Asda has boosted its sustainability credentials with two new product lines.

The retailer has become the first UK outlet to sell king prawns under the Best Aquaculture Practice certification scheme, which guarantees responsible sourcing. The prawns are supplied by Cumbrian Seafoods, which already supplies a range of MSC Atlantic cod and haddock.

It is also trialling a new form of vacuum packaging across its beef range in Northern Irish stores. The packaging replaces traditional 'box packaging' and allows the meat to retain its natural juices for longer, giving extended shelf life.

All the meat in the range is locally sourced from Northern Irish suppliers. "Vacuum packaging has been a chef's secret for years as it's widely known that, being airtight, it locks in the meat's flavour and freshness and allows the meat to gently mature," said Northern Irish chef Paula McIntyre.