Using antimicrobials as a food safety measure during phytosanitary treatments in mangoes

Prevention of plant-borne pest infestation necessitates use of phytosanitary procedures, as in the case of U.S.-imported mangoes. Supplementation of hydrothermal disinfestation and/or post-process cooling waters with chemical sanitizers could provide mango packers with antimicrobial interventions reduce or prevent microbial pathogen transmission on mangoes. The current study determined: i) the effectiveness of chlorine (CL) or lactic acid (LA) addition to water used for hydrothermal and cooling treatments to reduce Salmonella survival on mangoes during disinfestation treatment, and; ii) Salmonella internalization into stem scars following hydrothermal and cooling treatments in sanitizer-supplemented water. Salmonella survival during post-treatment storage and effects of treatments on mango color and firmness were also determined. A 2.0 log-cycle reduction was obtained on stem scars subjected to hydrothermal treatment; reductions of 2.2 and 1.3 log-cycles were obtained on stem scars with LA and OCl− treatment, respectively. An additional 1.0 log-cycle reduction during cooling was observed for OCl−-treated mangos; Salmonella were not detected (<2.0 log CFU/10 cm2) on LA-treated mangos. On hydrothermal-treated rinds, a 0.5 log cycle reduction was obtained for control fruit; a reduction of 1.7 log cycles was obtained for both LA- and OCl−-treated fruit. Internalized Salmonella were detected in stem scar tissues obtained following hydrothermal treatment and cooling by enrichment, and survived storage at 10 °C for 12 days. In general, there were no differences in the reduction of Salmonella between CL and LA, although in two occasions CL was less effective. However, mango color was compromised by use of LA. Chlorine use both in hot and cool dips is recommended for minimizing Salmonella transmission on mango surfaces.