Preparation and Biological Activity of Chitin Nanofibers
| Autor: | Yeh, Wen-Yan, 葉文燕 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 Chitin is a biopolymer with nano-sized fibrillar morphology and excellent material properties. Chitin nanofibers have several unique properties, such as small size, light weight, high surface-to-volume ratio, high porosity, high stiffness and strength, and biological activity make these nanomaterials extensively explored for applications in the biomedical and food industries. More recently, many reports have indicated that chitin nanofibers have antifungal activity (Aspergillus niger), can be used for food packaging films. The beneficial effects of chitin nanofibers for wound healing were also described, which can be used for wound dressing. However, there have been rare reports to evaluate the antioxidant and antibacterial activity of chitin nanofibers. The aim of this study is to prepare several kinds of β-chitin nanofibers with different degree of deacetylation by ultrasonication, β-chitin nanofibers, partially deacetylated β-chitin nanofibers and deacetylated β-chitin nanofibers, respectively. The effects of physicochemical characteristics of β-chitin nanofibers on the antioxidant and antibacterial activity are discussed. The results demonstrate that the width of β-chitin nanofibers decreased with the increase of ultrasonication time. The antioxidant activity of ultrasonicated β-chitin nanofibers improved significantly, ferrous ion-chelating ability was improved 13.55%, ABTS+ radical scavenging activity was improved 5.01%, DPPH radical scavenging activity was improved 6.83%. The degree of deacetylation of β-chitin, partially deacetylated β-chitin and deacetylated β-chitin are 25.49%, 35.01%, 64.76%, respectively. The degree of deacetylation increase from 25.49% to 35.01% could also improve antioxidant activity significantly, ferrous ion-chelating ability can be improved 34.84%, ABTS+ radical scavenging activity can be improved 11.79%, DPPH radical scavenging activity can be improved 2.35%. The concentrations of β-chitin nanofiber suspensions were limited (0.5 mg/mL), they were too low to against Escherichia coli and Staphylococcus aureus. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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