Do any of you knowledgeable types out there know how long a tin of beans would last submerged in seawater? Would they still be good to eat after two months? I'm not talking about mega depths here, say thirty metres. Presumably it would take years for the saltwater to eat through the can and spoil its contents?
posted
The deeper the water the better the preservation. A can of beans only partially submerged say on the beach would not last very long four months to a couple years depending on the amount of abrasions or dents in the can, combined withthe amount of rewetting followed by exposure to air and changes in temperature.
But in deep water were there is little oxidation process the cn could last decades to hundreds of years- although it would build up sediment similar to a coral reef. An old can would be very hard to recognize in an ocean situation after a year- it would appear like a grey or brown lump of clay.
posted
My own experience with cans is that, sooner or later, the stuff inside them goes bad. I've monitored Spam for years...after about twenty years the first one mildly-exploded...I'm about ten years into a newer can.
In Heinlein's Space Cadet, there are scenes involving discovering nearly-a-century-old cans of maple syrup and packages of flour. The syrup was fine but the flour showed no tendency to rise. The climate was tropical. And my own above-mentioned experience with cans and other food products has made me doubt the validity of this experiment. (Mention was made of "embalmed corned beef," though.)
posted
I saw a program in the 1980s where they found a shack in the south east islands that had bottles of colas. The colas were still drinkable, but they lost the fizz and they tasted flat
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posted
A can of Beans in the ocean for an extended period of time?
what is this for, a Lost-On-A-Deserted-Island book?
anyway, really, it really depends on the climate. In my humble opinion, (correct me if Im wrong, please.) a can in colder water will last longer because there are less bacteria to destroy the contents.
posted
There are a few basic factors in food spoilage. Ome major factor is what kind of food it is. Syrup will never spoil unless it has been contaminated. You can even use it as a preservative. Dry flour is also naturally resistant to spoiling. Another factor is what degree of protection the food has against contamination from air, moisture, and bacteria. There is also the question of how completely the food is sterilized. And there is the issue of temperature and such.
If something is canned in a sterile, hermetically sealed container, then it cannot really spoil until the container has been breached. Meats (particularly "meat" which is made from diverse tissues ground together) can autodigest to a certain extent, and corrosive processes within the can will poison the food in certain cases, but you won't see actual rotting. Obviously, sterilization must take place after the food is hermetically sealed.
Many foods (like flour) can be "dry packed" with CO2. Simply keeping these foods away from both oxygen and water is sufficient to prevent microbe growth. The main criterion is that these foods have a very low water content. If even a little moisture is present, then anaerobic microbes (particularly mold) can destroy everything.
Low temperature does reduce the rate at which foods spoil, but unless the food is frozen solid spoilage will proceed, albeit at a reduced rate.
I can't speak to the issue of flour rising, since normally flour cannot rise.
posted
The "flour" I mentioned, from Space Cadet, was probably "hotcake mix," or somesuch. Memory sometimes serves me ill. My book collection is in its usually disorganized state, as I am, and I can't easily lay my hands on one of the five or six copies of the book I've bought over the years...
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posted
The trouble with flour won't be that it won't rise. It'll be that it's infested with bugs. There's a certain percentage of insect parts and eggs allowed into packaged food. After a while, those things hatch. The result is not pretty. Might be edible, perhaps, I don't know. But not pretty.
I know this from experience. *shudders at the memory*
posted
If the flour is dry packed with CO2, that won't happen. It also won't happen if the flour is kept completely dry, or if it is sterilized by heat, gamma radiation, or other means after being hermetically sealed.
Flour needs moisture in order to go bad. Well, that's actually true of most foods, but flour is supposed to be dry.
posted
But even if stored without moisture, surely flour won't last forever, will it? After all, flour, like the aforementioned tin of beans, was once living matter...the further you get from the point where it was [he said euphemistically], er, "processed," the less likely it would be edible...
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posted
There has to be some actual process that is affecting the food in order for it to go bad.
Time, in and of itself, doesn't actually do anything. Something else has to get at the food. For some foods, particularly organ meat, this can be an internal chemical process that needs only the molecules originally present (including a lot of water) and enough thermal energy to allow biochemical interactions to occur. For something like dry flour packed with CO2, there aren't enough potential chemical interactions for anything to happen. How long does it take for sand to "go bad"?
It seems intuitive to assume that all food must go bad given enough time, but it simply isn't true. Even meat can be preserved indefinitely if you hermetically seal it, gamma pasturize it, and then keep it at a constant temperature well below freezing.
posted
They have edible flour from Pompei which was preserved in jars during the volcanic eruption of ash some two thousand years ago.
Of course for Beef if there were no decay then the meat would be tough. That is why you slaughter, then hang the meat. To let it soften with age and drain the blood. Putting it in a fridge at 39 degrees is to control insects and foriegn microbes access to the meat.
posted
Rather late in this discussion, I remembered a relevant commentary on the shelf life of Spam, from Biggest Secrets, William Poundstone, 1993. (One of three books (that I know of) telling "all" about a number of things. Indispensible references from time to time.) Pages 69 through 71 are what's relevant here.
Spam, it's claimed, has an "eternal shelf life." The write up goes on to tell a little of the history of Spam, then goes into the gory details (what it is, how it's made). The final paragraph says:
quote:There is a record of canned meat (not Spam, obviously) remaining edible for 114 years. However, a Hormel brochure suggests using all canned foods within two years. Says Hormel: "It is important to keep in mind that all foods are substances which are derived from living matter. All living things have life spans that are characteristic of the species." Even Spam.
I probably had that in mind when I posted yesterday...
posted
you know what MAMMOTH meat tastes like?!? :O I might suggest honey, cause they found some in a pharaohs tomb that was still edible... (lost in memories of thousand year old honey.)
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posted
I remember reading a report from an eighteenth century antiquarian who unearthed a sealed lead coffin that dated to the crusades. Upon opening it, he found that the body was still supple and that it was immersed in a sticky fluid. What made me freeze mid-paragraph was the line that the liquid: '... tasted like mushroom sauce.'
I was startled.
They had mushroom sauce in eighteenth century england?
[This message has been edited by hoptoad (edited November 21, 2006).]
posted
Unfortunately, some of the "preservative" properties of lead are a result of heavy metal toxicity. Corrosion uses up all the oxygen in a sealed container, which would be fine except that the oxide formed is a sweetish white poison.
Adding large quantities of poison to a food is a good way to "preserve" it, but it won't be safe for human consumption...um, no pun intended.
Speaking of such things. John Franklin's ill-fated 1845 expedition to discover the Northwest passage took 8000 cans of meat. The cans were soldered shut with lead. In the 1980s, the discovery of the bodies of two of Franklin's sailors buried in the permafrost of Beechey island stirred up some interest. Autopsies revealed high levels of lead-poisoning in both sailors leading the investigators to guess that the condition probably effected the whole expedition. What is interesting is that lead poisoning leads to physical weakness and disorientation.
posted
I thought the interesting part was that their doctor, himself already suffering from lead poisoning, had tried an autopsy of one of the sailors. The...um, autopsied corpse clearly revealed that the doctor was already suffering from severe mental impairment. Kinda like when J was pretending to be a doctor Posts: 8322 | Registered: Aug 1999
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posted
If I recall right, they also tracked down some of the cans from the Franklin expedition and found they were soldered with lead. Talk about a thoroughly bad idea...
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