Properties and applications of kumquat

kumkwat

Kumquats are exotic fruits, which – because of their appearance – are sometimes called a “golden orange” or a “dwarf orange”. Despite its similarity to citrus fruits, kumquat does not belong to the Citrus genus. Nevertheless, just as citrus fruits, it is characterized by a high vitamin C content and high nutritional value. How do you eat kumquat, how does it taste and what are its medicinal properties?

What is a kumquat and what does it look like?

Kumquat is a species of oriental shrubs or small trees that originated in southern China. They have also been cultivated for hundreds of years in Japan, Taiwan, India or Southeast Asia, but did not reach Europe (and then North America) until the mid-19th century. Like citrus, kumquat belongs to the Rutaceae family, but is included in a separate genus: Fortunella.

Kumquat fruits resemble oranges in their color, shape and skin texture, but are much smaller. Depending on the variety, they can be round, oval or oblong, and their length does not exceed 4 cm – so in size they are much closer to large olives or cherry tomatoes. The average weight of a single kumquat fruit is only 12 grams.

What properties does kumquat have?

Domestic fruits, especially citrus, are often promoted as a source of many vitamins that are an integral part of a healthy diet. Many are also associated with medicinal properties – such as the use of cranberries for cystitis or blackberry leaves for diarrhea. Exotic fruits are not different. Kumquat is a rich source of vitamins – especially vitamin C. One hundred grams of the fruit covers as much as 55% of the daily requirement for this vitamin, as well as 11% of the requirement for vitamin A and 2.7-8.5% for B vitamins. It also contains many minerals needed for the proper functioning of the body, including copper (Cu), potassium (K), calcium (Ca), iron (Fe), manganese (Mn), and magnesium (Mg).

In addition to its rich nutritional value, enhanced by its high dietary fiber content, kumquat fruits contain numerous compounds with medicinal properties. These are primarily:

  • The essential oil – a mixture of terpenes that exhibit antimicrobial, anti-inflammatory, analgesic, diastolic, and antiarrhythmic effects
  • Carotenoids – natural pigments that reduce the risk of developing certain cancers and eye diseases, also acting as antioxidants and photoprotectors
  • Flavonoids (and other polyphenols) – compounds with strong antioxidant activity, protecting the body against the effects of oxidative stress and beneficial in the prevention of many civilizational diseases.

What are the applications of kumquat?

Kumquat fruit can be a source of vitamins and minerals, as well as a healthy addition to your menu. With its health-promoting chemical composition, consuming kumquat helps reduce the risk of lifestyle diseases such as diabetes, hypertension, certain cancers and cardiovascular diseases. Studies also point to the beneficial effects of its fruit on the lipid profile and liver health – kumquat extracts help lower “bad” LDL cholesterol and raise “good” HDL cholesterol; they also protect against the development of cirrhosis and improve liver enzyme ratios (AST and ALT).

In addition to regulating liver function, kumquat in your diet will support digestive processes and alleviate gastrointestinal discomfort (bloating, constipation, indigestion). Combined with their low calorie content (100 g of fruit is only 70 kcal), kumquats can work well as a part of weight loss diets.

Other medicinal properties of kumquat used in its potential applications include immune-stimulating and anti-inflammatory properties related to its high vitamin and polyphenol content, supplementation of iron deficiencies, stimulation of red blood cell production in anemia, and antimicrobial activity.

Kumquat in cosmetics

With its high content of nutrients and antioxidant compounds, kumquat is also of interest in cosmetology. Cosmetics use extracts of the whole fruit – both the peel and pulp of kumquat have similar composition and properties – at concentrations of 5-10%. The isolated essential oil can also serve as an ingredient, but it should not be applied to the skin at concentrations above 5%.

Kumquat is used in skin, nail and hair conditioners, deodorants, moisturizing tonics and anti-aging products. Like extracts of nettle or field horsetail, kumquat also works well in hair preparations. It not only has nourishing and moisturizing properties, but also reduces sebum production and gives hair extra softness and bounce.

How to eat kumquats?

In the case of less popular exotic fruits, many people wonder how they should be eaten. The kumquat may cause additional hesitation due to its peculiar appearance. After all, it resembles an orange, which is eaten only after peeling, while also being much smaller. It may come as a bit of a surprise, but kumquat should be eaten whole, along with the peel. It is sometimes recommended to blanch the fruit with hot water beforehand, but this is not at all necessary. However, for extra softness and to release the aroma of the juicy essential oil, it is advisable to lightly crush the fruit in your hand before consuming it; in order to feel the fullness of its flavor, it is recommended to chew it longer in your mouth.

Kumquat can be consumed in many forms. In addition to fresh fruit, you can also find kumquat as candied fruit, which retains its properties longer during long transportation and storage. Kumquat is also great for making preserves such as jams, marmalades, jellies, syrups and juices. In addition to soft drinks, it is sometimes used in the production of liqueurs, in which case it is believed that its peels alone work better instead of the whole fruit.

What is the taste of kumquat?

A lack of knowledge of what it tastes like and what it goes well with may also discourage from trying kumquat for the first time. Thanks to its rich chemical composition, the taste of kumquat is quite unique. At first it is slightly spicy and tart, astringent, to be followed after a while by a sweetness of growing intensity. Importantly, it is the skin, and not the flesh, that accounts for this sweet taste. This combination makes kumquat fruit work well not only as an accompaniment to fruit salads and sweet desserts, but also to dry dishes based on tender meats and fish.


Literature:

  1. Flis-Kaczykowska A I Dmowski P. Ocena wybranych wyróżników jakości owoców cytrusowych. ŻYWNOŚĆ. Nauka. Technologia. Jakość 2020; 27(2): 121-129.
  2. Li X, Meenu M i Xu B. Recent Development in Bioactive Compounds and Health Benefits of Kumquat Fruits. Food Reviews International 2022.
  3. Pawełczyk A, Żwawiak J i Zaprutko L. Kumquat Fruits as an Important Source of Food Ingredients and Utility Compounds. Food Reviews International 2021.