Emco has filed a patent for an inclusion in packaging that controls or modifies the atmosphere and ultimately extends shelf life.
The inclusion comprises of a fill material that reacts with water vapour to generate oxygen and absorb or generate carbon dioxide.
There are two versions listed, Standard Product and Water Impermeable, the latter for application in “wet” fresh produce such as prepared fruit and salads, salad meals and ready to eat / ready to cook recipe dishes.
The idea includes an envelope impermeable to liquid water and permeable to water vapour and gases.
It is targeted at whole fresh produce such as soft fruits – strawberries, raspberries, blackberries, blueberries and stone fruit to extend shelf life.
Shelf life improvement
Emco claims that significant improvements in the operational life of the product may be achieved by introducing the control layer with controlled water vapour transmission rate and oxygen transfer rate.
“The inventor, has, however additionally discovered that further benefits may be obtained by selectively modifying the relative composition of the mixture of the compounds by comprising the fill material,” said inventors John Hirst and Nigel Parker.
“The fill material may comprise an active ingredient that generates oxygen and absorbs carbon dioxide when activated by water vapour; and a water vapour control that absorbs water vapour in order to regulate the reaction of the active ingredient, wherein the active ingredient is present in an amount from 25% to 65%, and the water vapour control is present in an amount from 25% to 65%.”
The invention relates to combined oxygen generating and carbon dioxide absorbing or generating packaging inclusions, in the form or a gas permeable envelope, containing a water vapour activated mixture.
How it works
A fill material contained in the envelope, which is activated by water vapour to generate oxygen and absorb carbon dioxide being designed to maintain a predetermined percentage composition of oxygen and carbon dioxide in modified atmosphere (MA) and controlled atmosphere (CA) packaging.
The inventors noted that the envelope is a laminate material which comprises a permeable sealable layer and a control layer of polyamide or polyethylene having a thickness of 10um to 20um.
“The inventors have realised that the control layer should have sufficient gas permeability and allow water vapour to permeate without allowing liquid water to pass. By limiting the water vapour transmission rate and oxygen transmission rate, the operation life of the packaging device in use may be extended.”
The control layer may have a water vapour transmission rate of 10g to 200g/m2 in 24 hours at 1 bar and 23 degrees Celsius and 85% relative humidity and an oxygen transfer rate in the range 650cm3 – 20,000cm3 in 24 hours at 1 bar at 23 degrees Celsius.