Surface-Enhanced Raman Spectroscopy for Rapid Screening of Cinnamon Essential Oils

Area of Science:

• Analytical Chemistry
• Food Science
• Spectroscopy

Background:

• Cinnamon essential oils are widely used but susceptible to adulteration, particularly with cassia cinnamon, which contains higher levels of potentially harmful coumarin.
• Current analytical methods like HPLC and GC for coumarin detection are time-consuming and require extensive sample preparation.
• Rapid, nondestructive screening methods are crucial for quality control and authenticating cinnamon essential oil.

Purpose of the Study:

• To develop a rapid, nondestructive screening method for analyzing cinnamon essential oils.
• To detect coumarin adulteration and differentiate between cinnamon oil sources (bark vs. leaves).
• To validate the developed method using theoretical calculations and commercial samples.

Main Methods:

• Utilized surface-enhanced Raman spectroscopy (SERS) for analyzing cinnamon essential oils.
• Compared experimental SERS spectra with theoretical calculations using the DFT method BP86/6-311++G(d,p).
• Determined the limit of detection for coumarin and analyzed commercial cinnamon essential oil samples.

Main Results:

• Achieved a limit of detection for coumarin at 1 × 10^-6 M (1.46 mg/L) using SERS with colloid paste substrates.
• Successfully differentiated cinnamon essential oils derived from bark (cinnamaldehyde) versus leaves (eugenol).
• Detected coumarin in two of seven commercially available cinnamon essential oil samples, indicating adulteration.

Conclusions:

• SERS provides a highly sensitive and rapid method for screening coumarin in cinnamon essential oils.
• The developed SERS method is effective for quality control, food authentication, and adulteration detection.
• This study demonstrates the first application of SERS for rapid screening of cinnamon essential oils.