Life Sciences Commons^™

Reusable Light-Activated Antimicrobial Materials Prepared With Food Ingredients, Andrew T. Gagon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microbial contamination and proliferation in food processing, distribution and storage continues to be a real risk in spite the wide variety of food processing and preservation techniques available. Some of these techniques (such as heat treatments and the use of chemical preservatives) may require substantial amounts of energy and their effects in the general population and the environment may be harmful. This has generated an interest over alternative methods of food preservation. The use of reusable light-activated materials may represent an effective approach. In this study, a polypropylene plastic was modified with either zein, which is found in corn, or …

Antimicrobial Properties Of Different Chitosans Against Gram-Negative And Gram-Positive Foodborne Pathogens In Food Products, Nancy Katherine Rubio Zapata

LSU Doctoral Dissertations

Chitosan is a polymer derived of the deacetylation of chitin that is one of the most abundant material in nature. Chitosan solutions applied as edible coatings, and dipping solutions have shown positive results in the extension of shelf life on seafood and meat products. The purpose of this study was to evaluate the antimicrobial activities of a newly invented high molecular weight water-soluble (HMWWS) chitosan against selected Gram-negative (Salmonella Typhimurium, Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae) and Gram-positive (Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus) foodborne pathogens (initial inoculation of 6.5 Log). Chitosans with …

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, …

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. …

Development And Evaluation Of Novel Vaccination Strategies For Campylobacter Control In Poultry, Xiang Liu

Masters Theses

Chicken is the primary natural host of Campylobacter, the leading bacterial cause of human enteritis in the US and other developed countries. Thus, mitigation of Campylobacter in chicken using innovative approaches, such as vaccination, will have a significant impact on food safety and public health. Our previous studies have demonstrated that the two outer membrane proteins, CmeC (the essential component of the CmeABC multi-drug efflux pump) and CfrA (a ferric enterobactin receptor), are feasible candidates for immune intervention against Campylobacter. DNA vaccine has appeared to offer various advantages for poultry, particularly when combined with in ovo vaccination. Chitosan-encapsulated …

Chitosan Reduces Enteric Colonization Of Campylobacter In Young Chickens, But Not On Post-Harvest Chicken Skin Samples, Hanna Royce Arambel

Graduate Theses and Dissertations

Worldwide, Campylobacter is one of the leading causes of foodborne bacterial gastroenteritis causing an estimated 1.3 million infections in the United States alone. Consumption and/or cross-contamination of raw or undercooked poultry products have been linked as the most common source of Campylobacter infection, making the poultry industry a target for Campylobacter reduction strategies. Campylobacter is prevalent in most poultry flocks in the United States, with as many as 90% of flocks Campylobacter-positive at the time of slaughter. It is estimated that a reduction of Campylobacter in poultry would greatly reduce the risk of campylobacteriosis in humans. Unfortunately, there are …

Chitosan-Gallic Acid Films As Multifunctional Food Packaging, Stephanie Beth Schreiber

Masters Theses

Chitosan is a good candidate for multifunctional food packaging because of its biocompatibility, biodegradability, antibacterial properties, secondary antioxidant activity, film forming ability, resistance to lipids and because of its structure which is very desirable for grafting various compounds to it. For this research, we took advantage of chitosan’s amino group that has nuceleophilic character at a pH above its pKa, which is 6.3. Gallic acid, a phenolic compound with primary antioxidant properties was grafted to chitosan using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Grafting was evaluated using FTIR-ATR and ¹H and ¹³CNMR. FTIR showed evidence of grafting on the amino …

Depolymerization Of Chitosan By High-Pressure Homogenization And The Effect On Antimicrobial Properties, Deidra Shannon Lyons

Masters Theses

The focus of this study was to look at relationship between polydispersity caused by high pressure homogenization and molecular weight dependent antimicrobial activity of chitosan. It has been shown that chitosan has antimicrobial activity against bacteria, fungi, and viruses. Chitosan is obtained by partial de-N-acetylation of chitin which, consists of a ß 1-4 copolymer of glucosamine and N-acetylglucosamine residues. In this experiment we compared chitosan of sixteen different molecular weights after being processed through a high pressure homogenizer. Processed chitosan (420 kDa average molecular weight, 30% of acetylation) was dissolved in a 1% (v/v) acetic acid in water to a …

Effectiveness Of Different Molecular Weights And Concentrations Of Chitosan On Enteric Viral Surrogates, Robert Hamilton Davis

Masters Theses

Chitosan is known to be antibacterial and antifungal, but information on its effectiveness against foodborne viruses is limited. Enteric viruses are a major concern in food safety, especially human noroviruses which are the leading cause of nonbacterial gastroenteritis. The overall goal of this research was to determine the antiviral effectiveness of chitosan. The specific objectives were to determine the effects of molecular weight (MW) and concentration of chitosan against the cultivable enteric viral surrogates, feline calicivirus (FCV-F9), murine norovirus (MNV-1), and bacteriophages (MS2 and phiX174). Purified chitosans (53, 222, 307, 421, ~1,150kDa) were dissolved in water, 1% acetic acid, or …

Efficacy Of Organically Certifiable Materials And Natural Compounds Against Foliar Hemibiotrophic And Necrotrophic Fungi In Cantaloupe And Tomato, Merari Feliciano-Rivera

University of Kentucky Doctoral Dissertations

Kentucky reported a solid 13.1% growth in certified organic land from 1997 to 2002. The relative lack of research on disease management practices in Kentucky consistent with organic regulations is an issue that needs to be addressed to provide more reliable information to local farmers. Thus, the first objective of this research was to investigate the potential disease control obtained with natural, organically certifiable spray materials against Colletotrichum orbiculare in vitro and in vivo. The second objective was to test certifiable spray materials in combinations to identify synergistic interactions. The third objective was to evaluate Organic Material Review Institute …

Physical Characteristics And Metal Binding Applications Of Chitosan Films, Joshua B. Jones

Masters Theses

Chitosan films are an excellent media for binding metal ions due to the electrostatic nature of the chitosan molecules. Addition of cross-linking or plasticizing agents alters texture of the films, but their effect on metal-binding capacity has not been fully characterized. The objective of this research was to determine effects of plasticizers and cross-linkers on physical and metal-binding properties of chitosan films and coatings prepared by casting and by spincoating. Chitosan films were prepared using 1% w/w chitosan in 1% acetic acid with or without (control) additives. Plasticizing agents were tetraethylene glycol (TEG) and glycerol while citric acid, ethylenediamine tetraacetic …

Development And Testing Of A Machine-Coatable Chitosan Coating Applied To A Flexible Packaging Sealant, Steffen Rau

All Theses

Chitosan is a naturally derived material that has anti-microbial properties. Studies have shown that chitosan is effective when it is in contact with the surface of the product upon which the antimicrobial effect is desired. This suggests that chitosan should be on the inside surface of the package. In this work, a machine coatable chitosan coating was developed for application to the sealable (LDPE) side of a PET/LDPE lamination. The viscosities and percent solids of the coating were evaluated over 12 days. The coating was tested using manual drawdowns (Mayer rods) and also on a gravure coating line. Adhesion properties …

Development And Characterization Of Antimicrobial Food Coatings Based On Chitosan And Essential Oils, Shuang Chi

Masters Theses

The objectives of this research were (1) to evaluate antimicrobial effects of essential oils incorporated in chitosan edible films against Listeria monocytogenes and Escherichia coli O157:H7, (2) to evaluate effectiveness of the films on a meat product, (3) to characterize physical properties of chitosan films enriched with essential oils, and (4) to determine whether the addition of oregano essential oil to bologna can influence consumer liking of the product.

Anise, basil, coriander, and oregano essential oils were tested for antimicrobial activity by paper disc diffusion test with concentration of 1 to 24 ml/disc. Chitosan films incorporated with those essential oils …

Antimicrobial Use Of Native And Enzymatically Degraded Chitosans For Seafood Applications, Todd Andrew Nicholas

Electronic Theses and Dissertations

Millions of pounds of crab and shrimp shell waste are created every year by the seafood industry. This waste is very resistant to biodegradation and disposal is problematic. Crustacean shells are composed mainly of chitin that can be converted to chitosan by deacetylation. Many current shelf life extension and pathogen inhibition methods employ the use of various chemical preservatives. Chitosan, an abundant natural polysaccharide, possesses antimicrobial as well as functional properties that may be useful in improving quality of stored foods. These properties may be influenced by a number of factors that must be studied before determining the most useful …

Effect Of Chitosan As A Stabilizer In Hot Sauce, Richard Arnold Schlottmann

LSU Historical Dissertations and Theses

By the use of mild demineralization in the purification of chitin from shrimp shells and optimizing the deacetylation of this chitin, chitosan capable of producing viscosities of 9600 cps were produced. This is substantially higher than the viscosity of the commercial product, whose viscosity is only 1000 cps. The effectiveness of this high quality chitosan as a stabilizer in hot sauces was then investigated. From prelim­inary studies using the commercially produced chitosan, it was concluded that the method of incorporating the gum into the hot sauces was very important. Therefore, three methods of adding the chitosan to the hot sauces …