Development and evaluation of ultraviolet systems to enhance food safety and food security

Food-safety and food-security issues caused by microorganisms are of constant concern worldwide. Ultraviolet (UV) radiation, a non-thermal physical approach that can effectively inactivate microorganisms, has been extensively studied as a means of disinfecting food and food-related materials such as packaging. The UV wavelength conventionally used for food disinfection is 254 nanometers (nm), which lies within the part of the spectrum known as ultraviolet C or UVC (i.e., 200-280 nm. However, 254 nm UVC’s applications in low-resource settings such as war zones and impoverished areas are limited by its high consumption of commercial electricity. Its other key limitation is that direct exposure can cause severe damage to mammals’ skin and eyes. As steps toward mitigating both these issues, we first developed a UVC treatment system – Tribo-sanitizer – that does not require a commercial power supply. To power the system’s low-pressure amalgam UVC lamp, we developed a free-standing rotational triboelectric nanogenerator (FSR-TENG) that can convert low-frequency mechanical energy into high-voltage electricity. Following further design innovations – e.g., the introduction of an air gap into the design of its circuit – Tribo-sanitizer was able to inactivate two notorious foodborne pathogens, Escherichia coli O157:H7 and Listeria monocytogenes, in multiple matrixes, including liquid, food-contact surfaces, and fresh produce’s surfaces. Second, we built on the above work by designing another novel treatment system incorporating krypton chlorine (KrCl) microplasma-based lamps. Such lamps emit 222 nm or far UVC light, which has been found to be human-safe but still germicidal. Specifically, a treatment frame and a 3D treatment chamber were developed to test 222 nm far-UVC radiation’s efficacy at inactivating dangerous fungi in suspension, on solid surfaces and on real cereal grains. The results show that 222 nm far-UVC’s antifungal abilities were comparable to those of its non-human-safe 254 nm counterpart. Moreover, 222 nm far-UVC did not cause quality loss to the cereal samples, and was capable of degrading two mycotoxins, namely aflatoxin B1 and deoxynivalenol, in aqueous solutions. In sum, our work effectively addressed the disadvantages of conventional UVC systems, and thus has the potential to make a major contribution to food safety and food security.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Food Science & Human Nutrition

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Jin, Zhenhui

Contributors dc:contributor

• Wang, Yi-Cheng
• Miller, Michael
• Banerjee, Pratik
• Stasiewicz, Matthew

• Ultraviolet C
• Triboelectric Devices
• Human-safe Far Ultraviolet C
• Post-harvest Loss
• Produce Safety

Statement dc:rights

• Copyright 2024 Zhenhui Jin

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/124676

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F124676