Life Sciences Commons^™

Chemical Disinfectants For The Inactivation Of The Emerging Foodborne Aichi Virus, Andres Ignacio Arreaza

Masters Theses

Aichi virus (AiV) is an emerging virus responsible for gastroenteritis outbreaks worldwide. Improved decontamination methods are being researched to control AiV spread. The effects of common hard surface disinfectants including benzalkonium chloride (BAC), potassium peroxymonosulfate (KPMS), tribasic sodium phosphate (TSP) as well as sodium metasilicate (SMS) and calcium hypochlorite (Ca(ClO)₂) [calcium hypochlorite] against AiV need to be explored. The objective of this research was to determine their effects against AiV using suspension and carrier tests over various contact times at room temperature. Phosphate buffered saline (pH 7.2 as control), 0.64% BAC, 10% KPMS, 10% TSP, 0.16 and 0.3% …

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 O157:H7, respectively. …

Self-Assembled Casein Nanostructures To Deliver Novel Functionalities, Kang Pan

Doctoral Dissertations

The nanoscale micellar structure of caseins can be manipulated by mechanical forces, solvent quality, and pH to reduce turbidity, encapsulate hydrophobic compounds, and improve dispersion stability and rheological properties. The goal of this dissertation was to control the nanostructure of self-assembled caseins to deliver functionalities. The combination of treatments at pH 11.0 and acidification with citric acid was first studied to produce translucent skim milk dispersions at pH 5.5-7.0, resulting from the significantly reduced dimensions of reassembled casein nanoparticles. Using sodium caseinate (NaCas), soluble soybean polysaccharide (SSPS), and high-speed homogenization, a food grade delivery system was studied to encapsulate thymol …

Gallic Acid-Grafted Chitosan Films As Antioxidant Food Packaging, Ping Guo

Masters Theses

Chitosan is the second most abundant natural polysaccharide in the nature. Due to its biodegradability and film forming ability, chitosan has the potential to be used as an alternative to petroleum-based polymers for food packaging. The presence of a primary amine as well as primary and secondary hydroxyl groups enable chitosan to be chemically modified with various functional groups. Gallic acid (GA) is a natural occurring antioxidant (AOX), which can be grafted to chitosan using by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The first project deals with the effect of ethanol (EtOH) concentration on efficiency of grafting GA onto chitosan. …

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 …

Preparation And Characterization Of Acid-Induced Gels At Ph 1.0-4.0 And Thermal-Stable Dispersions At Ph 5.5-6.0 Using Preheated Whey Protein, Kangkang Li

Masters Theses

Whey protein (WP) is a good source for producing protein-rich products, including satiety foods and beverages. Thermal aggregation of WP during sterilization or pasteurization impacts food quality important to shelf-stable beverages. Preheating WP improves the thermal stability at neutral acidity, and forming complexes with other molecules to provide charge and/or steric hindrance can be used to improve thermal stability of WP at acidic conditions. Conversely, aggregation properties of preheated WP upon acidification can be used to create unique functional properties. Therefore, studying properties of preheated WP can broaden its application in the food industry.

Gelation of preheated WP and pectin …