Enhanced shelf-life of peach fruit in alginate based edible coating loaded with TiO2 nanoparticles

Abstract

This study was conducted to determine the effects of nanoparticle based edible coatings on post-harvest quality of peach fruits during 7 days storage at ambient temperature. The edible coatings consisted of sodium alginate (SA) supplemented with green synthesized titanium dioxide (TiO2) nanoparticles and mousami peel extract (MPE). TiO2 nanoparticles with diameters ranging from 5 nm to 20 nm were synthesized with Citrus limetta (mousami) peel extract. The structural analysis of TiO2 nanoparticles were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Transmission electron microscopy (TEM). The optical properties were studied by UV-VIS spectroscopy which confirmed the anatase phase of TiO2 nanoparticles. Different nanoemulsion coatings of SA, SA-TiO2 nanoparticles (SA-NT) and SA-NT-MPE were developed to study various post-harvest quality attributes of peaches. Coating treatment significantly reduced percent weight loss, retained antioxidant activity and ascorbic acid content than control samples. The coating had a significant (p<0.05) impact on polyphenol oxidase activity, titratable acidity and firmness of peach samples during storage. Similarly, coated peach samples retained color index and slowed down the yeast and mold count during the storage period. At the end of the storage period, coated samples with coating solutions containing TiO2 nanoparticles and MPE exhibited the lowest yeast and mold counts (4.17 ± 0.12 log10 cfu g−1) whereas uncoated peach samples showed the highest yeast and mold counts (7.15 ± 0.09 log10 cfu g−1). Therefore, this study demonstrated the ability of nanoemulsion as coating agent in maintaining the quality and extending the self-life of peach fruit for up to 7 days at ambient temperature.