Citrus australasica

Citrus australasica

The lemon caviar or finger lime (Citrus australasica F. Muell., 1858) is a small tree species of the Rutaceae family.

Systematics –
From the systematic point of view it belongs to the Eukaryota Domain, Plantae Kingdom, Magnoliophyta Division, Magnoliopsida Class, Sapindales Order, Rutaceae Family, Aurantioideae Subfamily and therefore to the Citrus Genus and to the C. australasica Species.
The term is synonymous: Microcitrus australasica (F.Muell.) Swingle, 1915.

Etymology –
The term Citrus derives from the Latin name of the cedar and lemon, from the Greek Greek κέδρος kédros cedar and κίτρον kítron lemon. The specific australasic epithet comes from Australasia, that is the area constituted by Australia and South Asia.

Geographical Distribution and Habitat –
Citrus australasica is a citrus fruit of Australian origin that grows on the north-eastern coast of New South Wales and part of Queensland. It is a species of the undergrowth both of the wet and dry rainforest and which today is cultivated in all parts of the world with a climate suitable for its cultivation.

Description –
The Citrus australasica is a small tree of 2 – 7 m.
The leaves are small and pointed, 5-25 mm wide and 12-60 mm long.
The flowers, small, white with 6-9 mm long petals that contain small beads similar to pearls. The flowering of the plant occurs between June and October.
The fruit is cylindrical, sometimes slightly curved, 5-10 cm long, with a smooth or slightly corrugated skin that can have different colors: blue, brown, reddish, green, as well as the pulp: red, pink, yellow, green.

Cultivation –
The lemon caviar, in its environment of origin, produces fruit throughout the year, and in particular during the austral summer, between January and March. It must be harvested by hand, paying great attention to the sharp thorns.
In cultivation it must be borne in mind that while grafts with European species are difficult, hybridizations are rather easy. Such hybridizations also allow the transfer to European species of the typical colors of Australian species.
For details of the cultivation technique, see the following sheet.

Uses and Traditions –
The fruit of the finger lime, unlike many other citrus fruits, does not contain a fibrous part inside and the grains, similar to those of the pomegranate, can be extracted with a spoon. Its taste is slightly sweeter than a lemon. The beans explode one by one in the mouth, releasing their aromatic juice. The fruit vaguely resembles caviar and is requested and appreciated by several chefs.
This fruit, one of the six citrus fruits originating in Australia, already existed in Gondwana (the mass of lands that comprised the lands of the southern hemisphere millions of years ago). It was collected and consumed by the Aboriginal people 60,000 years ago. With the colonization of the nineteenth century the arid lands on which finger lime grows were used for European crops. Only in the last ten years has this fruit been recognized for its potential in the kitchen. It is now grown in small quantities in Byron Bay and New South Wales, where a cooperative of 15 farmers was born. However, the lime finger risks disappearing with intensive farming and industrial agriculture.
In Italy it is known as Lemon caviar or lemon caviar or citrus caviar due to the appearance of its pulp: inside the green skin, in fact, there are many small translucent spheres that resemble fish eggs and which have an intense citrus flavor, very similar to that of lime.
Finger lime has important beneficial properties, is rich in vitamin B6 and can be used in a thousand ways in the kitchen.
The fruit ripening period is between January and April; once harvested, the lime fingers have a duration of almost five weeks if stored at a temperature of 5-10 °, while the pulp can last even several months if stored at -18 °.
Finger lime is a fruit that has excellent nutritional values, is very rich in vitamins and contains a high amount of mineral salts.
The nutrients per 100 grams of product are: Water 92 g, Carbohydrates 7 g, Sugars 1 g, Fibers 2 g, Vitamin A 1%, Vitamin C 32%, Iron 2%, Calcium 2%.
Finger lime is a fruit that therefore contains a lot of vitamin C, vitamin B6 and is also rich in vitamins B1, B2, B3 and beta-carotene. Even the peel is rich in active ingredients including limnocitrine and furanocumarin, antioxidant phenolic compounds and Omega 3; in addition, the finger lime contains a lot of citric acid, malic, gallic, folic, lutein and zeaxanthin.
As you can guess from its nutritional values, the calories of the finger lime are very few because it is a fruit that contains a very high percentage of water and very few sugars: we are talking about 20 calories per 100 grams of Lemon Caviar. This allows you to consume this fruit without problems within a slimming diet, even better in summer because its taste is really refreshing and pleasant.
Thanks to its high content of vitamins, antioxidants and mineral salts, finger lime is a fruit particularly rich in virtues and beneficial properties. Besides being used for different therapeutic purposes, this fruit with a thousand virtues has been an important food source for Aboriginal people for centuries. Even today, however, finger lime can be used to strengthen the immune system, improve the appearance of the skin and help in case of nausea; moreover, it seems that this fruit is able to promote good humor thanks to the high content of vitamin B6. Finally, lemon caviar has important antiseptic and antiviral properties, promotes digestion and is an excellent diuretic.
Moreover, thanks to the high content of compounds with antioxidant properties, finger lime is a valid ally against aging: these substances are in fact very useful for fighting the activity of free radicals, very reactive molecules or atoms that damage cellular structures and endanger our health. Antioxidants act just like natural anti-aging agents, slowing down cellular aging. Some studies have shown that regular and prolonged intake of finger lime can lead to a marked decrease in the probability of contracting some types of cancer.
Since this fruit is very rich in citric acid, malic acid, gallic acid and vitamins, all very useful substances for the well-being of the skin, it has very useful properties for delaying the appearance of wrinkles, attenuating the signs and mitigating aging.
It is also useful in pregnancy as it contains a high quantity of folic acid, that is vitamin B9, a fundamental substance for the correct development of the fetus’ nervous system in the first months of pregnancy, and it seems that it is also very effective in fighting and combating nausea, a typical symptom of the first trimester of pregnancy.
Also the sight can benefit from the regular consumption of finger lime, in particular thanks to its high content of vitamin C and flavonoids: if the first has the power to improve eyesight and prevent degeneration and aging of the eyes, the flavonoids are useful to combat the risk of cataracts.

Preparation Mode –
The fruits of Citrus australasica contain a delicious juice with a sour taste that explodes in the mouth and that is a cross between the lemon and the lime.
Even today, however, its food use is little known, but it is particularly suitable for flavoring sweets and drinks, in close analogy with the lemon peel, its close relative. If used in alcoholic beverages it shows a marked and pleasant digestive property.
The lime finger can be eaten as is or used in the kitchen. First, it must be cut in half with a sharp knife horizontally; if you want to consume it naturally, just use a teaspoon to remove the spheres from the recess in which they are located, otherwise you can press lightly with your fingers to let the pearls come out and then use them to create fresh and refined dishes. There are different varieties and each one is particularly suitable for some types of dishes: the Colette and Ricks Red varieties are combined with fish, Tasty Green is perfect for salads while the Yellow variety is suitable for making decidedly original jams and jams.
The pairing par excellence is the one with fish: crudité di mare, smoked salmon, oysters, linguine with seafood and a thousand other dishes can be enriched with pearls of finger lime. Also great for garnishing puddings, creams and ice creams, while if you don’t feel like cooking you can simply use it to enrich an iceberg salad seasoned only with extra virgin olive oil and a pinch of salt. Finally, more and more bartenders are using finger lime balls to add a touch of class to cocktails and long drinks.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– Treben M., 2000. Health from the Pharmacy of the Lord, Advice and experiences with medicinal herbs, Ennsthaler Editore
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Conti F., Abbate G., Alessandrini A., Blasi C. (edited by), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.

Attention: Pharmaceutical applications and food uses are indicated for informational purposes only, do not in any way represent a medical prescription; therefore no responsibility is assumed for their use for curative, aesthetic or food purposes.