does freezing food items kill parasites?

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Kfen
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does freezing food items kill parasites?

Post by Kfen » September 17th, 2013, 8:49 am

I always hear that freezing will kill parasites, but no one ever has definitive proof, or exact guidelines i.e temps and duration. So does anyone out there know for sure how to kill all parasites by freezing?

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Kelly Mc
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Re: does freezing food items kill parasites?

Post by Kelly Mc » September 17th, 2013, 11:02 am

Freezing and thawing kills organisms by destroying intracellular membranes. But some microbial life , especially those with oocysts or egg stages are protected by a durable matrix of carbohydrate. But even these are documented to be destroyed in temps of zero and below under duration of time that vary it seems with studies and organism. Developed ascarids are most readily destroyed by freezing though. Other microbial life is drastically suspended and many disintigrate and lose infectivity because of the freeze/thaw process. Keep in mind too, that most home freezers are not at deep freeze temps. A conventional freezer in the home often reads at 15 degrees, or even higher in thse set of energy saving times. The most reliable means of sterilization is high temperature treated. Which would not be suitable for our food items for the temps required would cook the tissues.

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Don Becker
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Re: does freezing food items kill parasites?

Post by Don Becker » September 17th, 2013, 6:22 pm

A conventional freezer in the home often reads at 15 degrees, or even higher in thse set of energy saving times.
The freezer built into my refrigerator has a recommended setting of 0 degrees. The standalone freezers in my garage are both set to -5 degrees.

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Kelly Mc
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Re: does freezing food items kill parasites?

Post by Kelly Mc » September 17th, 2013, 6:30 pm

That's good, I had to change mine as my temp gun read 13 degrees. Its good to check. A standard recommended time for a protocol freeze is a solid 30 days.

VICtort
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Re: does freezing food items kill parasites?

Post by VICtort » September 17th, 2013, 9:53 pm

Kelly's reference to 30 days of freezing at Zero d. or less is consistent with what I have been advised...that 30 days will kill most parasites. I have experimented a lot with the controversial practice of collecting "wild food", such as d.o.r. snakes, bull frogs, pigeons, rodents, fish, etc. I freeze them a minimum of 30 days but often much longer. I am unaware of any parasite issues, and when fecal samples were tested, they came back "clean". I have heard the practice is risky, but problems arise with domestic sources also. I sometimes think we may be over concerned about parasites, it has rarely been a problem for my animals, maybe I have been lucky...

Vic

Jimi
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Re: does freezing food items kill parasites?

Post by Jimi » September 19th, 2013, 3:54 pm

I sometimes think we may be over concerned about parasites, it has rarely been a problem for my animals, maybe I have been lucky...
I agree, because - among other reasons - my experiences have been similar. Similar, long-term, sustained, and numerous.

Another reason - people, I think, can & often do go too quickly from a reasonable, testable hypothesis, to a state of "common knowledge", without the testing: "Huh, that could probably lead to some problems" morphs into "Oh yeah, for sure you don't wanna do that, for God's sake!" They/we just skip the pesky proof part.

Collecting wild food is great if you have a reasonably clean source and plenty of freezer space. A vacuum sealer is nice too, for freezer burn. I don't see what the fuss is about. For some critters - eastern hogs, wild-caught Crotalus "ornatus", juvenile & some male Trimeresurus, and similar ilk - it beats the hell out of trying to make them eat stuff - like domestic rodents - they just don't want to eat. And which might even be less healthy for them than wild-caught prey. There's a thought...

cheers,
Jimi

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Kelly Mc
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Re: does freezing food items kill parasites?

Post by Kelly Mc » September 25th, 2013, 5:46 pm

For me, I like to delete wishful thinking from my keepers palette of concerns - I am not so worried about what is in my frozen rodent prey, but what may be on it, if i am using a dealer that also deals in reptiles. I dont delude myself in picturing diligent workers donned in nitrile processing the frozens to be shipped. Wet turtles, soiled bedding, and multitudes of snakes and lizards of unknown health status, those same hands on my animals food is a potential i choose to aknowledge. All i can do is do what i can with what information i have or even intuit, if thats all i have to work with. So i like to make sure my freezers mad cold, and dont mind allowing for a little overkill coming into play.

Jimi
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Re: does freezing food items kill parasites?

Post by Jimi » September 26th, 2013, 5:11 am

those same hands on my animals food is a potential i choose to aknowledge
Another great point. Same as "the bagged spinach problem", but without any sort of regulatory inspection. Dirty dirty dirty. Yuck.

Hmmm...besides the freezer, got any ideas on how to combat this? Blacklight or something? Simple washing?

Cheers,
Jimi

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Kerby Ross
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Freezer temps.....

Post by Kerby Ross » September 26th, 2013, 6:32 am

**A conventional freezer in the home often reads at 15 degrees**

Then good luck keeping ice cream in that freezer. Ice cream MELTS at 15 degrees!

:)

Kerby...

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Kelly Mc
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Re: does freezing food items kill parasites?

Post by Kelly Mc » September 26th, 2013, 7:40 am

Yeah Jimi, I thought of the black light option too, but havent followed up on finding out more.

I also started raising my own mice for a while but it wasnt fair to my partner to have yet more animals here in this house.

The other alternative is to go with a company that only does rodents.

But like the spinach thing and so many other quality control issues - you have to take measures into your own hands - and not be blindly assured.

As for the freezer thing, a friend of mine and myself did an investigation of sorts, on freezer temps and home tap heat temps and settings. It was fun but we didnt notice the ice cream.

Kfen
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Re: does freezing food items kill parasites?

Post by Kfen » September 29th, 2013, 7:55 am

I too don't worry myself too much with parasites, especially with rodents, but the question came up in a conversation I was having. I would have some concern when using other wild caught herps (i.e lizards and frogs) as feeders.

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