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There are only two processes that spoil meat—bugs including microorganisms, insects
and other creatures that feed on it and oxidation. Living organisms only grow in the presence of
moisture and multiply rapidly at warm temperatures. Today we can protect meat from all tiny
creatures but microorganisms. If we reduce the temperature, the bacterial activity slows
drastically. Freezing does the same thing, but it adds another factor to make the environment
radically unsuitable for their survival. It converts the meat’s moisture into ice, that
microorganisms can't use as a source of water. Frozen meat doesn't spoil by microorganisms. But
remember, even though most microorganisms die, some survive freezing and they remain
dormant. As soon as you defrost the meat and its temperature warms up to their favorite
lukewarm, they begin to make up for lost time and multiply quickly.
Most microorganisms only grow in the presence of oxygen, but some need an oxygen-
free environment to thrive. Still others can grow in either. Most prefer neutral acidity (pH 7). Not
many grow in acid conditions (below pH 5). So meat is relatively safe in acidic conditions, as in
an acid marinade, or in a pickling solution, but lack of oxygen doesn't guarantee its safety. The
bacteria of the dreaded deadly botulism live in low-acid, oxygen-free conditions. Fortunately,
heat readily destroys this deadly toxin.
Oxidation, the second reason for spoilage, only affects fat. It is particularly hard on
unsaturated fats. That means meats like chicken, fish and pork are more susceptible, while meats
high in saturated fats, like beef and lamb, oxidize more slowly. Oxidation of the fat is simply a
chemical reaction that turns meat rancid. A mildly oxidized meat has a slight rancid, unpleasant
flavor but a strongly rancid meat is quite repulsive, difficult to swallow. Even if you somehow
manage to swallow it, rancid meat is also difficult to digest.
Oxidation (or rancidity) is an irreversible chemical reaction that goes on spontaneously
in the fat of either raw and cooked meats. Storing meat in the refrigerator slows the process down
a lot because chemical reactions slow at lower temperatures. Below freezing it slows down even
more. In fact, oxidation is the only limiting factor when storing meat in the freezer—without
oxidation, a well-wrapped meat (to prevent drying) would keep indefinitely.
If it weren't for oxidation, we could eat the mammoth that they found frozen in Siberian
ice for 20,000 years. It should be perfectly edible and certainly well aged. Russians claimed they
actually tasted it and liked it, but then, they are not used to our tender, prime-grade, corn-fed
western beef..
Wrapping
The only way to stop oxidation is eliminating oxygen completely from the environment
surrounding the meat. Meat packed in perfect vacuum will last forever. Commercial vacuum
packaging doesn't eliminate all oxygen from the package but greatly reduces it and extends
shelflife significantly. A vacuum-packed meat has a shelflife of at least four weeks, while a
standard packaged meat lasts less than a week. Today whole-sale processors ship almost all meat
to retailers in huge vacuum packs. The old-fashioned butcher shop where the butcher carves up
fresh carcasses is as rare as steak tartar. With carefully controlled operating-room-like hygienic
conditions and vacuum packaging, meat packagers extended shelf-life of pork, for example, to an
unbelievable 45 days. That allows them to ship fresh pork by refrigerated trucks from the east to
the west coast, then by ocean liners to Southeast Asia and still arrive in top condition as fresh
pork.
While we see meat in the display case on trays sealed in plastic wrap, high-tech (called
play © erdosh 45
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