title: Internalization of Salmonella typhimurium into mango pulp and prevention of fruit pulp contamination by chlorine and copper ions.
abstract: Outbreaks of Salmonella infections associated with fresh mango consumption have occurred in recent years. The study's objective was to assess the effectiveness of chlorine and copper ions to reduce Salmonella typhimurium from hydro-cooling water and prevent fruit pulp contamination of heat-treated mangos. Mature green Tommy Atkins' mangos were immersed in water at 46.1 degrees C for 100 min. Heat-treated mangos were then introduced, during 30 min, in 25 degrees C water containing 6 Log(10) CFU/ml of Salmonella with or without disinfectants (5 and 8 mg/l of either chlorine or copper ions). Chlorine at 5 and 8 mg/l reduced 6 Log(10) CFU/ml of Salmonella. Copper ions at 5 and 8 mg/l reduced 3.26 and 4.3 Log(10) CFU/ml, respectively. 2 Log(10) of Salmonella penetrated into mango pulp when disinfectants were not applied to 25 degrees C water. Both chlorine and copper ions were effective in preventing fruit pulp contamination by Salmonella typhimurium. Of residual chlorine, 2.37 and 3.54 mg/kg were detected in mango pulp after the treatment of 5 and 8 mg/l, respectively. Copper ions at 5 and 8 mg/l showed a residual content of 0.1 and 0.6 mg/kg on mango pulp, respectively. The chloride and copper residual levels in the pulp did not exceed the daily ingestion rates recommended by the National Academy of Sciences. Salmonella entered mango pulp by vascular elements and lenticels, both natural structures measuring an average diameter of 21 and 112 microm, respectively. The results illustrate the potential for pathogen penetration if heat-treated mangos are cooled in non-disinfected water. Also, appropriate chlorine or copper ion concentration prevents fruit pulp contamination.
authors.affiliation: Food and Environmental Microbiology Laboratory, CIAD Culiacán, Mexico.
authors.forename: Marcela
authors.initials: M
authors.lastname: Soto
authors.forename: Gladys
authors.initials: G
authors.lastname: Chavez
authors.forename: Manuel
authors.initials: M
authors.lastname: Baez
authors.forename: Celida
authors.initials: C
authors.lastname: Martinez
authors.forename: Cristobal
authors.initials: C
authors.lastname: Chaidez
mesh_terms: D002713:Chlorine / Q000008:administration & dosage / Q000494:pharmacology; D003300:Copper / Q000008:administration & dosage / Q000494:pharmacology; D004196:Disease Outbreaks / Q000517:prevention & control; D004202:Disinfectants / Q000008:administration & dosage / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology / Q000592:standards; D005638:Fruit; D006358:Hot Temperature; D031022:Mangifera / Q000382:microbiology*; D008452:Maximum Allowable Concentration; D012475:Salmonella / Q000187:drug effects* / Q000254:growth & development; D012478:Salmonella Food Poisoning / Q000517:prevention & control; D013997:Time Factors
chemical_list: D004202:Disinfectants; D002713:Chlorine; D003300:Copper