Naslov
Changes in surface properties of cantaloupe and populations of Escherichia coli ATCC 25922 after exposure to chlorine or hydrogen peroxide

Autori
Okuku, Dike O. ; Piližota, Vlasta ; Sapers, Gerald M. ; Cooke, Peter H. ; Soroka, Douglas S.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
2000 IFT Annual Meeting Technical Program Book of abstracts / - Chicago (IL) : Institute of Food Technologists, 2000

Skup
2000 IFT Annual Meeting

Mjesto i datum
Dallas (TX), Sjedinjene Američke Države, 11.06.2000. - 14.06.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
cantaloupe; sanitation; Escherichia coli; hydrogen peroxide; chlorine

Sažetak
There are several reports of outbreaks of food-borne disease through consumption of fruits contaminated at the surface with enteric pathogens. Microbial safety of fresh cut cantaloupes available in salad-bar operations is of concern. Surface charateristics of cantaloupe may affect bacterial attachment and the efficacy of washing treatments. Our objectives were to investigate changes in surface properties of sanitized cantaloupe and of Escherichia Coli ATCC 25922 attached to the external surface of inoculated cantaloupe. The external surface of cantaloupe before and after exposure to 1000 ppm chlorine or 5 % hydrogen peroxide solution were examined by scanning electron microscopy (SEM). SEM and direct plating onto agar media were used to observed microbial attachment and viability, respectively. Surface properties of Escherichia Coli ATCC 25922 were characterized using hydrophobic interaction chromatography (HIC) as revealed through bioluminescence ATP assay. Observation of the outer surface of cantaloupes showed a meshwork of raised uneven tissue (netting) separated by smooth polygonal areas of subsided epidermis (cuticle). Hydrogen peroxide and, to a lesser extent, chlorine treatment reduced the number of micrometer-sized debris and bacteria associated with the net and depressions in the cuticle. Most of the attached organisms were observed at the cuticle with lesser numbers found at the netting. Chlorine was more effective in reducing attached E. coli (£24 h after inoculation) at the netting or at the cuticle, compared to hydrogen peroxide treatment, SEM observation revealed morphological changes in organisms attached at the cuticle after exposure to hydrogen peroxide. Surface properties of E. coli were categorized as hydrophilic. These results suggest preferential attachment of bacteria to the cuticle layer at the cantaloupe surface, and bacteria attached at these areas appeared to be more resistant to detachment by washing treatments.

Izvorni jezik
Engleski

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