risks of vacuum packing?

[badjak]

I am not sure if this is in the right forum, but I didn't know where else to post it.
I have been searching a bit about vacuum packing and it looks that in certain circumstances it can increase the botulism risk, but the exact conditions are not really clear to me.
I am looking at doing the following and would like to know if this is safe:

situation 1:
I want to cold smoke chicken breast (chicken will be wet cured with sodium nitrite in the brine)
After smoking I will cook it till an internal temperature of just above 70 oC (either in simmering water or in the oven)
After cooling down, I debone and slice thinly and vacuum pack per portion and freeze.
It shouldn't take long to defrost a pack and will then eat it without reheating it

situation 2:
We have been making beef biltong without using nitrites. It doesn't get stored as it is being eaten faster than we can make it.
We now have someone who has asked if they can sell some for us. They would like it vacuum packed and then keep it in the fridge for up to 2 weeks or so (until sold).
We have suggested instead to pack it in sealed plastic bags with a couple of breathing holes is it, but they are not keen on that as they say it tends to get mouldy in the fridge.
We are now thinking of sealing the portions in bags with holes, then vacuum packing in packs of 5 so they can take out small batches of the freezer, take out of the vacuum pack and keep in the fridge
What would be the best/safest option here (besides the obvious: use nitrites)

situation 3:
This is on a bit of a different level: but what are the consequences of vacuum packing raw meat and keeping it in the freezer till we want to use it (defrosting either under running cold water in the vacuum pack or in the fridge)?

What is your take on these different situations?

[wheels]

There's info about this here:

http://www.food.gov.uk/multimedia/pdfs/ ... ck0708.pdf

and here:

http://www.food.gov.uk/multimedia/pdfs/ ... cguide.pdf

HTH

Phil

[badjak]

Thanks Phil,
That makes it pretty clear for situation 1 and 3.

With regards to the biltong:
We use 17 gram salt per kg of meat (actually a bit more as there is worcestershire sauce in the soak).
The type of biltong we are looking at will lose 50-60% of its weight during drying, making the salt content between 3.4-4.25% correct?
So if we keep our recipe and make sure the meat loses 52% of its weight we should be sure of a minimum salt content of 3.5% and therefor safe for a longer period than 10 days under refrigeration.
Any flaws in my reasoning?

[wheels]

Sounds logical.

Also, it I would have thought it would have "a water activity of 0.97 or less throughout the food and throughout all components of complex foods". Although why the requirement is only for it to be below Aw 0.97 when the limit for growth of Clostridium botulinum is Aw 0.91 eludes me.

Phil