Submitted to: Journal of Food Protection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/28/2003
Publication Date: 3/1/2004
Citation: Ukuku, D.O., Pilizota, V., Sapers, G.M. 2004. Effect of hot water and hydrogen peroxide treatments on survival of salmonella and microbial quality of whole and fresh-cut cantaloupe. Journal of Food Protection. 67:432-437. Interpretive Summary: While there are numerous reports in the literature on use of chlorine as a sanitizer treatment for fresh produce, information on the use of hydrogen peroxide and other potential alternative sanitizers are limited. Whole cantaloupes were immersed in an inoculum containing Listeria monocytogenes and Salmonella (8 log CFU/ml) for 10 min and then stored at 4 or 20 C for up to 5 days. Inoculated melons were dipped in hot water, boiling water or heated hydrogen peroxide (70EC) for 60 s at 0, 3 and 5 days after inoculation. All heat treatments reduced Listeria numbers to below detection levels. Salmonella was reduced to less than 1.5 log on the surface of whole cantaloupe and found to be below detection in fresh-cut pieces. The results of the study indicated that the test conditions were capable of decontaminating whole melons contaminated with Listeria. However, treatments were not as effective against Salmonella. All treatments substantially reduced the transfer of pathogens from the interior tissue during slicing to make reliable pieces.
Technical Abstract: Cantaloupe melon has been associated with Salmonella outbreaks. Contamination may have been introduced into the flesh from the rind by cutting or contact of cut pieces with contaminated rinds. Our objectives were to investigate the efficacy of hot water or 5% hydrogen peroxide (70C) treatment of rind in reducing transfer of Salmonellae and Listeria monocytogenes to the fresh cut tissue. Whole cantaloupes were immersed in 8 log 10 CFU/mL inocula containing a mixed cocktail of three Salmonellae (Stanley H0558, Poona RM2350, Saphra 97A3312) or a cocktail of three L. monocytogenes strains (Scott A, CCR1-L-G, and ATCC 15313) for 10 min. The inoculated melons were stored at 4 or 20C for up to 5 d and at 0, 1, 3, or 5 d were immersed in hot water (70C or 100C ) or 5% hydrogen peroxide (70C) for 60 s. Hydrogen peroxide treatment (70C) caused a 4.0 log reduction of L. monocytogenes or 4.5 log reduction of Salmonella from an initial population of 4.1 or 4.64 log10 CFU/cm2, respectively. Fresh-cut pieces prepared from the control melons were L. monocytogenes or Salmonella positive while those from the melons exposed to boiling water or hydrogen peroxide (~70C) were negative throughout storage. Fresh-cut pieces prepared from melons exposed to hot water (70C) 1 to 5 d after inoculation were negative for L. monocytogenes and positive for Salmonellae. The results of this study suggest that boiling water or heated hydrogen peroxide treatment for 1 min can decontaminate melon surface before fresh-cut preparation.