NATICK, Mass. (July 28, 2015) -- Scientists at the U.S. Army Natick Soldier Research, Development and Engineering Center, or NSRDEC, are investigating high-barrier, non-foil materials, which have the potential to be lighter in weight, less expensive, and more environmentally friendly than foil-based packaging.
The non-foil materials - which are based on nanotechnology - could be used for military ration packaging and for food packaging that supports deep space missions for NASA. The Advanced Materials Engineering Team, or AMET, part of NSRDEC's Combat Feeding Directorate, or CFD, is working on the nanocomposite materials, which are an ideal packaging choice for shelf-stable processed foods.
Nanocomposite films can improve the barrier, mechanical and thermal properties of non-foil food packaging films.
"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, a materials engineer in NSRDEC's CFD.
Nanocomposite packaging can be lighter in weight and less expensive than foil pouches and can potentially reduce the amount of solid waste, enhance the quality of the rations and reduce the warfighter'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, thus better preserving food freshness and better ensuring safety. The packaging will comply with the meal, ready to eat, or MRE, requirement of maintaining a three-year shelf life. The packaging will maintain up to a five-year shelf life for space applications.
Food sterilization techniques, in combination with proper packaging, play an important role in providing this 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 that the 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 these methods are so attractive for both the U.S. 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, in an effort to not only preserve freshness and food safety, but also 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," Ratto said.
The U.S. Army Natick Soldier Research, Development and Engineering Center is part of the U.S. Army Research, Development and Engineering Command, which has the mission to ensure decisive overmatch for unified land operations to empower the Army, the joint warfighter and our nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.