[size=75]From Wikipedia, the free encyclopedia [/size]
The pistachio (Pistacia vera L., Anacardiaceae; sometimes placed in Pistaciaceae) is a small tree up to 10 m tall, native to mountainous regions of Iran, Turkmenistan and western Afghanistan. It has deciduous pinnate leaves 10–20 cm 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 (a nut in the culinary sense, but not a true botanical nut) with a hard, whitish shell and a striking kernel which has a mauvish skin and light green flesh, with a definitive flavour.
When the fruit ripens, the husk changes from green to an autumnal yellow/red and the shells split partially open (see photo). This is known as dehiscence, and happens with an audible pop.
Pistachio is often confused with some of the other nine species in the genus Pistacia, such as P. terebinthus and P. lentiscus. These species have a very different distribution, in the Mediterranean and southwest Asia, and have much smaller nuts, lacking the hard shell of P. vera. Their turpentine-flavoured nuts were a popular food in antiquity. Finds of Pistacia from pre-classical archaeological sites, or references in pre-classical texts, always refer to one of these other species (often P. terebinthus).
Pistachio (in the sense of P. vera) was first cultivated in Western Asia. It reached the Mediterranean world by way of central Iran, where it has long been an important crop. Although known to the Romans, the pistachio nut appears not to have reached the Mediterranean or most of the Near East in any quantity before medieval times. More recently pistachio has been cultivated in California (first commercial harvest in 1976) and Australia. The word pistachio is a Persian loanword, coming into English through Italian, and is a cognate to the Modern Persian word پسته Peste’.
The kernels are often eaten whole, either fresh or roasted and salted, and are also used in ice cream and confections such as baklava. In July 2003, the Food and Drug Administration (FDA) approved the first qualified health claim specific to nuts lowering the risk of heart disease: “Scientific evidence suggests but does not prove that eating 1.5 ounces (42.5g) per day of most nuts, such as pistachios, as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease”.. In research at Pennsylvania State University, pistachios in particular significantly reduced levels of LDL, the ‘bad’ cholesterol, in the blood of volunteers. Pennsylvania State University’s Department of Nutrition and Sciences has also conducted related research on other health benefits of pistachios, including an April 2007 study concluding that pistachios may calm acute stress reaction, and a June 2007 study on the cardiovascular health benefits of eating pistachios.
On the Greek island of Chios, the husk or flesh of the pistachio fruit surrounding the shell is cooked and preserved in syrup, a spoonful of which would traditionally be offered as a sweet delicacy to guests.