Active packaging films based on the nanoform of chitin, alginate, and layered double hydroxides: characterization, mechanical properties, permeability, and bioactive properties

Their unique characteristics make plastic films frequently utilised for packaging products. However, this petroleum-derived material has a long history of being linked to environmental contamination and hazardous degradation. Petroleum plastic can be substituted with edible packaging. The objective of this study was to combine sodium alginate with chitin, both in their nanosized form to formulate active packaging films containing different ratios of Zn/Al-layered double hydroxides (LDHs). Subsequently, active packaging films were formulated via a green method with different percentages (0%, 1%, 3%, and 5% w/w) of LDHs. The LDH particles were shaped as rectangular rods with a length of about 60 nm and width of around 20 nm. The films were evaluated for their physicochemical, topological, thermal, mechanical, water vapour, oxygen permeability and antimicrobial properties. Results indicated that active packaging with LDHs (3%) enhanced mechanical properties (tensile strength) by two-fold. Moreover, the addition of LDHs led to decreased permeability properties. Additionally, the antimicrobial study showed that the films with LDHs possessed a broad spectrum of antibacterial and antifungal activities, and the time required for bacterial killing was recorded to be less than 16 hours for films containing 5% LDHs. Thus, the formulated films show potential for use as active packaging.