Bagasse lignin for single-used food packaging applications: UV-barrier, antioxidant, migration and cytotoxicity

This study examined PLA biocomposite films made from organosolv lignin extracted from Thai agro-waste, specifically sugarcane bagasse (BG), to assess their suitability for food packaging, focusing on their physical, thermal, optical, UV-shielding, antioxidant, and migration properties. Extracted BG-lignin exhibited free radical scavenging ability with an EC50 value of 400 µg/ml, reducing DPPH absorbance by 50%. PLA composite films with BG-lignin dosage from 0.1 to 1.0 wt.% were successfully fabricated via conventional blown film extrusion. Addition of BG-lignin at 0.5 wt.% and 1.0 wt.% to PLA films decreased UV transmittance from 90% to 30% and 12%, respectively, without compromising optical clarity. Moreover, DPPH scavenging activity of all composite films with different BG-lignin contents (0.1-1.0 wt.%) reached 50% within 24 h, while overall migration values and cytotoxicity level are below the permissible limit. This study demonstrates the potential application of PLA/BG-lignin composite films for single-used ketchup sachets. These films effectively reduce ketchup color change under UV light exposure.