Placing a living mycelium tablet insert inside existing food packaging can keep produce fresher for longer, according to details laid out in a patent.
The invention provides a method for delaying food spoilage by placing the insert into packaging so that it can absorb oxygen and generate carbon dioxide.
According to a patent published last month, and listing Oliver Poyntz as the applicant, the innovation is based around an insert for prolonging the shelf life of packaging food and especially fruit and vegetables.
The invention proposes a living mycelium tablet insert encased in a perforated polymer film and placed inside existing food packaging that reduces the concentration of oxygen in the atmosphere, through respiration.
This increases levels of carbon dioxide and inhibits the rate of respiration of fruit, vegetables and undesirable microorganisms that cause food spoilage, so keeps produce fresher for longer.
Reducing oxygen concentration below 8% and/or elevating CO2 concentration above 10% also retards ripening in fruit because it delays the effects of ethylene gas.
Once the packaging is opened it can be resealed and the insert will continue to adjust the levels of carbon dioxide keeping fruit and vegetables fresher for longer, claims the patent.
Mycelium is the vegetative part of a fungus and the insert can be manufactured by loosely pressing a suitable, sterile, substrate into a tablet form.
“Once pressed the tablet may then be inoculated with…Enokitake mushroom or any other edible filamentous fungi that is able to cope with 2°C temperatures, which means it is still actively respiring when moved along refrigerated food supply chains.”
The tablets are then heat-sealed in perforated film, according to the patent.
“The film is required as it reduces moisture loss from the tablet once it is placed inside the food packaging, it also stops the food being contaminated with particles from the tablet were it to ever fall apart. If there were too much water lost from the tablet the rate of respiration of the mycelium would slow.
“The tablets are then placed inside existing plastic trays or punnets along with the fruit and/or vegetables before being sealed, e.g. heat-sealed in plastic film bags.”
The patent cites tests indicating that the myceliual inserts keep fruit and vegetables looking and feeling fresher for at least two days longer than standard packaging.
“Some fruit and vegetable packing companies already use modified atmosphere packaging that involves altering the concentration of gases within the packaging,” the patent states.
“The drawbacks of this method are that the machinery used to alter and seal modified atmosphere packaging is expensive when compared to traditional automated packaging machines and once the packaging is opened the modified atmosphere is lost.”
The patent is not the first to see the potential of mycelium, with Sealed Air partnering with Ecovative, the company behind EcoCradle mushroom packaging this year.
Ecovative’s protective packaging is made from agricultural by-products and mushroom roots (mycelium) and has been targeted as a replacement for plastic foam.