Finger Lime or Citrus Caviar: Benefits and Uses

The "finger lime" resembles fingers and caviar, but the reality is that it's a citrus fruit with antioxidant functions. Do you want to know more? If so, keep reading!

Written and verified by the nutritionist Maria Patricia Pinero Corredor.

Last update: 16 October, 2022

The finger lime or citrus caviar is known by science as Microcitrus australasica. It’s a fruit belonging to the citrus that has the shape of a finger. Its crystalline pulp resembles small pearls – hence its resemblance to traditional caviar. However, in this case, it doesn’t grow in the sea, but on trees.

This is considered a gourmet ingredient in modern cuisine. When fresh, there’s a burst of flavor that blends between lime, lemon, and grapefruit. However, it’s less acidic and more refreshing. For this reason, it’s can’t be missing from summer recipes.

The finger lime is a gift of nature that, in addition to its sensory peculiarities, provides several interesting health benefits. In this article, we’ll tell you all about them.

What is the “finger lime”?

Australia has six native citrus species, but the best known is the finger lime. It’s native to the rainforests located in the coastal border regions of Queensland and New South Wales.

The tree has the scientific name of Microcitrus australasica. It can measure between 3 and 10 meters in height. It grows slowly and can bear fruit between 5 and 17 years after planting.

The fruit is cylindrical and comes in various colors, such as pink, yellow, orange, and green. It compares in size to a gherkin, and its shape resembles an index finger.

The pulp consists of hundreds of tiny vesicles of spicy, crunchy, translucent, and spherical pulp, whose first impression is reminiscent of caviar eggs. That’s why it’s often referred to as citrus caviar, vegan caviar, or citrus pearls.

The nutritional value of fingers limes or citrus caviar

The nutritional value of finger lime is somewhat similar to that of other citrus fruits, except that it may have higher values in certain vitamins. The following is the content in grams (g) per 100 grams of fruit (vitamins and minerals are expressed in milligrams):

• Calories: 50.19
• Humidity: 84,4 g
• Fat: 1 g
• Protein: 1,6 g
• Ashes: 0,6 g
• Carbohydrates: 5 g
• Total sugars: 1.2 g
• Fiber: 7.2 g
• Vitamin C: 88 mg
• Magnesium: 140 mg
• Zinc: 0.85 mg

The calorie and moisture content is similar to oranges, lemon, grapefruit, and tangerine. In addition, its fiber value is high, so these three components make it ideal for use in weight loss diets.

The carbohydrate value is half that of other citrus fruits, with a predominance of simple sugars such as glucose, fructose, and sucrose. On the other hand, it has more than twice as much vitamin C as other fruits.

Magnesium and zinc stand out as its main minerals. Some scientists have shown that this citrus fruit contains high levels of antioxidants. However, its action as a free radical blocker is less than that of wild linden, plums, or lemon myrtle.

The main components are caffeic and vanillic phenols. The peel provides much volatile ingredients that give it a characteristic bitter taste. Among them, limonene, sabinene, citronellal, alpha, beta pinene, and citral all stand out.

The benefits of finger lime

The main benefits of finger lime have to do with its nutritional contribution and with the bioactive compounds that are part of its pulp and peel. Let’s take a look at them in detail.

It works as an antioxidant

The high presence of vitamin C in citrus caviar allows it to act as an antioxidant that contributes to boost the immune system. This vitamin promotes the activity of neutrophils, monocytes, lymphocytes, and killer cells.

It can also help maintain the cellular integrity of the skin, as ascorbic acid defends against aging. In addition, it’s involved in collagen formation, healing, and burn recovery.

Studies have also shown that vitamin C reduces thrombus formation, facilitates the absorption of dietary iron, fights bacterial and viral diseases, and prevents lipid oxidation.

The presence of phenolic compounds in the peel and juice of the finger lime also contributes to the antioxidant action. It’s for this reason that the fruit can be used as a base in the preparation of certain cosmetics.

It promotes good vision and skin health

The wide variety of colors of citrus caviar is given by the presence of beta-carotene, which can be transformed in the body into vitamin A. This vitamin is able to prevent blindness and strengthen night vision.

In addition, vitamin A softens and moisturizes the skin, prevents respiratory infections, helps produce sex hormones, and is involved in the growth and development of bones.

It brings potassium to the diet

The potassium value of finger lime is as high as that of other fruits. In fact, a 100-gram serving provides 250 milligrams of the mineral, contributing to heart function and muscle contraction. In addition, the European Food Safety Authority states that potassium contributes to normal neurological function and blood pressure control.

It helps improve digestive function

The high proportion of fiber in this citrus fruit helps improve digestive function, as cellulose and hemicellulose prevent constipation. In addition, soluble fiber, such as pectin, improves digestion and nutrient absorption. When consumed, it causes satiety and prevents hunger in weight loss diets.

Uses of citrus caviar in the kitchen

Before using finger limes in the kitchen, some care must be taken to ensure the sensory characteristics of the fruit are well preserved and to take advantage of all of its culinary benefits.

Recommendations before preparing it

When using citrus caviar vesicles, certain precautions must be taken. For example, the tips of the fruit should be removed, and then, with the same knife, carefully cut the peel on four sides lengthwise.

When opening the fruit, make sure that the oil from the peel doesn’t come into contact with the caviar, as this will affect the taste. Then, carefully remove the vesicles with a teaspoon or with the thumbs, placing them in a bowl, before removing the seeds.

It’s recommended to keep the whole fruit at no less than 5 degrees Celsius in a refrigerator. This way, it will last between 2 to 3 weeks without modifying its characteristics.

Culinary uses

The tiny pearls of this citrus fruit can be used as a flavoring or coloring, as a garnish on hors d’oeuvres, soups, meats, and cream cheese. It is also used as vegan caviar on smoked salmon with a sour cream dressing.

The pearls can also be blended cold for desserts, such as mousses and soufflés. They are often also added to dressings for vegetable and fruit salads, sauces, and drinks.

Its juice can be extracted like that of any other lime. When mixed into preparations, it gives a burst of flavor. It’s sometimes used in carbonated beverages, such as mineral water or lemonade.

Several Australian chefs even use it in guacamole, dried fruit rolls, and in ceviche with local fish and limes. It also goes very well with bivalve shellfish, such as oysters and clams.

Finger limes can be added to cocktails, champagne, and even sushi. They’re also used for garnish and as a substitute for lemon slices on steamed, grilled or fried fish, lobster, or scallops.

Some recipes with finger limes or citrus caviar

Here are some simple recipes to prepare that will leave more than one with the desire to continue tasting the burst of flavor of the finger lime.

1. Guacamole with finger lime

Mash 1 or 2 avocados and then add garlic, salt, and hot sauce to taste. Mix well before adding the pearls of 5 citrus caviars. Stir gently.

For a touch of originality, add a cup of corn and a cup of black beans. Olives and capers can also be part of the recipe. The pulp of the vegan caviar can be placed on top as a garnish.

2. Oysters with finger lime

Instead of lemon or lemon juice, use finger lime pearls on fresh oysters. This fruit can be gently tossed with rice vinegar, chopped green onions, and freshly ground black pepper.

3. Shrimp and finger lime

Take the shrimp and season with sweet paprika, chopped cilantro, garlic, and finely sliced red onion. Stir-fry for a few minutes. Then, top with citrus caviar pearls and enjoy.

Is finger lime a healthy ingredient?

The nutritional benefits of this vegan caviar translate into significant health improvements. The presence of vitamin C at levels that double the content of other fruits, as well as phenols and vitamin A, make it a potent antioxidant.

In addition, the high fiber content improves the digestive process. So, what are you waiting for? Are you going to try it?