Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/30219
Title: | Bioactive Systems for Real-time Food Quality Monitoring and Preservation to Improve Food Safety and Reduce Waste |
Authors: | Khan, Shadman |
Advisor: | Didar, Tohid F. |
Department: | Biomedical Engineering |
Publication Date: | 2024 |
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. |
URI: | http://hdl.handle.net/11375/30219 |
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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