The current priority for modified atmosphere packaging (MAP) systems for meat and poultry is not to provide improved barrier or longer shelf-life, according to a major supplier, but to create other benefits for consumers and, above all, retailers.
Luc Sauban, European marketing manager for case-ready protein at Sealed Air Cryovac, explained that different grades of ethylene vinyl alcohol (EVOH) layer still met most shelf-life requirements.
He said: "There are other materials that we are exploring, but we don't see a huge demand for higher barrier. Retailers are always looking for longer shelf-life. But then there is always the option of vacuum packaging." In any case, consumers might be wary of fresh products with a much-extended shelf-life, he added.
Instead, system suppliers such as Sealed Air are looking elsewhere.
In the past, contact between the lidding film and packaged red meat, for instance, meant the contact area was starved of oxygen, and this would lead to discoloration. This, in turn, meant that tray walls had to be higher to provide headspace, said Sauban.
The firm says its Mirabella film is a solution. This incorporates an inner permeable layer allowing oxygen to the meat. "This can bring down the size and cost of trays," he said. "It frees up more capacity in transit and on-shelf."
Mirabella has been introduced in France and parts of Central Europe. Trials are underway with retailers in the UK, said Sauban, and the first introduction is expected later in the year.
A further challenge revolves around the viability of biopolymer-based films in barrier and MAP applications. Biome Bioplastics, part of the Stanelco group, is working to improve moisture barrier mainly with its starch-based biopolymers, which tend to naturally absorb water, said md Paul Law.
"We can combine the resin with additives, and we've seen significant improvements here," said Law. The biopolymer can then be coated with a thin layer of EVOH which ... does break down over time, he added.