As innovations in processing prolong the shelf life of beverages, so too are developments in packaging. Liquid board packaging is an example of how the industry can meet both the retail and consumer demands of preserving the quality and freshness of beverages, says Raymond Dube, Nampak Liquid Cartons Managing Director.

With the rise in demand for fresh, healthy products by consumers, along with many retailers requiring an extended shelf life of products to reduce waste, packaging has just as an important role to play as processing in ensuring that the quality of beverages is preserved.

Ensuring shelf life is one of the key functions of Liquid Board Packaging (LBP), as well as protecting the product from spoilage and tampering, while guaranteeing freshness and hygiene. Thanks to advancements in packaging design technology, these functions can be fulfilled, where every aspect of the LBP carton, from its materials to its seal and shape, has been developed for a specific purpose in keeping goods safe on the shelf for future use. 

Providing barrier protection
For milk and dairy products, fruit juices and other liquids stored in LBP cartons, barrier protection is critical in maintaining the quality of the product and prolonging its shelf life. Exposure to light, oxygen, heat, micro-organisms, and other physical and chemical factors, makes the beverage susceptible to degradation in quality. If fruit juice is exposed to strong UV light, for example, this can cause a reaction with certain vitamins to result in changes in composition, colour, and flavour. 

LBP cartons are made up of various layers, which are essential to food protection. Poly-coated boards are suitable for low-acid beverages, such as milk and mageu, while alu-coated boards are preferred for liquids with a high acid content, like fruit juices and wine. Made from virgin wood, the paperboard acts as an effective insulator keeping products colder for longer, as well as providing rigidity and strength, so that the product inside the carton is less affected by fluctuations in its environment. Cartons also excel because they have much better light barriers than other competing packaging substrates like glass or plastic.

High seal integrity
How the carton is sealed and capped is equally important for a product’s shelf-life. Fresh beverages in cartons distributed through the cold chain typically use a single tamper evident cap. Longer shelf-life product distributed at ambient temperature and merchandised on shop shelves tend to use double tamper evident closures. This second seal makes the carton airtight and protects the products for longer.   

These Two-step openings for liquid cartons require firstly unscrewing the cap and then pulling out the lug. This double tamper evidence ensures freshness, preventing oxygen and light from entering the carton and affecting the beverage’s quality. In addition, many consumers feel reassured by the extra precaution for hygiene and safety.

Why appearance matters
LBP gable-top cartons have been designed to be space-efficient, not only for manufacturing, filling, and distribution purposes, but for storage and shelf life. 

The square shape of the carton allows for the optimisation of volume and surface area on the shelves. As the cartons butt-up against each other there is no space for warm air to circulate between them and affect their temperature. Therefore, the cartons help each other and the beverage there in stay cold. 

Meeting current consumer demands
As consumers are seeking more sustainable solutions when it comes to packaging, manufacturers must find innovative ways to ensure that shelf-life is not compromised while developing eco-friendlier alternatives for packaging perishables.

Nampak’s two-litre PurePak gable-top milk carton is a recent innovation that combines the need for prolonged shelf-life with the demand for sustainable packaging. The brown carton is made from unbleached board and therefore has a better light barrier. The board is from responsibly managed FSC certified forests and is 100% recyclable in South Africa. 

Eliminating the bleaching process keeps the fibres stronger, which means that less board is required for each carton, reducing its carbon footprint while increasing rigidity. Additionally, the carton runs on existing filling lines without modifications in machine settings. After the milk is heat treated to reduce the microbial count beyond normal pasteurisation, it is packaged under ultra-hygienic conditions to extend the shelf life to 35 days under refrigeration. 

Packaging is an essential means in extending the shelf life of beverages. Through development and innovation, liquid gable-top cartons are well positioned to meet the demands for product integrity, quality, freshness and sustainability, to the consumer. Elopak, Nampak’s licensor for Purepak cartons, have produced their 1 billionth brown board carton! A remarkable accomplishment, in testimony of the markets desire for sustainable packaging.