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Name: Garrett
Status: Student
Grade:  6-8
Location: CA
Country: United States
Date: November 2005


Question:
Which food collects more bacteria, cooked or raw food?



Replies:
The cooking process kills bacteria. So if you take some raw hamburger and some cooked hamburger and set them side-by-side, the cooked meat will have no living bacteria on it whereas the raw meat will have living bacteria. Now that the two meat samples are sitting out, though, they will both "collect" bacteria at the same rate, as particles in the air land on them. The raw meat starts out with more living bacteria, though, and so it will have a larger bacterial population. The bacteria will reproduce, and so those populations will grow on both samples, but the raw meat, which starts with a larger population of bacteria, will soon have a much larger population than the cooked meat. It is also worth noting that the two samples will have quite different populations of bacteria; the cooked meat will only have bacteria it acquired from the immediate surroundings, whereas the raw meat will have bacteria that it carried all the way from the meat processing plant. Finally, we should point out that the primary benefit of refrigeration is to slow down bacterial growth and reproduction. Bacterial populations will still grow in the refrigerator, but much more slowly than at room temperature.

C.Perkins



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