Bioplastic from shrimp shells combined with green tea extract and its application in food preservation

Abstract

    The growing environmental burden of plastic waste highlights the urgent need for sustainable alternatives in food packaging. Chitosan, a natural polymer derived from shrimp shell waste, offers excellent film-forming and biodegradable properties, while green tea extract (GTE) provides bioactive compounds with antibacterial activity. In this study, bioplastic films were prepared by blending chitosan with polyvinyl alcohol (PVA) and varying amounts of GTE (5, 7, and 10 mL). The biofilm synthesized with chitosan and green tea extract exhibited a smooth surface morphology, with tensile strength ranging from 12.51 ± 0.25 to 26.66 ± 0.53 MPa, elongation at break ranging from 388.3 ± 7.8% to 546.8 ± 10.9%, and can inhibit the growth of Escherichia coli (E. coli) bacteria. Incorporation of GTE reduced solubility, improved tensile strength, and enhanced antibacterial activity against Escherichia coli, with inhibition zones increasing proportionally with GTE content. Fourier transform infrared spectroscopy (FTIR) confirmed hydrogen bonding interactions between chitosan and phenolic compounds in GTE, while scanning electron microscopy (SEM) revealed uniform, compact surfaces. Biodegradability tests showed rapid degradation, with films losing over 90% of mass within 53 days. These findings suggest that chitosan–PVA–GTE films are promising eco-friendly packaging materials with improved mechanical durability, antibacterial functionality, and environmental sustainability.