Accelerated aging / Accelerated Shelf Life Testing (ASLT)

I recently studied about accelerated aging / Accelerated Shelf Life Testing (ASLT). Since it's not my field, it raised some queries which I need be answered by independent experts.

While using the caculator provide on website http://www.accelerated-aging.com/
For values 37, 25 and 2, I got AATD as 159 days for 1-year shelf life claim.

Do manufacturer really do 159 days testing for 1-year shelf life claim or there exist any other accelerated techniques. I fear that keeping in mind the rapid product development and market pressure, 159 days are more than enough.

Also, as I understood, ASLT is primarily used for estimating physical and chemical aging. Could this test be used for microbial activity also? If yes, what could be the maximum testing temperature?

Thanks for any kind of help.

Regards:
M.Zeeshan Zaki.

Accelerated shelf-life testing simply does not work for microbial parameters.
Microorganisms that might spoil your product tend to have a specific temperature at which they will grow, so upping the temperature may supress them and favour other microorganisms.
In my experience manufacturers often do shelf life testing over the course of a year (or longer) as a means to verify the long shelf life they've estimated for their product. It's a tricky area and there's no easy answer for how you can avoid this!

I recently studied about accelerated aging / Accelerated Shelf Life Testing (ASLT). Since it's not my field, it raised some queries which I need be answered by independent experts.

While using the caculator provide on website http://www.accelerated-aging.com/
For values 37, 25 and 2, I got AATD as 159 days for 1-year shelf life claim.

Do manufacturer really do 159 days testing for 1-year shelf life claim or there exist any other accelerated techniques. I fear that keeping in mind the rapid product development and market pressure, 159 days are more than enough.

Also, as I understood, ASLT is primarily used for estimating physical and chemical aging. Could this test be used for microbial activity also? If yes, what could be the maximum testing temperature?

Thanks for any kind of help.

Regards:
M.Zeeshan Zaki.

ASLT time span depends a lot on your selected accelerated temperature, secondly Q10 also change with type of focused parameter i.e. ascorbic acid loss, physical deterioration or rancidity all have different Q10 values. Thus during the calculation of shelf life on the basis of ASLT these details are always considered. The caluclator given in that website works with Q10=2 but not for all requirements of ASLT.
As far as microbiological ASLT is concerned usual practice (for most of the products being stored at ambient temperature) is incubating the product at certain incubation temperature and then conciding it with ASLT for chemical and physical characters of product to calculate the real shelf life.

Dear Zeeshan,

You may find the extract below of interest. This contains a “worked” illustration of the use of ASLT for predicting the possibility of achieving a desired shelf-life (1yr) for a frozen food (pizza) via trials over a shortened time scale at an elevated temperature. As per previous posts the general application is considered to have various reservations.

ASLT in shelf life prediction.png   1.28MB   99 downloads

Rgds / Charles.C