11 replies to this topic

[jalex194021]

We are setting up a new system to treat our cherries. Instead of treating the water, we wish to spray the cherries with PAA. The FDA states that the maximum for PAA is 80 ppm, what I am trying to find out is what is the minimum ppm that can be applied to the fruit? Any ideas out there?????

[Marshenko]

There are different ranges based upon manufacturer or solutions and other considerations, but I would say 25-80 would be an acceptable range.  Personally I would want to target 50-60, which gives you a buffer each way.

 

Here's some stuff from University of Tennessee:

 

https://extension.te...nts/SP798-B.pdf

 

From UMass:

 

https://ag.umass.edu...rs-chlorine-paa

 

From Univ. of Vermont:

 

https://www.hort.vt...._Sanitizers.pdf

 

From Cornell:

 

https://rvpadmin.cce...ads/doc_676.pdf

 

From URI (slide 23):

 

https://web.uri.edu/...tation-2016.pdf

Edited by Marshenko, 24 April 2019 - 03:19 PM.

[juanolea1]

We are setting up a new system to treat our cherries. Instead of treating the water, we wish to spray the cherries with PAA. The FDA states that the maximum for PAA is 80 ppm, what I am trying to find out is what is the minimum ppm that can be applied to the fruit? Any ideas out there?????

https://extension.te...nts/SP798-B.pdf

[LostMyMind]

You may want to cross check with the manufacturer's label limits as well (as I've seen manufacturer's limits for a crop that were different than guidance).

 

Another thing that you might want to think about is when setting your limits is how you will test.  Basically, consider what your testing methodology will measure when setting limits.  We use PAA test strips and they go in increments such as 0, 50, 100, 250, 500, 1000 for high range and 0, 10, 20, 50, 85, 160 for normal.  We use two different types of strips to cover both too low and too high applications.  Ideally you would align your operating limits with what you can test for (or find a methodology that lets you test for the limits you have to use). 

 

Finally, if possible, I like to do a correction action range (wide as you can legally/realistically get) and then a operating range (smaller limits).  You live in the operating range whereas you would adjust the application if/when it goes outside those limits before you hit the "oops" stage.  This helps you avoid having to take a corrective action step where you would have to document, rework or destroy product, etc..  Easier to make baby adjustments than deal with lost product, productivity, etc.

 

Anyway, good luck. Hope this helps somehow....

 

Todd  

 

PS: I've seen a 30% price difference in PAA through different sources, so get multiple quotes.  

[Marshenko]

Definitely with the pricing... yeah.

 

Might be smart either way to "get a quote" from EnviroTech, because then you'll be able to talk with Dr. Howarth about the subject, and he's one of the leading experts in the field of PAA applications.

 

https://envirotech.com/

 

You may want to cross check with the manufacturer's label limits as well (as I've seen manufacturer's limits for a crop that were different than guidance).

 

Another thing that you might want to think about is when setting your limits is how you will test.  Basically, consider what your testing methodology will measure when setting limits.  We use PAA test strips and they go in increments such as 0, 50, 100, 250, 500, 1000 for high range and 0, 10, 20, 50, 85, 160 for normal.  We use two different types of strips to cover both too low and too high applications.  Ideally you would align your operating limits with what you can test for (or find a methodology that lets you test for the limits you have to use). 

 

Finally, if possible, I like to do a correction action range (wide as you can legally/realistically get) and then a operating range (smaller limits).  You live in the operating range whereas you would adjust the application if/when it goes outside those limits before you hit the "oops" stage.  This helps you avoid having to take a corrective action step where you would have to document, rework or destroy product, etc..  Easier to make baby adjustments than deal with lost product, productivity, etc.

 

Anyway, good luck. Hope this helps somehow....

 

Todd  

 

PS: I've seen a 30% price difference in PAA through different sources, so get multiple quotes.  

[Scampi]

I wouldn't recommend test strips for PAA, particularly when spraying direct vs in the wash........the supplier should be able to give you a 3 part test kit.

 

I agree about shopping around.........not just for price, but for efficacy as well  (ask to see lab results)

[Marshenko]

Masters Co. also sells a very easy to use colorimeter which makes testing so, so much easier than doing titrations, which can be a pain if you are using the droppers and not your own pippetors.

 

https://www.masterscoinc.com/

 

Model is MP9700-E ... it was developed in conjunction with EnviroTech.  Here's the PDF - it is at the bottom of page 2:  https://docs.wixstat...a8e6b15d73d.pdf

 

 

 

I wouldn't recommend test strips for PAA, particularly when spraying direct vs in the wash........the supplier should be able to give you a 3 part test kit.

 

I agree about shopping around.........not just for price, but for efficacy as well  (ask to see lab results)

[LostMyMind]

USDA monitors our PAA application for canker purposes.  They use test strips, so we mirror what they use, since that's what they hold us accountable via.  I agree completely that there are more accurate methodologies for monitoring (and we have alternatives in house), but there have been some issues (before me) when the USDA apparently wouldn't accept our test results - just what their strips said.  Ergo - we use the exact same test strips they do.  #SoManyPossibleHashTags

 

 

I wouldn't recommend test strips for PAA, particularly when spraying direct vs in the wash........the supplier should be able to give you a 3 part test kit.

 

I agree about shopping around.........not just for price, but for efficacy as well  (ask to see lab results)

[SQFconsultant]

I see that 100 to 200 is range for surfaces  and my notes show a min of 60 for fruit such as cherries.

Edited by SQFconsultant, 24 April 2019 - 05:21 PM.

[Marshenko]

We use Oxonia Active at 1300-2600ppm, but it is only like 6% PAA...

Edited by Marshenko, 24 April 2019 - 05:31 PM.

[srg0117]

Anybody has any convenient methods to find the concentrations? The test strips seems to be having very less precision.

 

My target range will be 200-250ppm of PAA (Validated already as this is a CCP) and the products are a wide variety of fresh produce.

[kfromNE]

Anybody has any convenient methods to find the concentrations? The test strips seems to be having very less precision.

 

My target range will be 200-250ppm of PAA (Validated already as this is a CCP) and the products are a wide variety of fresh produce.

 

Use a ppm test kit. Usually 4 chemicals to add. Once you do it a lot, you get very fast at it. 

Since it is a CCP - I'd only use a ppm test kit and not strips.