Bay leaf is a popular culinary spice used in the west. You can find it in a pot of spaghetti boiling on the stove or in a herbaceous batch of oven-baked chicken. Bay (Laurus nobilis L.) leaf also known as a Turkish laurel, is a plant commonly used as a seasoning in meats, soups and fish. They are widely cultivated in Europe, America and Arabian countries but are native to the Mediterranean. Bay leaves are typically used in their dried form as they impart a more subtle eucalyptus flavor compared to their fresh counterpart. Overall, fresh bay leaves have a characteristic flavour of strong, spicy, bitter and pungent flavor with cooling undertones.
Flavor Compounds Found in Bay Leaves
A variety of flavour compounds can found in bay leaves. The compound found in the highest concentration is cineole, in particular 1, 8-cineole. 1,8-cineole can also be found in plants like basil, cassia and fennel and interestingly also possess the ability to kill pathogens and herbivores. As a result, cineole is used in mouthwashes like Listerine because it kills oral bacteria which produce bad smelling volatile components like mercaptans, skatole, and diamines. Cineole’s flavour is minty, camphoreous, cooling, eucalyptus and medicinal.
Another component found in the oils of bay leaves is linalool. Linalool is compound described as being citrusy, orangey, lemony, floral, waxy, aledhydic and woody. These scent characteristics make it preferable in the use of hygiene and cleaning agents like soaps and detergents. Another compound found in high concentrations is α-terpinyl acetate. α-terpinyl acetate has a taste of woody, citrus, spicy, floral, grapefruit and seedy. Methyl eugenol is a phenylpropene and the methyl ether of eugenol. It is described as tasting spicy, cinnamon, clove, fresh, peppery and woody. Last but not least is the compound known as eugenol. Eugenol is another phenylpropene extracted from certain essential oils like clove oil, nutmeg, cinnamon and basil. In low concentrations it tastes sweet, warm, spicy, clove-like and has phenolic and woody nuances
Why add Bay Leaves to recipes?
If you ever consumed a stew with bay leaves you might have thought that the flavor was undistinguishable, pointless even. However, you might be wrong. Bay leaves as discussed above contain flavor compounds that are cooling and minty. These chemicals are expressed strongly during the beginning of the cooking process. It is likely you don’t notice them because stews and soups are allowed to simmer for hours. During the cooking process these predominant eucalyptus notes die down and transform to more herbaceous notes. These herbaceous notes might not be as prominent when compared to other spices like black pepper but I can assure they are essential! The moral? Bay leaves although not highly detectable in stews are integral for a full-body dish.
Seasonal Variations
Bay leaves experience compositional changes in their essential oils depending on the time of year. Volatile components such as 1,8-cineole are found to be in higher concentrations during the month of June compared to March. The amount of oil extracted from the leaves also differs. Oil yields were found to be higher September (0.36%) compared to March (0.13%). This is likely due to the prolonged higher temperature causing the oil to liquidity. There is a positive correlation between essential oil percentages in the leaves and atmospheric temperature. Therefore, warmer temperatures mean more oil that can be extracted from a leave.
References
Parthasarathy, V. A. (2008). Chemistry of spices. Wallingford, Oxfordshire: CABI.
López-Alt, J. K. (2014). Ask the Food Lab: What’s the Point of Bay Leaves? Retrieved January 11, 2018, from http://www.seriouseats.com/2014/03/ask-the-food-lab-whats-the-point-of-bay-leaves.html
