The pomegranate tree, Punica Granatum L., belongs to the Punicaceae family and has about 500 varieties. It can reach a height of over five meters, but is often cultivated as shrub with a maximum height of three meters (plantation cultivation). Its reddish-brown to grey bark changes over the years from a smooth to a scaly appearance. The usually thorny branches are square-shaped and end up with leathery lancet-shaped leaves. The tree needs a hot and dry climate without periods of frost to grow. It owes its robustness not only to its low demands for low soil quality but also to the fact that it can bear longer periods of drought. It grows best in protected, not too sunny locations.
2. Origin/flowering time/harvest
The name of the fruit is probably derived from the Latin "malum granatum", which translated means "grainy apple". The origin of the tree points to the countries Iran, Armenia and Afghanistan, although today it is cultivated almost all over the world with an appropriate climate. The largest producers are India, Iran, China and the USA, with a worldwide production volume of approx. 3.5 million tons (as of 2016).
Depending on the geographical area of cultivation, the flowering period begins in spring, although several flowering periods per year are possible. After an average of 150 days, the ripe fruit is harvested. The size and weight of these vary - depending on the growing region and type - from 5-20 cm and 140-1000 grams. The pomegranate itself is considered a pseudo-fruit.
Even if the tree bears fruits after only one year, commercial use of the tree is only possible after three years. The harvest is done by hand.
The fruit itself consists of a reddish leathery skin, juice and seeds. Over hundreds of these red seeds can be in one fruit. They carry only three percent of the total weight of the fruit (approx. 30 % juice and 67 % pulp). About 12-20 % of the seed’s weight is oil. The seeds can be divided into different hardness classes, with scales with three or six hardness levels.
The seeds are gently pressed under exclusion of heat, light and atmospheric oxygen (cold pressing). The exclusion of oxygen avoids oxidation and the associated reduction in oil quality.
The oil has to be processed further and finally gets its typical light yellow colour.
Pomegranate seed oil is characterized by a very high content (over 90%) of unsaturated fatty acids. The lion's share is made up by punicic acid, an isomer of alpha and gamma linolenic acid. In addition to the fatty acids, other components can be found: proteins, vitamins, polyphenols, flavonoids, plant steroids (estrone and coumestrol). These ingredients determine the pharmacological and cosmetic effects.
Punicic acid seems to have a positive inhibitory effect on the prostaglandin biosynthesis. Inflammations could be reduced and thus have a positive influence on several diseases, such as intestinal or biliary inflammation or diabetes.
Due to the high content of unsaturated fatty acids and vitamin E, formed radicals are neutralized, whereby additional ingredients are supposed to stimulate collagen formation. The oil is therefore used in the cosmetic industry where it is often combined with almond or jojoba oil.
5. Further properties/facts
The oil should be stored cool (10-20 ° C), dry and light shielded. Thus a shelf life of up to 12 months can be guaranteed.
Depending on the area where the oil is used, the cultivation area can play a decisive role. On the certificate of analysis the pucic acid with more than 65 % is the decisive marker. Oils from Iran contain the highest percentage of vitamin E (alpha and beta tocopherol), which plays an important role in the cosmetic industry. If the oil is from Brazil, a high percentage of beta-sitosterol must be expected.