Modified atmosphere processing could boost quality and shelf-life

Lynneric Potter, Campden’s packaging technologist, Department of Food Manufacturing Technologies, told FoodProductionDaily.com: “Modified atmosphere processing is the preparation of a product in an atmosphere other atmospheric air. It is a novel technique and can be used alongside modified atmosphere packing. ​

“We are researching this technique on a small scale so are using a glove box which we can pump different gases into and reduce oxygen levels to below 1 per cent.”​

Enzymatic browning​

Working through hermetically-sealed gloves in the glove box in an atmosphere of less than one per cent oxygen, researchers were able to dice fruit and vegetables without the enzymatic browning caused by cutting in an oxygen-rich environment. The technique was also used to chop, puree or juice fruit and vegetables.

“There has been limited research carried out in this area but depending on the application, modified atmosphere processing may reduce browning or discoloration of a product by significantly reducing exposure to oxygen​,” said Potter.

When fresh produce is cut, it starts to brown quickly due to tissue damage, PPO (polyphenol oxidase) enzymes oxidise with exposure to oxygen causing browning. “If the oxygen is removed this reaction can be reduced or delayed maintaining the fresh cut colour of the produce for longer without the use of sulphur dioxide,” ​said Potter.

In addition to processing foodstuffs within the glove box, researchers are also studying the effects of bagging and sealing foods in the same low-oxygen environment. After bagging and sealing, the product can be withdrawn through a port which is also atmospherically controlled.

Quality and shelf-life​

Campden acquired the glove box through its participation in an EU-funded project (SO2SAY)​ to replace the use of sulphur dioxide as a preservative but maintain the quality and shelf-life of the product.

If the technique proves successful, Potter believes there is potential for many other applications including fresh produce meat, fish and other foodstuffs.

Modified atmosphere processing and packaging also offers significant potential to extend foodstuffs’ shelf-life but this has yet to be explored.

Campden is unaware of other UK groups using this technique. Although it has traced trials of modified atmosphere processing tested with fish using carbon monoxide to maintain its colour, the technique could not be used commercially in the EU.

Finally, Potter stressed: “This is a very novel technique at the early stages of research​.”