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Full-Text Articles in Life Sciences

Chemopreventive Effects Of Cranberry In Association With The Alteration Of Gut Microbiota, Xiaokun Cai Nov 2016

Chemopreventive Effects Of Cranberry In Association With The Alteration Of Gut Microbiota, Xiaokun Cai

Doctoral Dissertations

Accumulating evidence showed that microbiota play important roles in colonic inflammation and inflammation-associated colon carcinogenesis. Fruits and vegetable are known to have protective effects against colon carcinogenesis. Cranberry fruit contains large amount of flavonoids, phenolic acids and dietary fiber, which has been studied for their potential chemopreventive effect from in vitro model. To better understand the effect, we studied the protective effects of whole cranberry powder against colitis in mice treated with dextran sulfate sodium (DSS) and inflammation-associated colon carcinogenesis in mic treated with azoxymethane (AOM) and DSS, and its impact on gut microbiota.

In DSS-induced colitis mice model, 1 ...


Biopolymer Electrospun Nanofiber Mats To Inactivate And Remove Bacteria, Katrina Ann Rieger Nov 2016

Biopolymer Electrospun Nanofiber Mats To Inactivate And Remove Bacteria, Katrina Ann Rieger

Doctoral Dissertations

The persistence of antibiotic resistance in bacterial pathogens remains a primary concern for immunocompromised and critically-ill hospital patients. Hospital associated infections can be deadly and reduce the successes of medical advancements, such as, cancer therapies and medical implants. Thus, it is imperative to develop materials that can (i) deliver new antibiotics with accuracy, as well as (ii) uptake pathogenic microbes. In this work, we will demonstrate that electrospun nanofiber mats offer a promising platform for both of these objectives because of their high surface-to-volume ratio, interconnected high porosity, gas permeability, and ability to contour to virtually any surface. To provide ...


Label-Free And Aptamer-Based Surface Enhanced Raman Spectroscopy For Detection Of Food Contaminants, Shintaro Pang Nov 2016

Label-Free And Aptamer-Based Surface Enhanced Raman Spectroscopy For Detection Of Food Contaminants, Shintaro Pang

Doctoral Dissertations

The development of analytical methods to detect food contaminants is a critical step for improving food safety. Surface enhanced Raman spectroscopy (SERS) is an emerging detection technology that has the potential to rapidly, accurately and sensitively detect a wide variety of food contaminants. However, SERS detection becomes a challenge in real complex matrix, such as food, since non-specific matrix signals have the potential to drown out target associated Raman peaks. In this dissertation, we focused on the development and application of label-free, aptamer-based SERS in order to improve the accuracy and specificity of target contaminant detection in food. To accomplish ...


Bacteriophage-Based Colorimetric Detection Of Escherichia Coli In Drinking Water, Juhong Chen Nov 2016

Bacteriophage-Based Colorimetric Detection Of Escherichia Coli In Drinking Water, Juhong Chen

Doctoral Dissertations

One of the major safety causes in drinking water is from the bacteria contamination, especially in developing countries and resource-limited settings. Although many of these Escherichia coli (E. coli) strains in drinking water are nonpathogenic, they sever as the indicator for bacterial contamination. And, the more widely used method to detect E. coli in drinking water is to determine the activity of β-galactosidase (β-gal), which is released by E. coli. Rapid, sensitive and inexpensive detection of E. coli in drinking water can reduce the risk of food-borne bacteria infection and stop the disease widely spreading.

In this degree research, phage-based ...


Characterizing Colorectal Cancer Cells And Their Interactions With Polymethoxyflavones By Raman Microscopy, Hua Zhang Nov 2016

Characterizing Colorectal Cancer Cells And Their Interactions With Polymethoxyflavones By Raman Microscopy, Hua Zhang

Doctoral Dissertations

Polymethoxyflavones (PMFs), especially Nobiletin (NBT) and 5-demethylnobiletin (5DN), have been widely studied and proved to have anti-cancer effects. However, their exact modes of action against cancer cells are not fully understood. Raman spectroscopy is a molecular vibrational spectroscopy can be used to measure overall biochemical function of single cells noninvasively and without adding any chemical labels. Herein, we characterized the cellular responses of human colorectal cancer HT29 and HCT116 cells, that grow on the gold coated slides, to the treatments of NBT and 5DN using Raman microscopy. Raman microscopic images obtained indicated the different modes of action of these two ...


Functionalized Electrospun Nanofibers For Food Science Applications, Minhui Dai Jul 2016

Functionalized Electrospun Nanofibers For Food Science Applications, Minhui Dai

Doctoral Dissertations

This work is separated into two individual parts. The first part demonstrates the ability to electrospin reagents into water-soluble nanofibers resulting in a stable on-chip enzyme and a microphage storage format.

1a) Polyvinylpyrrolidone (PVP) nanofibers were spun incorporating the enzyme horseradish peroxidase (HRP). Scanning electron microscopy of the spun nanofibers was used to confirm the non-woven structure with an average diameter of 155±34 nm. The HRP containing fibers were tested for a change in activity following electrospinning and during storage. A colorimetric assay was used to characterize the activity of HRP reacting with the nanofiber mats in a microtiter ...


Novel Advancements For Improving Sprout Safety, Kyle S. Landry Jul 2016

Novel Advancements For Improving Sprout Safety, Kyle S. Landry

Doctoral Dissertations

All varieties of bean sprouts (mung bean, alfalfa, broccoli, and radish) are classified as a “super-food” and are common staples for health conscious consumers. Along with the proposed health benefits, there is also an inherent risk of foodborne illness. When sprouts are cooked, there is little risk of illness. The purpose of this dissertation was to explore novel techniques to minimize or prevent the incidence of foodborne illness associated with the consumption of sprouts. Three areas were investigated: 1) the use of a biocontrol organism, 2) the use of a novel spontaneous carvacrol nanoemulsion, and 3) the influence of the ...


Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman Jul 2016

Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman

Doctoral Dissertations

Many packaged foods use synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit metal promoted oxidation and/or microbial growth that may cause food spoilage. Consumer demand for foods without synthetic additives has prompted growing interest in alternative preservation methods. Our research group has previously developed non-migratory metal chelating active packaging materials by surface immobilization of polymeric chelators and demonstrated their ability to inhibit lipid oxidation in model food emulsions. The work presented in this dissertation investigates the synthesis, performance stability, and practical application of metal chelating surface modifications to optimize design of non-migratory metal chelating active packaging materials.

Metal ...


Enzyme Stabilization In Hierarchical Biocatalytic Food Packaging And Processing Materials, Dana Erin Wong Jul 2016

Enzyme Stabilization In Hierarchical Biocatalytic Food Packaging And Processing Materials, Dana Erin Wong

Doctoral Dissertations

The partnership of biocatalysts and solid support materials provides many opportunities for bioactive packaging and bioprocessing aids beneficial to the agricultural and food industries. Biocatalysis, or reactions modulated by enzymes, allows bioactive materials to assist in bringing a substrate to product. Enzymes are proteins which catalyze reactions by lowering the activation energy required to drive the production of a desired product. Enzymes are commonly utilized in food processing as catalysts with specificity in order to enhance product quality through the production of beneficial food components, and to break down undesirable components that may be harmful or may decrease product quality ...


Structuring Solid/Oil/Water Emulsions To Deliver Water-Soluble Bioactive Food Ingredients, Yun Zhang May 2016

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 ...


Optimization Of The Fabrication, Stability, And Performance Of Food Grade Nanoemulsions With Low And High Energy Methods, Jennifer Komaiko Mar 2016

Optimization Of The Fabrication, Stability, And Performance Of Food Grade Nanoemulsions With Low And High Energy Methods, Jennifer Komaiko

Doctoral Dissertations

There is interest in the production of emulsions by low-energy methods because no expensive equipment is required thus making emulsion formation inexpensive and simple to implement. The goal of this research is to establish the major factors that affect emulsion formation using low-energy methods and possible applications of the emulsions and nanoemulsions formed by this method. Lastly, the use of natural emulsifiers with low- and high-energy methods was investigated.

Initially, formation of nanoemulsions using isothermal low energy methods was investigated with a model system (hexadecane, Brij 30). Preliminary experiments showed that nanoemulsions could only be formed when the surfactant was ...