Potential of lignocellulosic fractions from Posidonia oceanica to improve barrier and mechanical properties of bio-based packaging materials

This work reports on the valorization of residues from Posidonia oceanica leaves for the purpose of obtaining lignocellulosic fractions of interest for the development of bio-based materials for food packaging. The lignocellulosic fractions were characterized, thereby confirming the purification of cellulose and showing increases in crystallinity and thermal stability after the consecutive extraction steps. Subsequently, pure lignocellulosic films were obtained and characterized and the pure cellulose film showed the best properties in terms of mechanical performance and water vapor permeability. Finally, composite starch films containing lignocellulosic fractions were developed by melt compounding and characterized. Although the film containing the pure cellulose additive showed the optimum improvement in terms of mechanical properties (with an increase of 85% in the elastic modulus and 38% in the tensile strength), similar water vapor permeability reduction (~40%) was achieved with the least purified fractions, explained by their effect on starch gelatinization, as evidenced by SAXS/WAXS.