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Food Science

University of Tennessee, Knoxville

Essential oils

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Full-Text Articles in Life Sciences

Combinations Of Multiple Natural Antimicrobials With Different Mechanisms As An Approach To Control Listeria Monocytogenes, Savannah Grace Hawkins Aug 2016

Combinations Of Multiple Natural Antimicrobials With Different Mechanisms As An Approach To Control Listeria Monocytogenes, Savannah Grace Hawkins

Masters Theses

To improve food safety and shelflife requires the use of preservation processes, such as physical (heat, refrigeration) or chemical (antimicrobial addition) processes. Regulatory approved synthetic food antimicrobials (preservatives) have some uses but are very limited in their spectrum of activity. Thus, alternatives are needed to conventional chemical antimicrobials. One method is to use naturally occurring antimicrobials, especially those found in spices and herbs, essential oils (EO) and essential oil components (EOC). EOs have been shown to have antimicrobial activity but the activity is highly variable. Finding a combination of EOs, EOCs, or other natural antimicrobials that act synergistically would allow ...


Improving Antimicrobial Activity Of Lauric Arginate By Combination With Essential Oils For Novel Applications, Qiumin Ma Aug 2015

Improving Antimicrobial Activity Of Lauric Arginate By Combination With Essential Oils For Novel Applications, Qiumin Ma

Doctoral Dissertations

Lauric arginate (LAE) and essential oils (EOs) are highly efficacious in broth media but are required at much higher concentrations in food products to inhibit foodborne pathogens. Because high levels of LAE and EOs affect organoleptic properties of food products, this dissertation was studied for the potential of lowering their usage concentrations by using them in combination. Antimicrobial activities of LAE and EO used alone or in combination were characterized in Chapter 2. Synergistic and antagonistic effects of LAE-EO combinations and cinnamon leaf oil/eugnol/thymol were observed for inhibiting Gram-positive Listeria monocytogenes and Gram-negative Salmonella Enteritidis and Escherichia coli ...


Synergistic Interfacial Properties Of Casein And Small Molecule Surfactants For Fabrication Of Essential Oil Nanoemulsions, Dan Su May 2015

Synergistic Interfacial Properties Of Casein And Small Molecule Surfactants For Fabrication Of Essential Oil Nanoemulsions, Dan Su

Masters Theses

Nanoemulsions of essential oils are important for delivery of flavors and antimicrobial preservatives in food systems. The overall goal of this work was to study the formation and properties of essential oil nanoemulsions fabricated with sodium caseinate (NaCas) or its hydrolysates and small molecule surfactants (SMSs). The first group of lemon oil nanoemulsion was prepared with NaCas and Tween 20 using a phase inversion temperature (PIT) method. The combination of NaCas and Tween 20 reduced the turbidity and droplet dimension of emulsions than using them individually. Heating at 90 °C for >1 h resulted in transparent nanoemulsions for samples with ...


Fabrication Of Zein Nanoparticle-Biopolymer Complexes To Deliver Essential Oils In Aqueous Dispersions, Huaiqiong Chen Aug 2014

Fabrication Of Zein Nanoparticle-Biopolymer Complexes To Deliver Essential Oils In Aqueous Dispersions, Huaiqiong Chen

Doctoral Dissertations

Zein, alcohol-soluble corn proteins, easily precipitate as nanoparticles after dispersing a stock zein solution with a polar solvent into water. The process can be used to nanoencapsulate essential oils (EOs). However, the stability of hydrophobic zein nanoparticles is a challenge for their application in aqueous food systems. The goal of this dissertation reseach was to stabilize zein nanoparticles in aqueous dispersions by forming complexes with water-soluble biopolymers. The stabilization of zein nanoparticles was first studied using sodium caseinate by dispersing hot 50% aqueous ethanol solution with both polymers in water. The nanoparticles contained κ-casein and zein, and the spray-dried nanoparticles ...


Antimicrobial Activity Of Essential Oils And Their Components Against Lactic Acid Bacteria, Laurel Dunn Gann Dec 2013

Antimicrobial Activity Of Essential Oils And Their Components Against Lactic Acid Bacteria, Laurel Dunn Gann

Masters Theses

Efficacy of plant essential oils against spoilage lactic acid bacteria was examined using two different study methods with the goal of determining minimum inhibitory (MIC) and minimum lethal concentrations (MLC) of the essential oils. The initial study included the incorporation of the essential oils, or their major constituents, into agar to allow uniform dispersion of the substance throughout an agar surface. Individual cultures of nine lactic acid bacteria species (Pediococcus acidilactici, Pediococcus damnosus, Lactobacillus fermentum, Lactobacillus fructivorans, Lactobacillus brevis, Lactobacillus buchneri, Lactobacillus plantarum, Leuconostoc mesenteroides, and Leuconostoc citrovorum) were spot inoculated onto de Man, Rogosa, and Sharpe (MRS) agar containing ...