OT Campylobacter

[Andrew Gabriel]

I have always assumed all the raw meat I buy is full of bacteria that I don't want to eat and can contaminate food which is not going to be cooked.

Another factor is bacteria from the meat which gets on the outside of the raw meat packaging which might contaminate other items in your shopping bag. This is not as bad as it used to be (prepacked raw meat is always in sealed packages now), but it is still present and you should always pack raw meat products in a separate disposable bag. (I reuse it as my kitchen bin liner.)

[Johny B Good]

+1

That was a point well made in the wikipedia article.

[Nightjar]

...

The term you are looking for is disinfect, which is a much less stringent requirement than sterilisation. Sterilisation implies reducing the bug count to a level where the probability of being able to culture them from the sample is extremely low.

Harry is wrong about not being able to sterilise meat at home, but it does need specialised equipment that most people are unlikely to own unless they are heavily into home canning.

[harryagain]

The entire contents of the can have to be raised to 130degC for three minutes = 30psi/2bar steam Or 120degC for ten minutes.

These are recognised times for sterilsiation and can be achieved in a pressure cooker.

But you need some way of measuring the temperature in the centre of the can/jar/other container. And you have to be sure air is eliminated.

[Nightjar]

134C for three minutes or 121C for 15 minutes are the recognised medical standards.

Serious canners use an autoclave, which gives you much better control of temperature and pressure.

There are formulae, based upon the size and shape of the can, which allow you to calculate how long you need to hold it at what temperature to be sure of achieving that. Flat wide cans or long tall cans are best. Cans that are equal in height and diameter are worst.

[newshound]

Terrible thing, aphasia

[harryagain]

A pressure cooker IS an autoclave. Much less to go wrong than the ones encountered in hospitals and surgeries etc.

Also depends on viscosity of the fluid inside containers, nature of fluid and if any solids are present. All serious production autoclaves have a thermocouple to either measure a dummy item in the chamber or to actually measure the temperature inside part of the load. Depending on manufacturer.

Also to prevent the door being opened whilst the load is still hot.

Everything is recorded.

[harryagain]

No, he is exactly correct. There are few chemicals can sterilise at even near to room temperature. Formalin+low pressure steam and ethylene oxide have been used in the past.

Both considered too dangerous to use today.

[Nightjar]

An autoclave is a pressure cooker, but not every pressure cooker is an autoclave.

Much less accurate when you need to ensure sterility.

You see; you do know the difference.

[harryagain]

Accuracy is spot on as temperature depends on a dead weight safety valve not some electronic device.

[Nightjar]

Autoclaves do not need to rely upon electronics, even if that is common in modern hospital autoclaves. They do, however, give you accurate readouts of temperature and pressure, rather than working by guesswork.

[newshound]

That was exactly my point. Presumably on account of my age, I have increasing difficulty retrieving nouns from memory, and now I am evidently having trouble with verbs as well.

In the good old days when we had to build advanced test equipment out of chips, the standard response when diagnosing a fault in someone else's apparatus was to say "I see what you have done wrong, you have used "write-only memory".

[Nightjar]

Now I recall what aphasia means :-)