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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Characterization and Interventions for Foodborne Pathogens » Research » Publications at this Location » Publication #401189

Research Project: Validation and Commercialization of Innovative Processing Technologies

Location: Characterization and Interventions for Foodborne Pathogens

Title: Pulsed Light Can Inactivate Salmonella in Packaged Tomatoes and Reduce Microbial Loads without Affecting Quality

item Mukhopadhyay, Sudarsan
item Ukuku, Dike
item Jin, Zhonglin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Microbial safety of produce like tomatoes and leafy greens continues to be a major concern. Since post-processing contamination is one of the major contributing factors to foodborne illness, it is important that treatments are applied after packaging. However, once packaged, treatment options are very limited. Pulsed light (PL) is uniquely suited in this situation since it is a non-aqueous, touch free decontamination option that is capable of penetrating food packaging enclosures. The purpose of this study was to investigate the efficacy of high intensity short time PL application on inactivation of Salmonella in packaged cherry tomato. Tomatoes were spot inoculated on stem scars. A bacterial cocktail containing three outbreak strains of Salmonella was used as inoculum. Tomatoes were packaged in Polyethylene (PE) films of 25.4, 50.8 and 76.2 micrometer thickness. Both packaged and unpackaged inoculated tomatoes were treated with PL for up to 60 s. Treated and untreated tomatoes were stored at 10 degrees centigrade for 14 days. Samples were analyzed for surviving populations of Salmonella, native microbiota and quality. Experiments were conducted independently in triplicate. Data analyzed using ANOVA and Duncan's LSD method. A 10 s (10.5 Joule per square cm) PL treatment was considered optimum. Direct treatment for 10 s provided 1.9 ± 0.17 log CFU/g reduction of Salmonella. For packaged tomatoes, log reductions decreased with increasing film thickness but not significantly (P > 0.05). Also, no significant difference in decontamination efficacy between packaged and unpackaged tomatoes was observed. Treatment significantly reduced native microbiota by >1 log. Fruit firmness and visual appearance were not significantly affected by the treatment. These data suggest that 10 s high intensity PL treatment may be used to enhance microbial safety and reduce post processing contamination of packaged cherry tomato.