Shri Nathji is always fascinated by dry fruits, pistachios being his favorite, followed by ‘kish-mish’–raisins, and akhrot–walnuts. Shri Nathji enjoyed Pistachios immensely. Shri Nathji also makes it a point to send a parcel of pistachio nuts to HH Pran Nathji –, as these were scarce and too expensive in London.
The pistachio, is a small tree originally from Iran and Iraq, which now can also be found in regions of Syria, Lebanon, Turkey, Greece, Tunisia, Kyrgyzstan, Tajikistan, Turkmenistan, Pakistan, Egypt, Italy (Sicily), Uzbekistan, Afghanistan (especially in the provinces of Samangan and Badghis), and the United States, specifically in California. The tree produces an important culinary nut.
Archeologists have found evidence from excavations at Jarmo in northeastern Iraq that pistachio nuts were a common food as early as 6750 BC. The Hanging Gardens of Babylon were said to have contained pistachio trees during the reign of King Merodach-Baladan about 700 BC. Pistachio seed along with nut cracking tools were discovered by archaeologists at the Gesher Benot Ya'aqov site in Israel's Hula Valley, dated to 780,000 years ago.
Pistachio is a desert plant, and is highly tolerant of saline soil. It has been reported to grow well when irrigated with water having 3,000–4,000 ppm of soluble salts. Pistachio trees are fairly hardy in the right conditions, and can survive temperatures ranging between −10 °C (14 °F) in winter and 40 °C (104 °F) in summer. They need a sunny position and well-drained soil. Pistachio trees do poorly in conditions of high humidity, and are susceptible to root rot in winter if they get too much water and the soil is not sufficiently free-draining. Long, hot summers are required for proper ripening of the fruit.
One can see an ancient forest of wild Pistachio at the Jylgyndy Forest Reserve, which is located in the Nooken District of Kyrgyzstan.
The bush grows up to 10 metres (33 ft) tall. It has deciduous pinnate leaves 10–20 centimeters (4–8 inches) long. The plants are dioecious, with separate male and female trees. The flowers are apetalous and unisexual, and borne in panicles.
The fruit is a drupe, containing an elongated seed, which is the edible portion. The seed, commonly thought of as a nut, is a culinary nut, not a botanical nut. The fruit has a hard, whitish exterior shell. The seed has a mauvish skin and light green flesh, with a distinctive flavor. When the fruit ripens, the shell changes from green to an autumnal yellow/red, and abruptly splits part way open. This is known as dehiscence, and happens with an audible pop.
Iran, the United States and Turkey are the major producers of pistachios. The trees are planted in orchards, and take approximately seven to ten years to reach significant production. Production is alternate bearing or biennial bearing, meaning the harvest is heavier in alternate years. Peak production is reached at approximately 20 years. Trees are usually pruned to size to make the harvest easier. One male tree produces enough pollen for eight to twelve nut-bearing females. Harvesting in the United States and in Greece is often accomplished by using shaking equipment to shake the nuts off the tree. After hulling and drying, pistachios are sorted according to open mouth and closed mouth shell. Sun drying has been found to be the best method of drying. Then they are roasted or processed by special machines to produce pistachio kernels.
In research at Pennsylvania State University, pistachios in particular significantly reduced levels of low-density lipoprotein (LDL cholesterol) while increasing antioxidant levels in the serum of volunteers.
Human studies have shown that 32–63 grams per day of pistachio nut can significantly elevate plasma levels of lutein, alpha-carotene, beta-carotene, and gamma-tocopherol.