Chemical composition and mesophilic anaerobic digestion of commercial compostable food packaging: Implications for bio-waste management

Abstract

This study assessed the chemical composition and mesophilic anaerobic biodegradability (BI) of 34 commercial compostable food packaging products, including sixteen bags, twelve coffee capsules, and six other products (cups, forks and straws). Thermogravimetric analysis and spectroscopy techniques allowed to determine the proportions of polymers (PLA, PBAT, PBS, PHBV, PE, cellulose, and starch) and additives (inorganic and organic). Six compositional clusters were identified: PHBV-based products (BI = 92 ± 1 %), cellulose-based products (BI = 85 ± 9 %), PLA-based products (BI = 30 ± 20 %), PBAT/starch-based bags (BI = 25 ± 8 %), PE/starch-based bags (BI = 9.5 ± 0.5 %), and PBS/PLA-based capsules (BI = 6.6 ± 3.0 %). Only select cellulose-based products (three bags, one cup, and one capsule) and the PHBV-based products (five capsules and one straw) exhibited a biodegradability over 80 %. Analyzing product composition reveals components that affect biodegradability in anaerobic digestion, thus aiding manufacturers to eco-design more sustainable food packaging.