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This study investigated the microbial control efficacy of five pre-drying treatments and three drying protocols commonly used by small and medium dried peach processors. Salmonella spp. and Enterococcus faecium (Ef) were used for inoculation. Except for blanching, 10-min dipping treatments in ascorbic acid, citric acid, lemon juice, or sodium metabisulfite reduced Salmonella by 0.54–2.40 Log CFU/peach half. The detection of Salmonella in used dipping solution highlighted the potential risks of cross-contamination during dipping treatments. Drying in an oven or a dehydrator at 60 °C reduced the inoculated Salmonella and Ef by 1.47 and 0.91 Log CFU/peach half. The internal temperature of peach halves reached during sun-drying is lower than the internal temperature reached during oven- or dehydrator-drying. Exposure to simulated sunlight (UV) could resulted in up to 6.75 Log reduction of Ef with higher reduction observed from peach halves with lower water activities. Salmonella and Ef could survive on dried peaches for up to 90 days with greater reduction observed on dried peaches made with sulfur dioxide treatment and at ambient temperature. Ef showed higher resistance than Salmonella in two pre-drying dipping treatments and survived better than Salmonella on dried peaches made without sulfur treatment at ambient temperature. • Pre-drying treatments, except blanching, reduced Salmonella by 0.54–2.40 Log CFU/peach half. • Pathogens could be transferred from inoculated peach surfaces to dipping solutions. • Oven- or dehydrator-drying at 60 °C could not achieve a 4–5 Log pathogen reduction. • Bacterial control efficacy of sun exposure correlated with product water activities. • E. faecium survived better than Salmonella on dried peaches during storage. [ABSTRACT FROM AUTHOR]

To fill the current knowledge gap in the survival of foodborne pathogens on dried fruits, this study monitored the survival of three common pathogens on dried apricots. Sun-dried apricots made with (DAS) and without sulfur dioxide (DANS) treatments were used and were inoculated using a dry (sand) or a wet (phosphate-buffered saline, PBS) carrier. The survival of Shiga-toxin-producing Escherichia coli (STEC), Salmonella spp. and Listeria monocytogenes (LM) on inoculated dried apricots was monitored for three months during ambient temperature storage. When dried apricots were inoculated with the wet carrier, all three pathogens survived the 48- hour drying period. After drying and during ambient temperature storage, the number of culturable pathogen cells decreased as the storage time increased. Among all three pathogens, STEC survived with higher culturable numbers for a longer period of time than the other two pathogens on DANS over the 90-day storage period. When pathogens were inoculated via the dry carrier, Salmonella survived with higher culturable numbers among three pathogens on DANS, indicating its enhanced survivability after being dried on sand and exposed to stress conditions before inoculation. In addition, regardless of the inoculation carriers, pathogens survived for longer periods of time or with higher levels on DANS, indicating the antimicrobial properties of free SO 2 contained in DAS. In summary, based on the results of this study, pathogens can survive on dried fruits; factors affecting pathogen survival include the types of test pathogens, inoculation methods, and the use of sulfur dioxide. • Salmonella , Listeria monocytogenes and STEC can survive on dried apricots. • The presence of free SO 2 inhibits the survival of foodborne pathogens. • The use of liquid carrier gives higher initial inoculation levels than dry carriers. • Salmonella shows enhanced survivability when inoculated with dry carriers. [ABSTRACT FROM AUTHOR]

Importance: Given the involvement of Vibrio parahaemolyticus ( Vp ) in a wide range of seafood outbreaks, a systematical characterization of Vp fitness and transcriptomic changes at temperatures of critical importance for seafood production and storage is needed. In this study, one of each virulent Vp strain ( tdh + and trh +) was tested. While no difference in survival behavior of the two virulent strains was observed at 10°C, the tdh + strain had a faster growth rate than the trh + strain at 30°C. Transcriptomic analysis showed that a significantly higher number of genes were upregulated at 30°C than at 10°C. The majority of differentially expressed genes of Vp at 30°C were annotated to functional categories supporting cellular growth. At 10°C, the downregulation of the biofilm formation and histidine metabolism indicates that the current practice of storing seafood at low temperatures not only protects seafood quality but also ensures seafood safety., Competing Interests: The authors declare no conflict of interest.