Accelerated shelf life study - please help!
We are currently doing trials on testing various stabilizers in our dairy products - namely yogurt, drinking yogurt, flavored milk and also mayonnaise and long life non dairy cooking cream. But real time shelf life analysis takes time so could anyone please guide me if and how I can do an accelerated shelf life study for this scenario? Most information I have seen is for studying the effects of storage temperature or stress tests. I am not sure if that helps here since we want to analyze the effect of the stabilizers? Please help!!!!
Hi Roshni,
Shelf Life / ASLT is quite a wide-ranging (Book size) topic / technique and has many posts on this Forum.
JFI, this 2016 post contains a variety of links to other threads on aspects of shelf life -
http://www.ifsqn.com...ram/#entry99563
These 2 posts (there are many others) contain attachments with substantial info on ASLT -
http://www.ifsqn.com...ant/#entry96746
http://www.ifsqn.com...ood/#entry59745
You could also search for "alst" via this page -
Thanks Charles. But my query remains unanswered All the articles on ASLT I have seen deals with temperature and humidity effects. My query is: if we are formulating same product with different stabilizers to confirm which stabilizer works best, how can we apply ASLT in this case? For e.g. We are testing for cooking cream which is a long life product with 6 months shelf life. To compare the different formulations if we do real time shelf life analysis, we have to wait 6 months to know which stabilizer is good There would be a practical way of doing this? Please advise. Thanks.
Hi r.raju,
The difficulty with generalising shelf life, and ALST, is the variety of possible scenarios. There are whole books on this topic which typically have a chapter on ALST but which IMEX are often regrettably short on actual examples. It's a probably lucrative business for food specialists.
Briefly, the necessity as per the various refs is -
(1) to determine whether (a) safety/(b) non-safety criteria are to be prioritised, eg (a) L.monocytogenes vs (b) flavour. (Product/Presentation/Packaging / storage temperature are relevant).
(2) specify the determining criteria for shelf life from within the selected (a,b).
(3) Evaluate the possibility of applying ALST. The relevant, basic, formulae are given in the attachments linked in post 2 whoser implementation IIRC builds on case-by-case knowledge of (2) above. A few specific examples using various criteria are on the net.
No direct experience on stabilizers but based on the model iso/fssc22000 haccp plan for yoghurt on this forum i anticipate that "b" is relevant for traditional types. Perhaps you already know your appropriate organoleptic(?) criteria for (2)?
PS - long life yoghurt, etc is a specialised area and is also discussed on 1-2 threads here.
Hi r.raju,
most of such testing using Q10 (-> Arrhenius) which means the basis in a (pseudo) first order kinetic to get a linearity you need to extrapolate. First order means you should have only 1 variable e.g. temperature - all other parameters should be kept constant. This is hard to achieve in complex matrices like food. Another problem is that effective testing is in many cases not possible because you can not apply high temperatures (the higher the delta to your storage conditions the better for testing), e.g. a chocolate covered biscuit will be modified heavily with increasing temperature.
Which parameter(s) can be measured a) which show sufficient relation to stability b) with sufficient sensitive methods? Sensory test gives a good idea but are hard to quantify for this purpose.
Microbial effects are hard to interpret especially if you have a flora of several mircoorganisms.
Oxidation is critical especially if autoxidtion is involved (reaction of radicals which cannot be described by this mathematics).
and,,,and ..etc.
I have used such testing for pharmaceuticals and medical devices with good experience. Such pharmaceuticals contains e.g. an active ingredient (sensitive analytical method available) in an defined inert matrix. ALST was very suitable for shelf life which has to be varified by real time testing afterwards.
In food industry I have used ALST only to get an impression on stability (e.g. after changing of fat based ingredients) but never for quantification and determination of shelf life.
Rgds
moskito