ARS | Publication request: ENSURING THE MICROBIAL SAFETY OF MINIMALLY PROCESSED FRESH-CUT FRUITS

Submitted to: Meeting Abstract
Publication Type: Proceedings/Symposium
Publication Acceptance Date: October 18, 2004
Publication Date: December 11, 2004
Citation: Ukuku, D.O., Fett, W.F., Liao, C., Sapers, G.M. 2004. Ensuring the microbial safety of minimally processed fresh-cut fruits. In: Proceedings of the United States-Japan Cooperative program in Natural Resources (UJNR) Food and Agriculture Panel, 33rd Annual meeting, December 11-18, 2004. Hawaii. p. 321-327.

Technical Abstract: Strong adherence of bacteria to the cantaloupe surface is favored by irregularities such as roughness, crevices, and pits, thus reducing the ability of washing or sanitizer treatments to remove or inactivate attached cells. The objectives of this study were to compare the efficacy of washing cantaloupes, previously inoculated with Salmonella at 4.68 log10 CFU/cm2, with water or 200 ppm chlorine for 2 min with agitation. Washing with water was ineffective in reducing the populations of attached Salmonella on cantaloupe surfaces. The efficacy of the chlorine treatment in eliminating Salmonella from the cantaloupe surface varied depending on the interval between inoculation and treatment. A 3 log reduction was achieved when treatment was applied at day 0, but at days 3 and 7 of storage at 5 or 25°C, population reductions were approximately 2 logs. From day 3 to 7, the strength of attachment for Salmonella on cantaloupe surfaces increased from 0.833 to 0.866 at 5°C and from 0.927 to 0.987 at 25°C. Salmonella was not detected in fresh-cut pieces prepared from sanitized melons at day 0, but was detected in fresh-cut pieces prepared at day 7 immediately after sanitizer treatment. The population of Salmonella transferred to fresh-cut pieces remained the same during storage at 5°C for 10 days, but increased to approximately 3 log in fresh-cut pieces stored at room temperature (25°C). In a separate study, apple disks previously inoculated with Salmonella at 7.0 log10 CFU/disk were sanitized with solutions of acetic acid (2.4%), H2O2 (3%) or trisodium phosphate (3%), individually or in combination, to decontaminate the surface. Only the combination of acetic acid and hydrogen peroxide was effective in reducing the Salmonella population on the inoculated apple disks.