|RODREGUEZ, ARMARYNETTE - University Of Puerto Rico|
|ORELLANA, LYNETTE - University Of Puerto Rico|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/29/2019
Publication Date: 9/1/2019
Citation: Olanya, O.M., Rodreguez, A., Niemira, B.A., Ukuku, D.O., Orellana, L., Cassidy, J.M. 2019. Inactivation of Salmonella enterica and Listeria monocytogenes on post-harvest tomatoes and carrots by radiation, sanitizer and biocontrol treatments. Meeting Abstract. (Abstract) South African Assn of Food Science & Technology(SAAFoST) Congress, Sept 1-4, 2019; IN SAAFoST 23rrd Biennial International Congress & Exhibition, 41 pg.
Technical Abstract: Control of foodborne pathogens on post-harvest produce may be improved by combining physical, chemical and biological treatments. The effects of gamma radiation (0.5 kGy), sanitizer (lovit), and competitive biocontrol microbes (Pseudomonas fluorescens) on the survival of Salmonella enterica and Listeria monocytogenes were evaluated on tomatoes and baby carrots. Produce storage temperatures (5 and 20C) and times (0-7days) and treatment combinations on pathogen reductions were also investigated. Significant differences (P<0.05) in Salmonella and Listeria populations and subsequent pathogen reductions were recorded when sanitizer, radiation and biocontrol treatments were applied on produce, relative to untreated control. Pathogen recovery varied with the treatments applied. At 5C, reductions of Salmonella (all treatments) on carrots and tomatoes ranged from 1.0-5.1 and 3.1-5.0 log CFU/g of produce, respectively. At 20C, inactivation of Salmonella populations on carrots and tomatoes were 1.3-4.7 and 2.2-6.5 log CFU/g of produce, respectively. The greatest reductions of Salmonella were recorded on sanitizer treatment (4.48±0.74 to 6.54±0.05 log CFU/g) and sanitizer plus radiation (3.67±0.21 to 5.44±0.39), relative to the control. The biocontrol treatment (0.91±0.16 to 2.34±0.31) had the least Salmonella reduction on produce. Similarly, L. monocytogenes populations was significantly (P<0.05) impacted by treatment combinations, as >4-5 log reductions were recorded. Treatments efficacies attributed to cell membrane damage and competitive exclusion in decreasing order of pathogen reductions were sanitizer > radiation > biocontrol. These results imply that inactivation of foodborne pathogens may be improved by treatment combinations as synergistic effects may enhance post-harvest pathogen control.