PLA/PBS/NFC Bionanocomposites Incorporating Thymol Nano-Capsule for Potential Active Food Packaging Applications Intan Syafinaz Mohamed Amin Tawakkal*, Nurul Afifah Zabidi, Siti Hajar Ariffin and Mohd Nazli Naim
Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia (intanamin[at]upm.edu.my)
Abstract
Active packaging has extensively reported for its food shelf-life extension, biodegradability, and minimizing solid waste disposal. Thymol essential oil (EO) can be applied as an active agent due to their high antibacterial and antioxidant properties, but due to its sensitivity to certain conditions such as high volatility, oxidation susceptibility, and degradation at high temperatures has limited its applications. Nanoencapsulation has emerged as a method to address these limitations. First, thymol EO-loaded chitosan nanoparticles (CN-T) was synthesized using the ionic gelation method. CN-T at 1:1 mass ratio nano-capsule had a smaller average particle size (33- 64 nm), proper polydispersity index, and high encapsulation efficiency. The synthesized CN-T at different concentrations (3,7, and 10wt.%) was then incorporated into PLA/PBS and PLA/PBS/NFC films. The morphological, optical, mechanical, thermal, barrier and antimicrobial properties of the films were characterized accordingly. The results showed that the incorporation of CN-T into the PLA/PBS/NFC matrix enhanced thermal stability of films (1.12%), increased tensile strength (30.54%), and water vapor permeability (2.99%), than the PLA/PBS/NFC films with free thymol and CN. Moreover, the FT-IR analysis indicated compatibility between CN-T and PLA/PBS/NFC matrix with the existence of intermolecular hydrogen bonds. The synergistic effect of CN-T effectively promoted antibacterial activity and showing an inhibitory rate against S. aureus. These results suggested that CN-T has a promising antibacterial properties for the development of a novel bio-based active packaging system. The films showed good potential for food packaging application, offering an alternative to conventional petroleum based plastics and helping to address environmental problems.
