Chloroplast genome comparison and chemical profiling support InDel based identification across cinnamon plants

Area of Science:

• Botany
• Molecular Biology
• Food Science

Background:

• Cinnamomum osmophloeum, a Taiwanese endemic species, is often misidentified as the invasive Cinnamomum burmannii in commerce.
• Accurate species identification is crucial for quality control and preventing the adulteration of cinnamon products.

Purpose of the Study:

• To develop a reliable DNA-based identification system for Cinnamomum osmophloeum.
• To differentiate C. osmophloeum from other cinnamon species, particularly C. burmannii, using molecular markers.
• To complement DNA identification with chemical profiling for robust authentication.

Main Methods:

• Comparative analysis of chloroplast genomes to identify insertion/deletion (indel) loci.
• Development and validation of chloroplast indel markers for species discrimination.
• Volatile compound analysis using solid-phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS).

Main Results:

• Fifteen indel loci were identified, with 14 polymorphic and 6 showing intraspecific variation.
• Eight validated indel markers successfully discriminated between cinnamon species.
• Chemical profiling revealed distinct volatile compound profiles for C. osmophloeum (cinnamaldehyde, linalool) and C. burmannii (borneol, eucalyptol).
• Analysis of commercial products indicated that five out of seven samples correctly matched C. osmophloeum genotypes.

Conclusions:

• Chloroplast indel markers offer a robust and rapid method for authenticating cinnamon species.
• DNA-based identification, supported by chemical profiling, effectively prevents the misidentification of C. osmophloeum.
• The developed system ensures the integrity of commercial cinnamon products, safeguarding against adulteration.