7 replies to this topic

[bonnie2018]

Hello everyone, thanks to admin for accepting me in this forum. I am Bonnie Tay , a research officer attached to the Malaysian Palm Oil Board. I am currently conducting storage stability test of a commercial palm olein sample,  I would like to know what is the acceptable range of a commercial oil after they are stored for a duration of time on the supermarket shelf? I have noticed that the PV value of the COA for freshly produced oil usually is very low at about 0.05 meq/kg or lower, but this is not the case for the commercial oil from the supermarket (after a few months  from their reception at the supermarket). The value of the PV seems to have increased to about 5 meq/kg. Is PV meq/kg of 5 -10 acceptable for oil after they have been stored. I don't find the oil rancid even with that value of PV.

[Gerard H.]

Hi Bonnie,

 

That's an interesting research, you are carrying out!

 

I have just been looking a bit around and I found the following:

• The PV values for fresh oils are below 10 mEq/kg
• The exposure to air will increase the PV value, as the oil continues to react with oxygen
• You will clearly remark a rancid taste, when the value become much higher, that means 30-40 mEq/kg (of course, that should be avoided). The best is always to keep the values as low as possible in the supply chain, by applying good practices

I hope that this gives you helpful input for your study.

 

Kind regards,

 

Gerard Heerkens

[Charles.C]

Hello everyone, thanks to admin for accepting me in this forum. I am Bonnie Tay , a research officer attached to the Malaysian Palm Oil Board. I am currently conducting storage stability test of a commercial palm olein sample,  I would like to know what is the acceptable range of a commercial oil after they are stored for a duration of time on the supermarket shelf? I have noticed that the PV value of the COA for freshly produced oil usually is very low at about 0.05 meq/kg or lower, but this is not the case for the commercial oil from the supermarket (after a few months  from their reception at the supermarket). The value of the PV seems to have increased to about 5 meq/kg. Is PV meq/kg of 5 -10 acceptable for oil after they have been stored. I don't find the oil rancid even with that value of PV.

 

Hi bonnie,

 

Edible oils not my field but for retail foods the typical requirement is that the product should comply with its specification at end of declared shelf life.

 

Does the specification for yr product have any specific claim otherwise ? eg only valid at time of production ?

[bonnie2018]

Thanks to Gerald Heerkens for your answer regarding the peroxide value. for this particular commercial oil , the company had  a specification for free fatty acid (<0.1%), moisture and impurities 0.1 % max , but peroxide value is not in the specification . However,  I am not sure whether what is the current practice of industry for specification of the oxidative parameter of the edible oil, not sure is there a requirement that PV, AV and totox value should be included for shelf life specification.  

But in the case of the commercial edible oil I mentioned, although not in specifications, but I had analysed the freshly produced oil , the Peroxide value is very low at 0.05 meq/kg, but as storage progresses the value of PV will also increase . But I had examined other types of edible oil as well which had been in storage for a while ,their PV tend to be about 4- 6 meq/kg . If they are analysed when they first arrived freshly from production site, the PV tend to be <0.1 meq/kg.

 

[Jerome]

Dear Bonnie,

I am interested to this topic? Could you give me a reference on how to proceed when analysing the shelf life of edible oils (or its based products such as mayonnaise)?

With regards

Jerome

Sent from my SM-G903F using Tapatalk

[bonnie2018]

Dear Jerome,

 

For edible oils ( I have no experience with other food item), oxidative parameters such as peroxide value, anisidine value, totox value = 2 x Peroxide Value + Anisidine Value, accelerated test using Rancimat for induction hours measurement are commonly used to test stability of the oil. Other contributing factor e.g. free fatty acids, trace metal content especially iron and copper , moisture and impurities are also measured.

regards, bonnie

[bonnie2018]

Dear Jerome ,

 

You can find reference for shelf life for food products in this book: Oxidative Stability and shelf life of foods containing oils and fats. 2016 AOCS Press. Published  by Elsevier Inc.  Publisher : Nikki Levy, Acquisition Editor:nancy Maragioglio.

[bonnie2018]

Dear Bonnie,

I am interested to this topic? Could you give me a reference on how to proceed when analysing the shelf life of edible oils (or its based products such as mayonnaise)?

With regards

Jerome

Sent from my SM-G903F using Tapatalk

Reference for shelf life

 

 

Title of Book: Oxidative Stability and Shelf Life of Foods Containing Oils and Fats

1st Edition

 

 

Editors: Min Hu Charlotte Jacobsen

eBook ISBN: 9781630670573

Hardcover ISBN: 9781630670566

Imprint: Academic Press and AOCS Press

Published Date: 20th January 2016

Page Count: 564