Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2016
Publication Date: 8/1/2016
Citation: Ukuku, D.O., Mukhopadhyay, S., Geveke, D.J., Olanya, O.M., Niemira, B.A. 2016. Minimal thermal treatments for reducing bacterial population on cantaloupe rind surfaces. Meeting Abstract. Volume 1, Page 1.IAFP Annual Meeting.St. Louis, Missouril July 31-August 3, 2016.
Technical Abstract: Cantaloupe melon has been associated with outbreaks of foodborne illness due to consumption of contaminated fresh-cut pieces. Surface structure and biochemical characteristics of bacteria play a major role on how and where bacteria may attach and also complicates decontamination treatments and this has led to higher incidence of foodborne illness. In this study, we evaluated the effect of minimal thermal treatment using 3% hydrogen peroxide (H2O2) and water H2O at 80 degrees C to reduce microbial populations on cantaloupe rind surface and fresh-cut pieces. Whole cantaloupes rind surfaces were inoculated with Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes at 4.5, 5.1 and 3.6 log CFU/cm2, respectively and were stored at 5 and 22 degrees C for 7 days before washing and minimal thermal treatment using 3% hydrogen peroxide (H2O2) and water H2O. All treatments were for 300 s and the rind surfaces were examined with scanning electron microscopy and bacterial inactivation on a range of agar media. Efficacy of washing treatment in reducing attached bacteria and minimizing transfer to fresh-cut pieces were investigated at day 0, 3 and 7 of storage. Initial attachment was highest for E. coli O157:H7 and lowest for L. monocytogenes, but Salmonella exhibited the strongest attachment at all days tested. Washing with 3% H2O2 alone led to significant (p<0.05) reduction of bacteria and caused some changes in bacterial cell morphology. Bacterial inactivation on cantaloupe rind appeared to be dependent on duration of contact time. No bacterial pathogen was determined in fresh-cut pieces prepared from minimally heated 3% H2O2 and H2O treatments including enriched fresh-cut samples. Microbial safety for all fresh-cut pieces from treated cantaloupes was established at day 6 of storage at 5 degrees C and day 3 at 10 degrees C. Minimal thermal H2O and 3% H2O2 treatment at 80 degrees C of cantaloupes surfaces designated for fresh-cut preparation will enhance the microbial safety of fresh-cut pieces, and will drastically reduce the incidence of foodborne illness, and costly recalls of contaminated produce.