This project is focused on the development of multilayer cellulose-based material structures for active packaging in two different application approaches: moisture control for secondary packaging and antimicrobial protection for primary packaging.
Thus, an active packaging strategy was employed to upgrade and confer new properties to cellulose-based packaging in order to enable more performant applications that can extend product shelf life. The effect of liner papers with and without barrier capacity on modifying the phenomena of adsorption (scavenging) and desorption (release) from active layers was studied. Two active layers were produced: one composed of corrugated fluting paper containing an essential oil compound (carvacrol) with release capacity, and a second one composed of cellulose fiber foam containing calcium chloride with high moisture scavenging capacity. The release of carvacrol was modified by the addition of liner papers, either barrier or non-barrier, resulting in an active corrugated board with controlled release of carvacrol oriented in a specific direction. The moisture scavenging capacity of the active cellulose foam layer was modified by the addition of barrier liners, providing a barrier-shift type property that retards moisture diffusion through two barrier papers for longer periods of time, thereby maintaining stable relative humidity inside packaging. Barrier liner papers employed in multilayer structures significantly modified the desorption/adsorption phenomena of active layers, often shifting from non-linear diffusion to linear diffusion.
The performance of the active multilayer materials was simulated in packaging simulation boxes to observe their behavior. Active corrugated board trays were evaluated for their ability to increase strawberry shelf life, extending it from 6 to 9 days under the same conditions. On the other hand, the active cellulose foam packaging was tested in corrugated board boxes to evaluate its capacity to control moisture inside the headspace of the boxes when external humidity increased.
