الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Chitosan (Cht) is one of the most common biopolymers that can be used in the formation of coatings or films and offers a wide range of unique applications in the food industry, including preservation of foods from microbial deterioration and extension of their shelf life Cht used as edible coat to extend shelf life and improve the quality of both fresh and frozen foods due to their nontoxicity, eco-friendly, and biodegradable nature .
Cht also was extracted and transformed into nanoparticles (NPs) via ionic gelation and fortified with cloves (Syzygium aromaticum) buds extract (CLE) for usage as antimicrobial composites against foodborne bacterial pathogens (Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus) and as edible coating (EC) for shrimp (Fenneropenaeus indicus) biopreservation throughout refrigerated storage as shrimp is a highly valuable and perishable foodstuff that could rapidly spoiled. The synthesized CLE/Cht -NPs were electrostatically cross-linked and appeared with spherical shapes and homogenized distribution, with 159.4 nm mean size diameter and positive charge of 17.4 mV. The entire agents (Cht-NPs, CLE and CLE/Cht-NPs) exhibited remarkable antibacterial activities toward all foodborne pathogens; CLE/Cht-NPs were significantly the most forceful. The scanning micrographs of treated S. Typhimurium with CLE/Cht-NPs displayed NPs ability to attach and destroy bacterial cells. The ECs-treated shrimp exhibited sharp decrease in microbial groups load (aerobic microorganisms, E. coli, Enterobacteriaceae and Staphylococci) during refrigerated storage (4 ºC) for 10 days. Additionally, the sensorial attributes (appearance, odor, color and texture) of EC-treated samples preserved their elevated qualities for storage duration. The EC blend contained 1.5 % from Cht/NPs and 1.0 % from CLE. The CLE/Cht-NPs could be impressively recommended as effectual natural composites for shrimp’s biopreservation during cold storage.
Cht was extracted from shrimp shell waste and transformed into nanoparticles (NPs) via ionic gelation and mixed with selenium nanoparticles (Se-NPs) which green synthesized by cinnamon (Cinnamomum zeylanicum) extract (CIE) for usage as antimicrobial composites against foodborne bacterial pathogens (Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus and Listeria monocytogenes) and as edible coating for food. The phytosynthesized CIE/Se-NPs composite was obtained with a mean diameter of 23.2 nm. The entire agents (CIE, CIE/Se-NPs and CIE/Se/Cht-NPs) exhibited remarkable antibacterial activities toward all foodborne pathogens; CIE/Se/Cht-NPs were significantly the most forceful. Transmission microscopy displayed well distribution and spherical shapes of the phytosynthesized NPs.The scanning micrographs indicated that CIE/Se-NPs were attached to bacterial cells and led to their complete lysis/explosion with exposure prolongation. The CIE/Se-NPs composites are recommended for the effective control of foodborne bacterial pathogens, applying a simple and ecofriendly phytosynthesis protocol.