The Effect of Pre-Harvest Chitosan and Nano-Chitosan Application on The Shelf Life and Quality of Fresh Pistachio (Pistacia vera L. Cv. 'Ahmad-Aghaei')

Pistachio is one of the most important strategic products of Iran, which is extremely important from various economic and social aspects. In unfavorable conditions during storage, the quality of pistachios decreases due to adverse reactions. The objective of this study was to investigate the effect of pre- harvest foliar application of chitosan (500 and 1000 mg.L-1), Nano-chitosan (250 and 500 mg.L-1) and distilled water (control) on the quality and shelf life of pistachio (Pistacia vera L. cv. ‘Ahmad-Aghaei’) at four different times (0, 25, 50 and 75 days after harvest) in a cold room at 4±0.5 °C and 80±5 % RH. The findings showed that in the treatment of Nano-chitosan containing 250 mg.L-1, the lowest weight loss (WL), the highest amount of total phenolic content (TPC), total antioxidant capacity (TAC), protein, and oil were observed on the 25th day after harvest. The highest amount of flavonoids was observed in Nano-chitosan treatment containing (500 mg.L-1) on day 25. Nano-chitosan treatment containing (500 mg.L-1) increased shell firmness and had the highest amount of shell firmness. Also, the parameter of neutral detergent fiber (NDF) content showed a different trend in four measurement times, and pistachios coated with chitosan and Nano-chitosan had higher NDF than the control. The highest amount was observed in chitosan treatment containing 500 mg. L-1 on day 50 after harvest. Considering the increase of 30 days of shelf Life post-harvest of nano-chitosan treatments compared to the control, therefore the application of nano-chitosan per-harvest at a concentration of 250 mg.L-1 can be recommended as a safe and low cost strategy to increase the postharvest life of Pistachio fruit 'Ahmad Aghaei ' cultivar.