Characterization of Antifungal Edible Nano-Coating Materials Prepared by Some Waste Peel Extracts

Abstract

In developing countries, a large amount of a peel waste generated from fruits and vegetables that has led to big nutritional, economic loss and environmental problems. The present study aims to prepare edible nano-coatings, mainly chitosan nanoparticles (CsNps) developed by incorporating fruit peel extracts (pomegranate or banana) as a low-cost natural edible coating material to improve the
antifungal activity and functional properties of the edible coating. The synthesized nanoparticles were characterized by Dynamic light scattering (DLS) and zeta potential (ZP), Fourier transform infrared (FTIR) spectroscopy analysis, high-resolution transmission electron microscopy (HR-TEM) and Xray spectroscopy (XRD). Total phenolic contents (TPC) were 27.79 and 19.78 mg GAE/100g DW for  pomegranate peel extract (PmPE) and banana peel extract (BaPE), respectively. While the antioxidant activity (AA) was 87.07 and 79.81% for the same extracts. The antifungal activity of CsNps coating either alone or loaded with fruit waste peel extracts (FPE) of PmPE or BaPE was evaluated against the tested phytopathogenic fungi (Botrytis cinerea, Alternaria alternata, penicillium digitatum, Aspergillus flavus and Aspergillus niger) at concentrations of 0.2, 0.4 and 0.8 mg/ml (by mycelial radial growth). The results showed that chitosan nanoparticles loaded with pomegranate peel extract (PmPE-CsNps at 0.8 mg/ml) had highly effective (100 %) which achieved completely inhibition against all tested phytopathogenic fungi. The synthesized nano-coatings were non-cytotoxic for the
normal human fibroblasts (MRC-5). In conclusion, CsNps loaded with PmPE or BaPE provide an effective, low-cost, edible nanocoating with higher antifungal and antioxidant activities.