Shelf life of Foods

What is Shelf Life?

The reference to “shelf” clearly implies that the term is related to the commercial life of the product, thus to a packaged product, delivered through the common routes of distribution, not to a generic, “natural life.”

Shelf life is defined as the period of time under defined conditions of storage, after manufacturing or packing, for which a food product will remain safe and be fit for use. During this period, a food product should retain its desired sensory, chemical, physical, functional or microbiological characteristics and, where appropriate, comply with any label declaration of nutritional information when stores according to the recommended conditions. Therefore, it is obvious that shelf life is a very important and multifaceted requirement of all manufacturers and processed food products.

The safety of food is both a fundamental and legal requirement. It follows that all food product offered for sale must be safe although they do not necessarily have to be of the highest quality.

Since shelf life is such an important requirement, it should be of interest to everyone involved in the food chain. There is the growing realization that a high standard of food safety can only be achieved by adopting a comprehensive and integrated approach, covering the whole of the food chain “from farm to table”. At the other end of the food chain, consumers, too, have a significant part to play. For instance, by minimizing the exposure of foods to high temperatures, particularly during summer months, and by observing carefully any recommended storage and usage instructions, consumers are ensuring that the intended shelf life of their food will not be reduced.

Who is responsible for determining the shelf life?

The responsibility for determining the shelf life of the product lies with the manufacturer or the packer. While ideas for new products and for improvements to existing products can originate from within a food business and from external sources such as a current or prospective customer, shelf-life evaluation and testing as very much integral parts of every product development programme. Today, almost without expectations, retailers do independently evaluate the shelf life of food products, particularly their own-label ones.

Labelling of shelf life

Food labelling regulations that apply to all food that is ready for delivery to the ultimate consumer or to a catering establishment, subject to certain expectations, is that it should be marked labelled with the appropriate minimum durability indications.

• In the case of food that is highly perishable and in consequence likely after a short period to constitute an immediate danger to health, a “use by” date.
• In the case of food other than one specified above, an indication of minimum durability, a “best before date”.

The ‘best before ’ date and the ‘used by’ date must be followed by any special storage conditions which need to be observed, such as ‘keep refrigerated at 0°C to +5°C’ or ‘keep in a cool, dry place”. The date of minimum durability is defined as the date until which the foodstuff retains its specific properties when properly stored.?

Food that requires ‘use by” dates are following:

• Dairy products, e.g. dairy-based desserts.
• Cooked products, e.g. ready-to-eat meat dishes, sandwiches
• Smoked or cured ready-to-eat meat or fish, e.g. hams, smoked salmon fillets.
• Prepared ready-to-eat foods, e.g. vegetable salad such as coleslaw.
• Uncooked or partly cooked pastry and dough products, e.g. pizzas, sausages rolls.
• Uncooked products, e.g. uncooked products comprising or containing either meat, poultry or fish.
• Vacuum or modified packs, e.g. raw ready-to-cook packed in modified atmosphere.

The range of product which is given ‘use by’ date differs from country to country. It is the manufacturers and processor’s responsibility to decide to which category their products belong and whether a ‘use by’ or ‘best fore’ date is an appropriate indication. In general, the date must be given as a day, month, and year.?

For the ‘best before’ date category, the following forms of durability indication are allowed:

• Food that will not keep for more than 3 months- ‘best before’ followed by the month and the month.
• Food that will keep more than 3 months but not more than 18 months- ‘best before end’ followed by the month and the year or the year only.
• Foods that will keep more than 18 months- ‘best before end’ followed by the month and the year or the year only.

Since food deteriorates continually rather than suddenly, the ‘best before date’ does not automatically mean the food is not fit for consumption or losses all its acceptability immediately after the date.

Once a date mark either ‘use by’ or ‘best before’ is set and declared, it becomes a contract between the food company and its customers to the effect that, provided the food is stored according to the recommended conditions, it should last at least as long as its states shelf life.

Shelf life is defined as the length of time a product may be stored without becoming unsuitable for use or consumption. Shelf life depends on the degradation mechanism of the specific product. Most can be influenced by several factors: exposure to light, heat, and moisture; transmission of gases; mechanical stresses; and contamination by things such as microorganisms.?