Potential of extrusion-blown poly(lactic acid)/cellulose nanocrystals nanocomposite films for improving the shelf-life of a dry food product

The potential of neat poly(lactic acid) (PLA) and PLA/cellulose nanocrystal (CNC) blown films in extending the shelf-life of crackers, a moisture-sensitive food product, was assessed. Product's shelf-life, i.e., the time required by the crackers to reach its critical moisture content (CMC) of 8%, was determined experimentally from moisture content versus storage time plots at a constant temperature (25 degrees C) and various conditions of relative humidity (RH). Neither crackers within PLA nor PLA/CNC packages reached the CMC when stored below 50% RH at 25 degrees C, indicating that crackers packaged in both films were shelf stable at these conditions. Above this RH, the crackers inside both packages reached the CMC at different times, however crackers in CNC-based packages had approximately 40% longer shelf-life than those in neat PLA package. The shelf-life of crackers packaged in films predicted from various simulation mathematical models supported the experimental data that the crackers packaged in the PLA/CNC films had higher shelf-life compared to those packaged in neat PLA films; clearly demonstrating the potential of CNC-based films to extend the shelf-life of dry-foods.