Influence of washing treatment on native microflora and Escherichia coli population of inoculated cantaloupes

The influence of chlorine or hydrogen peroxide treatment on populations of Escherichia coil 25922 on the external surface of inoculated cantaloupe was investigated. Surface treatment with 70% EtOH, followed by immersion in 10 (8) CFU/mL E. coli inoculum deposited an average of 4.4 log(10)CFU/cm(2) ce ll population on the cantaloupe surface. The efficacy of washing inoculated cantaloupe was dependent on storage interval between inoculation and treat ment Dipping the cantaloupes in solutions containing 1000 mg/L chlorine or 5% peroxide for 5 min, within 24 h of inoculation, caused a 2 log(10) CFU/c m(2) reduction of the indigenous surface microflora and a 3-4.0 log(10) CFU /cm(2) reduction in E. coli. The efficacy was less when the interval betwee n inoculation and treatment exceeded 24 h. Chlorine appeared to be a better antimicrobial agent than hydrogen peroxide against E, coli ATCC 25922 inoc ulated on cantaloupe surfaces while hydrogen peroxide was better in reducin g surface microflora of cantaloupe.