Bay leaf (plural bay leaves) refers to the aromatic leaves of several plants used in cooking. These include :-

• Fresh or dried bay leaves are used in cooking for their distinctive flavor and fragrance.
• The leaves are often used to flavor soups, stews, braises and pâtés in Mediterranean cuisine.
• The fresh leaves are very mild and do not develop their full flavor until several weeks after picking and drying.
• California bay leaf – the leaf of the California bay tree, also known as California laurel, Oregon myrtle, and pepper wood, is similar to the Mediterranean bay laurel, but has a stronger flavor.
• Indian bay leaf is somewhat similar in appearance to the leaves of bay laurel, but is culinary quite different, having a fragrance and taste similar to bark, but milder.  
• Indonesian bay leaf or Indonesian laurel is not commonly found outside of Indonesia, this herb is applied to meat and, less often vegetables. 

If eaten whole, bay leaves are pungent and have a sharp, bitter taste. As with many spices and flavorings, the fragrance of the bay leaf is more noticeable than its taste.

Uses

Bay leaves are a fixture in the cooking of many European cuisines (particularly those of the Mediterranean), as well as in the Americas. They are used in soups, stews, meat, seafood and vegetable dishes. The leaves also flavor many classic French dishes. The leaves are most often used whole and removed before serving (they can be abrasive in the digestive tract). Thai cuisine employs bay leaf in a few Arab-influenced dishes,

In Indian and Pakistani cuisine, bay laurel leaves are sometimes used in place of Indian bay leaf although they have a different flavor. They are most often used in rice dishes like biryani and as an ingredient in garam masala. Bay (laurel) leaves are frequently packaged as tejpatta (the Hindi term for Indian bay leaf), creating confusion between the two herbs.

In the Philippines, dried bay laurel leaves are added as a spice in the Filipino dish Adobo.

Bay leaves can also be crushed or ground before cooking. Crushed bay leaves impart more of their desired fragrance than whole leaves, but are more difficult to remove, and thus they are often used in a muslin bag or tea infuser. Ground bay laurel may be substituted for whole leaves, and does not need to be removed, but it is much stronger due to the increased surface area and in some dishes the texture may not be desirable.

Bay leaves have been used in entomology as the active ingredient in killing jars. The crushed, fresh, young leaves are put into the jar under a layer of paper. The vapors they release kill insects slowly but effectively, and keep the specimens relaxed and easy to mount. The leaves discourage the growth of molds. They are not effective for killing large beetles and similar specimens, but insects that have been killed in a cyanide killing jar can be transferred to a laurel jar to await mounting. It is not clear to what extent the effect is due to cyanide released by the crushed leaves, and to what extent other volatile products are responsible. 

   Some members of the laurel family, as well as the unrelated but visually similar mountain laurel and cherry laurel. Have leaves that are poisonous to humans and livestock. While these plants are not sold anywhere for culinary use, their visual similarity to bay leaves has led to the oft-repeated belief that bay leaves should be removed from food after cooking because they are poisonous. This is not true - bay leaves may be eaten without toxic effect. However, they remain very stiff even after thorough cooking, and if swallowed whole or in large pieces, they may pose a risk of scratching the digestive tract or even causing choking. Thus, most recipes that use bay leaves will recommend their removal after the cooking process has finished.

Medicinal Uses for Bay Leaf

In Ancient times, bay leaves (Laurus nobilis), also known as laurels, came to symbolize wisdom to the Greeks and Romans, who crowned kings, poets and athletes with intricate wreaths of its glossy, feathery leaves. High achievements today are still associated with laurels. For example, a poet laureate is an accomplished poet, and graduates from college are awarded baccalaureates (Baca Laurie, Latin for "laurel berry").

Reportedly, both the leaves and the fruit of Laurus nobilis are often used for matters of women's health. These include increasing fertility, inducing menstruation, contraception and speeding up childbirth. Improving digestion and relieving gastrointestinal discomfort are also common reported uses, which may be due to components with diuretic, antispasmodic, antibacterial and purgative properties. Cultures throughout the world have traditionally used bay leaves to treat various conditions. However, while some initial research has indicated possible benefits, further clinical evidence supporting the use of bay leaf for any human indication is needed.

Ayurveda: In Ayurvedic medicine, Laurus nobilis has been used as a component of remedies for paralysis, gas, abdominal cramping and antidotes to poison.

Central Asian medicine: In Afghanistan, bay leaf may be mixed with anise and Casuarinas equisetifolia, and then inserted into the vagina to facilitate pregnancy. In Iran, the dried fruit may be decocted and taken orally to improve appetite and digestion. Also, an infusion of the dried leaf taken orally is considered to ease many ailments, including gas, cramps, and amenorrhea inflamed mucous membranes. This infusion may have diaphoretic, diuretic, and emetic activity.

Indian medicine: In Indian medicine, the leaf and fruit are believed to facilitate menstruation when taken orally. The fruit may also treat diarrhea and conditions of abnormal vaginal discharge. The oil is included in topical treatments for dandruff and rheumatism. The leaves may be used to prevent or treat infections, as a digestive aid, to induce sweating, as a sedative and as a gargle to soothe a sore throat.

Mediterranean medicine: In Greece, a hot water extract of the leaf may serve as an oral contraceptive. In Israel, the essential oil of the bay fruit may be used topically for wounds and for pain due to rheumatism or neuralgia. Also, a steam bath using dried bay leaves and other plants may be used to treat colds or to maintain overall good health. In Morocco, bay leaves are chewed to clean the teeth and may also be taken internally in cases of liver ailments. In Tunisia, dried bay leaves are taken orally for their potential sleep-inducing effect and are also used topically to ease symptoms of rheumatism.

Middle Eastern medicine: Jordanians may drink a decoction of bay leaves to stimulate appetite and treat diarrhea. In Israel, a hot water extract of dried bay leaves may serve as a component of an intravenous treatment for respiratory ailments. In general, the essential oil may be used in aromatherapy or topically for bruises, sprains or rheumatism.

European medicine: The leaves may have been burned to fend off plagues. For sprains, a poultice of the leaves steeped in oil may have been considered to relieve pain. The fruit is purportedly taken orally to speed childbirth. In England, a hot water extract of the fruit has been reportedly used to stimulate menstruation. In Italy, there are many reported uses for bay leaves and fruits. An infusion of the leaf may be drunk to improve digestion or sleep. Drinking an ethanol and water extract is believed to treat an upset stomach. The fruit might be used as a laxative. The essential oil may be used topically to soothe bruising and hemorrhoids. A blend of olive oil and dried bay fruit soaked in alcohol might be applied to painful joints. A decoction of the dried leaves may be a topical treatment for inflammation. A poultice of bay leaves might be applied to insect bites. A leaf infusion may also act as an antispasmodic, sedative and digestive.

American/American Indian medicine: In the United States, drinking a decoction of dried bay leaves has been considered useful as an astringent, as a treatment for gas, and as a digestive aid.

Latin/South American (Amazonian) medicine: In Argentina, dried bay leaves are prepared in a decoction for oral use to treat infections of the respiratory and urinary tracts. Reportedly, the fruit is eaten to hasten childbirth. To promote menstruation, 3-4 drops of leaf juice are put in water, which is then taken by mouth. In Peru, dried bay fruits or leaves are prepared in hot water and the extract is then taken by mouth to promote circulation or applied topically to help treat growths and sores.

Health benefits of bay leaf

Bay leaf was highly praised by the Greeks and the Romans, who deeply believed that the herb symbolizes wisdom, peace, and protection.

• The spice contains many notable plants derived compounds, minerals and vitamins that are essential for optimum health.
• Fresh leaves are very rich source of vitamin-C; provide 46.5 mg or 77.5% of RDA per 100 g. Vitamin-C (ascorbic acid) is one of the powerful natural anti-oxidant that help remove harmful free radicals from the body. Ascorbic acid also has immune booster, wound healing and anti-viral effects.
• Furthermore, its fresh leaves and herb parts are very good in folic acid; contain about 180 mg or 45% of daily-recommended values per 100 g. Foliates are important in DNA synthesis and when given during the peri-conception period, they can help prevent neural tube defects in the baby.
• Bay leaves are an excellent source of vitamin A; contain 6185 IU or 206% of recommended daily levels per 100 g. Vitamin A is a natural antioxidant and is essential for healthy visual sight. It is also required for maintaining mucus membranes and skin health. Consumption of natural foods rich in vitamin A has been found to help to protect from lung and oral cavity cancers.
• The spice is indeed a very good source of many vitamins such as niacin, pyridoxine, pantothenic acid and riboflavin. These B-complex groups of vitamins help in enzyme synthesis, nervous system function, and regulating body metabolism.
• This noble spice is a good source of minerals like copper, potassium, calcium, manganese, iron, selenium, zinc and magnesium. Potassium is an important component of cell and body fluids that helps control heart rate and blood pressure. Manganese and copper are used by the body as co-factors for the antioxidant enzyme, superoxide dismutase. Iron is essential for red blood cell production and as a co-factor for cytochrome-oxidase enzymes.

Medicinal uses of bay leaf

• Medicinally, the benefits of the bay leaf and its berries are plentiful. It has astringent, diuretic, and appetite stimulant properties.

• Essential oil from the bay leaves contains mostly cineol (50%); furthermore, eugenol, chavicol, acetyl eugenol, methyl eugenol, α- and β-pinene, phellandrene, linalool, geranial and terpineol are also found.

• Infusions of herb parts are reputed to soothe the stomach and relieve flatulence and colic pain.

• The Laurie acid in the bay laurel leaves has insect repellent properties.

• Bay laurel infusions are used to soothe the stomach ulcers and relieve flatulence.

The components in the essential oil can also be used in many traditional medicines in the treatment of arthritis, muscle pain, bronchitis and flu symptoms.