Characterization of biodegradable/non-compostable films made from cellulose acetate/corn starch blends processed under reactive extrusion conditions

Abstract

The manufacture of food packaging materials from food hydrocolloids has been widely studied during the last decades and multiple alternatives have been investigated, with research mainly focusing on improving the physicochemical and mechanical properties of the different materials. Processing food hydrocolloids by reactive extrusion (REx) for the development of food packaging has, however, been poorly studied. Four film systems were prepared from corn (Zea mays) thermoplastic starch (TPS) containing either cellulose acetate (C) or chromium octanoate (Cat -a potential food grade catalyst), or a blend of both (C + Cat). Processing was done under REx conditions using a twin-screw extruder. An exhaustive study of the resulting materials was carried out in terms of the structural, physicochemical, thermal, surface, mechanical and compostable properties related to their potential use in food packaging applications. The most hydrophobic material was the C-containing film. However, this physicochemical behavior was different on the film surface, thus suggesting molecular rearrangements within the material. The Cat-containing films were darker than the other materials. The mechanical behavior observed in the Cat-containing films was particularly interesting as it suggests that these film systems could be used as shape memory materials for food packaging applications, as long as the following mechanical conditions are not exceeded: 5.02% strain and 0.43 MPa stress. All the films tested were biodegradable. We confirmed that Cat-containing film systems produced non-compostable materials at high concentrations (1 mg/mL), as measured by its effect on lettuce seedlings. This confirms that biodegradable materials are not necessarily compostable.

Recent advances in starch‐based films toward food packaging applications: Physicochemical, mechanical, and functional properties

“…Films should also be transparent and clear in color to meet the aesthetic demands of consumers. Other considerations include UV transmittance, sensory properties, toxicity, and biodegradability or compostability (Gutierrez, Toro‐Marquez, Merino, & Mendieta, 2019; Herniou–Julien, Mendieta, & Gutierrez, 2019; Osorio, Aznar, & Nerin, 2019). Heat sealing is another important property for many packaging applications that hinders the practicality of simple starch film formulations.…”

Use of Statistical Design Strategies to Produce Biodegradable and Eco-Friendly Films from Cashew Gum Polysaccharide and Polyvinyl Alcohol

“…Moreover, after polymerization, films were submitted to washes for removal of unbound polysaccharides, which may have affected the amount of material retained in the film network. In general, the thickness values of the produced CGP/PVA films were similar to those from commercial chitosan-starch films [33] and lower than those from cellulose/acetate/starch [34] and cellulose/polymethacrylate blended films [26].…”

Essential Oil-Containing Polysaccharide-Based Edible Films and Coatings for Food Security Applications

“…The polymer was recently explored in conjunction with chitosan to develop nano-zinc oxide reinforced food packaging films [ 17 ]. Cellulose acetate (CA) is another semisynthetic cellulose derivative that has been explored for food packaging applications [ 18 , 19 ]. Some of the other cellulose derivatives that have been extensively explored as coating materials in both food and pharmaceutical industries include hydroxyethylcellulose (HEC) [ 20 ] and hydroxypropyl methylcellulose [ 21 ], in coating materials for enteric-coated tablets and capsules.…”