Shelf Life Validation Frequency

Good day!

We are going to start our shelf life study next month (Jan) for our vegetable oils (crude and refined coconut oil) and copra expeller cake (ingredient for feeds).  We plan to validate 6 months and 1 year shelf life claims.

We have a chemical lab capable of doing FFA, Color, Iodine Value, Moisture Content, sensory test. We plan to conduct these quality tests every month for a duration of one year.

We do not have a micro-biology lab (for testing of e-coli, salmonella, etc ). 

My question is:  What is the frequency and intervals that we should send/test samples of our product to an outsource laboratory for validation and verification of the required tests? (chemical, physico-chemical), micro-bio, functional, sensory, etc).

All we are sure of is the to test the baseline(1st month), after 6 months, and after 12 months.  I was told by the outsource lab that we must test seven samples (or frequency of seven sample tests in the course of one year) for a shelf life of 12 months?  Can someone please validate this info?

Thanks and looking forward to your replies.

Good day!

 

We are going to start our shelf life study next month (Jan) for our vegetable oils (crude and refined coconut oil) and copra expeller cake (ingredient for feeds).  We plan to validate 6 months and 1 year shelf life claims.

 

We have a chemical lab capable of doing FFA, Color, Iodine Value, Moisture Content, sensory test. We plan to conduct these quality tests every month for a duration of one year.

We do not have a micro-biology lab (for testing of e-coli, salmonella, etc ). 

 

My question is:  What is the frequency and intervals that we should send/test samples of our product to an outsource laboratory for validation and verification of the required tests? (chemical, physico-chemical), micro-bio, functional, sensory, etc).

 

All we are sure of is the to test the baseline(1st month), after 6 months, and after 12 months.  I was told by the outsource lab that we must test seven samples (or frequency of seven sample tests in the course of one year) for a shelf life of 12 months?  Can someone please validate this info?

 

Thanks and looking forward to your replies.

Hi Artemis,

The frequency probably depends on a variety of factors, eg Product specification/actual compliance, relevant criteria for shelf-life, absolute/rate of change of relevant criteria, specific methodology of testing (eg direct/indirect).

Personally I would ask the lab as to their basis for number of samples/frequency. Offhand, their frequency sounds not unreasonable for a "stable" type situation/direct testing.

From a micro standpoint there are two ways to do a shelf life study, one is to send your samples periodically to be tested (or send one large batch and have the lab test them periodically) and see what microorganisms levels are like; or two is to do a challenge study where spoilage organisms and pathogens are actually introduced into the product and they are monitored over the course of your product's shelf life.

The major drawback of the first option is that if there are no microorganisms of concern in your product at the start of your study, then you will see no change through the shelf life. This can give a false sense of security if, for example, there is no mold in the product when you begin, but you are seeing mold as an issue from customer complaints.

A challenge study on the other hand will actually show you how quickly your product will spoil if these organisms are present. This is much more valuable because if your product is clean, great! But if something gets in there, you want to make sure it is either killed (pathogens), or at least maintained at low levels (spoilage organisms). 

Hope this is helpful!

From a micro standpoint there are two ways to do a shelf life study, one is to send your samples periodically to be tested (or send one large batch and have the lab test them periodically) and see what microorganisms levels are like; or two is to do a challenge study where spoilage organisms and pathogens are actually introduced into the product and they are monitored over the course of your product's shelf life.

 

The major drawback of the first option is that if there are no microorganisms of concern in your product at the start of your study, then you will see no change through the shelf life. This can give a false sense of security if, for example, there is no mold in the product when you begin, but you are seeing mold as an issue from customer complaints.

 

A challenge study on the other hand will actually show you how quickly your product will spoil if these organisms are present. This is much more valuable because if your product is clean, great! But if something gets in there, you want to make sure it is either killed (pathogens), or at least maintained at low levels (spoilage organisms). 

 

Hope this is helpful!

Hi Ebb,

The challenge study you introduced looks more like a CCP validation for me. We did this challenge study for kill step validation, where Enterococcus facilum was used as an Salmonella surrogate. For shelf life validation, I'm not sure if you can actively introduce pathogen into product, and test for its growth. That implies a failure of kill step IMO. 

From my limited experience, shelf life validation is done either under standard storage condition, or by accelerated shelf life study (temperature and humidity modified). Trend analysis is done through out the shelf life on multiple samples. However there must be more methods on different food category, and I'm really interested in this part.

Hi BostonCream,

The lab we work with does the two studies you mention. I should say that, depending on product, accelerated shelf life study can sometimes yield different results than standard (or at least it has in our case). I would suggest Artemis check with the lab about appropriate intervals for the product in question. 

Hi Artemis,

I should also mention that the intervals your lab brings up are what we use for standard stability. Our lab allows us to discontinue testing, however, at any interval in which the product fails the specified limits. So the "must" in the seven sample requirement shouldn't be something carried on if there is no need for it. Hope this is helpful. 

Hi Ebb,

 

The challenge study you introduced looks more like a CCP validation for me. We did this challenge study for kill step validation, where Enterococcus facilum was used as an Salmonella surrogate. For shelf life validation, I'm not sure if you can actively introduce pathogen into product, and test for its growth. That implies a failure of kill step IMO. 

 

From my limited experience, shelf life validation is done either under standard storage condition, or by accelerated shelf life study (temperature and humidity modified). Trend analysis is done through out the shelf life on multiple samples. However there must be more methods on different food category, and I'm really interested in this part.

The challenge study with pathogens is more of a CCP validation, I should not have included it, but when you challenge your product with molds, yeasts, lactics and analyse them over the course of your shelf life, it will give you data on what would happen to your product when these organisms end up in there. Spoilage organisms could be introduced into your product post heating process or other CCP (from air, gmp failure, etc) and can be what cause your customer complaints. If you do a shelf life on your product without actually introducing the spoilage organisms you can't conclude at the end of your shelf life that your product is stable for that period of time. If there were no spoilage organisms present to begin with, then you will get no data about microorganism behavior from this type of study. 

This is not something that is done at your facility, this is done at the laboratory. You provide samples, the lab inoculates them, and evaluates them over time. 

Using a surrogate at your facility is definitely for CCP validation, you are testing how your process in your plant is working.