption that organic produce is more nutritious, environmentally friendly, and better-tasting. There have been several studies that have reported significant differences with organic and conventionally grown produce. Organic fruits and vegetables have been shown to have higher dry matter, antioxidants. In addition, it has also been shown to be smaller …

Pregenomic And Genomic Effects Of 24,25-Dihydroxyvitamin D3, Yang Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the United States, the major dietary source of protein is poultry meat, particularly chicken. Phosphorus absorption in chickens is a critical problem in poultry production. It therefore is important to understand the cellular and molecular regulation of phosphorous absorption in intestine to increase efficiency of the process. This would provide the benefits of reducing feed costs and reducing phosphorous excretion, thereby contributing to the sustainability of agriculture in the United States. Therefore, the focus of this thesis is determining the effect of vitamin D metabolites involved in phosphate homeostasis using the chicken as a model.

Measurement Techniques For Steady Shear Viscosity Of Mozzarella-Type Cheeses At High Shear Rates And High Temperature, Prateek Sharma, Tzvetelin T. Dessev, Peter A. Munro, Peter G. Wiles, Graeme Gillies, Matt Golding, Bryony James, Patrick Janssen

Nutrition, Dietetics, and Food Sciences Faculty Publications

While measuring steady shear viscosity of Mozzarella-type cheeses in a rotational rheometer at 70 °C, three main difficulties were encountered; wall slip, structural failure during measurement and viscoelastic time dependent effects. Serrated plates were the most successful surface modification at eliminating wall slip. However, even with serrated plates shear banding occurred at higher shear rates. Because of the viscoelastic nature of the cheeses, a time dependent viscous response occurred at shear rates <1 >s−1, requiring longer times to attain steady shear conditions. Prolonged continuous shearing altered the structure of the molten cheeses. The effects of structural change were greatly reduced by …

Growth And Gas Production Of A Novel Obligatory Heterofermentative Cheddar Cheese Nonstarter Lactobacilli Species On Ribose And Galactose, Western Dairy Center, Utah State University, Megan Jane Ostler, Jeff Broadbent, Craig J. Oberg, Donald J. Mcmahon

Nutrition, Dietetics, and Food Sciences Faculty Publications

An obligatory heterofermentative lactic acid bacterium, Lactobacillus wasatchii sp. nov., isolated from gassy Cheddar cheese was studied for growth, gas formation, salt tolerance, and survival against pasteurization treatments at 63°C and 72°C. Initially, Lb. wasatchii was thought to use only ribose as a sugar source and we were interested in whether it could also utilize galactose. We conducted experiments to determine the rate and extent of growth and gas production in carbohydraterestricted (CR) de Man, Rogosa, and Sharpe (MRS) medium under anaerobic conditions with various combinations of ribose and galactose at 12, 23, and 37°C, with 23°C being the optimum …

Gas-Forming Nonstarter Lactorbacilli, Megan Jane Ostler, Jeff Broadbent, Craig J. Oberg, Donald J. Mcmahon

Nutrition, Dietetics, and Food Sciences Faculty Publications

An obligatory heterofermentative lactic acid bacterium Lactobacillus wasatchii sp. nov. isolated from gassy Cheddar cheese was studied for growth, gas formation, salt tolerance and survival against pasteurization treatments at 63°C and 72°C. Initially, Lb. wasatchii was thought to only use ribose as a sugar source and we were interested in whether it could utilize galactose. Experiments to determine rate and extent of growth and gas production in carbohydrate restricted (CR) de Man, Rogosa, and Sharpe (MRS) medium under anaerobic conditions with various combinations of ribose and galactose at 12, 23, and 37°C were conducted with 23°C being the more optimum …

Growth Inhibitory Properties Of Lactose Fatty Acid Esters, Seung-Min Lee, Guneev Sandhu, M. K. Walsh

Nutrition, Dietetics, and Food Sciences Faculty Publications

Sugar esters are biodegradable, nonionic surfactants which have microbial inhibitory properties. The influence of the fatty acid chain length on the microbial inhibitory properties of lactose esters was investigated in this study. Specifically, lactose monooctanoate (LMO), lactose monodecanoate (LMD), lactose monolaurate (LML) and lactose monomyristate (LMM) were synthesized and dissolved in both dimethyl sulfoxide (DMSO) and ethanol. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined in growth media. LML was the most effective ester, exhibiting MIC values of