Life Sciences Commons^™

The Stability Of Carotenogenic Food Colorants And Strategies To Prolong The Shelf Life In Process Cheese Spread, Ann Marie Doneski Craig

Doctoral Dissertations

Food quality is often times measured by the way one perceives the food, particularly with respect to color and texture. Color quality often pre-determines expectation making it an important parameter to understand. The same can be said for textural properties of food. Maintaining color and texture are just two ways in which the shelf-life of food can be measured. One particular product that has experienced problems in this area is processed cheese spread in which the US military uses as part of the Meal, Ready-to-Eat (MRE) rations. The cheese spread is one of the most highly accepted products in the …

Sonochemical And Hydrophobic Modification Of Chitin And Chitosan, Tao Wu

Doctoral Dissertations

Chitin and chitosan are linear polysaccharides consisting of acetyl-glucosamine and glucosamine units with many potential applications in biomedicine, agriculture and food industry. In the food industry, chitosan can be used as antimicrobial agent and to create active packaging to improve food quality and extend shelf life. Commercial applications of chitosan are closely associated with its functional properties and biological activity, which are primarily governed by two structural properties: degree of acetylation (DA) and molecular weight (MW). The overall goal of this study was to develop methods for tailored modification of DA, MW and functionalities of chitosan.

The research was conducted …

Gene Expression Analysis Of Escherichia Coli O157:H7 At 10 And 37°C And Under Acidic Conditions Using High Density Oligonucleotide Microarrays, Kristina K. Carter

Doctoral Dissertations

This purpose of this investigation was to use DNA microarrays to study gene expression in E. coli O157:H7 under refrigerated and acidic conditions. Total RNA from E. coli O157:H7 grown to 7 log CFU/mL under control (37 °C, pH 7), refrigerated (10°C, pH 7), acid adapted (37°C, pH 5.5, then lowered to 3.5), and acid shocked (37°C, pH 7, then lowered to 3.5) conditions was extracted using an optimized Qiagen RNeasy procedure. Total RNA was converted to cDNA, labeled, and hybridized onto an Affymetrix GeneChip® E. coli Genome 2.0 Array. Results were analyzed using Analysis of Variance (ANOVA) and a …

Application Of Solid Phase Micro-Extraction With Gas Chromatography-Mass Spectrometry For The Determination Of Geosmin And 2-Methylisoborneol In Processed Navy Beans (Phaseolus Vulgaris), Coesha Ancoinette Fairley

Doctoral Dissertations

This investigation was conducted to address the issue of musty bean products. The main objectives of this study were to: (1) identify the source of the musty, off-flavor in processed navy beans, (2) determine and identify the associated off-flavor compounds (geosmin and 2-methylisoborneol (2-MIB)), and (3) isolate the microorganism(s) responsible for production of the compounds.

To confirm the presence of geosmin and 2-MIB in processed baked beans, an automated gas chromatographic method employing solid phase micro-extraction (SPME-GC-MS) was used. Artificially musty baked beans, known musty beans, and raw ingredients (bacon, navy beans, and water) were analyzed. Results of this investigation …

Boiling And Microwaving Effects On Hydrophilic Oxygen Radical Absorbance Capacity Of Frozen Vegetables, Merry Frances Rogers

Masters Theses

Decreased risks of chronic illnesses, such as cancer, occur with increased consumption of dietary antioxidants. Vegetables are a particularly rich source of dietary antioxidants but these are primarily water soluble compounds. This research determined effects of microwaving or boiling on the antioxidant capacities of commercially frozen vegetables. Hydrophilic components were extracted by Acetone/Deionized water/Acetic Acid (700:295:50, v/v) from commercially frozen broccoli, carrots, sweet corn, and sweet peas before and after microwaving for 5 min or boiling for 10 min. The Oxygen Radical Absorbance Capacity (ORAC) assay was employed to determine the antioxidant capacity. Additionally, color and texture analyses were performed. …

Development Of A Real-Time Pcr Assay For Detection And Quantification Of Escherichia Coli O157:H7 In Apple Juice, Nancy Rabalais Detrana

Doctoral Dissertations

Apple cider/juice contaminated with Escherichia coli O157:H7 has been implicated in several foodborne illness outbreaks, but due to the presence of reaction inhibitors, detection by polymerase chain reaction (PCR) is often difficult. The studies presented in this dissertation were conducted to evaluate techniques to improve detection of E. coli O157:H7 in apple juice using a fluorogenic probe-based real-time PCR assay without prior enrichment. Two commercial DNA extraction and purification procedures, GenEluteTM Bacterial Genomic DNA Kit and PrepMan® Ultra Sample Preparation Reagent, were combined with two real-time PCR chemistries, SYBR® Green I dye and TaqMan® probes for potential use in the …

Color And Mechanical Properties Of Chitosan Films During Storage, Gagan Rajpal

Masters Theses

Chitosan, a deacetylated product of chitin, is a copolymer of 2-amino-2-deoxy-D glucopyranose and 2-acetamido-2-deoxy-D glucopyranose. Chitosan has many functional properties and has various applications in food, agriculture, pharmaceutical, cosmetic industries. However, little is known about the fate of chitosan and its films during prolonged storage. Although it has been reported that chitosan films treated with dry heat or saturated steam became brown, data available on physical characterization of chitosan films is still conflicting.

This study was conducted to determine chemical stability and mechanical properties of chitosan films as affected by (1) type of acid used for film preparation (acetic, lactic, …

Volume 5, Number 2 (2007), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• Diversifying Research