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kev
06-11-2005, 06:06 PM
Hello to all,:)

My request is a simple one,

I may be asked to explain why it is preferable to blast freeze (-25c) freshly butchered meat as opposed to the tradition method of -20C.

What effect does either have on the meat?

What are the advantages/disadvantages of either method?

Look forward to your replies guys,

Regards,
Kev

chillin out
06-11-2005, 07:42 PM
Hi Kev,

The bigger the temp diff - the quicker it will get the meat cold.

Which will help stop bacteria forming/growing.

Chillin:) :) :)

PobodysNerfect
07-11-2005, 01:11 AM
Kev,

There are many things to consider when freezing food. I have attached a few pages from a food science book.

Regards,

Jan

lana
07-11-2005, 09:55 AM
Hello to all,:)

My request is a simple one,

I may be asked to explain why it is preferable to blast freeze (-25c) freshly butchered meat as opposed to the tradition method of -20C.



Hi there,
In the blast freezer the temperature is normally -35 or -40C. If the room temperature is -25C then it is a normal cold room.
In order to preserve the quality of the food and also reduce the core temperature to the required value then the food must be cooled very quickly with low temperature.
If not then the ice build up on the surface of the food will act as an insulation therefore, the core temperature will not reach to the required temperature.
Cheers :)

US Iceman
07-11-2005, 01:48 PM
I have attached a few pages from a food science book

The pages you provided look very interesting. Can you provide the book information please?

Title, Author, ISBN, etc.

Thank you in advance.

Regards,
US Iceman

Carlo Hansen
07-11-2005, 04:56 PM
This tread is very interesting, because I am going to make some test regarding this problem in the next 2 months.
Here in denmark many butchers let the beef cattle hang
about 2 - 3 weks before the cutting out and this means that the meat will lose about 8-10 % of the weight in this period with a traditionel cooling room.
Concerning pig meat, they blast freeze them shortly before they are going to the cooling room, if they not do the cut out the next day, but let them hang 3-4 days they will have to pay more for the cut out.
I have build a new cooling trailer, witch allov a cooling temperature at 1,5 C and with a RH about 95-96%.
I think this can reduce the drying up of the meat.
I will bring the test in this forum.

Best regards
Carlo Hansen

patrickj
07-11-2005, 07:05 PM
Kev,

There are many things to consider when freezing food. I have attached a few pages from a food science book.

Regards,

Jan
Dear jan,

I was trying to see what is in the attachments but failed due to a reading error of the Acrobat Reader.Would you please check on this and advice me.
Thanks,
Patrickj

Peter_1
07-11-2005, 07:11 PM
I may be asked to explain why it is preferable to blast freeze (-25c) freshly butchered meat as opposed to the tradition method of -20C.

What effect does either have on the meat?

What are the advantages/disadvantages of either method?


What do you mean with the traditional method? Hanging the meat in an ordinary freezer at -20C?
Blast freeze fastens the freezing process and prevents that the water molecules inside the meat can stick together to bigger water droplets which can form meat deforming cristals. (the freezing water molecules tears the meat inside)

PobodysNerfect
08-11-2005, 01:40 AM
I was trying to see what is in the attachments but failed due to a reading error of the Acrobat Reader.Would you please check on this and advice me.


Maybe you need a new Acrobat Reader.



I have build a new cooling trailer, witch allov a cooling temperature at 1,5 C and with a RH about 95-96%.
I think this can reduce the drying up of the meat.

Carlo,

What are you going to transport in that trailer? Pig carcasses coming from the blast freezer, completely chilled pigs or something else?

Regards,

Jan

Carlo Hansen
08-11-2005, 06:03 AM
Hi Jan

The trailer is not for transport. It is made for test with a
new cooling system.
It is easy to place the trailer on diff. places.
I am going to make some test by a couple of butcher`s, they have shown interest for this new system.

Cooling system:

http://www.wulffdata.dk/

Best regards
Carlo Hansen

Peter_1
09-11-2005, 07:22 AM
Here in denmark many butchers let the beef cattle hang
about 2 - 3 weks before the cutting out
2 to 3 weeks hanging there :confused: :eek: :eek:

Here, it must hang legally due to the BSE crisis 2 days so that all the tests can be done, but then it's cut immediately and the parts that are not direct sold are vacuum packed or packed in an inert atmosphere

dogma
17-03-2008, 08:21 PM
Is meat hung for up to 15hrs after slaughter and before freezing still?

Or do most abattoirs send the carcass straight through the washer and into the blast freezer?

15hrs was an old guideline for enzymatic tenderisation.

:) :)

The MG Pony
17-03-2008, 09:28 PM
2 to 3 weeks hanging there :confused: :eek: :eek:

Here, it must hang legally due to the BSE crisis 2 days so that all the tests can be done, but then it's cut immediately and the parts that are not direct sold are vacuum packed or packed in an inert atmosphere

Same here traditionaly it is hung for 3 weeks or so by all local farmers.

eserunlu
26-07-2008, 09:23 AM
Hi to all.
someone can help me?? how can i calculate blast freezing capacity? and someone can give me the data tables including blast freezing temperatures, blast freezings times of all foods, vegetables etc.
u can e-mail me also
eser_unlu@hotmail.com

Peter_1
26-07-2008, 09:43 AM
Location 'jhgj', where's that somewhere on earth?
How you can calculate the freezing time? With Planck constants/numbers, Biot number, ....
I think you're not aware that a blast freezer is one of the most difficult jobs to do it right. A lot of experience is involved which can't be given just in some basic information.
Freezing time is based on so many variables that numbers can be given from 10 minutes freezing time till 2 days.

Ohhh, BTW Welcome.

nevgee
27-07-2008, 01:59 AM
As an off shoot, to slice bacon it was necesary to stiffen it by freezing down to say -4 C this took time and caused a loss of moisture during the proccess. This loss in moisture equated to loss of profit ..so we built blast freezers to quickly freeze the exterior surface of the bacon sides say 5-6mm then the sides were put into a tempering chill room to stiffen up. The quick freeze of the surface then prevented moisture loss from the bacon sides thus keeping weight thus saving profits for ASDA and Danish Bacon ... :D

Blast freezing would normally have been done at -35/-40C but freezing meat too quickly can cause cold shortening or toughening the meat especially if done straight from slaughter. I thought there was still a need to let the meat hang before being frozen.

US Iceman
27-07-2008, 03:45 AM
Blast freezers and coolers are almost a complete science to themselves. Some lunch meats are also cooled for slicing to keep the fat from smearing.

Each product is different and each process required or used can be different.

And...freezing times are always a fun discussion which I think is what Peter was pointing out.;)

sudarshan
13-08-2008, 07:34 AM
What Is The Freeezing Time Required For Meat And Vegetables Above & Below Freezing Point And At The Time Of Latent Heat Of Fusion For Calculating Tr

eserunlu
18-08-2008, 03:35 PM
'jhgj' means i have no time to write place :) im from turkey. i need blast freezing times data sheets for all foods. is there any table for this? sometimes i need for vegetable, meat, chicken etc.