4 replies to this topic

[paulkaye]

Hi,

I'm looking at the production of a range of food products which are physically similar to soups; some will be smooth blends and others will be 'chunky'. They will be marketed as 'fresh' and are to be distributed and sold chilled/refrigerated. Due to market and other forces, they will be limited in their preservative qualities:

• No artificial preservatives
• No added sugar/salt
• Average water potential

I'd like to ask the forum the following:

• General observations/comments?
• What shelf-life can I expect to achieve?
• How can I extend shelf-life?

Again, all comments and suggestions should err on the side of caution - I'm a safety nut and the brand wouldn't survive even one scare.

Many thanks in advance,

Paul

[GMO]

Not my field of expertise but I do have experience in ready meals. Typically ready meals with similar properties can acheive 10 day life maximum. There are ways I'm aware of to extend this. I believe some manufacturers hot fill which enables shelf life extension, another possibility is to do post pack pasteurisation so you retort in the sealed filled pack (cook in high temperature / pressure steam to the equivalent of 90 degrees for 10 mins) which should have minimal effect on the eating quality of a soup I suspect. The reason for this is to kill of Clostridium botulinum spores. Not being a microbiologist, I've got no idea how they get around this with hot filling (perhaps someone can enlighten me?) Generally for chilled foods 10 days is the maximum life you'd give unless there is some specific hurdle factor that will prevent C. botulinum growing or you're doing some serious heat treatment.

Edited by GMO, 04 January 2011 - 10:35 AM.

[paulkaye]

Thank you, GMO.

I tend to think of these products as ready-meals so your comments are very relevant. Does your 10-day shelf-life refer to anoxic packaging of any sort (e.g. CO/N2)? I'm surprised botulism is an issue in such a short time - I imagined it would only become an issue after 30 days or so.

[GMO]

Thank you, GMO.

I tend to think of these products as ready-meals so your comments are very relevant. Does your 10-day shelf-life refer to anoxic packaging of any sort (e.g. CO/N2)? I'm surprised botulism is an issue in such a short time - I imagined it would only become an issue after 30 days or so.

It's been advice in the past. This report summarises it nicely although not everyone agrees with it but it was originally based on advice from the advisory committee on the microbiological safety of food. I wouldn't just think of CO2/N2 gas flushed; the environment in the bulk of your soup will be anaerobic irrespective of the head gasses.

http://www.ifr.ac.uk..._report0707.pdf

I suppose the onus would be if you think it's ok after 10 days it would be good practice to prove it or prove the hurdle factors / treatment. There is probably some bunce in that "10 day rule" but I've got no idea where the danger point is and I know ready meal manufacturers in the UK use 10 days as a rule of thumb.

[paulkaye]

Ok, thanks GMO - I'll have a read of that doc and will probably proceed with the 10-day rule in the back of my mind.