Pistachios: benefits, varieties, nutritional values and where to find them

Discovery Nuturally , Magazine

Published : 08/24/2021

Pistachios

A unique treat characterised by its delicate sweetness and emerald green colour: pistachios.

Although known as a shell fruit, the pistachio (Pistacia Vera) is botanically a seed. Its origins are very ancient, with archaeological finds revealing its use since the seventh millennium BC in Turkey.

Let's discover together all the secrets and characteristics of pistachios.

Pistachio

Botanical aspects

The name “pistachio” comes from the Persian pesteh and the Arabic fustaq, which are evocative names and recall the sound of the shell opening when the pistachio is ripe. The plant is native to Syria, but according to some studies the initial cultivation area also includes Asia Minor, Palestine and Turkmenistan. Its average height is around 4-5 metres, but it can also exceed 8-10 metres. It has an ash-grey bark, a broad crown and compound leaves, i.e. a small branch bearing several small leaves.

Pistachio fruits

The pistachio tree flowers between April and May and must not suffer frost from this period onwards. Harvesting takes place from the end of August to October. The plants go into production every two years and for this reason plantations are made at different times and in different areas, so that a constant harvest can be had throughout the year. The fruit is oval in shape, grows in clusters and is red when ripe. When the fruit and the shell inside it have finished growing, the seed begins to swell. This process increases the internal pressure and within six weeks the shell splits. The seed is single, elongated and light green in colour.

Production and processing of pistachios

Harvesting takes place in different ways depending on the type of pruning carried out. If the plantation is spontaneous, manual harvesting is used. If it is pruned to a greater extent, mechanical harvesting is used.

Manual harvesting: Harvesting is done by hand. The bunches of pistachios are hit with long sticks and dropped onto nets or tarpaulins. The hull covering the shell is removed and the pistachios are dried in the sun.
Automatic Harvesting: In this case, the harvest is carried out mechanically using special shakers that drop the fruit. The removal of the husks is also mechanical, while drying takes place in hot air.

After harvesting, processing takes place in several stages.

Smalling: The most common method of removing the husk from the shell is by water jets. Another popular method is to pass the fruit through a machine equipped with two parallel belts rotating at different speeds. The product is then introduced into a water separator, inside a tank with running water. Here the ripe fruit goes to the bottom, while the unripe, closed or green fruits with residual hulls float.
Opening with water: pistachios harvested when they are not fully ripe and therefore "closed" are opened with water. There are two different types of opening with water: in the first case the pistachios are soaked for 2-3 hours and opened mechanically with a nutcracker. They are then dried in hot air. In the second case, the pistachios are soaked in water for 12 hours or more. Again, they are dried with hot air and the shells open automatically.
Mechanical sorting: the pistachios must be separated from any fruit that may have remained closed. For this operation, a cylinder with hooks is used to hold the open pistachios. The closed pistachios are collected separately.

There are four main processes at the farm

Toasting: the most used method is by forced air. The pistachio is roasted inside an oven that allows continuous cooking.
Salting: salting can take place in a continuous or discontinuous line. The most commonly used salting is continuous, the pistachio is passed through a flavouring cylinder where it is mixed with salt.
Packaging: this is the final processing of the pistachio. If the primary packaging guarantees a "good protection" against the entrance of humidity and oxygen inside the package, the product will maintain its organoleptic characteristics longer.
Storage: the pistachio can be stored for two years without any inconvenience at a temperature below 14 degrees.

Countries of production and varieties of pistachios

There are many varieties of pistachios but the only real distinction that is made in Europe is between round and long varieties.

The largest producer of pistachios is Iran, followed by the United States, Turkey, China, Syria, Greece, Italy and Spain. Among the Californian pistachios, the best known varieties are Keran, introduced in 1957 and the most prized and widespread in California. Bronte, named after the Duke of Bronte (in Sicily, more precisely Catania). Red Aleppo is a very productive variety. Sfax, characterised by small seeds but excellent quality. Trabonella with a small, green seed.

In Italy, on the other hand, the pistachio plant is grown almost exclusively in Sicily, in particular Catania, Agrigento and Caltanisetta. The product's product characteristics are very good and the quality standard of the fruit remains constant.

In Turkey, pistachio cultivation is concentrated in the south/southeast regions. The fruit has an elongated oval shape and is relatively small, the seed is yellowish green in colour with a characteristic flavour and aroma.

Nutritional values of pistachios

Pistachios are a filling snack: they contain vitamins, minerals and are rich in fibre. A typical daily portion is about 30 grams of shelled pistachios, which is about 160-180 calories. As well as having an unmistakable aroma and flavour, pistachios contain a variety of minerals and vitamins in significant quantities. The main minerals highlighted by our analysis are: iron, magnesium, phosphorus, potassium, zinc, copper, manganese and selenium. Vitamins include Vitamin B6, Vitamin E, Vitamin K and Biotin. A study presented by the US Department of Agriculture found that pistachios have a positive effect on cholesterol: researchers conducted the experiment on 16 healthy adult patients, monitoring their condition for 9 weeks as they gradually increased their consumption of roasted or salted pistachios, from 0 to 85 g a day. The results confirmed a decrease in LDL cholesterol, commonly referred to as 'bad', and maintenance of HDL (good) cholesterol and triglyceride levels."

Curiosities

Pistachio provides a valuable oil used in confectionery, candies and cosmetics for its emollient properties. In Sicily the bark of the pistachio is used as a refreshing agent. In the first century AD, Emperor Vitellius introduced pistachios to Rome. Marcus Gavadius Apicius includes pistachios in his classic recipe book on Roman cuisine of the early empire.