Fatty acid profiles as discriminant parameters for coffee varieties differentiation

Area of Science:

• Agricultural Chemistry
• Analytical Chemistry
• Food Science

Background:

• Coffee quality is influenced by its chemical composition, including lipid content.
• Fatty acids are key components of coffee lipids and can vary based on species and processing.
• Understanding these variations is crucial for coffee authentication and quality control.

Purpose of the Study:

• To determine the fatty acid profiles of different coffee varieties (arabica and robusta).
• To investigate the impact of roasting on coffee bean fatty acid composition.
• To utilize fatty acid profiles as chemical descriptors for differentiating coffee types using chemometric methods.

Main Methods:

• Lipid extraction from green and roasted arabica and robusta coffee beans using Soxhlet extraction with hexane.
• Capillary gas chromatography for the separation and quantification of ten specific fatty acids (myristic, palmitic, palmitoleic, stearic, oleic, linoleic, linolenic, arachidic, eicosenoic, and behenic acid) as methyl esters.
• Application of Pattern Recognition techniques, including Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), for data analysis and sample discrimination.

Main Results:

• Ten fatty acids were identified and quantified in the coffee lipid extracts.
• Significant differences in fatty acid content were observed between arabica and robusta coffee varieties.
• Roasting significantly altered the fatty acid profiles of both coffee types.
• PCA and LDA effectively discriminated between green and roasted arabica and robusta coffees based on their fatty acid compositions.

Conclusions:

• Fatty acid profiles serve as reliable chemical markers for distinguishing between coffee varieties and processing states.
• Chemometric analysis of fatty acid data provides a powerful tool for coffee authentication and quality assessment.
• This study highlights the potential of lipidomic analysis in the characterization of coffee beans.