Vase life of rose flower is strongly affected by preservative solutions. Encapsulation of arginine (Arg) and phenylalanine (Phe) with chitosan nanoparticles (nCS) protects bioactive components from the ambient factors for a certain period. Therefore, a factorial experiment based on a Randomized Completely Design in three replications was done to investigate the effect of encapsulated arginine (nCS-Arg) and -phenylalanine (nCS-Phe) with chitosan nanoparticles on quality, antioxidant status, and longevity of rose flowers. Results showed that the maximum longevity was achieved with 16.3 days in roses kept in vase solution containing encapsulated arginine and phenylalanine with chitosan nanoparticles (nCS-Are-Phe) at 5 mg L−1 concentration. Also, they had higher relative water content (RWC), fresh weight, chlorophyll index, and fluorescence than control. Total phenol content (TPC), total flavonoid content (TFC), the activity of peroxidase (POX), phenylalanine ammonialyase (PAL), and superoxide dismutase (SOD) increased dramatically in rose petals kept in nCS-Are-Phe (5 mg L−1) solution while hydrogen peroxide (H2O2) and malondialdehyde (MDA) decreased. Against to the decreasing trend in protein and carbohydrate amount during vase life, the flowers keep in nCS-Are-Phe (5 mg L−1) preservative, had the higher amount of protein and carbohydrate by 1.4- and 2.6-fold, respectively, on 12th day. So, encapsulation of Are and Phe by a degradable nanochitosan is a desired method to avoid rapid metabolism, and sustained release in flowers vase solution. Consequently, Arg and Phe caused to extend rose vase life directly or indirectly through some byproducts production of their metabolism such as nitric oxide and polyamines.
