Nettle-Leaf Extract Derived ZnO/CuO Nanoparticle-Biopolymer-Based Antioxidant and Antimicrobial Nanocomposite Packaging Films and Their Impact on Extending the Post-Harvest Shelf Life of Guava Fruit

Abstract

Green synthesized metal oxide nanoparticles (NPs) have prominent applications in antimicrobial packaging systems. Here we have attempted for the fabrication of chitosan-based nanocomposite film containing Urtica dioica leaf extract derived copper oxide (CuO) and zinc oxide (ZnO) NPs for shelf-life extension of the packaged guava fruits. Electron microscopy and spectroscopy analysis of the CuO and ZnO NPs exhibited nano-scale size, spherical morphologies, and negative ζ-potential values. The NPs possessed appreciable antioxidant and antimicrobial activity (AMA) in order of CuO NPs > ZnO NPs >nettle extract. Therefore, this work establishes for the first time the successful synthesis of CuO NPs and compares its antimicrobial and antioxidant properties with ZnO NPs. On incorporation in chitosan, the polymer nanocomposite films were developed by solvent casting technique. The developed films were transparent, had low antioxidant but substantial AMA. The NP supplementation improved the film characteristics as evident from the decrease in moisture content, water holding capacity, and solubility of the films. The nanocomposite films improved the quality attributes and shelf life of guava fruits by one week on packaging and storage compared to unpackaged control fruits. Therefore, this study demonstrates the higher antimicrobial potential of the nettle leaf extract derived CuO/ZnO NPs for development of antimicrobial nanocomposite films as a promising packaging solution for enhancing the shelf life of various perishable fruits.

Green Synthesis of Silver Nanoparticles Coated by Water Soluble Chitosan and Its Potency as Non-Alcoholic Hand Sanitizer Formulation

“…Since the stability of the gel is indicated by low levels of syneresis, the gel with 1% chitosan was the most stable at a storage temperature of 5 • C. However, when both treatments are considered, gel with 2% chitosan concentration showed insignificant change. The same observations were reported by Kalia et al [65] when considering the water holding capacity of chitosan and chitosan-metal nanocomposites. The addition of ZnO and CuO nanoparticles to nanocomposites significantly reduced their water holding capacity (WHC) by up to 37%.…”

Recent advances in biobased and biodegradable polymer nanocomposites, nanoparticles, and natural antioxidants for antibacterial and antioxidant food packaging applications

“…The addition of biosynthesized CuO NPs promoted excellent antibacterial activity against Campylobacter, Salmonella, and S. aureus compared to ZnO NPs. In addition, the films improved the quality attributes and shelf-life of guava fruits by 1 week on packaging and storage compared to unpackaged control fruits (Kalia et al, 2021). In the study of Sougandhi et al (2021), CMC bio-nanocomposite films containing pectin and Cu NPs, obtained via green synthesis from Psidium guajava leaf extract, have been developed as promising candidates for active food packaging systems (Sougandhi et al, 2021).…”

Antimicrobial Properties of Food Nanopackaging: A New Focus on Foodborne Pathogens

“…For extending the shelf life of guava fruits, Kalia et al (2021) fabricated a chitosan-based nanocomposite film containing CuO and ZnO NPs synthesized from the nettle leaf extract. The antioxidant and antimicrobial activity of biologically synthesized NPs was in order of CuONPs > ZnONPs > nettle extract ( Kalia et al, 2021 ). Foodborne pathogens including E. coli O157:H7 can easily grow in white brined cheese.…”