Active Double-Layered Films Enriched with AgNPs in Great Water Dock Root and Pu-Erh Extracts.

Ewelina Jamróz,Paweł Krzyściak,Agnieszka Cabaj,Agnieszka Cholewa-Wójcik,Lesław Juszczak,Małgorzata Zimowska,Pavel Kopel,Joanna Tkaczewska

doi:10.3390/ma14226925

Abstract

A novel, eco-friendly, and biocompatible method was applied to form silver nanoparticles (AgNPs) in great water dock (Lapathi radix) (KB) and pu-erh (Camellia sinensis) (PE) extracts. The surface plasma resonance peak of green synthesized AgNPs at 451.8 nm for AgNPs+KB and 440.8 nm for AgNPs+PE was observed via spectral analysis of UV absorbance. In this study, double-layered biopolymer films (FUR/CHIT+HGEL) with AgNPs incorporated in KB solution (AgNPs+KB) and AgNPs in PE solution (AgNPs+PE), were successfully prepared using the casting method. The SEM, XRD, zeta potential and size analyses confirmed the presence of AgNP in the films. The addition of AgNPs in plant extracts improved antimicrobial and antioxidant activity and thermal stability, whereas WVTR experienced a decrease. The nanocomposite films’ orange-brown colour may aid in the protection of food products against UV rays. The composite films demonstrated antibacterial activity against food-borne pathogens and may offer potential in food packaging applications.

Highlights

There are several types of nanoparticle syntheses using physical, chemical and biological methods
These results are in line with those obtained in previous studies [1,4,21]
The presence of a strong surface plasmon resonance (SPR) peak in this region has been documented for various AgNPs ranging in size from 5 to 100 nm [22]

Summary

Introduction

There are several types of nanoparticle syntheses using physical, chemical and biological methods. Biological methods are more cost-effective and non-toxic to the environment, and using plant extracts for the synthesis of nanoparticles offers many advantages over other approaches. The use of plant extracts in the synthesis of AgNPs is a proenvironmental solution, because they are rich in reducing and stabilising substances, such as enzymes, polyphenols and proteins [2]. Thanks to this solution, toxic compounds, such as sodium borohydride (NaBH4), sodium citrate, and ascorbate that are not consumed by consumers are not used; their use in the preservation of food products is limited. Phytochemicals contained in the plant feature antioxidant and reducing properties and act on silver particles by creating nanoparticles (redox reaction) [1]

Methods

Results

Conclusion