Rapid chilling hogs - ashrae

[Sandro Baptista]

I don't agree with Ashrae pointing that the air temperature for chilling pigs carcasses is about 0ºC/-5ºC. Other good / better solutions can be set with air temperatures about -20ºC.

I would appreciate any comments from you guys.

[Tayters]

Hi Sandro.
Isn't the whole point about rapid chilling that if the chilling process is too slow, ice crystals form and puncture the cell walls of the product causing the cell insides to leak out.
If the chilling is quick however, the ice crystals don't have a chance to form thus the cell walls stay intact.

I've not read the Ashrae literature but are they differentiating between chilling and rapid freezing?

Cheers,
Andy.

[Sandro Baptista]

Hi Sandro.
Isn't the whole point about rapid chilling that if the chilling process is too slow, ice crystals form and puncture the cell walls of the product causing the cell insides to leak out.
If the chilling is quick however, the ice crystals don't have a chance to form thus the cell walls stay intact.

I've not read the Ashrae literature but are they differentiating between chilling and rapid freezing?

Cheers,
Andy.


Tayters I was talking about chilling. I mean get the temperature down from +40ºC to about +5ºC in less than 24 hours.

[Grizzly]

Guys.
It is all a case of terminology!
What you need for processing Hogs (Pork carcasses as we know them) is a rapid chill system.

What you are referring to Tayters is the reasoning behind Blast freezing and I think you are questioning Sandro's termanology also?
IE. very quick low temp freezing forming a protective ice crust.
Reducing the cellular damage caused by slow freezing.
This damage is called in the trade as PSE (pale, soft and extrudative (purges juices into the packaging))
This and the reason below are why you don't blast freeze. (Hogs that is!)

As you chill down the carcass moisture is extracted.
This is reducing the weight and therefore the value of the carcass is literally evaporating.
Which could be as much as say 1kg per hog.

So dropping the temp is not the answer.

Better airflow, moving product and variable evap finning.
All help reduce the ice build up caused by the huge amounts of moisture being removed.

Another thing that obviously will affect the operation is the way that the Hogs are positioned.
Spacings etc.

So Sandro.

Dropping the temps so low will indeed produce a much quicker hog core temp.
But the Hogs will be lighter and potentially damaged resulting in them being worth less to the customer.

Increased airflow and it's movement off coupled with the correct hog presentation within the airstream would seem to be the answer.
Grizzly

[Sandro Baptista]

Guys.
It is all a case of terminology!
What you need for processing Hogs (Pork carcasses as we know them) is a rapid chill system.

What you are referring to Tayters is the reasoning behind Blast freezing and I think you are questioning Sandro's termanology also?
IE. very quick low temp freezing forming a protective ice crust.
Reducing the cellular damage caused by slow freezing.
This damage is called in the trade as PSE (pale, soft and extrudative (purges juices into the packaging))
This and the reason below are why you don't blast freeze. (Hogs that is!)

As you chill down the carcass moisture is extracted.
This is reducing the weight and therefore the value of the carcass is literally evaporating.
Which could be as much as say 1kg per hog.

So dropping the temp is not the answer.

Better airflow, moving product and variable evap finning.
All help reduce the ice build up caused by the huge amounts of moisture being removed.

Another thing that obviously will affect the operation is the way that the Hogs are positioned.
Spacings etc.

So Sandro.

Dropping the temps so low will indeed produce a much quicker hog core temp.
But the Hogs will be lighter and potentially damaged resulting in them being worth less to the customer.

Increased airflow and it's movement off coupled with the correct hog presentation within the airstream would seem to be the answer.
Grizzly


On chilling process PSE also could happen if the chilling (not freezing) is take to long and the PH of the carcasses drops faster.

If the air temperature is lower/faster cooling the product will not loss so much water. However the cost of a refrigeration plant of this kind is more expensive.

[Grizzly]

Ok.

So you dissagree with me also!


Fair enough you do it your way.


By the way is this a chill tunnel or chamber?
Grizzly

[RANGER1]

Spray chiller would be the best I'd imagine time/weight loss.
It works for beef, with no weight loss .

Depends on how much water you have to "waste"

[josef]

I'm cold, hogs and beef -13 ° C, ammonia for 24 hours, no problem with the quality of meat.
Chicken -20 ° C for 4 hours. All of +2-5 ° C and without addition of water (EU Directive does not allow water). As you type, much depends on the size of the wind, which spacing from each other, but also many pieces in a refrigerator.
Such is the claim processing plants and my opinion.
Josef.

[Sandro Baptista]

I'm cold, hogs and beef -13 ° C, ammonia for 24 hours, no problem with the quality of meat.
Chicken -20 ° C for 4 hours. All of +2-5 ° C and without addition of water (EU Directive does not allow water). As you type, much depends on the size of the wind, which spacing from each other, but also many pieces in a refrigerator.
Such is the claim processing plants and my opinion.
Josef.

Josep, the times you talk about are already counting with the temperature equalization or only the mean temperature of the carcasses?

[josef]

Sandro, the final temperature, measured in all sections.

[Sandro Baptista]

Sandro, the final temperature, measured in all sections.

okay, it's after the equalizing cold store. That's right.