title: Application of water-assisted ultraviolet light processing on the inactivation of murine norovirus on blueberries.
abstract: In this study, a novel set-up using water-assisted UV processing was developed and evaluated for its decontamination efficacy against murine norovirus (MNV-1) inoculated on fresh blueberries for both small and large-scale experimental setups. Blueberries were skin-inoculated with MNV-1 and treated for 1-5 min with UV directly (dry UV) or immersed in agitated water during UV treatment (water-assisted UV). The effect of the presence of 2% (v/v) blueberry juice or 5% crushed blueberries (w/w) in wash water was also evaluated. Results showed that water-assisted UV treatment generally showed higher efficacies than dry UV treatment. With 12,000 J/m(2) UV treatment in small-scale setup, MNV reductions of >4.32- and 2.48-log were achieved by water-assisted UV and dry UV treatments, respectively. Water-assisted UV showed similar inactivating efficacy as 10-ppm chlorine wash. No virus was detected in wash water after UV treatment or chlorine wash. MNV-1 was more easily killed on skin-inoculated blueberries compared with calyx-inoculated berries. When clear water was used as wash water in the large-scale setup, water-assisted UV treatment (UV dose of 12,000 J/m(2)) resulted in >3.20 log and 1.81 log MNV-1 reductions for skin- and calyx-inoculated berries, respectively. The presence of 2% blueberry juice in wash water decreased the decontamination efficacy of water-assisted UV and chlorine washing treatments. To improve the inactivation efficacy, the effect of combining water-assisted UV treatment with chlorine washing was also evaluated. The combined treatment had better or similar inactivation efficacy compared to water-assisted UV treatment and chlorine washing alone. Findings of this study suggest that water-assisted UV treatment could be used as an alternative to chlorine washing for blueberries and potentially for other fresh produce.
authors.affiliation: Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.
authors.forename: Chuhan
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA. Electronic address: haiqiang@udel.edu.
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Chen
mesh_terms: D029798:Blueberry Plants / Q000821:virology; D004203:Disinfection / Q000379:methods*; D005511:Food Handling / Q000379:methods*; D005638:Fruit / Q000821:virology*; D029322:Norovirus / Q000302:isolation & purification / Q000528:radiation effects*; D014466:Ultraviolet Rays; D038301:Virus Inactivation; D014867:Water / Q000494:pharmacology
chemical_list: D014867:Water
keywords: Blueberry; Murine norovirus; UV light