Author
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Hagenmaier, Robert - Bob |
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Baker, Robert |
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Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/16/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Industry groups and government regulators have in recent months expressed some concern about the microbiological safety of fresh-cut produce, most of which contain lettuce. A safe, effective and approved method of reducing bacteria counts of foods is by irradiation with gamma rays. However, irradiation has not been used with lettuce because previous studies showed that high-dose irradiation was detrimental to its texture and appearance. In the present study, the authors used low- dose irradiation of lettuce in addition to the processes currently used, and have shown that bacteria counts were substantially reduced with little effect on texture and appearance. Use of low dose irradiation may be especially important to individuals who, because of their health, are most vulnerable to food with high bacteria counts. Technical Abstract: Irradiation at 0.2 kGy combined with a chlorine wash resulted in fresh- cut lettuce that had, 8 days after irradiation, aerobic plate counts of 290 cfu/g and yeast count of 60 cfu/g, compared with values of 220,000 cfu/g and 1,400 cfu/g, respectively, for non-irradiated control. Some deterioration of texture was observed at 0.8 kGy, but not at 0.2 to 0.5 kGy. The present study demonstrates the feasibility of combining chlorination and irradiation to produce fresh-cut, chopped lettuce with bacteria counts of 0.1 to 1% that of non-irradiated control. Such a product would seem of value as food for individuals whose diet cannot tolerate foods with abundant microflora. |
