Extending the viability of foods’ resources has a long history, helpingcommunities to survive periods of shortage. Today, the techniques of foodpreservation have evolved but are no less important in conserving thenutritional value of the food as well as the investment in labour and energy.
Aluminium foil plays a valuable role in modern preservation and deliverysystems thanks to its unique combination of properties.
Heat sterilisation using autoclaves has enabled food products to last, inextreme cases, for years without refrigeration. Even with the trend away fromtraditional rigid packaging towards lightweight pouches, such as alufoilcontainers and laminated cartons, the same preservation performance, without theweight and transportation demands, is possible.
Retortable ‘stand-up’ pouches are now a common packaging format with theperfection of coatings and laminates designed to resist autoclave sterilisation. An alufoil layer inthe pouch is essential for full protection against light and gases. The thinlaminate and slim format of the pack enables heat to penetrate quickly to thewhole of the product and also to cool very quickly. This means less overcookedproduct than with traditional cylindrical cans.
Sterilizable pouches are used in a variety of sizes and formats, savingspace and resources. Flexible pouches can also be used for three-dimensionalproducts, such as sausages or fish portions, and will take the shape of thecontents, excluding oxygen before sterilisation.
A high barrier alufoil laminate lid can extend the life of a short lifefresh product due to its heat and pressure resistance. Foil-lidded single ormulti-compartment plastic dishes, give long life protection for baby foods,snack meals, soups and vegetables. Canned foods such as fish are now routinelypacked using high barrier peelable alufoil lidding instead of heavy gaugering-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 ‘shelfstable’ foods. Close collaboration between container producers and ink andcoatings suppliers, allows the lidded alufoil dish to provide an excellentcombination of characteristics. It is compact, attractive in appearance, fullyprotective, yet easy to open and use.
The lightness of the foil and the stacking format of the empty containeroffers space and handling economy during filling . The aluminium finish can beenhanced with coloured lacquers and high quality multicolour printing.Development continues with alloy ‘tailoring’, down-gauging and digital printingtechniques, enabling shorter runs, and economy without loss of performance.
Aseptic filling of foil lined beverage cartons has been a highly successfultechnique. The aluminium foil barrier is a key part of the pack, enabling ashelf life of up to two years. Opening is simple with a perforated tear-off topseam. Cartons save space and resources before and after filling.
Sterilizable cartons are now popular for shelf stable vegetables and meatproducts. The foil-lined carton material makes minimum demands on resources.