Non-foil materials are lighter in weight, less expensive, and more environmentally friendly than foil-based packaging.
Nanocomposite materials incorporated into packaging
The Advanced Materials Engineering Team (AMET) is developing nanocomposite materials, which can be incorporated into packaging for shelf-stable processed foods.
"The incorporation of nanotechnology into barrier films has proven to be a critical ingredient in our packaging design that will allow us to achieve food protection properties only seen before through the use of foil-based systems," said Dr. Christopher Thellen, materials engineer, NSRDEC Combat Feeding Directorate (CFD).
NSRDEC is located at the US Army Natick Soldier Systems Center in Natick, Massachusetts, under the Army’s Research, Development and Engineering Command (RDECOM).
According to Thellen, nanocomposite packaging is lighter and less expensive than foil pouches and can reduce the amount of solid waste, enhance the quality of the rations and reduce a soldier’s logistical burden.
The technology is based on the incorporation of nano-clay particles into thermoplastic resins. The nanocomposite materials are 1,000 times smaller than conventional composite material fillers.
The high-barrier, non-foil material will decrease the permeation of oxygen and water molecules through packaging materials, preserving food freshness and safety.
The packaging will comply with meal, ready to eat (MRE), with a three-year shelf life and packaging for space applications will have a five-year shelf life.
Retorting - most common sterilization process for pre-packaged, low-acid foods
Food sterilization techniques, in combination with packaging, also play a part in extended shelf-life protection.
Retorting is the food industry's most common commercial sterilization process for pre-packaged, low-acid foods.
This process exposes food packages to high moisture and high temperature conditions. In some cases, the long retort process causes severe thermal impact to the food and the package, leading to a reduction in food quality and limiting the types of packaging materials that can be used.
Dr. Jo Ann Ratto, team leader, AMET, NSRDEC CFD, said implementation of a non-foil structure into food packaging will provide the ability to consider novel sterilization methods, such as microwave-assisted thermal sterilization, or MATS, and pressure-assisted thermal sterilization, or PATS.
MATS and PATS are desirable alternatives to retort sterilization as these methods reduce the time needed to raise the product temperature to that required for the thermal lethality of target bacteria.
A shorter process time can improve food quality and nutrient retention, which is one reason why these methods are favoured by the US military and NASA.
AMET is exploring polymeric packaging for these novel methods in collaboration with CFD's Food Processing Engineering & Technology Team. The two teams are also studying the effect of the various processing methods on vitamin stability, to preserve freshness and food safety and prevent nutrient loss.
"The nanocomposite research and development work has been challenging and rewarding for the Advanced Materials Engineering Team. After further demonstration and validation work, we will know if these materials have acceptable performance to be considered for incorporation into ration packaging for the warfighter," added Ratto.