UV-C LED Irradiation Reduces Salmonella on Chicken and Food Contact Surfaces

Abstract

Ultraviolet (UV-C) light-emitting diode (LED) light at a wavelength of 250–280 nm was used to disinfect skinless chicken breast (CB), stainless steel (SS) and high-density polyethylene (HD) inoculated with Salmonella enterica. Irradiances of 2 mW/cm2 (50%) or 4 mW/cm2 (100%) were used to treat samples at different exposure times. Chicken samples had the lowest Salmonella reduction with 1.02 and 1.78 Log CFU/cm2 (p ≤ 0.05) after 60 and 900 s, respectively at 50% irradiance. Higher reductions on CB were obtained with 100% illumination after 900 s (>3.0 Log CFU/cm2). Salmonella on SS was reduced by 1.97 and 3.48 Log CFU/cm2 after 60 s of treatment with 50% and 100% irradiance, respectively. HD showed a lower decrease of Salmonella, but still statistically significant (p ≤ 0.05), with 1.25 and 1.77 Log CFU/cm2 destruction for 50 and 100% irradiance after 60 s, respectively. Longer exposure times of HD to UV-C yielded up to 99.999% (5.0 Log CFU/cm2) reduction of Salmonella with both irradiance levels. While UV-C LED treatment was found effective to control Salmonella on chicken and food contact surfaces, we propose three mechanisms contributing to reduced efficacy of disinfection: bacterial aggregation, harboring in food and work surface pores and light absorption by fluids associated with CB.

Progress on Nutrient Composition, Meat Standardization, Grading, Processing, and Safety for Different Types of Meat Sources

“…This strategy could be useful to ensure beef safety and to help extend the shelf life of vacuum-packaged beef to safely reach distant markets. These two studies [ 11 , 12 ] further support the use of UV as a “no-touch” technology in the food industry to effectively sanitize high-touch surfaces where there may be a higher risk of meat contamination from pathogens. UV disinfecting technologies have been used for a number of years and they could be more effective with improved features in the future, given their constant innovation.…”

“…Six articles are presented on food safety. One article evaluates four antimicrobials on refrigerated pork loins [ 9 ], another assesses the antimicrobial application mode (immersion vs. spray) to reduce Campylobacter jejuni in chicken wings [ 10 ], four deal with physical and/or chemical interventions, such as the use of UV-C solely or in conjunction with antimicrobials [ 11 , 12 ], refrigeration technologies (dry chilling vs. spray chilling) combined with hot water washing by bio-mapping of indicator organisms on beef striploins during storage [ 13 ], and in-plant validation of a novel aqueous ozone generation technology compared to lactic acid solutions for suppressing the growth of natural microbiota, i.e., E. coli O157:H7 and Salmonella surrogates, on beef carcasses and trimmings [ 14 ].…”

“…Calle et al [ 11 ] evaluated the use of UV-C LED light for the destruction of Salmonella present on chicken breast and food contact surfaces. The antimicrobial properties of UV light have been explored elsewhere, mainly for applications in liquids, contact surfaces, and packaging materials, where its effectiveness has been demonstrated.…”

“…The growing interest in ultraviolet (UV) light was driven by its FDA approval in 1997 for surface decontamination of foods. According to the literature [ 11 , 12 ], several facts of UV irradiation use in food safety are reported: (a) pathogens absorb UV light, and thymine-dimers molecular lesions in the DNA are formed via photochemical reactions, ultimately leading to cell death, (b) UV light is currently used to control pathogens in water and for the decontamination of food contact surfaces and food packaging materials, (c) UV light-emitting diodes (LED) are increasingly being used as substitutes for mercury lamps, conventional sources of UV-light, for their smaller size and lesser generation of heat, (d) the emission spectrum of UV-LED can be tuned to emit UV light of specific wavelengths between 250 and 280 nm, which are the most effective at driving the photochemical reactions leading to the formation of thymine dimers, (e) UV-LED devices are more robust, durable, and safe compared to mercury lamps because they do not contain glass tubes that may break and contaminate workstations with mercury, (f) UV-C band irradiation stands out for its low cost, with no potentially hazardous chemical residues, and low carbon footprint [ 12 ].…”

“…In the USA, Calle et al [ 11 ] have shown that UV-LED could be used to disinfect skinless chicken breast (CB) as well as food contact surfaces such as stainless steel (SS) and high-density polyethylene (HD) inoculated with Salmonella enterica . The greatest reductions were obtained after 180 s of exposure on HD (5.2 Log CFU/cm 2 ), followed by 60 s on SS (3.5 Log CFU/cm 2 ), and 900 s on CB (3.0 Log CFU/cm 2 ).…”