Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Jimbee on 12/09/2024 08:13:32
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Why does freezing preserve food, apparently forever? I know it keeps food fresh for a very long time, because people sometimes thaw and eat frozen woolly mammoth, from mammoths that have died in North America and Siberia. The last wooly mammoth lived in Siberia about 2,000 BCE. So the frozen carcass would be at least 4,000 years old. People who have eaten thawed mammoth meat say it tastes a little different. But they usually don't get food poisoning from it.
So why does freezing something to the point when water freezes, 32 degrees F or 0 degrees C, preserve it so well? Absolute zero, which is −459.67 degrees F or −273.15 degrees C, is the when all molecular motion stops, or the coldest anything can reach. And nothing has ever reached absolute zero, scientists say. So why is the temperature water freezes enough?
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Most bacteria and fungi cannot function at significantly reduced temperatures and other degrading processes like rancidity are retarded. Cell cytoplasms are mostly water although various organic constituents may reduce the freezing point below that of pure water when the cytoplasm freezes all activity is arrested as nothing can move. To be certain of long term preservation most freezers go to around -20c.