Life Sciences Commons^™

Switchgrass Extractives Have Potential As A Value-Added Antimicrobial Against Plant Pathogens And Foodborne Pathogens, Alexander Ian Bruce

Masters Theses

Panicum virgatum (switchgrass), a perennial grass native to North America, is a leading biomass feedstock candidate for the manufacture of cellulosic ethanol. Switchgrass is considered a viable option for biofuel production due to its cheap production cost and ability to grow on marginal land. Biofuel derived from switchgrass has been shown to be very energy efficient, producing 540% more renewable energy versus nonrenewable energy expended. Switchgrass-derived biofuel is also estimated to have greenhouse gas emissions that are 94% lower than emissions from gasoline (Schmer et al 2008). Biofuels are created through biochemical processes that utilize various enzymes and microorganisms for …

Sorghum Phenolic Extracts: Chemical Characterization And Biological Activity Determination, James Jordan Bradwell

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Red sorghum contains phytochemicals such as 3-deoxyanthocyanidins and flavonoids with reported health benefits. The objective was to determine the chemical composition of sorghum phenolic extracts that were extracted with acidified methanol and separated into co-pigments and anthocyanin fraction by chromatographic procedure. In addition, the ability of sorghum extract to modify activation of the inflammasomes, a macromolecular protein complex involved in several malignancies, was evaluated. The total polyphenols, total flavonoids and total anthocyanins of the sorghum phenolic extract was quantified and phenolic profile was determined by high performance liquid chromatography. The ability to modify the inflammasomes was evaluated using THP-1 human …

Identification Of Potential Bacterial Surrogates For Validation Of Thermal Inactivation Processes Of Hepatitis A Virus, Marcel Schmidt

Masters Theses

Thermal treatment is a method for inactivating pathogens in a wide range of food products. Recent studies have shown that hepatitis A virus (HAV) has a D_72°C [D72 degree celcius] of 0.9 min in buffer which is greater than vegetative bacterial pathogens. Common surrogates, such as Listeria innocua, are not resistant enough to be used as surrogates for HAV, thus, new surrogates need to be identified. The purpose of this study was to compare the thermal inactivation kinetics (D- and z-values) of Staphylococcus carnosus in different foods and different incubation temperatures to identify a potential surrogate for HAV. …

Combinations Of Multiple Natural Antimicrobials With Different Mechanisms As An Approach To Control Listeria Monocytogenes, Savannah Grace Hawkins

Masters Theses

To improve food safety and shelflife requires the use of preservation processes, such as physical (heat, refrigeration) or chemical (antimicrobial addition) processes. Regulatory approved synthetic food antimicrobials (preservatives) have some uses but are very limited in their spectrum of activity. Thus, alternatives are needed to conventional chemical antimicrobials. One method is to use naturally occurring antimicrobials, especially those found in spices and herbs, essential oils (EO) and essential oil components (EOC). EOs have been shown to have antimicrobial activity but the activity is highly variable. Finding a combination of EOs, EOCs, or other natural antimicrobials that act synergistically would allow …

Volume 12, Number 1 (Spring/Summer 2016), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• The four pillars of the Institute of Agriculture
• Alumna forges partnership amid Waldo Canyon fire
• Fishery biologists revive a river

Structuring Solid/Oil/Water Emulsions To Deliver Water-Soluble Bioactive Food Ingredients, Yun Zhang

Doctoral Dissertations

Numerous delivery systems are studied for lipophilic bioactive compounds, but much work is needed for bioactive food ingredients soluble or dispersible in water. The overall hypothesis of this dissertation is that structured solid/oil/water (S/O/W) emulsions can be used to encapsulate water-soluble/dispersible ingredients to retain their release during processing and storage and control their release during simulated digestions. The encapsulation principle is to prepare spray-dried powder of water-soluble/dispersible compounds as the solid core that is coated by an oil layer emulsified by food biopolymers. The oil layer isolates the compounds from the continuous aqueous phase in emulsions to prevent the release, …

High Intensity Ultrasound Assisted Extraction Of Oak Compounds For Accelerated Aging Of Wines And Whiskies, Lindsay Elizabeth Rogerson

Masters Theses

Aging of wines and whiskies in oak barrels is a timely and expensive process which could be reduced by acceleration. The purpose of this study is to identify if the use of high intensity ultrasound (HIUS) assisted extraction as an alternative, accelerated aging method could be utilized in the production of an oak extract to be used in wine and whiskies. HIUS will also be compared to reflux and room-temperature control extraction treatments as other accelerated aging methods. Secondary objectives of this study were to compare the heat treatment of charred and toasted staves donated by an anonymous donor, their …

The Food Industry’S Perception Of Economically Motivated Adulteration And Related Risk Factors, Lindsay Colleen Murphy

Masters Theses

The United States of America has numerous safeguards in place to protect our food supply, including federal regulations and the food and beverage industry’s dedication to food safety. One of the issues that the food and beverage industry continuously battles is the prevalence of intentional adulteration. The Food Safety Modernization Act (FSMA) specifically addresses intentional adulteration and its sub-category of economically motivated adulteration (EMA) by requiring all facilities that supply food to the US to assess the vulnerabilities within their operation in order to prevent events that could cause public harm. The purposes of this study are threefold: (1) to …

Odor-Induced Taste Modifications In Teas, Rachel Elizabeth Isaacs

Masters Theses

Although odorants and tastants are perceived by two different sensory modalities, the perceived taste qualities of a solution may be modified with the addition of an odorant. While many studies have investigated odor-induced taste modifications in model solutions, there is a lack of conducted research examining odor-induced taste modifications in complex food systems. The research objective was to determine the effect of added vapor-phase stimuli on the perceived sweetness of a model solution and complex food system.

Eight vapor-phase stimuli (i.e. blueberry, caramel, ginger, honey, lemon, orange, peach, and strawberry) were selected for investigation. The study was conducted in two …

Stability Of Sorgum Bicolor Alcoholic Extract As Affected By Ph And Temperature, James Jordan Bradwell

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Storage stability of Sorghum bicolor alcoholic extract as affected by pH and temperature

Jordan Bradwell, Philipus Pangloli, Vermont P Dia

Department of Food Science and Technology, University of Tennessee Institute of Agriculture, Knoxville TN

Red sorghum contains phytochemicals such as 3-deoxyanthocyanidins and flavonoids with potential application in food as coloring and health promoting agents. The objective was to determine the stability of methanolic and ethanolic extracts of sorghum as affected by pH (2, 4 and 6) and temperature of storage (4 and 22 °C). The following parameters were measured: polyphenol concentration, absorbance at 490 nm and L*, a* and b*-values …

Volume 12, Number 2 (Fall/Winter 2016), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• The four pillars of the Institute of Agriculture
• Alumna forges partnership amid Waldo Canyon fire
• Fishery biologists revive a river