Submitted to: United States-Japan Cooperative Program in Natural Resources
Publication Type: Proceedings
Publication Acceptance Date: September 25, 2003
Publication Date: November 9, 2003
Citation: Ukuku, D.O., Sapers, G.M., Fett, W.F. 2003. Effect of nisin-edta, chlorine and hydrogen peroxide treatments in reducing transfer of naturally occurring microflora of whole melon to fresh-cut pieces. In: Proceedings of the United States-Japan Cooperative program in Natural Resources (UJNR) Food and Agriculture Panel, 32nd Annual meeting, November 9-15, 2003. Tsukuba, Ibaraki, Japan. p. 31-37. Technical Abstract: Efficacy of nisin-EDTA treatment as a sanitizer for reducing populations and transfer of native microflora of whole melons to fresh-cut melons was compared to that of chlorine (200 ppm) and hydrogen peroxide (2.5%) treatments. Whole cantaloupe and honeydew melons were washed with water, nisin (10 mg/ml)-EDTA (0.02 M), 200 ppm chlorine or hydrogen peroxide (2.5%) for 5 min at ~ 22C before fresh-cut preparation. Preliminary studies indicated that water washes, EDTA (0.002 to 0.2 M) or nisin (10 mg/ml) were not effective in reducing the populations of native microflora of whole melon when used individually. The predominant class of organisms on cantaloupe and honeydew melon were aerobic mesophilic bacteria followed by lactic acid bacteria, total gram-negative bacteria, yeast and mold and Pseudomonas spp. Nisin-EDTA, chlorine and hydrogen peroxide treatments were significantly (p<0.05) more effective in reducing native microflora than water washes. Nisin-EDTA treatments were significantly (p<0.05) more effective than chlorine or hydrogen peroxide in reducing populations of yeast and mold and Pseudomonas spp. on whole melon surfaces, but were not as effective as chlorine or hydrogen peroxide treatments for reducing aerobic mesophilic bacteria, lactic acid bacteria and total gram-negative bacteria. Although the total microbial population on the surfaces of cantaloupe and honeydew melons was significantly reduced by the nisin-EDTA treatment, the results suggest that treatment with nisin-EDTA before fresh-cut processing is not as effective as hydrogen peroxide and chlorine in reducing transfer of native microflora of whole melon to fresh-cut pieces.