Metabolomics Combined with Sensory Analysis Reveals the Impact of Different Extraction Methods on Coffee Beverages from Coffea arabica and Coffea canephora var. Robusta

Abstract

An untargeted metabolomics approach combined with sensory analysis was used to depict the impact of different traditional Italian extraction methods (i.e., Espresso, Neapolitan, Moka) along with Filter, on Coffea arabica and Coffea canephora var. robusta beverages. To this aim, polyphenols, Maillard reaction products, and coffee metabolites were screened by high resolution mass spectrometry and elaborated through both unsupervised and supervised multivariate statistical approaches. Multivariate statistics showed a distinctive chemical profile for Espresso preparation, while Moka and Neapolitan were very similar. The orthogonal projection to latent structures and discriminant analysis allowed the identification of 86 compounds showing a high VIP discrimination score (i.e., > 0.8). The 2,5-dimethyl-3-(methyldithio)-furan was a marker for the Filter preparation, while 1,2-disinapoylgentiobiose characterized both Filter and Neapolitan extractions. Caffeine (known to be a bitter compound) accumulated highly in Filter vs. Espresso, although at the sensory profile, bitterness was more perceived in Espresso. Vegetal aroma carried by pyrazines, pyridines, and phenolic acids were markers of Espresso, with Robusta showing higher values than Arabica. Notwithstanding, our findings showed that the extraction process played a hierarchically higher role in driving the chemical composition of the beverages when compared to coffee species.

Thermal Contaminants in Coffee Induced by Roasting: A Review

“…This type of coffee is obtained from inserting essences into the beans, to add more flavor to the beverage. The aromatization of coffee can occur after the roasting process (cooling), using water vapors with the most diverse types of vaporized essences in the beans, which absorb these droplets since they are still hot [ 76 , 77 , 78 , 79 ]. Gourmet coffee has superior quality, which comes from the cultivation and the preparation of the beverage.…”

“…This type of coffee goes through careful processes before packaging, during which the chosen beans must be ripe and of good quality. Further, it is produced only from the Arabica species [ 76 , 77 , 78 , 79 ], which has about 50% less caffeine than Robusta and is much more aromatic [ 76 , 77 ]. Gourmet coffee beans are roasted under milder temperature conditions, since the dark roast is commonly used to disguise defects that are not found in selected beans [ 80 , 81 ].…”

Integrating Metabolomics and Proteomics Technologies Provides Insights into the Flavor Precursor Changes at Different Maturity Stages of Arabica Coffee Cherries

“…Among the pool of green coffee constituents, however, carbohydrates (sugars), proteins, acids fraction, flavonoids, and lipids have been suggested to be the principal flavor precursors [ 4 ]. Carbohydrates represent 40–65% of dry green coffee beans, and Arabica coffee contains more sugars than Robusta coffee [ 5 ]. During the roasting process, 12–24% of the sugars are degraded during light roasting, while 35–40% of sugars are degraded upon dark roasting [ 6 ], contributing to the caramel aroma, black color, and characteristic taste via the Maillard reaction and caramelization.…”

Green Chemistry Applied to Ground Coffee Volatile Compounds Modification Aiming Coffee Aroma Improvement

“…Pyrazines, pyridines, and pyrroles are important compounds, which are related to desired attributes such as nutty, cocoa, and roasted notes [10]. On the other hand, some aldehydes, alcohols, and esters are related to undesired or less desirable attributes, such as green and fruity notes, usually associated with light coffee, which most customers do not accept well [11][12][13].…”