Table 2.

Physical characterization of selected essential oils.

Name	Organoleptic description	Solubility	Density (g/cm3)	Index of refraction	Optical rotation	Stability	References
Mentha piperita essential oil	Colorless to pale yellow-greenish liquid with Strong peppermint odor and sweet, balsamic taste, often masked by the distinct cooling effect	Soluble in 70% ethanol at 20°C	0.896–0.908 at 25°C	1.460–1.464 at 20°C/D	−28 to −17° at 20°C	Not specified	PubChem, n.d.
Cinnamon bark essential oil	Dark yellow clear oily liquid with sweet spicy aldehydic aromatic cinnamyl woody resinous honey powdery odor	Soluble in 70% ethanol at 20°C	1.010–1.030 at 25/25°C	1.5730 to 1.5910 at 25°C	−2 to 0 at 20°C	Darkens and thickens on exposure to air	Good Scents Company, n.d.; PubChem, n.d.
Thyme essential oil	Colorless clear liquid with herbal, phenolic odor	Soluble in 70% ethanol at 20°C	0.941 at 25°C	1.506 at 20°C/D	21.0 to +15.0	Not specified	Good Scents Company, n.d.; PubChem, n.d.
Cumin essential oil	Light yellow to brown liquid with strong, somewhat fatty and green odor	Soluble in 80% ethanol at 20°C; Soluble in fixed oils, mineral oil; very soluble in glycerine, propylene glycol, chloroform and ether	0.908–0.958 at 20°C	1.4940–1.5160 at 20°C	+1 to +8 at 20°C/D	Tends to darken on aging; quite sensitive to daylight, air, moisture and metals, as well as alkali.	PubChem, n.d.
Nutmeg essential oil	Colorless or pale yellow liquid with odor and taste of nutmeg	Soluble in fixed oils, mineral oil; slightly soluble in cold alcohol; very soluble in hot alcohol, chloroform, ether; insoluble in glycerine, propylene glycol, and water	0.859–0.924 at 25°C	1.4740–1.4880 at 20°C/D	+10° to +30 at 20°C/D	Not specified	PubChem, n.d.