Preparation, Characterization and Antimicrobial Activity of Sodium Alginate Nanobiocomposite Films Incorporated with Ε-Polylysine and Cellulose Nanocrystals

Abstract

Ternary nanobiocomposite films based on sodium alginate (SA) with cellulose nanocrystals (CNC) derived from shaddock peel and ε‐polylysine (ε‐PL) have been prepared and characterized. The tensile strength and Young's modulus of nanobiocomposite films increased from 51.18 to 67.68 MPa and from 4.8 to 7.6 GPa upon CNC loading from 0.5 to 2.5 wt %. The positive effects of the addition of CNC in SA matrix were also confirmed by reductions in water vapor permeability (WVP). SA‐based nanobiocomposites showed significant antibacterial activity against Escherichia coli and Staphylococcus aureus influenced by the ε‐PL content. The films exhibited homogeneous and cohesive structures, indicating strong interactions between the filler and matrix. In addition, the good dispersion of CNC in the SA matrix could increase the stability of ε‐PL and promote the diffusion of the antimicrobial agent from the films. Practical Applications Chilled duck is an important raw material for making the sauce duck, roast duck, favor duck and it has a very broad consumer market. The chilled duck stability during storage can be enhanced by film‐coating as a prominent technique, and therefore an nanobiocomposite film based on sodium alginate (SA) incorporation with ε‐polylysine (ε‐PL) and cellulose nanocrystals (CNC) derived from shaddock peel were prepared in this study. The film‐coating has a good antibacterial effect on preservation of chilled duck. This study will find a successful packing method for chilled duck and improve the shelf life.

Carboxymethyl cellulose‐based nanocomposites reinforced with montmorillonite and ε‐poly‐l‐lysine for antimicrobial active food packaging

“…This was attributed to the good chemical compatibility resulting from the hydrogen bonding interactions existing in filler/filler and filler/matrix. However, the film surface became less homogeneous when the content of ε‐PL exceeded 7.5 wt %, which may affect the mechanical and water vapor barrier performance.…”

“…The thermal stability of the film gradually weakened after further addition of ε‐PL, which was in agreement with the reports of Wu et al . and Tang et al . However, the thermal stability of CMC/MMT/ε‐PL7.5 wt % did not alter obviously compared with pure CMC film, which still meet the requirement of food processing.…”

Review of the application of ε‐poly‐L‐lysine in improving food quality and preservation

“…Due to its safety and wide antibacterial spectrum, ε‐PL has also been used in other foods, such as sausage (Mo et al, ; Yue & Liu, ), Tofu (Ge, ; Li, Yan, Tan, Gui, & Chen, ), and vinegar (Cheng, Wu, Yue, Wu, & Guo, ). Currently, the bacteriostatic effect of ε‐PL is also used to make a biopolymer‐based film (Tang, Pan, Sun, Cao, & Guo, ) and wrapping paper (Huang, Bao, Wang, & Duan, ). To extend the shelf life of packaged foods, polylysine‐loaded chitosan‐sodium alginate nanoparticles were synthesized (Liu, Xiao et al, 2018), and their bacteriostatic activity was three times higher than that of ε‐PL.…”

Synthesis, biological efficiency evaluation and application of sodium alginate-based polyurethane dispersions using cycloaliphatic isocyanate, as antibacterial textile coating

“…Mechanistically it can be said that presence of hydroxyl groups in SA might be responsible for the possible antimicrobial action. Maximum killing activity was observed when 0.25 moles SA was incorporated to the PU backbone and bacterial growth was inhibited in the vicinity of wells made for sample introduction to agar media [33]. The possible cause of antibacterial action might be due to the bacterial cell adhesion and ultimately entrapment by sticky SA incorporated PUDs, like being engulfed by it leaving no way for the passage of nutrients required for growth [34].…”