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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