This study aimed to investigate the postharvest application of edible coating of maltodextrin containing potassium nanoparticles (KNPs; 0-2%) and pyracantha extract (PE; 0-1.5%) on the maintenance of phenolic compounds, antioxidant capacity and microbial properties of ‘Rishbaba’ grape during 60 days at -1 °C using response surface methodology and central composite design. The results showed that the applied coating on Rishbaba grape maintained total phenol, total flavonoids, total anthocyanin, stilbenes (resveratrol and viniferin) and catechin. That also caused higher antioxidant capacity and lower mold and yeast growth in grape during the storage time. Finally, the best cold storage conditions of ‘Rishbaba’ grape were determined by using the edible maltodextrin coating containing 2% KNPs and 1.5% of PE for 34 days with a desirability of 0.728 in terms of investigated Characteristics. The optimized sample has the amount of total phenol (5.79 mg/g), total flavonoid (8.95 mg/g), total anthocyanin (6.48 mg/g) and the greatest ability to inhibit DPPH free radical (42.56%) and the lowest growth rate of mold and yeast (21 Cfu/g).
