A kumquat isn’t much bigger than a grape, yet this bite-sized fruit fills your mouth with a big burst of sweet-tart citrus flavor. In Chinese, kumquat means “golden orange.”
They were originally grown in China. Now they’re also grown in several other countries, including warmer areas of the United States, such as Florida and California. In contrast with other citrus fruits, the peel of the kumquat is sweet and edible, while the juicy flesh is tart.
This article covers the nutrition and health benefits of kumquats, as well as tips for eating them.
A BIG NUTRITIONAL PUNCH IN A SMALL FRUIT
Kumquats are especially notable for their rich supply of vitamin C and fiber. In fact, you get more fiber in a serving of them than most other fresh fruits.
A 100-gram serving (about 5 whole kumquats) contains:
- Calories: 71
- Carbs: 16 grams
- Protein: 2 grams
- Fat: 1 gram
- Fiber: 6.5 grams
- Vitamin A: 6 percent of the RDI
- Vitamin C: 73 percent of the RDI
- Calcium: 6 percent of the RDI
- Manganese: 7 percent of the RDI
Kumquats also supply smaller amounts of several B vitamins, vitamin E, iron, magnesium, potassium, copper and zinc.
The edible seeds and the peel of kumquats provide a small amount of omega-3 fats. As with other fresh fruits, kumquats are very hydrating. About 80 percent of their weight is from water.
The high water and fiber content of kumquats makes them a filling food, yet they’re relatively low in calories. This makes them a great snack when you’re watching your weight.
HIGH IN ANTIOXIDANTS AND OTHER PLANT COMPOUNDS
Kumquats are rich in plant compounds, including flavonoids, phytosterols and essential oils.
There are higher amounts of flavonoids in the kumquat’s edible peel than in the pulp.
Some of the fruit’s flavonoids have antioxidant and anti-inflammatory properties. These may help protect against heart disease and cancer.
The phytosterols in kumquats have a chemical structure similar to cholesterol, meaning that they can help block the absorption of cholesterol in your body. This may help lower your blood cholesterol.
The essential oils in kumquats leave a scent on your hands and in the air. The most prominent one is limonene, which has antioxidant actions in your body.
When consumed in a whole food, such as kumquats, the different flavonoids, phytosterols and essential oils are thought to interact and have synergistic beneficial effects.
SUPPORTS HEALTHY IMMUNE FUNCTION
In folk medicine in some Asian countries, the kumquat has been used to treat colds, coughs and other inflammation of the respiratory tract. Modern science shows that there are certain compounds in kumquats that support your immune system.
Kumquats are a super source of immune-supportive vitamin C. Additionally, some of the plant compounds in kumquats may also help bolster your immune system.
Animal and test-tube studies suggest that kumquat plant compounds may help activate immune cells called natural killer cells.
Natural killer cells help defend you from infections. They have also been shown to destroy tumor cells.
One compound in kumquats that helps stimulate natural killer cells is a carotenoid called beta-cryptoxanthin.
A pooled analysis of seven large observational studies found that people with the highest intake of beta-cryptoxanthin had a 24 percent lower risk of lung cancer. However, the research was not able to prove cause and effect.
MAY HELP COMBAT OBESITY AND RELATED DISORDERS
The plant compounds in kumquats may help fight obesity and associated diseases, including heart disease and type 2 diabetes.
Scientists are testing this in mice using extract from kumquat peels. This extract is especially rich in the flavonoids neocriocitin and poncirin.
In a preliminary study, normal-weight mice fed a high-fat diet for eight weeks gained significantly more weight than mice given a high-fat diet plus kumquat extract or a low-fat control diet. All groups consumed about the same amount of calories.
Further analysis showed that the kumquat extract helped minimize growth in fat cell size. Previous research suggests that the flavonoid poncirin may play a role in this fat cell regulation.
In part two of the same study, obese mice fed a high-fat diet for two weeks had a 12 percent increase in body weight. But, obese mice fed a high-fat diet plus kumquat extract maintained their weight. Both groups consumed about the same amount of calories.
In both parts of the study, kumquat extract also helped lower fasting blood sugar, total cholesterol, LDL (bad) cholesterol and triglycerides.
More research is needed, including research in people. Regardless, since kumquats can be eaten peel and all, you can easily tap into whatever benefits they may carry.
HOW TO EAT KUMQUATS
Kumquats are best eaten whole — unpeeled. Their sweet flavor actually comes from the peel, while their juice is tart. The only caveat is that if you’re allergic to the peel of common citrus fruits, you may need to pass up kumquats.
If the tart juice turns you off, you can squeeze it out before eating the fruit. Just cut or bite off one end of the fruit and squeeze. However, many people suggest popping the whole fruit into your mouth and biting in, which mixes the sweet and tart flavors.
It also may help to gently roll the fruit between your fingers before eating. This helps release the essential oils in the peel and mixes the flavors of the sweet peel and tart flesh. In addition, chew kumquats well. The longer you chew them, the sweeter the flavor.
If you want to soften the peel before eating the fruits, you can plunge them into boiling water for about 20 seconds and then rinse them under cold water. This isn’t necessary though.
As for the kumquat seeds, you can either eat them (although bitter), spit them out or pick them out if you cut the fruit.
TIPS FOR BUYING AND USING KUMQUATS
Kumquats grown in the United States are in season from November through June, but availability may vary depending on where you live. If you wait until the end of the season to look for them, you may miss out.
Check for kumquats in supermarkets, gourmet food stores and Asian grocery stores. If you live in a state where the fruits are grown, you also may find them at farmers markets.
The most common variety sold in the United States is the Nagami, which has an oval shape. The Meiwa variety is also popular, and is round and a bit sweeter.
If you can’t find kumquats in local grocery stores, you can also order them online.
If you can find and afford them, opt for organic kumquats since you typically eat the peel. If organic isn’t available, wash them well before eating as they may have pesticide residues.
When selecting kumquats, give them a gentle squeeze to find ones that are plump and firm. Choose fruits that are orange in color, not green (which could mean they’re unripe). Pass up any with soft spots or discolored skin.
Once you get them home, refrigerate the fruits for up to two weeks. If you store them on your countertop, they’ll only keep a few days. If you have kumquats that you can’t eat before they go bad, consider making a purée out of them and store this in your freezer.
Besides eating them whole, other uses for kumquats include:
- Chutneys, marinades and sauces for meat, chicken or fish
- Marmalades, jams and jellies
- Sliced in salads (fruit or leafy green)
- Sliced into a parfait, like the chia pudding parfait pictured above
- Sliced in sandwiches
- Added to stuffing
- Baked into breads
- Baked into desserts such as cake, pie or cookies
- Puréed or sliced for dessert toppings
- Tiny dessert cups (when halved and scooped out)
- Sliced and steeped in boiling water for tea
Recipes for these ideas can be found online. You can also buy ready-made kumquat jams, jellies, sauces and dried kumquat slices.
THE BOTTOM LINE
The kumquat has much more to offer than just a spunky name.
One of the most unusual things about these bite-size orbs is that you eat the peel, which is the sweet part of the fruit. This makes them an easy grab-and-go snack. Because you eat the peel, you can tap into the rich stores of antioxidants and other plant compounds found there.
The vitamin C and plant compounds in kumquats can help support your immune system. Some of these may even help protect against obesity, heart disease, type 2 diabetes and certain cancers, though more human research is needed.
If you haven’t yet tried kumquats, look for them starting around November and into the next several months. They just might become one of your new favorite fruits.