Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Life Sciences
Gallic Acid-Grafted Chitosan Films As Antioxidant Food Packaging, Ping Guo
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. …
Chitosan-Gallic Acid Films As Multifunctional Food Packaging, Stephanie Beth Schreiber
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 …
Effectiveness Of Different Molecular Weights And Concentrations Of Chitosan On Enteric Viral Surrogates, Robert Hamilton Davis
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 …
Physical Characteristics And Metal Binding Applications Of Chitosan Films, Joshua B. Jones
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 …