Biomedical Engineering Reference
In-Depth Information
particularly, merchandising of these products often results in them being subject to
physical stress through being knocked, dropped, stacked, etc. Consequently, cans
may become dented, jars can be cracked and lids can be loosened. In such circum-
stances, critical parts of the hermetically sealed container can be breached leading
to potential ingress of microbiological contaminants including spoilage organisms
and potential pathogens. It is essential that procedures are in place in-store fi rstly
to minimise the damage to such products through training, use of shelf ready pack-
aging, etc. and also to remove from sale any damaged stock. Normal good practice
is to exclude products where the tamper evident seal is breached, e.g., pop-up lids
or where damage has occurred to a vulnerable region of the can or jar, lids, seals
and seams.
7.8.1.2
Shelf Life
The durability of ambient stable foods is usually dictated by organoleptic
deterioration and not microbiological. While microorganisms may grow in some
products, e.g., bread, modifi ed atmosphere packaged products, etc., these would
generally be as a result of a microfl ora that either has little impact on the product or,
in some cases, may contribute to microbial spoilage, e.g., moulds, spore formers,
etc. The shelf life would be set to take account of these factors and therefore the key
issue for the retailer is to ensure good stock rotation to ensure that products are sold
within their allocated shelf lives. Most grocery items would consequently be labelled
with a 'best before' date (Directive 2000/13/EC (Anon.
2000b
), Regulation (EC)
1169/2011, Anon.
2011b
) that indicates it is not unsafe to eat after the date but that
it may not be organoleptically at its 'best'. Although not microbiological, shelf life
of certain grocery foods such as canned fruit is limited by the slow migration of
metals such as tin into the product and legal limits exist in the EU controlling the
maximum amount of such metals in products, i.e., 200 mg/kg tin in canned foods,
100 mg/kg tin in canned beverages, fruit juices and vegetable juices, etc. (Anon.
2006b
). Consequently, the management of some of these long shelf life products is
important, albeit safety is not usually compromised immediately after the end of
shelf life and so products are labelled with a 'best before' date.
7.8.2
Physical
7.8.2.1
Foreign Body
In addition to the potential microbiological risk presented by damage caused to
cans, jars and other foods in containers during storage and replenishment, the same
practices can impact on the presence of physical hazards entering the product.
While severe damage of this nature tends to result in catastrophic failure, i.e., glass
breakage, less visible damage can occur if damage is less pronounced and can
