Biodegradable Plastics from Mango Seed Starch for Sustainable Food Packaging-Effect of Citric Acid and Fillers

Starch based bioplastics were prepared and characterized with fillers carboxy methyl cellulose (CMC), chitosan (CS) and nanochitosan (NCS); plasticizer sorbitol and cross-linking agent citric acid (CA) at different loading levels. Structural, water resistance, water vapor permeability, solubility, mechanical, antimicrobial and biodegradation properties of the bioplastics were investigated. FTIR confirmed bonding of starch with cross-linking agent, fillers and plasticizer. The water uptake of the CMC bioplastics was decreased up to 70 % with 20 % CA addition. Bioplastics with CS and NCS showed lesser water uptake, only 12.5 % for CS bioplastic. The water vapour permeability (WVP) of all bioplastics was low in the range 2.16×10−7–6.29×10−7 gday−1 m−1 Pa−1. The CA addition increased water resistance and lowered WVP of the bioplastics by restricting the hydrophilic functional groups and forming more tight structures. The fillers CS and NCS additions enhanced the mechanical strength attributing to more hydrogen bonding between NH3+ of chitosan and OH− of starch. All bioplastics demonstrated good antimicrobial activities. These bioplastics offer an attractive alternative to non-biodegradable plastics used in food packaging due to its enhanced water resistance, antibacterial properties and biodegradability. © 2024 Wiley-VCH GmbH.