title: Effect of X-ray treatments on Escherichia coli O157:H7, Listeria monocytogenes, Shigella flexneri, Salmonella enterica and inherent microbiota on whole mangoes.
abstract: The aims of this investigation were to; (i) study the effect of X-ray treatments in reducing Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica and Shigella flexneri on whole mangoes, and (ii) study the effect of X-ray treatments on microflora counts (mesophilic counts, psychrotrophic counts and yeast and mould counts) of whole mangoes during storage at ambient temperature (22°C) for 30 days. A mixture of three strains of each test organism was spot inoculated (100 μl; approx. 8-9 log CFU ml(-1) ), separately, onto the surface (5 cm(2) ) of whole mangoes, air-dried (30 min), and then treated with different doses of X-ray (0, 0·1, 0·5, 1·0, and 1·5 kGy). Approximately 2·9, 1·8, 2·1 and 5·2 log CFU cm(-2) reduction of E. coli O157:H7, L. monocytogenes, Sh. flexneri and Salm. enterica were achieved by treatment with 0·5 kGy X-ray respectively. Furthermore, the populations of E. coli O157:H7, L. monocytogenes, Sh. flexneri and Salm. enterica were reduced to less than the detectable limit (2·0 log CFU cm(-2) ) by treatment with 1·5 kGy X-ray. Treatment with 1·5 kGy X-ray significantly reduced the initial inherent microflora on skin of whole mangoes and inherent levels were significantly (P < 0·05) lower than the control sample throughout storage at 22°C for 30 days.
  
  
  CONCLUSIONS
  Fresh produce was associated with 770 outbreaks between 1990 and 2005, resulting in 35 060 cases of illness that costs the US $39 billion annually. The food industry is looking for new preservation methods. This investigation indicated that X-ray treatment was very effective against Escherichia coli O157:H7, Listeria monocytogenes, Shigella flexneri and Salmonella enterica and inherent microflora on whole mangoes which could offer an applicable approach to control pathogens and spoilage bacteria for the mango industry.
authors.affiliation: Coastal Research & Extension Center, Mississippi State University, Pascagoula, MS, USA.|Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, MS, USA.
authors.forename: B S M
authors.initials: BS
authors.lastname: Mahmoud
authors.affiliation: Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, MS, USA.
authors.forename: R
authors.initials: R
authors.lastname: Nannapaneni
authors.affiliation: Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, MS, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chang
authors.affiliation: Coastal Research & Extension Center, Mississippi State University, Pascagoula, MS, USA.
authors.forename: R
authors.initials: R
authors.lastname: Coker
mesh_terms: D019453:Escherichia coli O157 / Q000528:radiation effects*; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000528:radiation effects*; D031022:Mangifera / Q000382:microbiology*; D064307:Microbiota / Q000528:radiation effects; D012478:Salmonella Food Poisoning / Q000517:prevention & control*; D019779:Salmonella enterica / Q000528:radiation effects*; D012763:Shigella flexneri / Q000528:radiation effects*; D014965:X-Rays
keywords: Escherichia coli O157:H7; Listeria monocytogenes; Salmonella enterica; Shigella flexneri; mango; spoilage bacteria