Extending the viability of foods’ resources has a long history, helping communities to survive periods of shortage. Today, the techniques of food preservation have evolved but are no less important in conserving the nutritional value of the food as well as the investment in labour and energy.
Aluminium foil plays a valuable role in modern preservation and delivery systems thanks to its unique combination of properties.
Heat sterilisation using autoclaves has enabled food products to last, in extreme cases, for years without refrigeration. Even with the trend away from traditional rigid packaging towards lightweight pouches, such as alufoil containers and laminated cartons, the same preservation performance, without the weight and transportation demands, is possible.
Retortable ‘stand-up’ pouches are now a common packaging format with the perfection of coatings and laminates designed to resist autoclave sterilisation. An alufoil layer in the pouch is essential for full protection against light and gases. The thin laminate and slim format of the pack enables heat to penetrate quickly to the whole of the product and also to cool very quickly. This means less overcooked product than with traditional cylindrical cans.
Sterilizable pouches are used in a variety of sizes and formats, saving space and resources. Flexible pouches can also be used for three-dimensional products, such as sausages or fish portions, and will take the shape of the contents, excluding oxygen before sterilisation.
A high barrier alufoil laminate lid can extend the life of a short life fresh product due to its heat and pressure resistance. Foil-lidded single or multi-compartment plastic dishes, give long life protection for baby foods, snack meals, soups and vegetables. Canned foods such as fish are now routinely packed using high barrier peelable alufoil lidding instead of heavy gauge ring-pulls offering economy coupled with ease of use.
Originally used for small portion packs of patés and fruit conserves, sealed smoothwall containers are now used successfully for all types of ‘shelf stable’ foods. Close collaboration between container producers and ink and coatings suppliers, allows the lidded alufoil dish to provide an excellent combination of characteristics. It is compact, attractive in appearance, fully protective, yet easy to open and use.
The lightness of the foil and the stacking format of the empty container offers space and handling economy during filling . The aluminium finish can be enhanced with coloured lacquers and high quality multicolour printing. Development continues with alloy ‘tailoring’, down-gauging and digital printing techniques, enabling shorter runs, and economy without loss of performance.
Aseptic filling of foil lined beverage cartons has been a highly successful technique. The aluminium foil barrier is a key part of the pack, enabling a shelf life of up to two years. Opening is simple with a perforated tear-off top seam. Cartons save space and resources before and after filling.
Sterilizable cartons are now popular for shelf stable vegetables and meat products. The foil-lined carton material makes minimum demands on resources.