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Full-Text Articles in Life Sciences

Analysis Of Food Colorants Using Raman Spectroscopy, Haochen Dai Oct 2022

Analysis Of Food Colorants Using Raman Spectroscopy, Haochen Dai

Doctoral Dissertations

Color is one of the most important quality attributes that affect consumers' selection of food. The increasing demand of consumers for natural colorants over artificial ones has placed challenges in both product development and regulatory practices. However, current analytical solutions for food colorants are mostly limited to a sophisticated laboratory setting with tedious sample preparation procedures. Herein, this research focuses on the analytical developments toward cost-effective determination of colorant adulteration and stability analysis. The main technique explored is Raman spectroscopy, which measures the inelastic light scattering and allows one to obtain unique molecular fingerprints for specific molecules. Compared with chromatographic …


Novel Approaches For Preventing Lipid Oxidation In Emulsion-Based Food Systems, Mitchell D. Culler Oct 2022

Novel Approaches For Preventing Lipid Oxidation In Emulsion-Based Food Systems, Mitchell D. Culler

Doctoral Dissertations

Consumer interest in “clean” labels has continued to be a key driver of consumer behavior and purchasing habits over the past decade. Food manufacturers are therefore eager to replace synthetic antioxidants such as ethylenediaminetetraacetic acid (EDTA) with natural alternatives, however alternative chelators that will bind iron at low pH remain elusive. Coupled with the current oil shortages and supply chain challenges that have arisen recently, there is an urgent need for innovative solutions to increase the oxidative stability of edible oils. One available strategy is diluting oils high in unsaturated fatty acids into more stable, more saturated oils, thus delaying …


Foaming Properties Of Dilute Pea Protein Solutions, Jiani Bao Jun 2022

Foaming Properties Of Dilute Pea Protein Solutions, Jiani Bao

Masters Theses

Plant-derived protein such as pea protein is a promising replacement for animal protein and is becoming popular in recent years because of its high nutritional value and potential reduction of environmental footprint. However, the increasing demand for plant-derived proteins is accompanied by the increase of wastes during protein processing such as wastewater containing dilute protein content, which may raise the cost for the downstream processing. Therefore, there is an emerging need to develop novel processing strategies to reduce waste while valorizing useful ingredients. Several researchers suggest that foam fractionation technology can be a viable approach to extract and concentrate protein …


Enhancement In Photoinactivation Of Food-Borne Pathogenic Bacteria With The Use Of Curcumin And Surfactants, Victor Ryu Jun 2022

Enhancement In Photoinactivation Of Food-Borne Pathogenic Bacteria With The Use Of Curcumin And Surfactants, Victor Ryu

Doctoral Dissertations

Photosensitizers and UV or visible light could photoinactivate bacteria. Curcumin was utilized as a food-grade photosensitizer, and an enhancement of its water-dispersibility, chemical stability, and antimicrobial activity when introduced into surfactant solutions was observed. Stock curcumin-surfactant solutions were prepared by titrating curcumin dissolved in ethanol into either Surfynol 465 or Tween 80 solutions (5 mM sodium citrate buffer). Stock curcumin surfactant solutions with different surfactant concentrations were diluted to 1 µM prior to irradiation. The resulting solutions also had surfactant concentrations below, near, and above their critical micelle concentrations (CMCs) of the respective surfactants. The antimicrobial activity of the curcumin-loaded …


Detection Of Benzoyl Peroxide In Flour Using Raman Spectroscopy, Yu Ho Mar 2022

Detection Of Benzoyl Peroxide In Flour Using Raman Spectroscopy, Yu Ho

Masters Theses

Benzoyl peroxide (BPO) is a common bleaching agent used in wheat flour. Due to its ability to damage existing nutrients in food and potential adverse effect to health, BPO have been strictly banned as a food additive in several countries and regions, such as China and Europe. However, the United States specifies that BPO is generally recognized as safe (GRAS). So, the WHO/FAO created a Codex Alimentarius Commission (CAC) to regulate the international BPO usage standard. According to the CAC, it is restricted at 75 mg/kg or parts per million (ppm). BPO is very unstable and easily converts to benzoic …


Double Emulsions Relevant To Food Systems: Fabrication, Characterization, And Applications, Jinning Liu Mar 2022

Double Emulsions Relevant To Food Systems: Fabrication, Characterization, And Applications, Jinning Liu

Doctoral Dissertations

Systems of the W/O/W type continue to be of growing interest to food scientists and technologists for two main reasons. First, there is the possibility of preparing a reduced-fat emulsion product by the replacement of a conventional oil-in-water emulsion by the equivalent W/O/W emulsion having a lower actual oil content but a similar in-mouth perceived texture. Second, there is the capability to encapsulate and protect a sensitive hydrophilic bioactive compound. However, it is always a bottleneck to obtain robust formulations using economically viable ingredients and processing operations. To improve its performance for practical applications in food production, efforts have been …


Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas Mar 2022

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 …


Analysis Of Plant And Animal Proteins Using Raman Spectroscopy, Noopur Bapardekar Mar 2022

Analysis Of Plant And Animal Proteins Using Raman Spectroscopy, Noopur Bapardekar

Masters Theses

There has been a notable rise in the alternative protein market in the recent years which promotes an interest in the research of both animal and plant proteins to establish better structure-function relationships. Over the years many analytical tools have been used to study proteins and compare them, however Raman Spectroscopy and Surface Enhanced Raman Spectroscopy (SERS) have not been as much used for this application. SERS consolidates Raman Spectroscopy that primarily measures molecular vibrations and nanostructures that enhance the weak Raman signals. The objective of this study is to explore the capability of the Raman instrumentation in combination with …


Fate And Effect Of Food-Grade Titanium Dioxide Particles/Polystyrene Nanoplastics On Nutrients Bioaccessibility Of Food In The Simulated Human Gastrointestinal Tract, Chunyang Li Feb 2022

Fate And Effect Of Food-Grade Titanium Dioxide Particles/Polystyrene Nanoplastics On Nutrients Bioaccessibility Of Food In The Simulated Human Gastrointestinal Tract, Chunyang Li

Doctoral Dissertations

Food grade titanium dioxide particles (E171), as whitening agent, are commonly used in chewing gums, candies, sauces, salad dressings, and powdered milk. Recently, nanoplastics (NPs) (defined as < 1 µm), which are degraded from plastic debris undergoing environmental process, have received global attention. Because nanoplastics are ubiquitous in aquatic and terrestrial systems, and have been detected in marine animals, table salts, drinking water, and air. Thus, the presence of E171 as additives in the food, and the nanoplastics in food chains, both pose potential risks to human health through retarded processes in the gastrointestinal tract (GIT). However, the knowledge about the fate of E171 or nanoplastics and their impact on digestive enzymes activity or nutrient bioaccessiblity are currently limited. Therefore, it is necessary to investigate potential impacts of E171 or nanoplastics on digestion processes and nutrient bioaccessibility in the simulated human gastrointestinal tract, which includes mouth, stomach and intestinal phases, to mimic the digestion processes of food incubating with E171 or polystyrene (PS) nanoplastics. The objectives of my dissertation and major findings are presented below: 1) The impacts of E171 on lipid digestion and vitamin D3 (VD3) bioaccessibility encapsulated within oil-in-water emulsions in a simulated human gastrointestinal tract model were explored; 2) The impacts of E171 on the bioaccessibility of minerals (Ca, K, Mg, Fe, Mn, Zn, P and S) released from spinach leaves using a simulated human digestion tract were investigated; 3) The impacts of various concentrations or different functional group (-COOH, -NH2) of PS NPs on the starch hydrolysis in the simulated …


Mapping Selected Polyphenols Metabolism By Gut Bacteria And Their Genes, Ermin Zhao Feb 2022

Mapping Selected Polyphenols Metabolism By Gut Bacteria And Their Genes, Ermin Zhao

Doctoral Dissertations

The human gut microbiome is a huge enzyme repository for dietary polyphenols metabolism, especially considering most of the polyphenols cannot be digested in the host and their biological functions are limited. Poor bioaccessibility based on traditional pharmaceutical ADME (absorption, distribution, metabolism, and excretion) assessment is the main problem facing the widely medical application of most polyphenols. Gut bacteria have the potential to mediate a wide range of biotransformation reactions of polyphenols, which leads to the production of many bioactive metabolites. In the past decades, mounting evidence in traditional ADME study have demonstrated gut bacteria play an irreplaceable role in dietary …