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Biotransformation Of Resveratrol And Its Implications In Biological Activities In The Colon, Fang Li

Doctoral Dissertations

Resveratrol (RES) is a natural polyphenol compound with a wide range of health-promoting activities, including protective effects against colon cancer and renal disease. However, the premise of these benefits has been dampened since RES shows a poor oral bioavailability due to its rapid and extensive biotransformation after oral consumption. The paradox (low bioavailability but high bioactivity) warrants further investigations to determine the contribution of RES metabolites to the health benefits associated with RES. We identified 11 metabolites of RES in mice with high-resolution HPLC-MS/MS, then quantified two major metabolites - dihydro-resveratrol (DHR) and lunularin (LUN). To further understand the chemopreventative …

Combination Regimens Using Dietary Components For The Chemoprevention Of Colorectal Cancer And Inflammation, Christina Dimarco-Crook

Doctoral Dissertations

ABSTRACT COMBINATION REGIMENS USING DIETARY COMPONENTS FOR THE CHEMOPREVENTION OF COLORECTAL CANCER AND INFLAMMATION September 2018 CHRISTINA DIMARCO-CROOK, B.S., IMMACULATA UNIVERSITY M.S., DREXEL UNIVERSITY Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Hang Xiao Dietary components have been found to effectively modulate multiple deregulated signaling pathways associated with the initiation and progression of carcinogenesis and inflammation in cellular and animal models. However, clinical studies have shown mixed results when examining the efficacy of individual dietary components, perhaps suggestive of the synergism that exists between multiple components within a particular food and the diet as a whole. Additional research is needed …

Applications Of Drosophila Melanogaster In Food Science Research, Phoebe Beverly Chen

Doctoral Dissertations

Drosophila melanogaster is a versatile model organism that provides several unique features, such as highly conserved disease pathways with humans as well as availability of environmental and genetic manipulations. Meanwhile, there is increasing interest in the potential role of bioactive food components, epigallocatechin gallate (EGCG) and conjugated linoleic acid (CLA), in metabolic research. However, there is limited knowledge on the sex-dependent effects of EGCG and CLA on energy metabolism. In this study, Drosophila melanogaster was used to investigate the sex-dependent effects of EGCG and CLA with respect to energy metabolism, including body fat, locomotion, and their key metabolic regulators. We …

Modulation Of Hepatic Lipid Metabolism By Insecticides And Food Bioactives, Jason Yang

Doctoral Dissertations

Recent studies reported the positive association between exposure to insecticides and increased risks of obesity and type 2 diabetes, which is closely associated with non- alcoholic fatty liver disease (NAFLD). However, the effect of insecticide exposure on NAFLD remains unknown. Therefore, this project investigated the roles of insecticide exposure in the development of NAFLD using HepG2 hepatocytes. First, 12 insecticides were tested for their effects on triglycerides (TG) accumulation and interactions with palmitic acid (PA), which induces steatosis. Among tested insecticides, permethrin and ivermectin significantly altered TG accumulation and interacted with PA. Further mechanistic studies showed that permethrin promoted lipogenesis …

Interaction Between Dietary Components And Gut Microbiota And Its Implication In Bioactivities And Metabolism In Colon, Min Gu

Doctoral Dissertations

The microbial cells that colonize the human body, including mucosal and skin environments, are at least as abundant as our somatic cells and certainly contain far more genes than our human genome. Gut microbiota dysbiosis is associated with the onset and progress of several diseases, like diabetes, obesity, inflammatory bowel disease. One of the environmental factor-diet intervention can modulate the compositions of gut microbiota, which in turn may contribute to altered health outcomes such as changes in the risks of chronic diseases. Orange peel has been a traditional herb in China, and some of its compounds has shown health benefits. …

Use Of Alamarblue As An Indicator Of Microbial Growth In Turbid Solutions For Antimicrobial Evaluation, Precious Henshaw

Masters Theses

The use of antibiotics in animal feed is a large cause of concern due to bacterial resistance, which occurs when bacteria change after exposure to antibiotics and become less affected by the drug. Consequently, the desire to find a replacement for these antibiotics has garnered interest in both farmers and consumers. The ideal substance would display antimicrobial activity without promoting bacterial resistance and would still function as a growth promoter in animals. One antimicrobial that fits this criterion is carvacrol, a compound found in oregano extract. Carvacrol exhibits antimicrobial activity in a number of bacteria, including E.coli O157:H7 and S. …

Understanding The Thermal Stability And Environmental Sensitivity Of Phycocyanin Using Spectroscopic And Modelling Tools, Cally Toong

Masters Theses

Phycocyanin (PC), a pigment-protein conjugate from Arthrospira platensis, is increasingly used in foods as a natural alternative to artificial blue dyes. Although PC has been classified as a color additive exempt from certification by the Food and Drug Administration, its limited stability has hindered its widespread application in food products. The objectives of this study were: a) to evaluate the photophysical properties of PC and their sensitivity to temperature, viscosity, and water activity, b) to monitor PC’s thermal degradation based on changes in the optical properties of its intrinsic fluorophores, namely its chromophores and aromatic amino acids, and c) to …

Development And Application Of A Sers Needle For One-Step Multi-Phase Analysis, Haoxin Chen

Masters Theses

Surface-enhanced Raman spectroscopy (SERS) is an emerging and sensitive technique in food analysis providing advantages of rapid detection, simple sample preparation and on-site detection capability over GC and LC methods. Most SERS applications focus on detecting trace amount of analyte in liquid as an alternative approach to HPLC. Herein, we invented an innovative SERS-active needle which is composed with an injection needle and a gold-nanoparticles coated fiber inside the injection needle. The gold nanoparticles-coated fiber was fabricated by reducing gold (III) on a chemically etched stainless wire. The SERS needle can be used to insert into the headspace and liquid …

Adding Increased Value To Strawberry Puree By Adding Xylo-Oligosaccharides To Improve Health, Haochen Dai

Masters Theses

Cancer is a global risk for human wellness and health. Dietary habits could profoundly affect the risk of certain cancer, such as colorectal cancer (CRC) (Platz, 2000). CRC has listed the third leading cancer among male and female in the United States (Stewart, 2014). Surprisingly, the consumption of dietary fiber has an inverse correlation with the mortality of CRC (Song, 2018). However, most Americans do not consume enough dietary fiber to meet the recommended level of dietary fiber intake (Clemens, 2012; Lee-Kwan, 2017). Hence, it is reasonable to increase the nutrient density, i.e., dietary fiber, of current food model. Xylo-oligosaccharides …

Screening Of Commercially Available Chlorine Based Sanitizers And Their Efficacy In Reducing Microbial Load Levels Of E. Coli O157:H7 At High And Low Organic Load Environments, Paola Martinez-Ramos

Masters Theses

The presence of postharvest sanitizers has shown to be an effective approach to reducing microbial cross contamination in agricultural washing operations. However, choosing an appropriate sanitizer can be challenging due to produce commodity, processing conditions and interference with organic load. Current research shows a wide variety of methods to mimic the organic load of vegetable processing conditions, with paddle mixing and blender as the most commonly used. Controlling and understanding the physiochemical properties of wash water is key in maintaining sanitizer efficacy. The effects of simulated wash water preparation method on the physiochemical properties were tested at 0 and 50 …

Optimization Of Peracetic Acid As An Antimicrobial Agent In Postharvest Processing Wash Water, Tiah Ghostlaw

Masters Theses

The Food Safety Modernization Act (FSMA) has a regulation stating that there can be no detectable generic Escherichia coli in agricultural water. The objective of this study was to optimize the use of peracetic acid (PAA) as a mitigating strategy in postharvest processing. This project began by investigating the impact of storage temperatures on stability of a commercially available PAA sanitizer. Regression analysis showed a quadratic relationship in the concentration of PAA over 12 weeks when storing the product at 4, 20 and 37°C. Stability of the product was also investigated in the presence of organic load over time at …

In Situ And Real-Time Monitoring And Characterization Of Pesticide Residues On And In Fresh Produce Using Sers, Tianxi Yang

Doctoral Dissertations

Understanding of the behavior and fate of pesticides in fresh produce is of great significance for effectively applying pesticides and minimizing pesticide residues in food. There is lack, however, of an effective method that can monitor and characterize pesticide behaviors including penetration, persistence and translocation. Herein, we developed a novel method for real-time and in situ monitoring of pesticide behaviors in fresh produce based on surface-enhanced Raman scattering (SERS) mapping method. Taking advantage of penetrative gold nanoparticles as probes to enhance the internalized pesticide signals, the internal signals from pesticides were successfully obtained in situ. We found that systemic pesticides …

Interaction Of Titanium Dioxide Nanoparticles (Nps) With Food Components And Mechanistic Studies Of Adverse Effects Induced By Titanium Dioxide Nps, Xiaoqiong Cao

Doctoral Dissertations

Many food products contain engineered inorganic nanoparticles (NPs), such as titanium dioxide (TiO₂) NPs as a part of food additive, due to both unintentional and intentional additions. There has been increasing concern about the health risks associated with foodborne inorganic NPs. However, the detailed understanding of the biological fate and potential adverse effects of foodborne TiO₂ NPs is not available despite a limited number of published toxicity studies on TiO₂ NPs. The purpose of this thesis was to characterize the interactions of TiO₂ NPs and food components including dietary flavonoids and dietary proteins, …

Development Of Methodology For Rapid Bacterial Detection In Complex Matrices Using Sers, Madeline Tucker

Masters Theses

Fresh foods, including meats and produce are the fastest growing market in the supermarket and the class of foods most likely to cause a bacterial foodborne illness. As the rate of consumption of perishable products increases, rapid detection of pathogens within the food supply becomes a critical issue. Current methods used for the detection of bacteria that cause food-borne illnesses are time consuming, expensive and often require selective enrichment. In this study we adapted a separation technique originally developed for PCR to extract bacteria from ground beef using β-cyclodextrin (β-CD) and milk protein coated activated carbon (MP-CAC) as filtration agents. …

Biological Effects And Action Mechanisms Of Dietary Compounds, Elvira Sukamtoh

Masters Theses

The food that we consume contain many dietary compounds which are biologically active. In this thesis we will discuss the biological effects of dietary compounds and the mechanisms behind their activities.

First, we studied on the anti-metastatic effects of curcumin, a dietary compound derived from turmeric, through lymphangiogenesis inhibition. Curcumin inhibited vascular endothelial growth factor-C (VEGF-C)-induced lymphangiogenesis in vivo and in vitro. Curcumin inhibited lymphangiogenesis, in part through suppression of proliferation, cell cycle progression and migration of lymphatic endothelial cells. Curcumin inhibited expressions of VEGF receptors (VEGFR2 and VEGFR3), as well as down-stream signaling such as phosphorylation of ERK …

Caenorhabditis Elegans Model To Study Antimicrobial Treatment On E. Coli O157:H7, Parita Patel

Masters Theses

An increase in antimicrobial resistance bacteria has endangered our ability to treat infectious diseases. Lack of good in-vivo model has made it difficult to study antimicrobial resistance. In this study, we have used an inexpensive and short life span in-vivo model namely, Caenorhabditis elegans (C. elegans) to study antimicrobial treatment using pathogenic Escherichia coli O157:H7, a multidrug resistance bacterium that causes life threatening infection in humans.

We have investigated the influence of live vs. heat killed non-pathogenic E. coli OP50 (OP50) as a food source on the growth and survival of infected C. elegans mutant AU37 with E. …

Reactive Carbonyl Compounds: Their Control And Consequences In Foods, Michael Freund

Masters Theses

Polyunsaturated omega-3 fatty acids (n-3 PUFAs) have been suggested to reduce risk for multiple diseases but animal studies on the beneficial effects of n-3 PUFAs are conflicting, possibly due to the presence of toxic lipid oxidation products in the oils used in these studies. In order to provide guidance for future research in n-3 PUFA supplementation, this study researched lipid oxidation and its inhibition in an animal feed system enriched with fish oil. Different storage conditions were tested, and it was found that samples stored at room temperature or above were at significant risk for oxidation with lag phases of …

A Living Model For Obesity And Aging Research: Caenorhabditis Elegans, Peiyi Shen

Doctoral Dissertations

Caenorhabditis elegans (C. elegans) is a free-living nematode that has been extensively utilized as an animal model for the research involving aging and neurodegenerative diseases, like Alzheimer and Parkinson, etc. Compared with the traditional animal models, this nematode possesses many benefits, such as small body size, short lifespan, complete sequenced genome and more than 65% of the genes associated with human diseases. All these characteristics enable this organism to be an ideal living system for obesity and aging studies. Piceatannol is a natural stilbene with many beneficial effects, such as anti-oxidative, anti-inflammatory, anti-atherogenic activities, however, its role on …

The Heat Shock Cognate 70 Protein (Hsc70) Is A Novel Target For Nobiletin In Colon Cancer Cells, Zili Gao

Doctoral Dissertations

Nobiletin (NBT) is a unique flavonoid mainly found in citrus fruits, and has been reported to inhibit colon carcinogenesis in multiple rodent models. However, the direct molecular targets of NBT are unknown. Heat shock cognate 70 protein (HSC70) contributes to cancer cell survival and resistance to chemotherapies, thereby the inhibition of HSC70 is a promising strategy in cancer chemoprevention. Using affinity chromatography, proteomics analysis and computer modeling, we demonstrated that NBT bound to HSC70 at its ATP-binding site and specifically inhibited its ATPase activity. The association between HSC70 and HSP90 is critical for the stability of their client proteins, which …

Utilization Of Modified Lecithin To Control Lipid Oxidation In Bulk Oils, Anuj Shanbhag

Masters Theses

Lipid oxidation is a major challenge faced by the food industry since it causes loss of quality in lipid containing foods which results in a decrease of shelf life. In order to delay the oxidation in lipids, food industries make use of antioxidants such as EDTA (ethylene diamine tetraacetic acid), BHA (tbutyl-4-hydroxyanisole), BHT (t-butyl-4-hydroxytoluene), and TBHQ (tert-butyl-hydroxyquinone). However, these antioxidants are chemically synthesized and consumers desire simpler and cleaner labels without artificially synthesized antioxidants. Also, artificially synthesized antioxidants such as t-butyl-4-hydroxyanisole (BHA) can cause cancer in humans. Previous studies have shown that phospholipids such as phosphatidylethanolamine (PE) and phosphatidylcholine (PC) …

Tocopherol Regeneration By Phospholipids In Soybean Oil-In-Water Emulsions: Effect Of Tocopherol Homologue And Emulsifier Type, Gautam Samdani

Masters Theses

Phospholipids can regenerate oxidized tocopherols and help delay lipid oxidation. The impact of emulsifier type, tocopherol homologue and phospholipid head group on tocopherol-phospholipid interaction was investigated in this study.

Three µmol tocopherol/kg emulsion and 15.0µmol/kg emulsion of PE or PS were dissolved in oil and emulsions were prepared. Tween 20 or bovine serum albumin(BSA) was used as emulsifier and the continuous phase contained 10mM imidazole/acetate buffer at pH 7. Lipid hydroperoxides and hexanal were measured as lipid oxidation products and the lag phase was determined. With Tween 20 as the emulsifier, α and δ-tocopherol had a hexanal lag phase of …

Extractable And Non-Extractable Polyphenols From Mango, Yuchao Ma

Masters Theses

Polyphenol from fruits and vegetables have been proved that can lower the risk of many chronic disease. However, most studies are only focus on the extractable polyphenols right now. Non-extractable polyphenols may also have many important biological effects. The objective of this study was to find the difference between the extractable polyphenol and non-extractable by alkaline hydrolysis, acid hydrolysis and enzyme hydrolysis, compare the total phenolic content, flavonoid content and tannin content, and study their anti-inflammation effect, anti-cancer effect and antioxidant effect. The results showed that NEP alkaline hydrolysis was the best way to extract mango polyphenol. It had the …

Designing Antimicrobial Polymer Coating To Inhibit Pathogenic And Spoilage Microorganisms, Anne Yu-Ting Hung

Masters Theses

Microbial cross-contamination remains an on-going challenge in the food sector despite implemented sanitation programs. Antimicrobial coatings with inherent self-sanitizing properties have been explored to enhance current cleaning practice and support food safety. Prior work has demonstrated successful incorporation of dual antimicrobial characters, cationic polymers and N-halamines, into one coating system. In addition to the rechargeable nature of N-halamines, the coating was reported to exhibit biocidal effects due to the inherently antimicrobial cationic moieties and the chlorinated N-halamines. However, while these polymer coatings were able to retain antimicrobial activity after repeated chlorination, signs of hydrolysis was observed for the N-halamine bonds, …

Effects Of Solid Fat Content, Synthetic Antioxidants And Headspace Oxygen Reduction On The Rates Of Oxidation In Surface And Total Lipids Of Crackers, Collin Alexander Hayes

Masters Theses

Unsaturated fats undergo a process known as oxidation by which they are degraded into undesirable compounds. Therefore it is important for food manufacturers to employ antioxidant strategies. Crackers were used as a model in these studies because of their dietary contribution to saturated, and because the properties of crackers are translatable to other low moisture foods.

The objective of this thesis was to determine if there was a significant variance in rates of oxidation between surface and total lipids in crackers and how solid fat content, synthetic antioxidants, and reduction of headspace oxygen affect those rates. It was hypothesized that …