UV‐C treatment on the safety of skim milk: Effect on microbial inactivation and cytotoxicity evaluation

Abstract

The efficacy of UV‐C irradiation as a nonthermal processing method for skim milk (SM) was investigated. SM inoculated with two surrogate viruses (MS2 and T1UV), and three bacteria (Escherichia coli ATCC 25922, Salmonella enterica serovar Typhimurium ATCC 13311, and Listeria monocytogenes ATCC 19115) was treated with Deanflow UV‐C irradiation, a spiral reactor with the fluid pumped around a central low‐pressure mercury UV lamp (40 W) emitting at 254 nm wave‐length. A series of known UV doses (0–168.33 mJ·cm2) were delivered to the samples. The microbial loads of MS2, T1UV, E. coli, Salmonella, and Listeria were reduced by more than 5 log10. The inactivation kinetics of all microorganisms were best described by log linear models with a low RMSE and higher coefficient of determination (R2 > 0.95). This study demonstrated that high levels of inactivation of pathogenic particles can be achieved in SM. Practical applications This scientific study provides evidence based data on the advantages of UV‐C light in achieving microbial reduction in skim milk. The irradiated skim milk did not show any toxicity on mice liver and intestinal cells. UV‐C irradiation is an efficient food preservation technology and offers opportunities for dairy and food processing industries to meet the growing demand from consumers for safer foods. This exploration would provide methodological evidence for commercialization of UV‐C processing of milk and dairy based beverages.

Evaluation of UV-A LED technology on the reduction of spiked aflatoxin B1and aflatoxin M1in whole milk: toxicity analysis using liver hepatocellular cells

“…However, we are yet to evaluate the characteristics of the degradation compounds from the UV-treated samples from our experimental conditions. Our results are in accordance with some of other UV-related studies with no toxic effect on the irradiated i.e., coconut water (Bhullar et al, 2018), skim milk (Ward et al, 2019), and apple juice (Chandra et al, 2017). The HepG2 cytotoxicity study on UV irradiated ultrapure water also demonstrated no significant loss of the active cells (Stanley et al, 2020).…”

“…The device was initially calibrated to 100 percent and 0 percent baseline. Optical properties were measured as per the method described by (Ward et al, 2019). Ultraviolet transmittance (UV- A T %/cm), which is a calculation of the fraction of incident light transmitted along the 1 cm path-length of the sample, was measured using eq.…”

Inactivation of Foodborne Viruses by UV Light: A Review

“…The inactivation of viruses in liquid foods has been studied using coconut water [ 150 , 151 ] and skim milk [ 152 , 153 ] challenged with phages MS2 and T1UV in two types of experimental set-up: collimated beam in a stirred batch reactor and a Dean vortex continuous reactor. Reductions in viral titer reached 4 log cycles for MS2 and more than 5 log for T1UV in coconut water [ 150 , 151 ] and at least 5 log for both MS2 and T1UV in skim milk [ 152 , 153 ]. It is widely known that the efficacy of UV treatments of liquid foods decreases with turbidity and suspended solids, which absorb or scatter the light before reaching the viral particles.…”

“…The formation of potentially toxic compounds due to the action of UV light on food components was also examined. No cytotoxicity was observed when skim milk was treated with up to 0.17 J/cm 2 [ 153 ] or coconut water with up to 0.4 J/cm 2 [ 151 ], fluences that were high enough to reduce viral titers substantially.…”

Predictive modeling of virus inactivation by UV

“…A variety of approaches have therefore been developed to decontaminate food, water, air, and surfaces that may contain infective viruses (2)(3)(4)(5)(6)(7). UV254 treatment, in particular, is gaining popularity as an alternative to more traditional chemical disinfection strategies (8)(9)(10). Viruses can have highly variable UV254 susceptibilities (11,12).…”