Human intestinal enteroids and predictive models validate the operational limits of sanitizers used for viral disinfection of vegetable process wash water.

Vegetables are globally associated with a considerable number of foodborne outbreaks caused by viral infections, specifically human norovirus. In fresh produce industry, washing represents a critical step for food safety as process wash water (PWW) needs to be maintained at appropriate microbial quality to prevent water-mediated cross-contamination. This study aimed to explore the disinfection efficacy of chlorine (free chlorine, FC), chlorine dioxide (ClO2) and peracetic acid (PAA) in PWW against infectious human norovirus and Tulane virus (TV). First, we tested the extent of TV inactivation in baby leaf, bell pepper, and vegetables mix PWW and monitored the viral decay by cell culture. Then, inactivation kinetics were defined for infectious human norovirus exposed to FC, ClO2 and PAA in baby leaves PWW using the human intestinal enteroids (HIE) system. Finally, kinetic inactivation models were fitted to TV reduction and decay of sanitizers to aid the implementation of disinfection strategies. Results showed that >8 log10 human norovirus and 3.9 log10 TV were inactivated by 20 ppm FC within 1 min; and by 3 ppm ClO2 in 1 min (TV) or 5 min (norovirus). PAA treatment at 80 ppm reduced ca. 2 log10 TV but not completely inactivated the virus even after 20 min exposure, while 5 min treatment prevented norovirus replication in HIE. TV inactivation in PWWs was described using an exponential decay model. Taking these data together, we demonstrated the value of applying the HIE model to validate current operational limits for the most commonly used sanitizers. The inactivation kinetics for human norovirus and TV, along with the predictive model described in this study expand the current knowledge to implement post-harvest produce safety procedures in industry settings.

Assessment and Prediction of Fish Freshness Using Mathematical Modelling: A Review.

Fish freshness can be considered as the combination of different nutritional and organoleptic attributes that rapidly deteriorate after fish capture, i.e., during processing (cutting, gutting, packaging), storage, transport, distribution, and retail. The rate at which this degradation occurs is affected by several stress variables such as temperature, water activity, or pH, among others. The food industry is aware that fish freshness is a key feature influencing consumers' willingness to pay for the product. Therefore, tools that allow rapid and reliable assessment and prediction of the attributes related to freshness are gaining relevance. The main objective of this work is to provide a comprehensive review of the mathematical models used to describe and predict the changes in the key quality indicators in fresh fish and shellfish during storage. The work also briefly describes such indicators, discusses the most relevant stress factors affecting the quality of fresh fish, and presents a bibliometric analysis of the results obtained from a systematic literature search on the subject.