Garlic oil is the

volatile oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

derived from garlic. It is usually prepared using steam distillation and can also be produced via distillation using

ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...

. It is used in cooking and as a seasoning, a nutritional supplement, and also as an insecticide.

Preparation

Garlic oil is typically prepared using steam distillation, where crushed garlic is steamed with the resultant condensation containing the oil. Garlic oil contains volatile sulfur compounds such as

diallyl disulfide Diallyl disulfide (DADS or 4,5-dithia-1,7-octadiene) is an organosulfur compound derived from garlic and a few other genus ''Allium'' plants. Along with diallyl trisulfide and diallyl tetrasulfide, it is one of the principal components of the dist ...

, a 60% constituent of the oil. Steam-distilled garlic oil typically has a pungent and disagreeable odor and a brownish-yellow color. Its odor has been attributed to the presence of diallyl disulfide. To produce around 1 gram of pure steam-distilled garlic oil, around 500 grams of garlic is required. Undiluted garlic oil has 900 times the strength of fresh garlic, and 200 times the strength of dehydrated garlic.

Ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...

can also be used to extract garlic oil. A type of garlic oil involves soaking diced or crushed garlic in vegetable oil, but this is not pure garlic oil; rather it is a garlic-infused oil.

Uses

Garlic oil is used as a

nutritional supplement A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in order ...

, and is sometimes marketed in the form of capsules, which may be diluted with other ingredients. Some commercial preparations are produced with various levels of dilution, such as a preparation that contains 10% garlic oil. Herbal folklore holds that garlic oil has antifungal and antibiotic properties, but there is insufficient

clinical research Clinical research is a branch of healthcare science that determines the safety and effectiveness ( efficacy) of medications, devices, diagnostic products and treatment regimens intended for human use. These may be used for prevention, treatm ...

confirming such effects. It is also sold in health food stores as a digestive aid. It can be used as an insecticide, diluted with water and sprayed on plants. Stabilized garlic flavor blend is a proprietary mixture of dehydrated

garlic powder Garlic powder is a spice that is derived from dehydrated garlic and used in cooking for flavour enhancement. The process of making garlic powder includes drying and dehydrating the vegetable, then powdering it through machinery or home-based app ...

infused with garlic oil, which increases the flavor of the garlic powder.

Potential adverse effects

Common

adverse effect An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a " side effect", when judged to be secondary to a main or therapeutic effect. The term compl ...

s of consuming garlic, garlic oil, and garlic supplements are breath and body odor, abdominal pain, nausea, vomiting, and other symptoms of

gastrointestinal disorder Gastrointestinal diseases (abbrev. GI diseases or GI illnesses) refer to diseases involving the gastrointestinal tract, namely the oesophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, ...

s. Garlic oil consumption may have anticoagulant effects in some people, causing bleeding, and may interfere with prescription drugs.

Health research

Garlic oil has been assessed in laboratory and preliminary

for its potential to affect human health, with inconclusive results, as of 2016.

Garlic-flavored oil

Garlic-flavored oil is produced and used for cooking and seasoning purposes, and is sometimes used as an ingredient in seasoning mixtures. This differs from essential garlic oil, and typically involves the use of chopped, macerated or crushed garlic placed in various vegetable oils to flavor the oil.

References