Effects of Active Packaging Based on Potato Starch/Nano Zinc Oxide/Fennel (Foeniculum vulgare Miller) Essential Oil on Fresh Pistachio during Cold Storage

The purpose of this study was to evaluate the effects of a combination of zinc oxide nanoparticles (Nano-ZnO) and fennel essential oil (FEO) on the quality characteristics of fresh pistachio. The potato starch-based films containing different levels of Nano-ZnO (1, 3, and 5% w/w), and FEO (1, 2, and 3% w/w) were prepared by the casting method. The fresh Akbari pistachios were packed in these bio-nanocomposite films. The physicochemical and sensory properties and the growth of Aspergillus flavus and aflatoxin B1 production were investigated during 15 days of refrigerated storage (~ 4°C). Results showed that by packaging fresh pistachios in bio-nanocomposite films, the moisture, carbohydrate, and fat contents of pistachios and the sensory parameters (texture, flavor, appearance, and overall acceptability) of them were improved during refrigerated storage. The weight loss of control significantly was higher than packed samples in bio-nanocomposite films (p<0.05). Usage of bio-nanocomposite films leads to a decrease in the growth of Aspergillus flavus and aflatoxin production in pistachios during storage periods. Finally, the results demonstrated that potato starch/5% Nano-ZnO/3% FEO bio-nanocomposite film improved the physicochemical and sensory properties and had the best effect on mold spoilage reduction of fresh pistachios; hence, it can be used as packaging for fresh nuts.