Hot Fill and Hold Temperatures - Question

Hello,

We make margarita mixes (pH <3.3). Our process involved cooking the product to 92 C, filling, inverting, and then cooling.

I recently came across a Tetra Pak study stating that there should be no loss in safety or quality if second pasteurization is complemented at 85 C. - (there is also a paper but this may be easier for reference)

As we got fill, if we lowered the pasteurization temperature to 85 C, the product would likely be around 80-81 C by the time it is filled and capped.

What would the risks be (if any) if we lowered our pasteurization temperature to 85 C.

Side note the reason we are looking at this is an estimated reduction in carbon footprint of 21%.

Thanks for any insight

With all due respect to TetraPak, who know their onions, they do have a vested interested in asserting that a second pasteurisation at that sort of temperature is viable for quality and safety - it's kind of critical to their business model, given that a large proportion of the juices being packed into Tetra formats will have undergone a preliminary pasteurisation (or similar, e.g. 5-log kill delivered as part of the concentration process) prior to the final packing.

In my experience of juices, a second pasteurisation will usually have some organoleptic impact - for this type of product a thermal process is inherently a balancing act between killing what needs to be killed, and trying not to do too much damage to the colour/flavour/aroma.

That having been said, the impact is very variable between product types, so I really don't think there is a one-size-fits-all answer on the quality element.

 

As for the micro, which is presumably the more significant focus for you, the temperature is only part of the control - without considering hold time, it's somewhat difficult to assess ;)

You might like to have a look at Pasteurisation Units (PUs) as an imperfect but sometimes useful way to compare time/temperature combinations.

 

In a general sense, I'd expect 80-85C to be a viable temperature for achieving 5-log in an acidic drinks product, subject to an appropriate hold time. Exactly what that time is will depend on your starting micro and the nature of your raw materials. Spoilage is generally the enemy here, so if you're using e.g. unpasteurised juices then yeasts may be your biggest challenge.