8 replies to this topic

[sutan77]

Hi

 

I would like to know the acceptable PV in foods such as nuts, high fat oil, shortening. I heard PV above 10 mEq/Kg will accelerate rancidity within storage time. Does anyone know if any references within food industries support this statement.

 

We are producing packed frying nuts, flat bread, chips. Rancidity always a big topic. It affected our FG. What is the best way to monitor rancidity as an indicator? PV is one of them but not clear what the limit is.

 

Thanks

[Charles.C]

Hi

 

I would like to know the acceptable PV in foods such as nuts, high fat oil, shortening. I heard PV above 10 mEq/Kg will accelerate rancidity within storage time. Does anyone know if any references within food industries support this statement.

 

We are producing packed frying nuts, flat bread, chips. Rancidity always a big topic. It affected our FG. What is the best way to monitor rancidity as an indicator? PV is one of them but not clear what the limit is.

 

Thanks

 

Chemical analysis of Foods /Pearson (paraphrasing) states that fresh oils usually have peroxide values well below 10 mEq/kg. A rancid taste is often just noticeable for peroxide values between 10 and 20. However, in interpreting such figures, it is necessary to take into account the particular oil or fat involved.

 

Note that the text refers to  2 varieties of rancidity, oxidative and ketonic. The peroxide value is particularly associated with the former.

 

Other parameters such as the Iodine value are also relatable to tendencies to oxidative rancidity.

 

IMEX of frying oils, FFA is a convenient process monitor. Opinions vary as to limits (and also depending on  the process/food/oil type/customer). Values in the 1-2% range are quite common IMEX for refined oils.

[sutan77]

Hi Charles

 

Thank you for your response

 

Agreed to the point of original manufacturer positive release of PV from supplier perspective. Refined oil or high fat products/raw material PV result approx 0.01 to 2 mEqO2/Kg. I believe the result was taken from the day of RM manufactured. 

 

As customer perspective or secondary manufacturer would be different. We could received the RM 6 months after the RM manufactured. I don't think PV value in the original COA is acceptable.

 

One example case, we received peanuts with 4 months left of shelflife. The COA result is 0.1 mEq/kg and spec from original manufacturer stated PV <3 mEq/kg. We tested the peanut upon delivery and the result was 5.8 mEq/Kg. Technically it is out of spec but nothings wrong with the product.  

 

I would like to set the acceptable PV value from customer or secondary manufacturer perspective. Hope there were industrial reference to support statement of "A rancid taste is often just noticeable for PV between 10-20" hence I can mitigate product rancidity risk by setting-up rejection level from PV.

 

Kind Regards

 

Sutan77

[Charles.C]

If you receive oil where the PV is not compliant with the seller’s spec.  I suppose you  have grounds for complaint.

Regarding rancidity, do note the PV caveat in my previous quote. Presumably based on the author's experience.

 

The spec. you mention was perhaps optimistic as, for example, compared to Codex, eg –

 Codex STAN 210.pdf   909.07KB   545 downloads

 

Some other specs seem even more "cautious", eg -

 tpeanut_nf.pdf   74.96KB   336 downloads

 

Maybe there is a cost-related aspect also ?

[dv8dawn]

^{Wow thats quite informative...thanks buddy!}

[sutan77]

Thanks Charles!!! The codex document is really informative. I can use it as reference of acceptable PV after storage.

 

The spec from original manufacturer was not optimistic but more realistic from my perspective. If they put <10mEq/Kg as acceptable PV after manufacturer means no storage time allowed. If the shelflife of RM is 12 months and manufacturer would release RM with 9.88 mEq/Kg. The defect will be carried over by the trader or 2nd manufacturer like us. The RM will be detoriated before 12 months but we can't reject it because it was within spec. 

 

Thanks again for the info!

 

Regards

 

Sutan77

[Charles.C]

Thanks Charles!!! The codex document is really informative. I can use it as reference of acceptable PV after storage.

 

The spec from original manufacturer was not optimistic but more realistic from my perspective. If they put <10mEq/Kg as acceptable PV after manufacturer means no storage time allowed. If the shelflife of RM is 12 months and manufacturer would release RM with 9.88 mEq/Kg. The defect will be carried over by the trader or 2nd manufacturer like us. The RM will be detoriated before 12 months but we can't reject it because it was within spec. 

 

Thanks again for the info!

 

Regards

 

Sutan77

 

You're welcome.

 

These additional data/links might be of interest for background.

 

 oxidative stability of oils.pdf   194.25KB   290 downloads

 

http://inhumanexperi...e-best-for.html

 

http://authoritynutr...y-cooking-oils/

[osmoses]

Thank you Charles for this information

[mus]

Hello, 

 

Anyone has an idea about the peroxide value in cheese?

 

Thanks