Survival and Inactivation by Advanced Oxidative Process of Foodborne Viruses in Model Low-Moisture Foods

Abstract

Enteric viruses, such as human norovirus (NoV) and hepatitis A virus (HAV), are the major causes of foodborne illnesses worldwide. These viruses have low infectious dose, and may remain infectious for weeks in the environment and food. Limited information is available regarding viral survival and transmission in low-moisture foods (LMF). LMFs are generally considered as ready-to-eat products, which undergo no or minimal pathogen reduction steps. However, numerous foodborne viral outbreaks associated with LMFs have been reported in recent years. The objective of this study was to examine the survival of foodborne viruses in LMFs during 4-week storage at ambient temperature and to evaluate the efficacy of advanced oxidative process (AOP) treatment in the inactivation of these viruses. For this purpose, select LMFs such as pistachios, chocolate, and cereal were inoculated with HAV and the norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV), then viral survival on these food matrices was measured over a four-week incubation at ambient temperature, by both plaque assay and droplet-digital RT-PCR (ddRT-PCR) using the modified ISO-15216 method as well as the magnetic bead assay for viral recovery. We observed an approximately 0.5 log reduction in viral genome copies, and 1 log reduction in viral infectivity for all three tested viruses following storage of select inoculated LMFs for 4 weeks. Therefore, the present study shows that the examined foodborne viruses can persist for a long time in LMFs. Next, we examined the inactivation efficacy of AOP treatment, which combines UV-C, ozone, and hydrogen peroxide vapor, and observed that while approximately 100% (4 log) inactivation can be achieved for FCV, and MNV in chocolate, the inactivation efficiency diminishes to approximately 90% (1 log) in pistachios and 70% (< 1 log) in cereal. AOP treatment could therefore be a good candidate for risk reduction of foodborne viruses from certain LMFs depending on the food matrix and surface of treatment.

New food safety challenges of viral contamination from a global perspective: Conventional, emerging, and novel methods of viral control

“…A ˂4 log 10 reduction was found for apples and blueberries having a smooth surface, while a 1.9 log 10 reduction was seen in cucumbers and no significant reduction at all in strawberries, both having a textured exterior. In other words, cracks, crevices, and openings on the outside of fruits and vegetables might reduce the virucidal effect of H 2 O 2 , because these are the places where viruses may find protection against H 2 O 2 (Nasheri et al., 2021). Eterpi et al.…”

“…H 2 O 2 is an oxidant that, by releasing hydroxyl radicals (•OH), affects basic cell constituents, such as lipids, nucleic acids, and proteins, and attacks the capsid and genome of viruses (Nasheri et al, 2021) and 5.30 log 10 for norovirus, type-1, and feline calicivirus F9 were observed on stainless steel. Genetically murine norovirus, type-1 is more related to human norovirus than feline calicivirus F9, as it belongs to the norovirus genus (Wobus et al, 2006).…”

“….9 log 10 reduction was seen in cucumbers and no significant reduction at all in strawberries, both having a textured exterior. In other words, cracks, crevices, and openings on the outside of fruits and vegetables might reduce the virucidal effect of H 2 O 2 , because these are the places where viruses may find protection against H 2 O 2(Nasheri et al, 2021) Eterpi et al (2009). investigated the antiviral effect of H 2 O 2 against various viruses dried on surfaces.…”

Inactivation of Foodborne Viruses by UV Light: A Review

“…Viruses are very stable in low-moisture foods. UV-C light applied in combination with ozone and hydrogen peroxide vapor can inactivate practically 100% (4 log) of FCV and MNV in chocolate, but only 1 log in pistachios and <1 log in cornflakes [ 163 ]. Table 3 lists the inactivation of different viruses on foods other than vegetables by conventional UV-C light ( Table 3 ).…”

Development of an RNA Extraction Protocol for Norovirus from Raw Oysters and Detection by qRT-PCR and Droplet-Digital RT-PCR

“…MNV stock were prepared as already described [23]. Briefly, murine BV-2 cells were inoculated with MNV-1 (kindly provided by Dr. Virgin, Washington University School of Medicine, St. Louis, MO, USA).…”