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Food- and waterborne viruses, such as human norovirus, hepatitis A virus, hepatitis E virus, rotaviruses, astroviruses, adenoviruses, and enteroviruses, are major contributors to all foodborne illnesses. Their small size, structure, and ability to clump and attach to inanimate surfaces make viruses challenging to reduce or eliminate, especially in the presence of inorganic or organic soils. Besides traditional wet and dry methods of disinfection using chemicals and heat, emerging physical nonthermal decontamination techniques (irradiation, ultraviolet, pulsed light, high hydrostatic pressure, cold atmospheric plasma, and pulsed electric field), novel virucidal surfaces, and bioactive compounds are examined for their potential to inactivate viruses on the surfaces of foods or food contact surfaces (tools, equipment, hands, etc.). Every disinfection technique is discussed based on its efficiency against viruses, specific advantages and disadvantages, and limitations. Structure, genomic organization, and molecular biology of different virus strains are reviewed, as they are key in determining these techniques effectiveness in controlling all or specific foodborne viruses. Selecting suitable viral decontamination techniques requires that their antiviral mechanism of action and ability to reduce virus infectivity must be taken into consideration. Furthermore, details about critical treatments parameters essential to control foodborne viruses in a food production environment are discussed, as they are also determinative in defining best disinfection and hygiene practices preventing viral infection after consuming a food product.

Even during the continuing world pandemic of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), consumers remain exposed to the risk of getting infected by existing, emerging, or re-emerging foodborne and waterborne viruses. SARS-CoV-2 is different in that it is transmitted directly via the airborne route (droplets and aerosols) or indirect contact (surfaces contaminated with SARS-CoV-2). International food and health organizations and national regulatory bodies have provided guidance to protect individuals active in food premises from potential occupational exposure to SARS-CoV-2, and have recommended chemicals effective in controlling the virus. Additionally, to exclude transmission of foodborne and waterborne viruses, hygiene practices to remove viral contaminants from surfaces are applied in different stages of the food chain (e.g., food plants, food distribution, storage, retail sector, etc.), while new and enhanced measures effective in the control of all types of viruses are under development. This comprehensive review aims to analyze and compare efficacies of existing cleaning practices currently used in the food industry to remove pathogenic viruses from air, nonfood, and food contact surfaces, as well as from food surfaces. In addition, the classification, modes of transmission, and survival of food and waterborne viruses, as well as SARS-CoV-2 will be presented. The international guidelines and national regulations are summarized in terms of virucidal chemical agents and their applications.

Recent advancements in ultraviolet light-emitting diodes (UV-LEDs) have allowed for their successful integration into continuous disinfection reactors including small-scale systems designed for low UV transmission (UVT) applications. This study characterized the performance of the first commercially available benchtop continuous-flow multiple-wavelength UV-LED system used for the treatment of juices and beverages in thin film. Three beverages (coconut water, blue lemonade, and pink lemonade), two juices (green juice blend and beet juice blend), and saline solution were inoculated with a non-pathogenic Escherichia coli indicator organism and treated at 281 nm. The volume averaged fluence delivered to the samples per pass ranged between 1.6 and 11.6 mJ cm−2 and was dependent on their absorption coefficients which ranged from 0.67 to 26.9 cm−1. Microbial inactivation ranging from 4.2 to 7.2 log10 was achieved within a reasonable number of passes or treatment time in pink and blue lemonade, coconut water, and saline solution which corresponded to an absorption coefficient below 6 cm−1 (UVT = 0.3%). Other than in beet juice blend, which had the highest absorption coefficient, a 1-log10 reduction fluence value in the range of other E. coli strains (previously reported in water) was reported (1.9–5.8 mJ cm−2). These results also suggest that the continuous-flow UV-LED system can be used to investigate inactivation kinetics and effects on nutritional and quality parameters at multiple wavelengths following treatment of low UVT water samples and high UVT juices and beverages with absorption coefficients up to 10–12 cm−1 (4.6e−3 to 6.3e−6% UVT).

Tiger nut milk is a low-acid health beverage that is marketed with the claims of being high in protein, monounsaturated fatty acid (oleic acid), fiber, starch, and minerals, in addition to...

Ultraviolet-C (UV-C) light is a non-thermal method for improving the safety and shelf-life of cold-pressed juices with minimal impact on quality and nutrition. Most previous studies have investigated fruit juices as opposed to particulate dense leafy green juices with very low UV transmittance (UVT). Pure kale juice is a common juice ingredient and represents the worst-case scenario in terms of low UVT green juices. This study validated the use of continuous benchtop UV-C treatment at 253.7 nm for 5-log reduction of non-pathogenic Escherichia coli P36 in kale juice. An average absorbed fluence of 108.3 mJ cm−2 resulted in a 5.8 log reduction of E. coli P36. At a fluence comparable to that reported for commercial juice processing (74.0 mJ cm−2), kale juice exhibited a decrease in absorption coefficient, while sedimentation, supernatant browning and pectin methylesterase activity increased with no effect on the chlorophyll content, colour, viscosity or antioxidant content.

Furan, which has been identified as a carcinogenic risk for humans, can be induced in different foods by UV-C light. In this study, we hypothesized that furan was produced by a UV light-induced free radical mechanism and antioxidants could suppress its formation. Our results demonstrated that, by adding antioxidants, such as butylated hydroxyl toluene, ascorbic acid or gallic acid, to simulated juice or apple cider during UV-C treatment, amounts of furan were significantly reduced. For example, the concentration of furan produced in apple cider by UV-C at 9.0 J/cm2 was 636 ppb but was less than 20 ppb with 0.25 ppm butylated hydroxyl toluene present, less than 3 ppb with 0.5% (w/v) ascorbic acid, and less than 1.0 ppb with 0.5% (w/v) gallic acid. These findings confirmed that antioxidants can be used as a safe and simple mitigation measure to control furan production in fruit drinks exposed to UV-light.

This study compared the inactivation efficacy and performance of UV-LEDs emitting at 259, 268, 275, 289, and 370 nm against a low pressure mercury lamp at 253.7 nm for the foodborne pathogens, E. coli, Listeria and Salmonella. Action spectra were determined for three pathogenic and three non-pathogenic strains and compared with UV absorbance of their bacterial DNA. The lethality of UV wavelengths correlated with bacterial DNA absorbance. At an equivalent UV dose (7 mJ·cm−2), UV-LEDs emitting at 259 and 268 nm achieved the highest log count reductions out of the tested wavelengths. Refrigeration (4 °C) increased irradiance of the 268 nm UV-LEDs while not affecting reduction of Listeria compared to 25°C. Combining 259 and 289 nm UV-LED wavelengths at an equivalent UV dose had a synergistic effect on reduction of E. coli and Listeria, yielding a 1.2 and 0.6 log higher reduction, respectively, than the expected additive effect. Industrial relevance UV-LED treatment at 259, 268, and 275 nm can either equal or, in most cases, surpass the inactivation efficacy of traditional LPM lamps at 253.7 nm. Further, the determined action spectra can be used to identify the optimum inactivation wavelength for common foodborne pathogens and hence increase processing efficiency. In some cases, inactivation efficacy can be improved by combining UV wavelengths in order to achieve a synergistic effect. The effectiveness of UV-LED treatment at refrigeration temperatures validates their use in cold environments. Overall, UV-LEDs have strong potential within the food industry due to their advantages and possibilities for incorporation into a wide variety of treatment systems.

Fungal disease of grain crops is a concern for the agricultural industry, resulting in economic losses. Aside from severe yield losses, mycotoxigenic fungi such as Penicillium and Fusarium can produce harmful mycotoxins, including deoxynivalenol (DON), zearalenone (ZEN), and ochratoxin A (OTA). This proof-of-concept study explored the feasibility and effects of ultraviolet (UV) C light at 253.7 nm to reduce fungal and mycotoxin loads on model surfaces as well as on maize and wheat kernels using benchtop 2D and 3D illumination strategies. Reduction of Penicillium verrucosum (98.6%) and Fusarium graminearum (88.8%) on agar was achieved using a UV-C dose of 100 mJ cm−2. Naturally occurring fungal growth resembling P. verrucosum on maize was reduced by 79% after exposure to 5000 mJ cm−2. Similarly, fungal growth resembling F. graminearum on maize was reduced by 60% with 1000 mJ cm−2. On wheat, significant reduction of fungal growth was not observed. Maximal reduction of DON (97.3%), ZEN (75.4%), and OTA (91.2%) on filter paper was obtained using 15,000 mJ cm−2. The overall reduction of DON (30%; 14%), ZEN (52%; 42%), and OTA (17%; 6%) on maize and wheat, respectively, was lower than on filter paper. Moisture and crude protein content as well as percent germination of maize kernels were not affected by UV-C treatment up to 5000 mJ cm−2. This study has shown that 3D UV-C treatment is a feasible option for reducing Fusarium and Penicillium growth on maize kernels and, at higher doses, decreasing ZEN by ~ 50%.

The comparative study determined the fate of vitamin C, chlorophyll, antioxidants, enzymes (polyphenol oxidase [PPO], peroxidase [POD]) and effect on color of wheatgrass juice processed by thermal, high hydrostatic pressure (HHP), or ultraviolet‐C light (254 nm; UV‐C) to inactivate Escherichia coli P36, Listeria innocua ATCC 51742, and Salmonella Typhimurium WG49. A thermal treatment at 75°C for 15 s, HHP at 500 MPa for 60 s, and UV‐C fluence of 69.2 mJ cm⁻² was required to achieve the target 5 log CFU reduction of the test bacteria. Thermal treatment resulted in a significant (p

Ultraviolet light (UV, UVC) disinfection is a well-established technology for air, water, and surfaces treatments. In the last decade, UV technology found more applications in food production chain because this is economic, effective, and versatile dry processing technology that can potentially improve safety and preservation quality of different categories of foods. Traditional way of generating UVC light is using high-voltage arc-discharge mercury or amalgam lamps that can generate photons solely at 253.7 nm. Light-emitting diodes or LEDs are semiconductor devices that can also emit UVC light, but depending on the material properties of the diodes, they can emit photons at multiple wavelengths in the UV range between 255 and 365 nm. The germicidal effects of UV LEDs against bacteria, viruses, and fungi already have been demonstrated and reported along with the first applications for disinfection of air, water, and surfaces made for the “point of use” integration. Despite the fact that there are no commercial applications in food production yet, the UV LEDs are the next wave in the LED revolution that can bring numerous advantages for food processing, safety, and plants facilities disinfection. This chapter will present the introduction in basics of LEDs technology and will discuss the unique advantages of this technology for food safety applications. Also, economical, energy saving, and sustainability aspects of UV LED applications are introduced.

Safety of food processing facilities and finished products can greatly benefit from application of UV light technologies to control microbial hazards through treatments of air, nonfood and food contact surfaces, ingredients, packaging, raw and finished products. Low-pressure lamps emitting light at 253.7 nm are currently approved as a main radiation sources for treatment of juices, surfaces, or vitamin D generation with the limitations in terms of ozone production. Currently, UV LED technology is quickly extending in the UVB and UVC germicidal range as alternative to traditional UV lamps. Despite the low efficiency of UVB and UVC LEDs (approximately at 4%), LEDs are on growing trend and UVA LEDs are already being incorporated into point-of-use units to serve the defense and outdoor industries and tested for water treatment. Food safety application is the next step of UV LED adaption by industry. This chapter will review the germicidal action of UVA, UVB, UVC, and blue light, existing research, and first reported application of UV LEDs against foodborne pathogens at multiple wavelengths. Understanding of bacterial action spectra is also discussed to provide basis for optimization of the most effective treatment using single or wavelengths combinations. Considerations for UV LED treatment of fresh produce with some reported effects on quality and nutritional attributes are included.

The basic of light-emitting diodes (LEDs) technology and manufacturing features will be presented in this chapter. The fundamental principles of light emission by semiconducting materials, design of LEDs chips and types of packages, requirements to LEDs system are discussed for better understanding of this new light technology. The differences and application areas in production and postharvest processing of fruit and vegetables of visible and UV LEDs are also included to better understand LEDs potential in food industry.

At present, there are a few techniques based on the unique properties of light to treat a variety of foods and food-related microflora that are explored for preservation operations and can result in improved quality, nutrition, and desired functionality. This includes continuous ultraviolet (UV)-C lamps and light-emitting diodes, pulsed UV (PUV) light, and pulsed light (PL). Each light-based technology is characterized by specific emission spectra, inactivation mechanisms, and unique advantages and disadvantages that lead to applications differences. This chapter will summarize the basics of generation and emission of PL and PUV, mechanisms of microbial inactivation, effects on quality and nutrition, and existing applications with emphasis on nutritional and other quality effects. Available light sources and commercial equipment, the pros and cons of the PL and PUV for preservation and improving quality and functionality of food and beverages are presented.

In this study, the evaluation of the performance of two thin-film UV-C reactors (annular and Taylor–Couette) and a coiled tube system is presented using actinometry and biodosimetry methods. The iodide/iodate actinometry method was found suitable for comparison of the efficiency of UV-C dose delivery of the UV-C continuous flow systems. Inactivation kinetics of Escherichia coli ATCC 8739 in quarter-strength Ringer’s solution (absorption coefficient α254 nm ∼ 0 cm−1) at various flow conditions at Reynolds numbers in the range of 26 to 3000 showed a good correlation between the different reactor types. In high UV-C absorbing liquids, the inactivation efficiency increases due to the improved radial mixing. The inactivation performance of the Taylor–Couette system correlates to the annular reactor when no rotation force is applied. The residence time distributions showed the narrowest distribution with the coiled tube system at comparable flow rates. The results indicate that, despite the laminar flow conditions, the performance of the Taylor–Couette unit becomes equal to the turbulent flow conditions of the coiled tube reactor by rotation of the inner cylinder.