Packaging technology that can reduce plastic use by 25% and extend the shelf life of fresh produce is set to appear across several major retailers.

The Integrity Seal system has already been adopted by M&S across its entire salad range, but now Asda is conducting trials with its salad suppliers Yorkshire Fresh Foods and Kane Foods.

The technology works by using thinner-gauge film and 'welding' the seams, rather than using the standard crimping technique.

It has the added benefit of extending the shelf life of produce by up to three days.

Another un-named retailer is also conducting trials, as is biscuit and snack manufacturer UB, according to the Waste & Resources Action Programme (Wrap), which helped develop the technology.

Consumer feedback had been strong, said Wrap, which now plans to extend the system to close the back seals of bags, further improving shelf life and plastic savings.