Comparative component biodegradation for a polylactic acid (PLA) and cellulose integrated packaging based on the cumulative evolved CO ₂

Abstract

Different bioplastics, such as polylactic acid (PLA) and cellulose, are increasingly used in fresh food packaging because they can constitute integrated and complex preservation systems while increasing sustainability. In this work, the biodegradation of the different components of an integrated packaging system composed of a rigid PLA tray, a heat-sealed PLA film, and cellulose sachets inside is discussed. Biodegradation tests were carried out both under composting and soil burial conditions, both based on the cumulative evolved CO ₂ . The different packaging components were cut into 1 × 1 cm squares to facilitate biodegradation. Nonbiodegradable polymeric materials were included in the tests for comparison. After 60 days, biodegradation between 11.5 and 22.7 % was obtained for PLA under composting conditions, while biodegradation of 3.0–6.8 % was obtained under soil conditions, respectively. The thickness of the PLA sheets considerably affected the degree of biodegradation under the two conditions. For cellulose sheets, biodegradation was 82.4 % and 85.1 % under composting and soil conditions, respectively, while in the case of nonbiodegradable polymers, the values obtained were less than 2.0 % after 60 days. The need arises for the previous separation and preconditioning of this type of material after use in integrated packaging, so that biodegradation occurs under the most favorable conditions.