Determining the shelf–life of food products - Part 1

What determines shelf life?  

The time period within which the food is safe to consume or has an acceptable quality to consumersWhen conducting a shelf life study, it is best to do so based upon the food product’s limiting factor•Microbial activity•Chemical or enzymatic activity•Lipid oxidation, browning•Moisture migration

Definitions  

‘Best-before’ means the date until when, provided the food has been stored in intact packaging and in accordance with stated storage conditions, it will be fully marketable and retain its quality.

Chilled foods are those foods that require storage at 5˚C or less to maintain their suitability and safety.

Date marking is the system for packaged foods with a shelf life of less than two years 

Microorganisms include moulds, yeasts and bacteria. Bacteria includes pathogens and spoilage organisms, spore-forming bacteria and those that may cause food poisoning through the production of toxins.

Perishable food is unprocessed or processed food that has a short shelf life at room temperature before showing signs of deterioration or spoilage (often mould or bacterial growth seen as fur or slime), e.g. fruit or pre-packaged bread.

Shelf life is the period of time, established under intended conditions of distribution, storage, retail and use, that the food would remain safe and suitable.

Shelf life testing requires foods to be stored under the expected conditions of storage and distribution for a period of time to determine at what point chemical changes, deterioration and/or spoilage of the food occurs.

Shelf-stable food is food of a type that, because of its composition (low moisture, high salt or sugar content) does not require to be refrigerated for storage or a food which would normally be stored refrigerated but which has been processed so that it can be safely stored in a sealed container at room temperature for a usefully long shelf life.

‘Use-by’ date is the date until when, provided the food has been stored in intact packaging and in accordance with stated storage conditions, it is safe to eat.  

 

Roy Betts, Head of Microbiology, explains predictive microbiology and challenge testing, and how the two complement each other in determining the shelf–life of products.