Postharvest operations of pistachio nuts.

The most important postharvest operations of pistachio nuts including handling, transportation, green hull removal, dehydration, bulk storage and packaging of pistachios were studied. Results showed that air temperature had pronounced effect on drying time and air velocity didn't any significant effect on drying time. The entire drying process occurred in falling rate period and constant rate period was not observed. The optimum conditions for bulk storage of pistachio nuts were between 0 and 10 °C and relative humidity (RH) of 65-70 % or kept at higher than 10 °C (e.g. 15 °C) and less than 32 % RH, and monolayer moisture content had the longest shelf life due to the minimum changes in its lipid quality factors. The higher temperatures and longer storage times will accelerated deteriorative reactions in pistachio nuts especially on fat component and nylon under vacuum is the best packages for pistachio nuts among other packaging materials were studied in this research.