Cinnamon Cassia Bark essential oil is widely used in food, fragrance, and pharmaceuticals. However, the extraction method significantly affects its chemical profile and sensory characteristics. The two main techniques—steam distillation and supercritical CO2 extraction—produce oils that can be distinguished by both organoleptic assessment and analytical methods such as GC–MS.
1. Sensory Evaluation
Aroma Profile
- Steam-distilled cinnamon Essensial oil: Has a sharp, spicy, and penetrating aroma, often dominated by cinnamaldehyde. Because distillation involves heat, the profile can feel slightly “cooked” or less rounded.
- CO2 cinnamon extract: Exhibits a warmer, fuller, and more natural cinnamon scent, with both the bright top notes and the deeper base notes preserved. The aroma is usually closer to the raw bark.
Color and Consistency
- Steam-distilled Essensialoil: Typically light yellow to reddish-brown, with a relatively thin consistency.
- CO2 extract: Often darker, more viscous, and may carry additional non-volatile compounds such as resins or waxes.
2. Solubility and Physical Properties
- Steam-distilled Essensialoil: Mixes more easily with ethanol and leaves little residue, as it contains mostly volatile molecules.
- CO2 extract: May produce a slightly cloudy solution in ethanol, reflecting the presence of heavier constituents such as coumarins or diterpenes.
3. GC–MS Profile Differences
Gas Chromatography–Mass Spectrometry (GC–MS) provides a clear fingerprint of extraction differences.
a. Dominant Compounds
- Steam-distilled Essensial oil: Strong peaks for cinnamaldehyde and eugenol. Minor compounds often reduced or absent due to heat degradation.
- CO2 extract: Broader spectrum including cinnamaldehyde, cinnamic acid derivatives, coumarin, cinnamyl alcohol, and other thermolabile compounds that do not survive steam distillation.
b. Marker Compounds
- Coumarin: Present in CO2 extract; typically absent or very low in steam-distilled oil.
- Cinnamic acid and esters: More abundant in CO2 extracts.
- Sesquiterpenes (e.g., caryophyllene): Stronger peaks in CO2 extracts due to low-temperature preservation.
c. Peak Distribution
- Steam distillation: Narrower profile, dominated by 2–3 major compounds.
- CO2 extraction: Wider profile with additional minor peaks, representing fatty acids, sterols, and thermosensitive constituents.
4. Practical Identification Steps
- Smell the sample – note whether the aroma is sharp/spicy (distilled) or warm/rounded (CO2).
- Observe the oil – check color and viscosity. Darker, thicker oils suggest CO2 extraction.
- Do a solubility check – cloudiness in ethanol points toward CO2 extract.
- Run GC–MS – confirm through presence of coumarin, cinnamic acid derivatives, and broader sesquiterpene profile in CO2 oils.
Example GCMS profile analysis of Cinnamon Cassia Bark Extracted by Steam Distillation vs Supercritical CO2
| Steam Disstillation | Supercritical CO2 Extraction | |
| Dominant Compounds | Cinnamaldehyde: 92.79% Total 11 compounds | Cinnamaldehyde: 84.2% Total 17 compounds |
| Marker Compounds | Coumarin: absent Sesquiterpenes (C15): 2.32% | Coumarin: present Sesquiterpenes (C15): total 5.68% |
| Peak Distribution | Peak narrower on minutes 5.7 to 19.6 | Peak profile wider on minutes 5.8 to 44 |