Harnessing chitosan-aloe vera gel and aloe extract for photodynamic inactivation of staphylococcus aureus under blue led light for improved food preservation | |
| Author | Sthapit, Ava |
| Call Number | AIT Thesis no.FB-24-03 |
| Subject(s) | Photochemotherapy Aloe vera Food--Preservation |
| Note | A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Food contamination by harmful microorganisms poses significant risks to food safety and quality, necessitating effective intervention strategies. This study explores the use of edible coatings combined with photodynamic therapy (PDT) as a novel approach to combat microbial contamination in fresh produce. The PDT method harnesses natural compounds that react to light, targeting surface microorganisms on food items. Aloe extract, mixed with chitosan and aloe vera, served as the photosensitizer in the edible coatings, which were subjected to blue LED light treatment. The antimicrobial efficacy of the coatings against S. aureus was evaluated, alongside characterization of coating properties. The results demonstrated a significant reduction in bacterial load, with the most effective formulation exhibiting a 99% reduction in bacterial counts. Mechanistically, PDT induced the generation of reactive oxygen species (ROS) from the photosensitizers, effectively destroying surrounding bacterial cells on the coating. Moreover, the incorporation of aloe extract in the coatings improved cross-linking within the polymer matrix, enhancing optical and mechanical properties. Application of the optimized coating onto strawberries effectively inhibited bacterial growth, extending shelf life and maintaining fruit quality parameters over a 7- day storage period at ambient temperature. Overall, this study highlights the potential of PDT combined with edible coatings as a sustainable and efficient approach for enhancing food safety and quality in fresh produce. |
| Year | 2024 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Loc, Thai Nguyen |
| Examination Committee(s) | Anal, Anil Kumar;Salin, Krishna R. |
| Scholarship Donor(s) | AIT Scholarship |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2024 |