Science Fair Project on Bacterial Growth on Packaged Salads

Posted on October 13, 2006  Comments (3)

Recently we have all seen quite a few stories on – Tainted spinach: All bacteria may not come out in the wash. Last year a high school student did her science projected on the problem. Hillel Academy student first tested spinach for science fair by Stacey Dresner

“Last year I heard some rumors going around about how some people were getting sick and scientists thought that the illness was coming from these convenient packaged salads,” explained Kaili, now a ninth grader at the Hebrew High School of New England in West Hartford. “This caught my attention and I decided that I wanted to look more into the issue for my science fair project.”

In her project, “Quantitative Analysis of Bacterial Growth on Packaged Salads and Effect on Antibiotic Resistance and Nutrient Content,” Kaili investigated several varieties of bagged salad greens.

She tested the bagged greens for bacteria content, and found “extensive growth of bacteria within 24 hours in the fresh “unwashed” samples.”

“I found the highest percents of bacteria in dark, leafy varieties such as spinach and Mediterranean” showing “a correlation between high levels of iron and high levels of bacteria.”

She washed the samples using different cleaning techniques n cleaning with sterile water, cooking with boiling water for five minutes, and using commercial cleaning rinse n water with a pinch of bleach. The only method that killed most of the bacteria was the commercial rinse. The others did not really inhibit bacterial growth.

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3 Responses to “Science Fair Project on Bacterial Growth on Packaged Salads”

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