On steam distillation, dried bay leaves produce 1-3% essential oil. This is a light yellow mobile liquid with a characteristic aromatic and spicy aroma. It has a eucalyptus-like odor due to the cineole content. Lawrence (1980) found that the yield of bay leaf oil could be up to 3%. Bay leaf oils from different parts of Turkey showed a high content of 1,8-cineole, sabinene, and a-terpinyl acetate. In one case, as much as 60% cineole has been obtained. Lower levels of a-pinene, a-phellandrene, and trans-p-osimen were also found (Sangun et al., 2007). Glycosidically bound volatile compounds have been investigated (Kilic et al., 2005). The aglycones found were benzyl alcohol, linalool diols, 1,8-cineole and its derivatives, sobrerols, and menthadien-8-ols.
Earlier investigations have been well covered by Prakash (1990). Major constituents reported were 8-terpinene, terpinolene, cineole, terpeniol, geraniol, and their acetates. Publications on P. racemosa have been well reviewed by Lawrence (2007). This includes studies wherein 1,8-cineole, terpinen-4-ol, methyl eugenol, thymol, and methyl chavicol were prominent components in various samples. Lawrence (2008) has also compiled results for laurel leaf oil.
According to the FCC, laurel leaf oil (Laurus nobilis) occurs as a light yellow liquid with an aromatic, spicy odor. It is soluble in most fixed oils, as it is in mineral oil, with cloudiness, and in propylene glycol. It is insoluble in glycerin.
Physical characteristics for laurel leaf oil as defined by the FCC are as follows:
Optical rotation -10 to -19°
Refractive index 1.465-1.470 at 20 °C
Specific gravity 0.905-0.929
Solubility 1 mL dissolves in 1 mL of 80% alcohol and remains in solution
on dilution to 10 mL