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http://hdl.handle.net/11375/30219
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DC Field | Value | Language |
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dc.contributor.advisor | Didar, Tohid F. | - |
dc.contributor.author | Khan, Shadman | - |
dc.date.accessioned | 2024-09-24T01:47:27Z | - |
dc.date.available | 2024-09-24T01:47:27Z | - |
dc.date.issued | 2024 | - |
dc.identifier.uri | http://hdl.handle.net/11375/30219 | - |
dc.description.abstract | Despite extensive mitigative efforts, foodborne illness and food waste continue to impose significant burdens on both human health and on the economy. While technical efforts seeking to develop breakthrough technologies that improve food safety and reduce waste have been reported extensively in literature, real-world translation has been limited. Recognizing that contamination monitoring, spoilage monitoring, and food decontamination represent some of the most promising mechanisms for improvement, this dissertation details the development of technologies that meet each of these three objectives. Importantly, real-time monitoring efforts were all enacted through optical biosensing to ensure high real-world applicability. Accordingly, contamination-prone food products were first subjected to extensive fluorescence assessment to evaluate sensing-relevant properties that stand to educate sensor design. To this end, optical fluorophores for target food products were identified. These findings were then applied towards the development of a fluorescent nucleic acid probe (fNAP) surface sensor, as a tool for contamination monitoring. To actualize the in-package integration of this sensor, a revolutionary packaging technology was developed. The system addressed long-standing barriers in in-package food sampling and sensing reagent integration. By combining our fNAP sensor and packaging technologies, we demonstrated 103 CFU/g detection of Salmonella in sealed whole chicken products in a completely hands-free, real-time manner. Alongside its high specificity and stability, the platform showed effective readout via a handheld fluorescence reader paired with a smartphone, suggesting grocer-level use of the system. On the other hand, the development of an effective spoilage monitoring technology was enacted on a consumer-level through the development of an inexpensive, colorimetric pH-based spoilage sensor, validated using fish. The system embeds food-safe, pH-responsive sensing agents inside environment-responsive microneedles. These microneedles offer strong baseline mechanical properties that switch to hydrogel-like properties upon exposure to fluid-rich environments. When applied to sealed fish products for real-time monitoring, non-destructive penetration through packaging films was followed by hydrogel form enactment by the fluid-rich fish matrix. This transition triggered sensing activity. A defined shift from purple to blue reliably signaled spoilage in proof-of-concept studies. Moreover, the increased surface area afforded by the microneedles was employed towards rapid testing of opened fish products that had already spoiled. Here, colorimetric spoilage detection occurred within 45 minutes. Finally, food decontamination efforts sought to deliver bacteriophages into fluid-rich food products with difficult-to-permeate surface layers – such as fruit and skin-containing meat products. This marked the first effort to actively deliver bacteriophages into interior food matrices. Extensive on-food microneedle material characterization was used to identify the optimal base material. These microneedles were loaded with E.coli-targeting bacteriophages and applied onto contaminated ready-to-eat chicken breasts. The microneedles yielded a nearly 3-log improvement in target reduction compared to flat patches used to deposit bacteriophages onto the product’s surface. Collectively, this dissertation presents several breakthrough on-food technologies that take unconventional approaches towards improving food safety and food waste. Experiences from operating in the smart food space were summarized into an assessment to guide future works. | en_US |
dc.language.iso | en_US | en_US |
dc.title | Bioactive Systems for Real-time Food Quality Monitoring and Preservation to Improve Food Safety and Reduce Waste | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | Biomedical Engineering | en_US |
dc.description.degreetype | Thesis | en_US |
dc.description.degree | Doctor of Philosophy (PhD) | en_US |
dc.description.layabstract | With global food insecurity at crisis levels, the need for smart food technologies that offer improvements in food safety and reduce food waste is pronounced. Contamination monitoring, spoilage monitoring, and food decontamination represent three key mechanisms through which impact can be enacted in this space. In this dissertation, platforms that offer breakthroughs across all three of these avenues are presented. First, the sensing-relevant fluorescence properties of contamination-prone foods are assessed to inform the design of fluorescence-based detection platforms. These findings are applied towards contamination monitoring, where improvements are afforded by a novel food packaging system that facilitates the in-package sensing activity of any integrated optical sensor. The platform is validated using a newly developed Salmonella sensor, yielding completely hands-free, in-package sensing of the high-risk pathogen using a handheld reader and smartphone. Contrarily, efforts to improve spoilage monitoring took a consumer-centric approach, yielding an inexpensive, pH-responsive, colorimetric spoilage sensor for at-home use. The sensing platform can be employed as either a real-time food monitoring platform applied to sealed food packaging, or as a rapid test to evaluate food quality before consumption. With regards to food decontamination, a platform to facilitate bacteriophage delivery into the interior matrices of contamination-prone foods is presented. Finally, insights gathered through the technical, commercial, and regulatory engagements performed as a part of this dissertation are summarized into a situational assessment seeking to guide future works in the smart food technology space. | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Khan_Shadman_2024Aug_PhD.pdf | 18.48 MB | Adobe PDF | View/Open |
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