Week 24 Shelf Life - We've Got SALSA Sussed
Week 24 Shelf Life
Hi Everyone!
Right, last Prerequisite Procedure is here!
This week’s subject is one I’m asked for guidance and
advice about on many occasions.
Shelf Life. The life of the product after production
until it has to be ‘Used By’ or it is ‘Best Before’.
So, what’s the difference?
Use By – The product must be consumed by
the ‘Use By’ the date applied to the pack. It must not be consumed after the
Use By date. After that date, pathogenic bacteria will grow to unsafe levels.
We understand this, because chilled and high-risk products are tested by a
laboratory to validate what the ‘Use By’ date should be. It is necessary to test,
to protect the consumer.
Best Before – The product is better Quality
if it is consumed before the Best Before date. After that date, the quality of
the product declines. Signs of deterioration such as visual quality, odour,
taste will appear. The assessments completed on ambient stable products are
called Organoleptic Assessments, which are sensory tests: Taste, Odour,
Appearance, Texture and Colour. Ambient stable products such as bread, jams,
marmalades, biscuits, cake etc, can be assessed through organoleptic testing
only.
Best Before dates are also applied to products such as
tinned products, and ambient jarred sauces. These types of product have to go
through a thermal process to ensure they are safe, such as sterilisation. These
types of products will require microbiological testing as well as organoleptic
testing.
Getting microbiological testing done for the products
which need it, is essential in order to determine product shelf life. Because,
if you get it wrong, you could cause someone to have food poisoning, become
very sick, be hospitalised and for the vulnerable categories of people, you
could cause death. So yes, this part of launching a product is very important!
After that rather morbid start to this week’s blog, let’s
get started on Shelf Life Controls…
What’s coming next…
Week
25 HACCP Team & HACCP Training
Shelf Life Control - what do you need to show your
SALSA auditor?
Shelf Life Procedure
You need to state in your Shelf Life
Procedure how to carry out the testing to validate that your Use By or Best
Before date applied to you pack is correct. You must show evidence of this.
Evidence comes in the form of laboratory test results or organoleptic
assessment results.
Low Risk Products
For Ambient stable products such
as bread, jams, chutneys and biscuits, you can carry out Organoleptic Testing,
which is a big word, but all it means is Sensory Testing. You have to keep a
sample of the product until the end of its shelf life, and then you need to do Sensory
Testing. You need to assess the following:
·
Appearance
·
Odour / Aroma
·
Texture
·
Taste
·
Colour
You need to document the results
and save them as your Shelf Life evidence.
The quality of these types of
products is affected before the safety of them is affected.
The product is likely to have
signs such as being stale, or soft, or discoloured, crumbly, less flavour, pale
etc as the quality depletes. Mould could present itself, particularly on
products like jam, which is a visual sign that it is not fit to eat. Some
people think that skimming mould off is sufficient and you can eat the rest. However
mould grows roots! The food gives us visual signs for a reason!
You should carry out Organoleptic
Testing when developing a new product, then at the very least annually
thereafter for each finished product. High risk products should also have this
type of assessment carried out on them. They also have to go through
microbiological shelf life testing, which we will come on to next!
It is necessary to keep a sample
of each batch of product you make. This is in case of quality or food safety
complaints. Organoleptic Testing more frequently than annually, is best
practice, and also gives you and your staff a lot of experience in monitoring
quality too. Of course, the frequency depends on how many finished products you
have, and it also needs to be practical for you too.
You need to record your
Organoleptic Testing, so here is an example record you could use for this
purpose. It may need to be tweaked depending on your product type. You can
record the product, batch, the shelf life you applied, then carry out testing
from the Date of Production (DOP) + however many days or weeks is appropriate
for your product type. Record scores for acceptable / borderline /
unacceptable, for each sensory test you do.
High Risk Products
As you can imagine, if you are
producing a High-Risk product, there will be more extensive microbiological
testing to be carried out.
High Risk products include Ready
to Eat (RTE) Chilled products. Long life products such as canned and jarred
need micro testing due to the Clostridium Botulinum risks. This pathogen thrives
in conditions with no oxygen and can have extremely nasty consequences.
There are many considerations.
Firstly, you need to consider all of the ingredients you are using and the
microbiological risks which apply to them. For example, chicken you would need
to consider Salmonella, Campylobacter and Clostridium Perfringens. But
Salmonella does not just apply to chicken and eggs, but also other raw
materials such as nuts, cocoa beans, veg and fruits, which maybe you wouldn’t
expect.
E. coli, you may know comes from
contaminated beef, from the cattle’s intestines. It can also be found in raw
milk or even contaminated vegetables. So perhaps there are some ingredients
which you might not expect to be at risk from these pathogens.
Staphylococcus Aureus comes from humans
and animals. Humans can be carriers of Staphylococcus Aureus, and if they are,
and they are handling your product, at any stage of processing a product, they
could potentially contaminate it. This is one reason why personal hygiene is of
utmost importance. You can control with hand washing. There are many carriers
of this pathogen so it cannot be eliminated from the work force,
And its not just pathogens - you
have yeasts and moulds to consider too!
What I am trying to say, it is so
important to do your homework on your ingredients, and the microbiological
risks they pose to your finished product. I have said it before in previous
blog topics, getting your Raw Ingredient Specifications are extremely
important. They have the microbiological information on them, (amongst a lot of
other information!).
I am telling you all of this
information on different pathogens, as you need to know what microbiological
tests to carry out on you finished product.
In addition to the pathogens, you
need to consider the packaging that you use for the finished product. The type
of packaging can make the product shelf life vary. Every time you change your
packaging, you must send off for a new test, to ensure it is still adequate.
Just like if you change an ingredient, you must test again. Any changes, new
tests must be carried out!
The tests have to be carried out
with the correct storage conditions in mind. You have to state storage
conditions on the pack for the consumer to follow. Tests have to be carried out
according to your storage instructions, and challenged, think of worst-case
scenario.
It is an extremely good idea to
get an expert to help you define the testing required, as it is so important to
get it right.
Microbiological Limits
The limits for Ready to Eat
products are stated in this publication from the Health Protection Agency:
‘Guidelines for Assessing the
Microbiological Safety of Ready-to-Eat Foods Placed on the Market’
This is a very helpful document
and one which I use on a frequent basis. In can be quite daunting trying to
decipher testing limits and results, so getting an expert to do this for you is
an excellent idea.
Laboratories
The laboratory that you use for
microbiological testing may be able to assist with the testing you need to
carry out and provide advice. However, not all of them do. If you are unsure
and need help with this, and many people do, please feel free to get in touch
to discuss what tests you need to be sending your products to the lab for.
Below is a list of labs some of my
clients have used in the past.
Foodtest Laboratories Ltd
Laboratory in South Kirkby,
England
Address: 52 Lidgate Cres,
Langthwaite Business Park, South Kirkby, Pontefract WF9 3NR
Phone: 01977 525289
West Yorkshire Analytical
Services
Laboratory
Address: Nepshaw Ln S, Gildersome,
Leeds LS27 0UQ
Phone: 0113 535 0178
Intertek Food Services
Laboratory
Stoke-on-Trent
01782 822355
ALS Life Sciences
Laboratory in Rotherham, England
Address: Aspen Court Centurion
Business Park, Bessemer Way, Rotherham S60 1FB
Phone: 01709 369699
Eurofins Food Testing UK
Limited
Laboratory
Address: i54 Business Park,
Valiant Way, Coven, Wolverhampton WV9 5GB
Phone: 01902 627200
Sending Samples to a Lab
You will be required to send in a
product, so that the lab can carry out the testing. For shelf life, they will
test the product at several intervals. For example, if you wanted a 10 day
shelf life, the product may be tested on 2 day intervals, such as day 2, 4, 6,
8 & 10. However, you also need to test it over your Required Shelf Life,
so you have at the very least 1 days tolerance, i.e. day 11 and perhaps day 12
is suggested.
If your product is a longer life
product, such as the tinned and jarred products we spoke about previously, then
you would test a week or a month after your Required Shelf Life to add in that
tolerance in too.
Of course, your processing methods
come into play for preventing the growth of the pathogens.
If you receive unexpected results
from the lab, you may require to tweak your processes, or your ingredients. You
may want to add preservatives, extend your cooking times, or lower your pH or
aw. These are all contributing factors to extend your shelf life and to
ensuring that no microbiologic pathogens can grow in your product for the shelf
life you prescribe.
·
Lowering pH increases the acidity, which most
pathogens do not like.
·
Lowering aw (available water) by adding sugar or
salt, removes water from the environment which can reduce and prevent pathogens
growing.
·
Preservatives are usually antimicrobial or
antioxidant, which prevents microbial growth.
·
Introducing or increasing heat treatment
temperatures such as a pasteurisation or sterilisation cook could be another
option.
Each pathogen is different. They
have different resistances to the above controls. As do yeasts and moulds.
A complex subject. One which needs
detailed investigation. For further information, please do not hesitate to
contact me as always!
Well that’s another topic
discussed!
See you next week for my favourite
subject ….. HACCP! I know, I am that
geek, who loves HACCP. Someone has to!
That’s it for now folks!
Have a good week!
Be careful and stay safe!
Ruth
Ruthshawconsultingltd@gmail.com
07732
966 836
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