Pistachio (scientific name Pistacia vera) is a bushy shrub growing up to a height of about 10 meters (33 feet). This plant produces pinnate deciduous leaves that shed annually. The leaves measure anything between 10 cm and 20 cm (4 inches and 8 inches) in length. Pistachio is a dioecious plant, meaning that separate trees of the species bear male and female reproductive parts. The unisexual and apetalous flowers appear in panicles.
Like plum, cherry and peach, the pistachio fruit is also a drupe. The elongated seed of pistachio fruit is its edible part. In fact, the seed of this fruit, which is generally believed to be a nut, is actually a culinary nut and not a botanical one. The pistachio shell has a natural beige hue, but when sold commercially, it is often dyed green or red. In the initial days, exporters dyed pistachio shells with a view to conceal the stains on them. Such stains were a result of hand picking the shells. These days, nearly all pistachios are harvested using machines and, hence, it does not cause any stain on them. As a result, they are not dyed unnecessarily, apart from meeting the ingrained expectations of the consumers. One can artificially change the color of roasted pistachio seeds to red by marinating them in a strawberry and salt marinade or in salt and citrus salts before roasting them.
The color of pistachio seeds is somewhat mauve, while the flesh of the fruit is pale green. Pistachio fruits have a typical flavour. Shells of ripened pistachio fruits have an autumn red/ yellow hue and they abruptly split open partially. Such splitting of the shell is called dehiscence and when it is usually accompanied by an audible pop sound. In fact, the splitting open characteristic of the ripened shells has been preferred by humans. The commercial cultivars of pistachio differ depending on how consistently their shells split open.
Archeological artifacts uncovered in Turkey bear evidence of the fact that people there have been using pistachio nuts since 7,000 B.C. In the first century A.D., pistachio was brought into Italy from neighbouring Spain. Thereafter, the cultivation of pistachio spread to various countries in the vicinity of the Mediterranean. In 1854, Charles Mason was the first to introduce pistachio into the United States. Mason used to distribute pistachio seeds in California, Texas as well as a number of other southern states of the country for experimental plantings. Few years later, some small pistachio plants were imported from France and planted in Sonoma, California, in 1875. Early in the 1900s, the United States Department of Agriculture brought together a collection of various pistachio species as well as different varieties of pistachio nuts at the Chico, California-based Plant Introduction Station.
As pistachios are loaded with several nutrients, they offer us various health benefits. In addition to being delicious tree nuts, the wholesome nutritional properties of pistachios have also been recognized. Similar to cashew, almonds and walnuts, pistachios also supply the people inhabiting the dry and arid areas of Central, South and West Asia with valuable proteins, fats as well as many essential minerals.
It has been established that pistachios are a wonderful energy source, as just 100 grams of these tree nuts provide use with 557 calories. These nuts also enclose rich amounts of mono-unsaturated fatty acids such as oleic acid. Pistachios are also a wonderful antioxidant source. Consuming pistachio nuts on a regular basis in one's diet helps to bring down the total and LDL (low density lipoprotein or bad) cholesterol in the bloodstream, while increasing the amount of good or HDL (high density lipoprotein). Findings of several scientific studies suggest that the Mediterranean diet, which contains high amounts of mono-unsaturated fatty acids, dietary fiber and antioxidants, helps to put of the development of coronary artery disease as well as strokes by supporting the blood lipid profile and ensuring its health.
Pistachios are also an excellent source of several phyto-chemicals like vitamin E, carotenes and polyphenolic antioxidant compounds that add to their general antioxidant effects. Several scientific studies undertaken to confirm the health benefits of pistachios have indicated that these natural compounds facilitate removal of the toxic free radicals from our body, thereby protecting us from diseases, infections and even various cancer forms.
The oil extracted from these tree nuts is called pistachio oil, which is considered to be among the healthiest cooking oils. Apart from its pleasing nutty aroma, pistachio oil possesses outstanding emollient properties. This oil keeps the skin moist, thereby preventing dryness. In addition to being used as cooking oil, pistachio oil is also used in the form of a base or carrier oil in traditional medications meant for aromatherapy and massage therapy. Pistachio oil is also used extensively in pharmaceuticals as well as cosmetic industry.
In addition to the above mentioned attributes of pistachio nuts, they also enclose unbelievable amounts of vitamin B6, which is necessary for making hemoglobin - the special protein that is responsible for transporting oxygen to the cells through the bloodstream. In addition, it has been found that vitamin B6 increases the quantity of oxygen carried by the blood.
Pistachios contain high amounts of vitamin B6, which has extensive positive consequences on our nervous system. The molecules that transmit messages throughout our body are known as amines and their development is not possible without amino acids. On their part, amino acids are made from vitamin B6. In addition, vitamin B6 has a crucial role in myelin formation. Myelin forms an insulated covering around the nerve fibers and ensures that there is optimal message transmission between the nerves. Vitamin B6 also facilitates the synthesis of melatonin, epinephrine, serotonin and an amino acid called GABA (gamma-amminobutyric acid). Precisely speaking, GABA plays a vital role by soothing transmission of impulses all throughout our nervous system.
Two types of carotenoids - lutein and zeaxanthin, are present in pistachios. These carotenoids are not found in several other nuts. Lutein as well as zeaxanthin serve the purpose of protective antioxidants. They protect the cells and tissues in our body from damages caused by the detrimental free radicals. In addition, these two carotenoids are said to lessen the chances of developing age-related problems, such as macular degeneration. It is worth mentioning here that macular degeneration is the primary cause of eye sight damage as well as acquired blindness among people in the United States.
Vitamin B6 is essential for a robust immune system. Since considerable amount of this nutrient is present in pistachio nuts, it is advisable that you consume them in sufficient amounts. However, intake of surplus amounts of vitamin B6 also helps to slow down the activity of the brain and, at the same time, reduce the efficiency of the immune system in combating infections. Pistachios contain vitamin B6, which facilitates the body in making healthy red blood cells (erythrocytes) and also ensures that the lymphoid glands like the spleen, thymus and lymph nodes remain healthy. At the same time, vitamin B6 promotes the production of white blood cells (leucocytes), which protect our body from various infections.
Pistachio nuts are also an excellent natural vitamin E resource. A potent antioxidant that is soluble in fat, vitamin E is indispensable for sustaining the veracity of the cell membranes and it is recommended often for healthy as well as youthful skin. Vitamin E is also effective in protecting our skin from the damages caused by ultra-violet (UV) rays, offering daily safeguard from premature aging and also putting off skin cancer.
Consuming pistachio nuts may also prove to be helpful in preventing type 2 diabetes. Just one cupful of these tree nuts also provides us with about 60 percent of our daily recommended dietary allowance of the essential mineral phosphorus. Apart from breaking down protein and converting it into amino acids, phosphorus helps in promoting glucose tolerance.
Pistachios with their shells removed have commercial use in confectionery, candies, ice creams, bakery goods, and sausages. They are also used for flavoring puddings. In addition, shelled pistachios can be added to casseroles, dressings and several other food preparations.
In present times, one can find pistachio trees growing naturally in various regions of Turkey, Lebanon, Syria, Tunisia, Greece, Xinjiang (China), India, Afghanistan (particularly in the Badghis and Samangan provinces), Tajikistan, Iran, Kyrgyzstan, Uzbekistan, Turkmenistan, Italy (Sicily), Egypt and in the United States, particularly in California. This plant has its origin in the eastern Mediterranean region (the stretch from Turkey and Cyprus to Syria and Israel), Xinjiang and Central Asian regions including Afghanistan, Uzbekistan, Kyrgyzstan, Turkmenistan, and Tajikistan. The seeds of pistachio fruits are consumed extensively in the form of a food.
Basically, pistachio is a plant common to desert regions and, hence, it possesses the ability to endure highly saline soils. It has been found that these trees grow excellently when they are irrigated with saline water containing anything between 3,000 ppm and 4,000 ppm soluble salts. When the conditions are favourable, pistachio trees are somewhat hardy and can withstand temperatures varying between -10°C (14°F) in winter and 48°C (118°F) during summer. Pistachio trees require a sunlit position and properly drained soil. These trees do not grow well in places having very high humidity. In addition, they are vulnerable to root rot during winter, provided they are fed with too much water and the soil is not free-draining enough. For the fruits to ripen properly, these trees require prolonged, hot summers.
Pistachios are beneficial for our health as they contain very less calories, but are rich in potassium and vitamin K content. The content of these nutrients per serving of pistachios is more compared to any other nut. For instance a serving of one ounce of dry roasted pistachios provides us with 160 calories, 15 grams of fats (which includes just 2 grams of saturated fat), 6 grams of proteins as well as 3 grams of dietary fiber.
Pistachios are also a wonderful vitamin E resource - they especially contain high concentrations of gamma-tocopherol. Each 100 grams of pistachios enclose roughly 23 grams of gamma-tocopherol. It is worth mentioning here that vitamin E is a potent antioxidant that is soluble in lipids and is necessary to sustain the veracity of the cell membranes of the skin and mucus membranes. This vitamin protects us from the harmful effects of free radicals.
Apart from the nutrients mentioned above, pistachios are also packed with several essential minerals such as calcium, potassium, copper, iron, manganese, zinc, magnesium and the trace mineral selenium. Precisely speaking, 100 grams of pistachio nuts supply us with 144 percent of our daily recommended dietary allowance (RDA) of copper. In fact, copper is one vital trace mineral that is necessary for transmission of nerve signals, promotes metabolism and also facilitates the synthesis of red blood cells (RBC).
Similar to the other plants belonging to the Anacardiaceae family, which also comprises cashew, mango, sumac and poison ivy, pistachios enclose a natural compound and irritant called urushiol. As a result, consumption of pistachio nuts may sometimes result in allergic reactions.
Generally, harvesting of pistachio nuts is undertaken when the husk that covers their shells becomes somewhat loose. Just shaking the trees once will help to dislodge the husk or hull covering from most of the properly dried mature nuts. While shaking the tree, you can collect the pistachio on a canvas or a trap. A full grown pistachio tree can produce about 50 pounds of dehydrated, hulled nuts. It is important to get rid of the hulls immediately after harvesting the nuts, as this will help to avoid the shells from becoming stained. In order to promote the splitting of the shells, you should immerse the hulled nuts in water with a view to make the shells moistened and, subsequently, dry them by spreading them out under direct sun. The split pistachio nuts can be salted by boiling them in a saline solution for five to ten minutes. Subsequently, you need to dry them again before storing for future use. If you store the salted pistachios in plastic bags and keep them in a refrigerator, they will generally last for a minimum of four to six weeks. Frozen pistachio nuts will last longer - for several months.