Ginger oil and lime peel oil loaded PBAT/PLA via cast-extrusion as shrimp active packaging: Microbial and melanosis inhibition

Biodegradable active packaging for shrimp was produced via cast sheet extrusion of poly (butylene adipate terephthalate) and poly (lactic acid) (PBAT/PLA) at different ratios, incorporating ginger oil (GO) and lime peel oil (LPO). Surface chemistry, mechanical and barrier properties, volatile mass fraction, and antimicrobial activities were investigated. Microbial growth and melanosis of packaged shrimp were monitored. Gas chromatography-mass spectrometry indicated major volatile components of LPO and GO as D -limonene (40.55%) and L -zingiberene (19.85%), respectively. Essential oil loading improved polymer compatibility via C-H bonding and modified the polymer crystallinity, leading to improved film flexibility but reduced tensile strength. GO incorporation showed greater release of volatile mass fraction from the film matrix than LPO, with increased oxygen permeability and water contact angle. High PBAT film (PBAT70/PLA30) allowed greater release of essential oil than high PLA film (PBAT30/PLA70), with higher antimicrobial activity against Bacillus cereus. Film containing LPO was more effective in inhibiting microbial growth, while film containing GO showed superior prevention of melanosis in packaged shrimp. A linear correlation was found between microbial growth and degree of melanosis in shrimp packaged in PBAT/PLA packaging containing GO and LPO. Both LPO and GO effectively enhanced film functional properties and showed promise for seafood packaging with different mechanisms of ameliorating product bacterial degradation.