Pilot plant scale-up of the production of optimized starch-based biocomposites loaded with cellulosic nanocrystals from Posidonia oceanica waste biomass

Posidonia oceanica biomass has been valorized to produce cellulosic nanocrystals with different purification degrees at lab- and pilot plant-scale. The cellulosic nanocrystals (10 % and 20 % (w/w)) were incorporated into corn starch, producing biocomposite films by melt mixing and hot-pressing at lab-scale. Biocomposite films showed remarkable improvements on the mechanical and water barrier performance (up to 10-fold increase in the elastic modulus and 2-fold decrease in the water permeability). Biocomposite packaging structures were also produced at pilot plant-scale by extrusion and thermoforming. Adjusting the plasticizer formulation and increasing the nanocrystals’ loading up to the maximum enabling good processability (10 % (w/w)) allowed the production of trays with enhanced water barrier and mechanical performance, which, unlike the pure starch, kept their shape upon storage. These results highlight the potential of P. oceanica nanocrystals to improve the performance of starch-based packaging structures and demonstrates the potential of the production process to be industrially applied.