9 replies to this topic

[foodsafetyboy]

Dear all,

I have read posts concerning thawing of frozen meat items and was very glad to see the response of experts.
I just have a few question concerning the thawing of aseptic juice concentrates:

• Since they are aseptically packaged, can I thaw them at room temperature? (without opening the aseptic packaging)
• What thawing temperature and time would your recommend for thawing same?
• Do you have any reference I could use for this thawing operation?

I am currently drafting a thawing procedure for frozen aseptic juice concentrates that will be used as raw materials in the production. I am just new to this industry (juice concentrates manufacturing) so it is really a big challenge drafting such procedures. Can anyone please help me?

Thanks in advance,
Food safety boy

[Simon]

Bump for foodsafetyboy...can anyone assist?

[Charles.C]

Dear foodsafetyboy,

Definitely not my area unfortunately but the typical answer for thawing seems to be - "very slowly"

Can see these 2 extracts for a couple of opinions, how representative they are, no idea.

 fruit.png   345.49KB   30 downloads
 fruit2.png   116.62KB   22 downloads

Rgds / Charles.C

[HPG]

Dear all,

I have read posts concerning thawing of frozen meat items and was very glad to see the response of experts.
I just have a few question concerning the thawing of aseptic juice concentrates:

• Since they are aseptically packaged, can I thaw them at room temperature? (without opening the aseptic packaging)
• What thawing temperature and time would your recommend for thawing same?
• Do you have any reference I could use for this thawing operation?

I am currently drafting a thawing procedure for frozen aseptic juice concentrates that will be used as raw materials in the production. I am just new to this industry (juice concentrates manufacturing) so it is really a big challenge drafting such procedures. Can anyone please help me?

Thanks in advance,
Food safety boy

Dear foodsafetyboy,
What product do you produce (using thawed aseptic juice concentrate)?
And how about packaging? is there any secondary packaging? are going to thaw with secondary packaging?
Because it's going to affect thawing time.

When I used to work at juice manufacturing, I didn't set the thawing time and temperature for frozen juice / puree since in my last company didn't have place with set-able temperature.
So I just use room temperature and a day (not exactly 24h) to thawing the frozen juice/puree.eventhough it's not 100% thawed the next day.
I don't have any reference before

I think you need to try thawing your own product. So you can set the time and temperature based on your trial, as long as it didn't affect the quality and microbiology aspects of the product.
Have you ever check the microbiology and quality aspects after you thawed?

Regards,
Hadi

[foodsafetyboy]

Dear foodsafetyboy,

Definitely not my area unfortunately but the typical answer for thawing seems to be - "very slowly"

Can see these 2 extracts for a couple of opinions, how representative they are, no idea.

 fruit.png   345.49KB   30 downloads
 fruit2.png   116.62KB   22 downloads

Rgds / Charles.C

Thanks Charles,
This is also informative.. appreciate it much..

[foodsafetyboy]

Dear foodsafetyboy,
What product do you produce (using thawed aseptic juice concentrate)?
And how about packaging? is there any secondary packaging? are going to thaw with secondary packaging?
Because it's going to affect thawing time.

When I used to work at juice manufacturing, I didn't set the thawing time and temperature for frozen juice / puree since in my last company didn't have place with set-able temperature.
So I just use room temperature and a day (not exactly 24h) to thawing the frozen juice/puree.eventhough it's not 100% thawed the next day.
I don't have any reference before

I think you need to try thawing your own product. So you can set the time and temperature based on your trial, as long as it didn't affect the quality and microbiology aspects of the product.
Have you ever check the microbiology and quality aspects after you thawed?

Regards,
Hadi

Hello Hadi,

Thank you so much for your insights.
We are actually doing aseptic juice concentrates from aseptic juice puree. The puree has three packaging, the drum, the plastic liner, and the aseptic bag. Like what you said, we are also thawing at room temperature in not more than 24h, but we are not monitoring the temperature of the product (I will include this on the procedure I am drafting for thawing). We are just relying on our ongoing finished product testing (microbiological).
I didn't put this as a CCP too because there are subsequent step to eliminate hazards, if any.

regards, food safety boy

[Charles.C]

Dear foodsafetyboy,

Don’t know what yr exact process is but after reading yr post, the short document attached below might be interesting also.

The only obvious comment is that all the fruit refs seem to avoid thawing at room temperature which is identical to my experience in another product area (seafood) where I used (large) zero degC water baths for the same kind of microbiological reasons. (With intermittent stirring, approx 10kg blocks/no packaging took 12-20hrs.)

However, if thawing with your primary packaging present, the time in a static, zero-subzero environment level will probably be eons, so I can understand the difficulty. But against the previous method, at ambient, you virtually hv an uncontrolled system. Swings and roundabouts . Depends on the results of course.

 Seven Steps to Aseptic Filling.pdf   84.31KB   170 downloads

Rgds / Charles.C

[foodsafetyboy]

Dear foodsafetyboy,

Don’t know what yr exact process is but after reading yr post, the short document attached below might be interesting also.

The only obvious comment is that all the fruit refs seem to avoid thawing at room temperature which is identical to my experience in another product area (seafood) where I used (large) zero degC water baths for the same kind of microbiological reasons. (With intermittent stirring, approx 10kg blocks/no packaging took 12-20hrs.)

However, if thawing with your primary packaging present, the time in a static, zero-subzero environment level will probably be eons, so I can understand the difficulty. But against the previous method, at ambient, you virtually hv an uncontrolled system. Swings and roundabouts . Depends on the results of course.

 Seven Steps to Aseptic Filling.pdf   84.31KB   170 downloads

Rgds / Charles.C

Hi Charles,

The attached pdf document you shared is exactly what we are doing here in my current work.
Thanks much Charles. I am learning from this site

For frozen meat, I understand that thawing at ambient temperature poses risk of bacterial growth on the surface of the item . However, if thawing of the raw juice puree (frozen) is in its aseptic bag (unopened) at ambient, I believe it will not promote bacterial growth based on our ongoing microbiological testing for the finished product and the material after thawing itself. It also is as per supplier's recommendation.

[joannaccsf]

Hello, I am currently doing  a research on this same topic. Did you end up finalizing yours? 

[pHruit]

Hello, I am currently doing  a research on this same topic. Did you end up finalizing yours? 

This thread is 10 years old, so  you might be lucky to get a response from the OP!

 

If you're thawing juice that is truly aseptic, then there should be no microbiological risk for ambient thawing. This format should be ambient-stable, with chilled/frozen storage being used for some types of juice, or where a particularly long shelf life is required, as it gives better long-term durability of the organoleptic characteristics that tend to be the limiting factor for shelf life. Nonetheless I'd suggest clarifying with your raw material supplier(s), just to get confirmation that this is the case - sometimes you'll see a note on specifications that short-term ambient storage and handling is fine, but temperature-controlled conditions are recommended for long-term storage.

 

For non-aseptic juices I know of plenty of sites that thaw at ambient temperatures, but it's not something I'd generally recommend - particularly with lower brix products in larger unit sizes, where the thawing time can be such that the outside can potentially start fermenting before the inside is thawed. Even without the obvious risks that should be apparent with a cursory consideration of the thawing profile, I've seen this go wrong plenty of times, and received a dismayingly large number of complaints to the effect of "we abused the product, it fermented, so we're rejecting it and want you to investigate..."

IMO the only exception where ambient "thawing" might be acceptable is for very high-Brix concentrates (typically those at or above about 65 °Brix), where they will still be liquid at -18°C so it's just a case of allowing the temperature to rise slightly so that the viscosity reduces to a point where your pumps can handle it - you're not "thawing" these products in the sense of needing to achieve a phase-change from a solid to a liquid. As long as you've got half-decent pumps, many of these are entirely useable before they get near 0°C, let alone above it, so a very short spell at ambient temperature can potentially be used without significant risk, as long as it is monitored and controlled.