Phytochemical Characterization and Comparative Tissue-Specific Metabolomics of Coffea arabica Using LC-HRMS.

Area of Science:

• Agricultural Chemistry
• Plant Biochemistry
• Analytical Chemistry

Background:

• Coffee (Coffea arabica) is a globally significant crop with diverse plant parts containing potentially valuable bioactive compounds.
• Understanding the metabolomic variations across different coffee tissues is crucial for identifying novel sources of natural products.
• Previous research has focused on specific compounds, but a comprehensive non-targeted metabolomic analysis of all major coffee plant parts is lacking.

Purpose of the Study:

• To perform a non-targeted metabolomic profiling of Coffea arabica bean, flower, leaf, cascara, and parchment.
• To quantify total phenolic, flavonoid, and terpenoid content and assess antioxidant activity in each plant part.
• To identify key metabolites responsible for the distinct chemical signatures across different tissues.

Main Methods:

• Liquid chromatography Orbitrap high-resolution mass spectrometry (LC-HRMS) for non-targeted metabolomic analysis.
• Chemometric methods including Partial Least Squares-Discriminant Analysis (PLS-DA) and Hierarchical Cluster Analysis (HCA).
• Assays for total phenolic content (TPC), total flavonoid content (TFC), total terpenoid content (TTeC), and antioxidant activity (DPPH assay).

Main Results:

• Distinct metabolite profiles were observed across different Coffea arabica plant parts.
• Leaf extract showed the highest TPC and TFC, while flower extract had the highest TTeC.
• Leaf extract exhibited the strongest antioxidant activity, followed by bean extract. Key discriminating metabolites included caffeine, chlorogenic acid, flavonoids, and lipids.

Conclusions:

• The study highlights significant tissue-specific accumulation of primary and secondary metabolites in Coffea arabica.
• Different plant parts of coffee possess unique profiles of bioactive compounds, offering potential for various applications.
• This metabolomic approach provides a foundation for future research into the bioavailability, safety, and functional uses of coffee-derived compounds.