Oxygen adversely impacts food flavor and nutrition. NASA’s proposed five-year shelf life for astronaut food requires aggressive measures to minimize oxygen. Previously, NASA packaged foods in containers with a high oxygen and moisture barrier. These materials have limiting properties. They contain a metal layer; therefore, they do not incinerate or melt-compress. As a result, they are a disposal burden. They also have only a three-year shelf life.
A printing ink was devised that removes oxygen from sealed containers. The oxygen scavenging ink removes residual oxygen from packaged foods. Oxygen permeating through the package over time is also removed. Oxygen scavenging packages allow non-foil containers, many with secondary uses.
The iron-containing print resin contains the following components.
1 part acrylic resin composed of: 87% acrylic acid (for iron binding, its acidity aids oxidation), 6.6% sodium acrylate (provides a high degree of water binding), 6.6% Esacure 1 photoinitiator (initiates UV polymerization and is the only photoinitiator FDA-approved for food contact), and 0.3% Trimethylopropane triacrylate (TMPTA) cross-linking compound that inhibits flaking
1 part aliphatic silicon acrylate (adds pliability to the polymer and promotes oxygen penetration)
2 parts iron powder <30 μ (removes oxygen via oxidation-rusting)
1 part MgCI-saturated water (GRAS deliquescent salt, captures moisture needed for reaction chemistry to proceed)
Components were dispensed into a 50mL syringe and mixed within the barrel until uniform. The syringe applied resin to the course (120 point) impression proofing roller. Each peelable lid consisted of four separate applications of iron-containing resin with ten minutes UV curing in an inert gas between each application. Commercial printers allow sequential application of resin and virtually instantaneous UV curing of polymers. Expense and the limited treatment volume made commercial printing impractical for the current prototype study. However, limited print testing with a hand roller indicated that color changes during oxidation of printed iron could provide some tracking of shelf life as oxygen is removed by the printed graphic.
The small business, PROVE IT, LLC, elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to PROVE IT, LLC, 851 Mill Creek Circle, Elgin, IL 60123. Refer to MSC-25145-1