Life Sciences Commons^™

Imidacloprid, A Neonicotinoid Insecticide, Impairs Lipid And Glucose Metabolism, Quancai Sun

Doctoral Dissertations

Emerging evidence suggests that environmental pollutants, including insecticides, are linked to excessive weight gain and altered glucose homeostasis. However, there is currently limited knowledge regarding the biochemical mechanisms by which exposure to insecticides contribute to obesity and its associated pathologies. We first studied the influence of fipronil (a phenylpyrazole family insecticide) on 3T3-L1 adipogenesis. Recently imidacloprid, a neonicotinoid insecticide, was reported to potentiate adipogenesis and insulin resistance in vitro. The current studies also determined the effects of imidacloprid exposure and its interaction with dietary fat in the development of adiposity and insulin resistance using both male and female C57BL/6J …

Use Of Different Ripening Inhibitors To Enhance Antimicrobial Activity Of Essential Oil Nanoemulsion, Victor Ryu

Masters Theses

The objective of this research was to study the impact of ripening inhibitor level and type on the formation, stability, and activity of antimicrobial thyme oil nanoemulsions formed by spontaneous emulsification. Oil-in-water antimicrobial nanoemulsions (10 wt%) were formed by titrating a mixture of essential oil, ripening inhibitor, and surfactant (Tween 80) into 5mM sodium citrate buffer (pH 3.5). Stable nanoemulsions containing small droplets (d < 70 nm) were formed. The antimicrobial activity of the nanoemulsions decreased with increasing ripening inhibitor concentration, which was attributed to a reduction in the amount of hydrophobic antimicrobial constituents transferred to the separated hydrophobic domain, mimicking bacterial cell membranes, by using dialysis and chromatography. The antimicrobial activity of the nanoemulsions also depended on the nature of the ripening inhibitor used: palm ≈ corn > canola > coconut which also depended on their ability to transfer hydrophobic antimicrobial constituents to the separated hydrophobic domain.

Extractable And Non-Extractable Polyphenols From Apples: Potential Anti-Inflammatory Agents, Makenzi Gennette

Masters Theses

With diet being such a huge factor in the development of diseases, emerging research has supported that apple consumption is a promising candidate for disease prevention due to the high phenolic content it possesses. These polyphenols can be found in two forms: extractable polyphenols (EP) and non-extractable polyphenols (NEP). Polyphenols have been shown to have strong anti-inflammatory and anti-oxidant properties, but up until this point, most researchers focus on EP fractions, while NEP are neglected. After the EP extraction using acetone and acetic acid (99:1) from the Apple Boost powder, three additional extraction methods were conducted on the remaining powder …

Influence Of Biomimetic Chelating Packaging On Natural Antimicrobial Efficacy, Paul Castrale

Masters Theses

The iron chelating molecule, ethylenediaminetetraacetic acid (EDTA) is used in food applications for the preservation of oxidation prone ingredients. Research has suggested that EDTA is also capable of enhancing the antimicrobial effectiveness of various compounds including naturally-derived antimicrobials. With consumer demand for cleaner food labels, there remains an opportunity to introduce new chelating technology to replace synthetically-derived EDTA. Through photographting and chemical conversion, hydroxamic acid ligands were covalently bound to polypropylene films resulting in polypropylene-graft-poly(hydroxamic acid) (PP-g-PHA). The resulting films demonstrated an ability to chelate 64 nmol/cm² from an iron saturated environment or 163 nmol/cm …

Investigating Natural And Induced Biofilm Dispersion In Listeria Monocytogenes, Brett Boulden

Masters Theses

Dispersion is a natural part of a biofilm life cycle in many bacterial species. Dispersion occurs when bacteria revert from a stationary, sessile state to a free-swimming, planktonic state and are freed from a biofilm. Bacterial biofilms consist of proteins, polysaccharides, and extracellular DNA that together make up the extracellular polymeric substances. Surrounded by this mucus-like substance, sessile cells can be extremely difficult to eradicate as compared to the planktonic form of Listeria monocytogenes. Biofilms are robust due to increased surface adherence, inhibition of diffusion of harmful compounds, and increased genetic diversity that exists within a biofilm. As a …

Methylglyoxal Influences Development Of Caenorhabditis Elegans Via Heterochronic Pathway, Jiaying Wang

Masters Theses

Methylglyoxal is a highly reactive dicarbonyl compound, which is widely distributed in food products and beverages, and is particularly high in Manuka honey. In addition to its antibacterial effects, methylglyoxal is also known as a major precursor of advanced glycation end products (AGEs), that produces altered macromolecules (such as proteins and DNA), leading to abnormal physiological changes. However, the effects of methylglyoxal on development is unclear. Thus, this study aimed to determine the role of methylglyoxal in this aspect using Caenorhabditis elegans (C. elegans). Treatment of methylglyoxal at 0.1 mM and 1 mM for 48 h significantly inhibited …

Epigallocatechin-3-Gallate Reduces Fat Accumulation In Caenorhabditis Elegans, Jinning Liu

Masters Theses

Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is a polyphenol that is most abundant in tea. It has been shown from many studies that consumption of EGCG can contribute to weight loss, however, the underlying mechanism is not fully understood. To determine how EGCG acts to reduce fat, an organism model Caenorhabditis elegans (C. elegans) is introduced, which is a useful animal system in exploring crucial biological mechanisms that are readily applicable to humans. In this study, different strains were raised for two days on a diet with or without 100µM and 200µM EGCG treatment: N2 (i.e., wild …

Understanding The Impact Of Oxygen Concentration And Active Packaging On Controlling Lipid Oxidation In Oil-In-Water Emulsions, David Johnson

Doctoral Dissertations

Consumer concern over synthetic food antioxidants have led researchers to seek alternative natural, or ‘clean’ label, solutions to prevent lipid oxidation. Unfortunately, natural antioxidants are often not as effective as their synthetic counterparts. As a result, there remains a need to develop active packaging strategies and maximize current antioxidant strategies in food applications. Active packaging, or packaging that has a function beyond being an inert barrier, is an attractive strategy to limit lipid oxidation in foods. Active packaging performs the work of an antioxidant without appearing on the package label. The work presented here builds upon active packaging development as …

Utilization Of Natural Emulsifiers And Their Derivatives To Formulate Emulsion-Based Delivery Systems For Hydrophobic Nutraceuticals, Cansu Gumus

Doctoral Dissertations

There is increasing consumer demand for food products that are more natural, sustainable, and environmentally friendly. Industry has responded by trying to identify natural alternatives to synthetic functional ingredients within these products. In this study, the ability of Maillard conjugation products, and several legume proteins were investigated to act as nature-derived or natural emulsifiers in oil-in-water emulsions fortified with hydrophobic nutraceuticals. Casein-coated oil droplets enriched with lutein were highly unstable to flocculation near their isoelectric point due to the reduction in electrostatic repulsion. However, casein-dextran-coated droplets were stable, which was attributed to strong steric repulsion by the dextran moiety. The …

Effects Of Permethrin, A Pyrethroid Insecticide, On Glucose And Lipid Metabolism, Xiao Xiao

Doctoral Dissertations

Over the last few decades, the decline of using organochlorine and organophosphorus insecticides has partially contributed to the rising utilization of newer synthetic insecticides, which are considered as less harmful and more environmental friendly than the older generation of insecticides. Pyrethroid insecticides are one of the newer insecticide classes reported with better biodegradability and low mammalian toxicity without sacrificing its insecticidal efficacy. Permethrin is one of the most widely used pyrethroid insecticides with structural similarity with natural pyrethrin insecticide from the flowers of Chrysanthemum cinerariifolium. Since its introduction in the 1970’s, permethrin has been extensively used in medicine, military, …

Biotransformation Of Polymethoxyflavones And Its Implication On Biological Activities, Minqi Wang

Doctoral Dissertations

In this thesis, the tissue distribution and in vivo biotransformation of nobiletin in rodents were demonstrated on three types of rodents, i.e.A-J female mice, CD-1 male mice and male F344 male rats. The effects of colonic metabolites of CD-1 mice on colonic carcinogenesis and inflammation were determined. In order to mimic the long-term dietary consumption of PMFs from food or dietary supplements, we applied oral administration by mixing PMFs with standard diet to rodents who have free access to food. Moreover, nobiletin (NBT), one of the most abundant PMFs in nature, and its major metabolties were incubated with mice …

Potential Enhancement Of Dietary Isothiocyanates Combination On Biological Activities, Kanyasiri Rakariyatham

Doctoral Dissertations

Isothiocyanates (ITCs) such as allyl isothiocyanate (AIT) and sulforaphane (SFN) are well-known bioactives with wide range of beneficial properties, which may be consumed simultaneously through diets containing cruciferous vegetables. However, biological activities of ITCs in combinations had not been well defined. The present study evaluated the potential efficacy of AIT, SFN and their combinations on three important biological properties: anticancer, anti-inflammation and antioxidant. Our results showed that the combination between AIT and SFN led to a stronger growth inhibition on A549 non-small cell lung cancer cells than treatments with the individual compounds. The enhanced effect was proved to be synergistic …

Investigating The Utilization Of Mushrooms In Beef-Based Products For Improved Health, Kristin Wong

Masters Theses

This research investigated the use of mushrooms in beef-based products as a means to reduce overall sodium and fat for food service applications. Initial product development used physical characterization analysis (color, moisture, texture, yield, fat, and sodium) to determine initial threshold of mushroom inclusion with minimal differences against an all-meat control. Additional physical analysis then investigated a variety of other factors (mushroom type, blanching, mushroom particle size, salt level, and meat/fat blend) to determine if there were other attributing ingredient characteristics that would yield statistical similarity to the all-meat control. Taco filling formulations with optimized ingredients were then fielded in …

Sodium Reduction In Turkey Breast Meat By Using Sodium Anion Species, Janamkumar Pandya

Masters Theses

Research studies show that an average American consumes 3,400 to 4,500 mg/day of sodium in their diet against the dietary recommendation of 1,500 to 2,300 mg/day. The majority of this sodium comes from processed foods. Excess sodium in the diet can potentially cause health issues such as hypertension, heart attack, kidney failure, and bone problems. The objective of this study is to understand sodium diffusion in a protein model using turkey breast meat and determine the opportunities of its reduction by changing the process conditions and combining table salt with other sodium salts.

Since proteins are a complicated system and …

Lung And Colon Cancer Chemoprevention By Polymethoxyflavones, Mingyue Song

Doctoral Dissertations

Cancer has been a leading cause of morbidity and mortality worldwide and characterized by the uncontrolled cell proliferation and an absence of cell death. Polymethoxyflavones (PMFs) is a unique class of flavonoids that almost exclusively found in the peel of citrus fruit. Studies have shown that PMFs exhibited numerous health promoting effects, including anti-carcinogenic and anti-inflammatory ones. Nobiletin (5,6,7,8,3’,4’-hexamethyoxflavone, NBT) is a major citrus flavonoid and has been the most studied PMFs for its potential health benefits. 5-Demethylnobiletin (5-hydroxy-6,7,8,3’,4’-pentamethoxyflavone, 5DN) is a unique flavonoid found in citrus fruits with potential chemopreventive effects against human cancers. In this dissertation, we first …

A Human Gut Commensal Ferments Cranberry Carbohydrates To Produce Formate, Ezgi Özcan, Jiadong Sun, David C. Rowley, David A. Sela

Food Science Department Faculty Publication Series

Commensal bifidobacteria colonize the human gastrointestinal tract and catabolize glycans that are impervious to host digestion. Accordingly, Bifidobacterium longum typically secretes acetate and lactate as fermentative end products. This study tested the hypothesis that B. longum utilizes cranberry-derived xyloglucans in a strain-dependent manner. Interestingly, the B. longum strain that efficiently utilizes cranberry xyloglucans secretes 2.0 to 2.5 mol of acetate-lactate. The 1.5 acetate:lactate ratio theoretical yield obtained in hexose fermentations shifts during xyloglucan metabolism. Accordingly, this metabolic shift is characterized by increased acetate and formate production at the expense of lactate. α-L-Arabinofuranosidase, an arabinan endo-1,5-α-L-arabinosidase, and a β-xylosidase with a …

Food-Grade Cationic Antimicrobial Ε-Polylysine Transiently Alters The Gut Microbial Community And Predicted Metagenome Function In Cd-1 Mice, Xiaomeng You, Jonah E. Einson, Cynthia Lyliam Lopez-Pena, Mingyue Song, Hang Xiao, David Julian Mcclements, David Sela

Food Science Department Faculty Publication Series

Diet is an important factor influencing the composition and function of the gut microbiome, but the effect of antimicrobial agents present within foods is currently not understood. In this study, we investigated the effect of the food-grade cationic antimicrobial ε-polylysine on the gut microbiome structure and predicted metagenomic function in a mouse model. The relative abundances of predominant phyla and genera, as well as the overall community structure, were perturbed in response to the incorporation of dietary ε-polylysine. Unexpectedly, this modification to the gut microbiome was experienced transiently and resolved to the initial basal composition at the final sampling point. …