Food Chemistry Commons^™

Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas

Doctoral Dissertations

Mycotoxins are toxic metabolites produced by fungus that can be parasites or saprophytes of crops or livestock forage. Consumer demand for plant-based foods and interest in animal-based foods originating from animals fed plant-based feed has been on the rise. Therefore, monitoring mycotoxins occurring in the food supply is more critical than ever. The goal of this project is to improve surface-enhanced Raman spectroscopy’s (SERS) ability to identify and detect mycotoxins using label-free SERS substrates. Two simple approaches were designed to enhance the detection of mycotoxins produced by the Aspergillus and Penicillium genera, ochratoxin A and aflatoxin B1. Ochratoxin A was …

Formulation Of Coffee Extract As Polymeric Nanoparticles And Studying Their Potential Biological Activities, Nouran Sharaf

Theses and Dissertations

Coffee extract was prepared and optimized (by solvent extraction) and subsequently entrapped into PLGA nanoparticles using single emulsion-solvent evaporation method (using Design Expert software). Dynamic Light Scattering, Scanning Electron Microscope, Fourier Transform-Infrared Spectroscopy and Folin Ciocalteau assay were used to characterize the NPs and to aid in selecting the optimum formulation conditions. The optimized NPs were in-vitro evaluated for their antimicrobial (by agar-well diffusion method), antioxidant (by DPPH assay) and anticancer (by MTT assay) activities. Finally, the release rate study was conducted for the NP sample showing the highly promising results.

The succeeded NP sample, in terms of the most …

Analysis Of Titanium Dioxide Nanoparticles In Foods Using Raman Spectroscopic Techniques, Janamkumar Pandya

Doctoral Dissertations

Titanium dioxide (TiO2) and its nanoparticles (NPs) are widely used in various applications. Recently, the presence of TiO2 NPs in food and consumer products raised safety concerns to human health and the environment. The goal of this project is to explore the capability of Raman Spectroscopy in the analysis of TiO2-NPs and apply this technique for the analysis of TiO2-NPs in food and environmental samples. Two approaches, i.e. the ligand-based and the mapping-based, were evaluated. The ligand-based approach utilized the surface enhanced Raman scattering (SERS) property of the TiO2 NPs as a substrate to enhance the signal of a surface …

Cold Atmospheric Plasma Stimulates Clathrin-Dependent Endocytosis To Repair Oxidised Membrane And Enhance Uptake Of Nanomaterial In Glioblastoma Multiforme Cells, Zhonglei He, Kangze Li, Laurence Scally, Eline Manaloto, Sebnem Gunes, Sing Wei Ng, Marcus Maher, Brijesh Tiwari, Hugh Byrne, Paula Bourke, Furong Tian, Patrick Cullen, James Curtin

Articles

Cold atmospheric plasma (CAP) is increasingly studied in a growing number of clinical trials for cancer treat-ment1,2 and research is ongoing to explore the combination of CAP with other therapies, including nanoparticles, radiotherapy and chemotherapy3–5.Gold nanoparticles (AuNPs) are known to be weakly-toxic to human cells and be readily manufactured and designed for targeting delivery of various therapeutic compounds into cells. Citrate-capped cationic AuNPs may adsorb serum proteins onto their surface and thereby stimulate receptor-mediated endocytosis6. Without special surface functionalisation, AuNPs enter cells and become trapped in vesicles6–8 or enter the nucleus, depending on their size/shape9,10. Meanwhile, AuNPs with functionalised surface …

Silver Mirror Substrate And Rolling Method For Improved Surface-Enhanced Raman Spesctroscopic Analysis In Food, Yanqi Qu

Doctoral Dissertations

Surface-enhanced Raman spectroscopy, short for SERS, is an emerging technology with great potential in food analysis due to rapid detection, high sensitivity, portable instrumentation, and simple sample preparation. However, it is always a bottleneck to obtain reproducible SERS measurements in real analytical cases due to the complicity of food systems and inhomogeneous aggregation of colloidal nanoparticles. To improve its performance for practical applications in food analysis, efforts have been made in improving the reproducibility, enhancing the selectivity and reducing the matrix interference to the analyte. Herein, a self-assembly silver nanoparticles mirror substrate was fabricated to improve the and the quantitative …

Hybridized Polymeric Nano-Assemblies: Key Insights Into Addressing Mdr Infections, Ryan Landis

Doctoral Dissertations

Multidrug-resistant (MDR) bacteria contribute to more than 700,000 annual deaths world-wide. Millions more suffer from limb amputations or face high healthcare treatment costs where prolonged and costly therapeutic regimens are used to counter MDR infections. While there is an international push to develop novel and more powerful antimicrobials to address the impending threat, one particularly interesting approach that has re-emerged are essential oils, phytochemical extracts derived from plant sources. While their antimicrobial activity demonstrates a promising avenue, their stability in aqueous media, limits their practical use in or on mammals. Inspired by the versatility of polymer nanotechnology and the sustainability …

The Effects Of Chitosan On Resveratrol-Loaded Zein Nanoparticles, Brian Sohn

Undergraduate Research Symposium Posters

Resveratrol is a naturally occurring polyphenolic compound showing health benefits, including anti-carcinogenic, anti-microbial, anti-HIV/AIDS, neuro-protective, and cardio-protective activities. It has been proposed as a promising dietary supplement or functional ingredient in foods to lower the prevalence of many chronic diseases. However, due to the molecule’s chemical instability, low bioavailability, and poor water solubility, its application was vastly limited. Therefore, extensive research has been conducted regarding microencapsulation of resveratrol. In this study, resveratrol was double encapsulated with zein, a prolamine protein found in maize, and chitosan, a hydrophilic, linear polysaccharide derived from chitin via a deacetylation reaction. Due to their biocompatible, …

Modification Of Gold Nanoparticles For Sers Application In Emulsion And Lipid Systems, Michael J. Driver

Masters Theses

Gold nanoparticles produced using the Turkevich method were able to have their hydrophobicity modified using octanethiol in a novel method for SERS application. Both amphiliphic GNPs and hydrophobic GNPs were produced and differentiated by Raman signals. The amphiliphic GNPs were able to enhance the SERS signals of the protein emulsifier in the emulsion in situ and the hydrophobic GNPs were able to enhance the SERS signals from canola oil. Further purification of the hydrophobic GNPs proved to have higher enhancement and sensitivity, but still poor consistency which is typical of SERS. Monitoring lipid oxidation using Raman and SERS using alternative …