Disinfection of Salmonella spp. on Tomato Surface by Pulsed Ultraviolet Light and Selected Sanitizers

Abstract

The efficacy of three sanitizers (10 mL/L peracetic acid, 10 mL/L hydrogen peroxide and 20 mL/L commercial GRAS disinfectant) for inactivating Salmonella spp. inoculated onto the surface of whole tomatoes stored up to 8 days was investigated when they were used alone or in combination with pulsed ultraviolet light (PUV). Ten mL/L peracetic acid alone resulted in an average 3 log 10 reductions throughout the 8-day storage. Ten mL/L hydrogen peroxide and 20 mL/L commercial biodegradable GRAS sanitizer alone yielded 1.41 and 1.29 log 10 reductions, respectively, on day 0, but from day 2 to day 8 of storage, their disinfecting effect dwindled, with no significant difference detected from control (water rinse) on day 8 (p ≤ 0.05). The 60s PUV treatments alone achieved less than 2 log 10 reductions, but when it was combined with 10 mL/L hydrogen peroxide, the bacterial reduction significantly increased to over 4 log 10 during the 8-day storage (p ≤ 0.05). Similarly, PUV also enabled 20 mL/L commercial GRAS sanitizer to have unchanged bactericidal effect throughout the 8-day storage period. Results from this study showed that sanitizers combined with PUV radiation could generate a significant and lasting inactivation of Salmonella spp. on the surface of tomatoes.

Effect of Pulsed Ultraviolet Light on Natural Microbial Load and Antioxidant Properties of Fresh Blueberries

“…This may indicate that shorter periods of PUV exposure are more effective than UV-C. The PUV light reduced Salmonella population as 1.35 log CFU/g on tomato surface after 60 s PUV exposure at 6.35 cm from the strobe (Williams et al, 2012). The population of TAPC after PUV treatment in our study supports that 60 s of exposure may not be enough to cause significant log reductions if microbial concentration on fruit surface is in high level.…”

“…The reducing effect of PUV light on microbial load and pathogens on various fruit and vegetables were reported, previously (Bialka and Demirci, 2007;Bialka et al, 2008;Manzocco et al, 2011;Hsu and Moraru, 2011;Oms-Oliu et al, 2010;Williams et al, 2012). Pulsed UV treatment was more effective after 90 s exposure time on Total Aerobic Plate Count (TAPC) of fresh blueberries.…”

“…They dramatically influence the shelf-life and consumer acceptance of fresh products. Fresh fruits and vegetables should be prepared with proper processing and sanitation procedures to have ready-to-eat status based on food regulations (Williams et al, 2012).…”

Effect of relative humidity on inactivation of foodborne pathogens using chlorine dioxide gas and its residues on tomatoes

“…), aqueous chlorine dioxide (ClO 2 ) (São José and Vanetti ), hydrogen peroxide (São José and Vanetti ) and peracetic acid (Williams et al . ). However, washing of postharvest produce with sanitizers is insufficient for reducing foodborne pathogens without incurring sensory loss (Beuchat ).…”