Document Details
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Document Type |
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Thesis |
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Document Title |
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DEVELOPMENT OF ECO-FRIENDLY ANTIMICROBIAL FOOD GRADE PACKAGING MATERIALS USING BIO-NANOCOMPOSITE FILMS تطوير مواد تغليف للأغذية مضادة للميكروبات و صديقة للبيئة باستخدام أغشية متراكبات حيوية متناهية الصغر |
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Subject |
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Faculty of Science |
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Document Language |
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Arabic |
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Abstract |
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Modern technologies can improve the effectiveness of food packaging materials to prevent foodborne pathogens and reduce environmental waste. Traditionally, food is packaged in plastic that is rarely recyclable, negatively impacting on the environment. Conversely, biodegradable wrapping materials can be instrumental in maintaining the health of ecosystems. Unfortunately, however, there are some obstacles in the utilization of bio-based materials ((e.g. chitosan, poly (vinyl alcohol) (PVA), potato starch, carboxymethyl cellulose (CMC), corn starch and Arabic gum)), including poor barriers against oxygen, odors, gases and mechanical properties that frequently cause a shorter shelf-life compared to conventional food packaging materials. Consequently, one effective solution to overcome these obstacles is to incorporate nanomaterials into a bio-based polymer, which can improve the properties of food packaging constituents via enhancing the antimicrobial activity, thus reducing foodborne pathogens. The main objective of this research is to investigate the possibility of using bionanocomposite films to reduce foodborne pathogens by enhancing the properties of the prepared films while incorporating biodegradable materials. In this study, antimicrobial bionanocomposite films were fabricated based on chitosan (CS), poly (vinyl alcohol) (PVA) and silicon dioxide doped with zinc oxide (ZnO-SiO2) nanocomposites, which was developed via the sol gel method and incorporated into PVA/CS blended with different ratios (0.50, 1.0, 3.0 and 5.0%) to achieve PVA/CS/ZnO-SiO2 bionanocomposites by the casting method. Subsequently, a series of tests were performed, beginning with the ZnO-SiO2 nanocomposites as well as PVA/CS/ZnO-SiO2 bionanocomposite films which were evaluated using SEM, FT-IR, XRD and final contact angle. The mechanical properties, gas permeability (GTR) and water vapor transmission rate (WVTR) of the achieved PVA/CS/ZnO-SiO2 bionanocomposite films were also assessed. Subsequently, antimicrobial activity was studied using the Kirby - Bauer and the CFU methods to assess the sensitivity and activity of microbes when exposed to the bionanocomposite films. Afterwards, the morphological changes of bacterial cells, when exposed to the influence of bionanocomposite films, were studied through the TEM. Finally, the toxicity of the bionanocomposite films was evaluated using Vibrio fischeri to assess the effect of bionanocomposite films in suppressing or inhibiting light emission. The first key result of these analyses was the superior displayed antimicrobial activity of fabricated bionanocomposites films against tested pathogens (i.e., Staph. aureus, Salmonella enterica, Pseudomonas aeruginosa, E. coli, Shigella sonnei and Candida albicans). Additionally, it was noticed that when there was an increase in the concentration of ZnO-SiO2 NPs, the number of bacterial colonies decreased, especially at concentration of 5% ZnO-SiO2 NPs. Furthermore, through the morphological study of gram-negative and gram-positive bacteria, accumulations and attractions of ZnO-SiO2 NPs were observed around the cell wall, which enhanced the possibility of an interaction between ZnO-SiO2 NPs and bacterial cells negatively affecting the integrity of the bacterial cell. Moreover, results illustrated that packaging bread sapmles using bionanocomposite films of 0.5% and 5% concentration and storing them at room temperature for 10 days significantly improved the appearance of bread compared to those packaged with either CS/PVA or the commercially widely-used polyethylene. The mechanical properties also showed a remarkable improvement in tensile strength when increasing the concentration of ZnO-SiO2, from 18 to 37.5 MPa. Finally, there was also a significant decrease in the oxygen and water vapor transmission rate observed when increasing concentrations of ZnO-SiO2, which enhances the improvement of the barrier of Bionanocomposite Films. We conclude that Bionanocomposite Films could be used effectively and feasibly to develop antimicrobial and environment-friendly food packaging materials. |
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Supervisor |
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Prof. Dr. Rashad Rizk Al-Hindi |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1443 AH
2022 AD |
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Added Date |
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Tuesday, March 15, 2022 |
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Researchers
| ناصر أحمد الطيار | Al-Tayyar, Nasser Ahmad | Researcher | Doctorate | |
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