Antimicrobial bio-nanocomposite films based on gelatin, tragacanth, and zinc oxide nanoparticles – Microstructural, mechanical, thermo-physical, and barrier properties

• Published in: Food chemistry 2021-08, Vol.354, p.129492, Article 129492
• Main Authors: Shahvalizadeh, Rahim, Ahmadi, Raman, Davandeh, Iskandar, Pezeshki, Akram, Seyed Moslemi, Seyed Amir, Karimi, Sanaz, Rahimi, Mahdi, Hamishehkar, Hamed, Mohammadi, Maryam
• Format: Article
• Language: English
• Subjects: Anti-Infective Agents - chemistry; Anti-Infective Agents - pharmacology; Antimicrobial biomaterials; Calorimetry, Differential Scanning; Color; Escherichia coli - drug effects; Food packaging; Food Packaging - methods; Gelatin - chemistry; Gelatin nanocomposite films; Metal Nanoparticles - chemistry; Nanocomposites - chemistry; Nanocomposites - toxicity; Permeability - drug effects; Staphylococcus aureus - drug effects; Tensile Strength; Tragacanth - chemistry; Tragacanth gum; Water - chemistry; Zinc oxide; Zinc Oxide - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.129492

[Display omitted] •Well-miscibility of tragacanth gum/gelatin/zinc oxide nanoparticles (ZnO-NPs).•Improved mechanical stress, barrier and thermal properties by addition of ZnO-NPs.•Homogenous microstructure of gelatin/tragacanth matrix including ZnO-NPs up to 5%.•Excellent antimicrobial activity against both S. aureus and E. coli bacteria. Gelatin and tragacanth were employed to fabricate antimicrobial nanocomposites with 1, 3, and 5% zinc oxide nanoparticles (ZnO-NPs). FT-IR and XRD proved new chemical interactions among GEL/TGC/ZnO-NPs and higher crystallinity of nanocomposites, respectively. DSC showed a significant increase in melting point temperature (Tm) from ~ 90 to ~ 93–101 °C after adding 1–5% ZnO-NPs. Ultimate tensile strength (UTS) was remarkably increased to 31.21, 34.57, and 35.06 MPa, as well as Young’s Modulus to 287.44, 335.47, and 367.04 MPa after incorporating 1, 3, and 5% ZnO-NPs. The ZnO-NPs dose-dependently reduced the water vapor permeability (WVP) of the films. FE-SEM analysis from surface and cross-section illustrated the compact and homogenous structure of the nanocomposites even up to 5% ZnO-NPs. The ZnO-NPs-containing nanocomposites had a good antimicrobial activity (~10–20 mm) against both Staphylococcus aureus and Escherichia coli. Generally, the results indicated that the prepared nanocomposite films are promising antimicrobial bio-materials for food packaging.