Specifically, my parents think that by freezing tinfoil it can be used again without the risk of any bacteria surviving because they believe that cold kills bacteria.
2006-08-26 11:25:03 · 17 answers · asked by Lionel C 1 in Science & Mathematics ➔ Biology
I believe it does..
Most bacteria cannot survive under "0" degrees..
2006-08-26 11:31:36 · answer #1 · answered by Redeemed 4 · 1⤊ 3⤋
Freezing certainly slows bacterial growth and will kill some types - even more if you reach freezing temperature and the H2O in them freezes.
More to the point, your parents can probably rely on the fact that without a constant source of food, combined with the cold, the levels of bacteria would be kept relatively low, and probably not enough to make them sick. They would be better off washing the tinfoil too if they really want to reuse it.
2006-08-26 11:58:15 · answer #2 · answered by Shofix 4 · 1⤊ 0⤋
Nah it doesn't kill bacteria. We keep our freezer stocks of bacteria at -80 celcius indefinitely in lab. We then bring them out, grow the bacteria up again and again and they do just fine. Just get new tinfoil! Bacteria is hard to kill. Even heating will allow some to survive (they can survive in dormant form because they can form spores) so even dishwashing or washing wouldn't be too great. Just get new foil, it's not that expensive. That sounds like my grandma, reusing everything.
2006-08-26 16:04:48 · answer #3 · answered by X 4 · 1⤊ 0⤋
It depends on the other conditions when freezing. In most situations, no, it simply stops or slows their growth. For example, when scientists want to save a culture of bacteria for future use, we usually freeze them at -80 C in glycerol. If you were to freeze them in water, the crystals may destroy them. It also depends how cold you're talking about... I would recommend washing with soap and hot water instead of freezing. If they really want to make sure they're killing the bacteria, they can bake the foil for several hours (dry heat takes a while actually), or they can buy an autoclave.
2006-08-26 12:43:59 · answer #4 · answered by Istra 3 · 0⤊ 0⤋
Freezing foil does not kill bacteria. Both Colostrum and Bacillus produce endospores, which are dormant bacteria. They can withstand extreme conditions--- when conditions return to normal, they come out of their dormant state, and become regular bacteria and reproduce. This is the reason that medical equipment has to be autoclave, at such extreme temperatures --- so the endospores are destroyed.
So, the moral of the story is: Don't reuse disposable tin-foil. Just get a new sheet... its cheap!
2006-08-26 13:44:20 · answer #5 · answered by Cliffo 3 · 1⤊ 0⤋
Freezing does not kill bacteria. It does put them on hold for awhile. Some bacteria live quite well at freezing temp. Some live in hot springs. Aluminum foil can be reused after washing. freezing not necessary if clean.Bacteria on meat and vegetables are still there when thawed.
2006-08-26 12:18:36 · answer #6 · answered by science teacher 7 · 1⤊ 0⤋
I did a research project on this for a test to see if bacter ia could survive deep space. Freezing in water kills some, but not all because the crystals cut the cells. Just exposing them to the cold does nothing at all.
2006-08-26 11:31:26 · answer #7 · answered by Erebus 3 · 2⤊ 0⤋
Freezing pauses the bacteria's activity but not kill it. Warming up or heating does indeed kill bacteria.
If you put milk in your fridge, it will not spoil as fast as if you put it in 25C temperture. So cooling slow down the bacteria's activity but it still active and your milk will be spoiled in a matter of days.
Make sense ?
2006-08-26 13:48:16 · answer #8 · answered by Duda .. 3 · 1⤊ 0⤋
No freezing will just place it in a dormant state. To killl bacteria it must be heated to over 150 degrees at least.
2006-08-26 16:58:06 · answer #9 · answered by celtic_knight65 1 · 1⤊ 0⤋
It can keep bacteria from spreading but it does not kill them.
2006-08-26 11:30:12 · answer #10 · answered by corbeyelise 4 · 0⤊ 0⤋