The Naked Scientists

The Naked Scientists Forum

Author Topic: ?bacteria destruction by freezing?  (Read 2228 times)

Offline CZARCAR

  • Hero Member
  • *****
  • Posts: 686
    • View Profile
?bacteria destruction by freezing?
« on: 11/10/2011 13:35:02 »
listeria news has tv saying to wash even bananas! Will freezing destroy listeria & other bacterium?


 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
?bacteria destruction by freezing?
« Reply #1 on: 11/10/2011 14:24:27 »
According to Wikipedia, Ice Cream is sometimes associated with Listeria. 

You do wash your ice cream, don't you?

Actually, it appears to be soft-serve ice cream, as one might find in some chain restaurants such as Dairy Queen, so it may be contaminated equipment, and not the frozen food.

Likewise, there was a study once that ice machines may harbor more bacteria than some public restrooms (with lots of disinfectant).

I did a search for Listeria Freezing.  I am getting a bunch of abstracts.  It seems to indicate that freezing will reduce the Listeria counts, but does not eliminate the pathogens, even after extended periods of freezing.

Here is a CDC summary on Google Books that seems to have some good information about freeze/thaw cycles.  See the section that starts at the bottom of page 163.
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8669
  • Thanked: 42 times
    • View Profile
?bacteria destruction by freezing?
« Reply #2 on: 11/10/2011 18:59:35 »
Freezing (strictly speaking thawing) will definitely ruin the bananas.
 

Offline CZARCAR

  • Hero Member
  • *****
  • Posts: 686
    • View Profile
?bacteria destruction by freezing?
« Reply #3 on: 11/10/2011 19:31:58 »
Freezing (strictly speaking thawing) will definitely ruin the bananas.
wrong!= try discounted banas already brown & freeze & they get browner, then from freezer to microwave for however long [1.5 min here] & maybe rotate halfway. Cut the bana tip off & squeeze out like toothpaste- mix with dry milk, fruit juice, or? Like a pudding, it holds its proof.
Thanx CK, I shudda asked about freezing methods to freeze rupture bacteria. Seems a bacteria has enuff water in it so freeze expansion would kill it,dunno, maybe weted so at least I can run up my fridge defrost bill?
 

The Naked Scientists Forum

?bacteria destruction by freezing?
« Reply #3 on: 11/10/2011 19:31:58 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums