Untargeted Metabolomic Approach Based on UHPL-ESI-HRMS to Investigate Metabolic Profiles of Different Coffea Species and Terroir

Coffee (Coffea spp., Rubiaceae) has evolved from an agricultural commodity to a specialty beverage, regarding the product's trading, appreciation, philosophies, and purposes of consumption. Consequently, part of the coffee industry has focused on the sensory complexion and high quality to meet engaged consumers. To evaluate the chemical profiles and distinctiveness of natural products from plants, metabolomics has emerged as a valuable tool. In this work, an untargeted metabolomic approach based on reversed-phase liquid chromatography coupled with mass spectrometry was performed, followed by multivariate statistical analysis to obtain the metabolic fingerprints of 21 coffee samples belonging to two species and five botanical varieties, as follows: Coffea arabica L. and Coffea canephora Pierre ex A.Froehner. The samples were obtained in the 2022 Edition of the Brazilian International Conference of Coffee Tasters, state of Rondonia, Brazil. Principal component analysis and orthogonal projections to latent structures discriminant analysis were performed using the metabolomic data, resulting in the discrimination of coffee samples based on their chemical profiles. Caffeine, 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one glucoside, roemerine, and cajanin were determined as chemical markers for C. canephora samples, and toralactone, cnidilide, 2,3-dehydrosilybin, and lysophosphatidylcholines LysoPC (18:2(9Z,12Z)) and LysoPC (16:0/0:0) for C. arabica samples. In addition to the genetic variability, our results showed the possible influence of a terroir factor in the production of secondary metabolites of coffee samples, mainly for individuals of C. canephora.

Automated summary

Coffee has transformed from an agricultural commodity to a specialty beverage, with a focus on sensory complexity and high quality. Metabolomics, a valuable tool for evaluating the chemical profiles of natural products, was employed to obtain the metabolic fingerprints of 21 coffee samples. Using metabolomic data, coffee samples were successfully discriminated based on their chemical profiles. Chemical markers for C. canephora samples were identified as caffeine, 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one glucoside, roemerine, and cajanin, while toralactone, cnidilide, 2,3-dehydrosilybin, and lysophosphatidylcholines LysoPC (18:2(9Z,12Z)) and LysoPC (16:0/0:0) were markers for C. arabica samples. Our results also suggested the possible influence of terroir in the production of secondary metabolites, particularly in C. canephora.