Cloves, Clove Oil and Eugenol - Culinary and Medicinal Uses
Cloves are a dark brown, aromatic spice that adds a strong and flavorful taste to foods and drinks. A large quantity of cloves can overpower a dish, but the taste of a small amount combines very well with the tastes of other spices and foods. Meats, stews, vegetables, cakes, fruits, teas and infusions can all benefit from the addition of cloves.
Cloves are the dried flower buds of the clove tree. This tree is native to the Moluccas, or the Maluku Islands, which are part of Indonesia and are sometimes known as the Spice Islands. Historically, the Moluccas were a very popular source of cloves, nutmeg, pepper and mace. Today cloves are cultivated in several countries, including Indonesia, Zanzibar and Madagascar. The spice is sold as intact flower buds and as a ground powder. Like other spices, cloves lose some of their flavor if they’re ground long before they're used.
The flavor of cloves is provided by their oil. A chemical called eugenol makes up seventy to ninety percent of clove oil and is the chief substance responsible for the aroma and taste of cloves. Eugenol also acts as an analgesic in the mouth, since it has the ability to temporarily block pain by numbing tissues. Clove oil has been used to ease the discomfort of toothache for hundreds of years. The oil has drawbacks as well as benefits, however.
The Maluku Islands, or the Moluccas
Cloves as a Spice
The flower buds of the clove tree are pink, but they turn red-brown as they're dried. The word "clove" comes from "clavus", the Latin word for nail. The name reflects the appearance of the dried flower buds, which look somewhat like rusty nails. The bud at the head of the "nail" is surrounded by four sepals.
Cloves have an intense flavor. They also taste pungent and only slightly sweet. I like to mix them with a sweeter spice, such as cinnamon, when I add them to food or drinks.
Cloves work very well in spiced drinks and spice cakes. They provide a nice taste to stewed fruit and grains as well. They are also a popular addition to curries, vegetable dishes and beans. They're sometimes used to "stud" meat and vegetables such as onions. Whole cloves are pushed into the food so that just the buds are visible. This process adds flavor to the food. The cloves are removed once the food is cooked.
Cloves are a traditional component of chai tea, or masala chai as it's sometimes called. This tasty and aromatic beverage originated in India but is now popular in many other parts of the world as well. It's made from black tea and mixed spices. The recipe usually includes milk and a sweetener, too. The spice mixture varies but traditionally contains cloves, cinnamon, nutmeg, ginger, star anise, peppercorns and green cardamom pods.
Cloves are also a traditional part of the spice mixture known as garam masala. This has a similar composition to the spice mixture used in masala chai, and like that mixture it varies slightly in composition.
Since cloves are generally eaten in small quantities a single serving doesn't provide many nutrients. A very important exception is manganese, however. One teaspoon of ground cloves provides about thirty percent of our daily manganese requirement.
Clove "nails" are hard structures and are quite difficult to grind. An electric grinder is needed to break them up. Sometimes it isn't necessary to grind the intact cloves, though. For example, in the chai tea recipe described in the video shown below, the cloves are boiled in liquid to release their flavor and are then filtered out of the liquid.
Masala Chai with Cashew Milk Recipe
A Spiced Apple Cider Recipe with Cloves
Clove Oil For Toothaches
Oil of cloves, or clove oil, is extracted from the buds, leaves or stems of the clove tree. It's rich in eugenol. The oil is far more potent than clove buds or ground cloves. It shouldn't be swallowed or come into contact with the gums, tongue or lips because it will damage tissue that it touches. However, many people report that clove oil relieves toothache pain. The oil is sold as an over-the-counter medicine in pharmacies.
Clove oil must be placed directly on a painful tooth without touching the rest of the mouth. The oil can be applied with a cotton swab. If you find that clove oil helps your toothache, remember that it's only a temporary solution. You need to visit a dentist very soon to get the cause of the toothache treated.
I've never tried using clove oil for a toothache, but I applied ground cloves to my gum when I had a root problem and they did relieve my pain temporarily. Even ground cloves can be irritating to gums if too much is used or if the cloves are used too often.
Some people apply clove oil diluted with olive oil to painful gums. Once again, it's great if you find that this mixture removes your gum pain, but you need to seek a dentist's advice as soon as possible to get the problem treated. Using cloves repeatedly increases the chance of tissue damage from clove oil, and even though oral pain may weaken or temporarily disappear with cloves treatment the infection in the tooth or gums may continue to get worse.
Dangers of Clove Oil
Ground cloves are considered to be safe if eaten in moderate quantities. However, inhaling smoke from clove cigarettes can cause breathing problems and damage the lungs.
Clove oil is a potentially dangerous substance. It can do more in our body than simply damage tissue. The ingestion of a large quantity of the oil can cause a coma, seizures, liver damage and kidney damage. Other detrimental effects of clove oil include nausea, vomiting, stomach pain, diarrhea and a rapid heartbeat. Clove oil is also thought to delay blood clotting and shouldn't be used before surgery.
It's very important to keep clove oil away from children, since even a small amount may have serious effects inside a child's body. Pregnant women and nursing mothers are generally advised to avoid using clove oil and to eat cloves only in the amount that would normally be added to food.
Antibacterial Clove OIl
Clove oil has been found to have antimicrobial activity against certain harmful bacteria and yeasts in food, but not (so far) against harmful oral bacteria while they are inside the mouth.
When looking at research reports it's important to notice whether an experiment was done "in vitro" (in lab equipment) or "in vivo" (in living things). Many substances have been found to work in lab glassware but not inside living bodies, where the substance is diluted, removed by body fluids, broken down, inhibited by other chemicals or not absorbed. In addition, a substance may work inside lab animals but not inside humans, whose bodies may not work in quite the same way as the bodies of animals.
Several researchers have found that clove oil fights certain oral bacteria in vitro, which is a hopeful sign for the future. Perhaps scientists will be able to create a safe and effective clove oil medicine to fight harmful bacteria in our mouths as well as relieve pain.
Eugenol and its Uses
Eugenol is the most abundant ingredient in clove oil and is responsible for both the beneficial and the harmful effects of the oil. It's found in cinnamon, nutmeg and allspice oils as well as in clove oil.
Eugenol is used in fragrances and perfumes because of its aromatic scent. It's sometimes used by dentists to numb the gums or to make a temporary filling when mixed with zinc oxide. However, eugenol use is less common in dentistry today than it was in the past. Eugenol has caused allergic reactions and contact dermatitis in some people.
Eugenol is also used as an insecticide to kill pests, especially those found in homes and gardens. It's appreciated because of its fast action when used at the appropriate dose and its relative safety for humans compared to some other chemicals. The insecticide is often sold as "eugenol oil". One problem with eugenol oil is that some pests require a higher concentration of eugenol to kill them than others. Since eugenol is responsible for the harmful effects of clove oil in humans, it's very important to be careful when using it as a pesticide.
Adding Cloves to the Diet
Whole and ground cloves provide a delicious taste to foods and drinks when they're combined with other spices. Ground cloves are a useful addition to a kitchen spice collection. They have a strong taste, however, so it's best to use them in small quantities, especially when someone isn't used to the spice.
Cloves are safe when used in reasonable quantities. Large amounts of cloves and isolated clove oil and eugenol need to treated with care. They can be helpful, but they're potentially dangerous as well.
© 2012 Linda Crampton
More by this Author
Vinblastine and Vincristine from the Madagascar periwinkle are used in cancer chemotherapy. L-dopa from velvet beans is used to treat Parkinson’s Disease.
Coffee has a range of health benefits. These may include antibacterial activity against tooth decay bacteria and harmful intestinal bacteria.
Proteus mirabilis is responsible for urinary tract infections in some people. The bacterium causes inflammation and the production of stones in the urine.